KR102199271B1 - Method and apparatus for processing call - Google Patents

Abstract

The present invention relates to a call processing method and apparatus. The disclosed call processing method provides messages requiring relocation of bearers including a bandwidth guaranteed bearer and a non-bandwidth guaranteed bearer in a communication environment in which a first network supporting a bandwidth guaranteed bearer and a second network not supporting a bandwidth guaranteed bearer are mixed. Receiving, confirming bearer support information of the second network, and transmitting a message related to relocation processing for a bandwidth non-guaranteed bearer excluding a bandwidth guarantee bearer to a second network based on the confirmed bearer support information Includes. The present invention does not cause silence due to the difference between the transmit bearer and the receive bearer because the relocation process is performed only on the bearers except for the dedicated bearer with guaranteed bandwidth when relocating the bearer for packet switched handover. There is an advantage of minimizing the silence time during over call processing.

Description

Call processing method and apparatus {METHOD AND APPARATUS FOR PROCESSING CALL}

The present invention relates to a call processing method and apparatus. More specifically, a call processing method that enables seamless transition when VoLTE (Voice over LTE) use is switched from LTE network to legacy network in a communication environment where LTE (Long Term Evolution) network and legacy network are mixed. And to an apparatus.

As is well known, 3GPP Release 8 describes an Evolved Packet Core (EPC), which is a network architecture, as one of mobile communication systems. EPC is a set of network nodes for 3GPP LTE system. EPC supports Evolved-UMTS Terrestrial Radio Access Network (E-UTRAN), which is an evolved radio access network (Evolved RAN), by evolving the core network of the existing 3GPP system architecture, and also increases the efficiency of the packet network. For this, it has an efficient network structure that simplifies network nodes. A wireless communication system including EPC and E-UTRAN may be referred to as an EPS (Evolved Packet System), and this is the LTE mobile communication system currently in service in Korea.

Meanwhile, in the early stages of building an LTE mobile communication system, a mixed communication environment with a legacy network such as a WCDMA (Wideband Code Division Multiple Access) mobile communication system appears, and in such a communication environment, a legacy network such as a WCDMA network while being able to access the LTE network A dual mode mobile communication terminal device that can also be accessed may be operated. In addition, in the early stages of the LTE mobile communication service, a WCDMA mobile communication system was used to provide a voice call service to a dual mode mobile communication terminal device, and an LTE mobile communication system was used to provide a data communication service.

Unlike this, VoLTE service uses LTE mobile communication system for voice calls as well as data communication. These VoLTE services are also called HD (High Definition) voice services. According to VoLTE service, it is possible to provide a clearer HD-level voice call service during a voice call, and users can share content such as maps, music, news, photos, etc. while showing the same screen as the other party in real time during a call. .

However, since the service area of the current LTE network is limited, there is a problem that the continuity of a voice call is not guaranteed in an area where the radio wave environment is poor, such as an area outside the limited area or a service cell border area. To solve this problem, there is a trend to provide voice call continuity by interworking with legacy networks. At this time, packet switched handover is a technology that handovers voice traffic to a packet switched network of a legacy network in order to provide call continuity when entering the LTE weak field during a VoLTE call. .

Meanwhile, in the VoLTE service, the VoLTE call uses a dedicated bearer rather than the default bearer of the EPS bearer, and this dedicated bearer is a guaranteed bit rate (GBR) bearer that can be guaranteed bandwidth.

However, legacy networks such as WCDMA networks do not support GBR bearers. Therefore, the process of sending and receiving a modify bearer request message and a modify bearer response message between a packet data network gateway (PGW) of the LTE network and a serving general packet radio service support node (SGSN) of a legacy network. Deleted from

Therefore, according to the packet switched handover call processing according to the prior art, there is a problem that silence occurs in the process of changing the bearer in order for the mobile communication terminal device to transmit VoLTE voice traffic. In detail, the mobile communication terminal device is waiting for voice traffic to be received through a VoLTE-dedicated GBR bearer. When the dedicated bearer is deleted, the packet data network (PDN) transmits voice traffic using another bearer, for example, a basic bearer. . At this time, in the basic bearer, since the mobile communication terminal device is not waiting to receive voice traffic, silence for several seconds occurs.

Korean Patent Application Publication No. 10-2009-0106572, publication date October 09, 2009.

According to an embodiment of the present invention, when a bearer is relocated for packet switched handover, silence time is minimized when processing a packet switched handover call by relocating only bandwidth-unguaranteed bearers excluding dedicated bearers with guaranteed bandwidth. Make it possible.

The problem to be solved of the present invention is not limited to those mentioned above, and another problem to be solved that is not mentioned will be clearly understood by those of ordinary skill in the art from the following description.

A call processing method according to an aspect of the present invention includes a bearer including a bandwidth guaranteed bearer and a bandwidth non-guaranteed bearer in a communication environment in which a first network supporting a bandwidth guaranteed bearer and a second network not supporting a bandwidth guaranteed bearer are mixed. Receiving a message requiring relocation for, confirming bearer support information of the second network, and relocating the bandwidth non-guaranteed bearer from which the bandwidth guarantee bearer is excluded based on the confirmed bearer support information It may include the step of transmitting a processing-related message to the second network.

A call processing method according to another aspect of the present invention includes the bandwidth guarantee bearer from the base station of the first network in a communication environment in which a first network supporting a bandwidth guarantee bearer and a second network not supporting the bandwidth guarantee bearer are mixed. And receiving a handover request message including a bandwidth non-guaranteed bearer, confirming bearer support information of the second network, and excluding the bandwidth guarantee bearer based on the confirmed bearer support information. It may include transmitting a bearer forward relocation request message for a non-guaranteed bearer to the packet-switched core network of the second network.

A call processing apparatus according to another aspect of the present invention is a call processing apparatus in a communication environment in which a first network supporting a bandwidth guarantee bearer and a second network not supporting the bandwidth guarantee bearer are mixed, wherein the bandwidth guarantee bearer and A message receiving unit that receives a message related to a relocation request for a bearer including a non-bandwidth-guaranteed bearer, a bearer check unit that checks bearer support information of the second network, and the bandwidth guaranteed bear based on the confirmed bearer support information. It may include a message transmission unit for transmitting a message related to the relocation processing for the bandwidth non-guaranteed bearer is excluded from the word to the second network.

According to an embodiment of the present invention, when relocating a bearer for packet switched handover, a relocation process is performed only for a non-bandwidth-guaranteed bearer excluding a dedicated bearer with a guaranteed bandwidth.

Therefore, the mobile communication terminal device does not wait for the reception of the voice traffic through the GBR bearer, but waits for the reception of the voice traffic from another bearer (for example, a data-only bearer), and the PDN (Packet Data Network) also uses the same bearer Since traffic is transmitted, silence due to the difference between the transmit bearer and the receive bearer does not occur.

Therefore, there is an effect of minimizing the silence time when processing a packet switched handover call.

1 is a network configuration diagram of a mobile communication service system that can employ a call processing apparatus and method according to an embodiment of the present invention.
2 is a block diagram of a call processing apparatus according to an embodiment of the present invention.
3 is a flowchart illustrating a call processing method according to an embodiment of the present invention.
4 is a flowchart illustrating a packet switched handover call processing process when a call processing apparatus according to an embodiment of the present invention is employed in an RNC.
5 is a flowchart illustrating a packet switched handover call processing process when a call processing apparatus according to an embodiment of the present invention is employed in an MME.
6 is a flowchart illustrating a packet switched handover call processing procedure when a call processing apparatus according to an embodiment of the present invention is employed in SGSN.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in a variety of different forms, and only these embodiments make the disclosure of the present invention complete, and are common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have, and the invention is only defined by the scope of the claims.

In describing the embodiments 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, a detailed description thereof will be omitted. In addition, terms to be described later are terms defined in consideration of functions in an embodiment of the present invention, which may vary according to the intention or custom of users or operators. Therefore, the definition should be made based on the contents throughout this specification.

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

1 is a network configuration diagram of a mobile communication service system employing a call processing apparatus and method according to an embodiment of the present invention. 1 illustrates a case where the WCDMA mobile communication network is operated as a legacy network, but the legacy network is not limited thereto. For example, other asynchronous mobile communication networks such as Global System for Mobile (GSM) or other synchronous mobile communication networks such as CDMA2000 may be used together with the LTE mobile communication network.

According to the mobile communication service system shown in FIG. 1, it is possible to provide VoLTE service targeting a dual mode mobile communication terminal device 300 that can access an LTE network and also access a legacy network such as a WCDMA network. I can.

The mobile communication terminal device 300 is a service area of the NodeB 210 in which the service area 111 of the eNodeB 110, which serves as a base station constituting the LTE mobile communication network, serves as a base station constituting the WCDMA mobile communication network. It can be operated in the service overlapping area included in (211). For example, the mobile communication terminal device 300 may be implemented in various forms such as a smart phone, a notepad, and a tablet computer.

A call processing apparatus according to an embodiment of the present invention (reference numeral 500 in FIG. 2) includes a Radio Network Controller (RNC) 220, a Mobility Management Entity (MME) 120, or a Serving General Packet Radio Service Support Node (SGSN) ( 230), it can be mounted on any one node or interlocked with any one node in a separately installed state.

eNodeB(110), MME (120), HSS(Home Subscriber Server)(130), SGW(Serving Gateway)(140), PGW(Packet Data Network Gateway)(150), MSC Server(160), PCRF(Policy & Charging Rule Function) 170 may constitute an LTE mobile communication network.

The eNodeB 110 communicates with the mobile communication terminal device 300 and serves as a base station to guarantee mobility. The eNodeB 110 includes radio bearer control, radio admission control, connection mobility control, and dynamic resource allocation to the mobile communication terminal device 300. It performs the same radio resource management function. In addition, IP header compression and encryption of user data streams, routing of user plane data to SGW 140, scheduling and transmission of paging messages, scheduling and transmission of broadcast information, It performs measurement and measurement report settings for mobility and scheduling.

In particular, the eNodeB 110 checks whether an intra handover occurs by the mobile communication terminal device 300 located in the service area 111 composed of a plurality of cells, and is changed when the intra handover occurs. The location information of the UE in units of cells is transmitted to the MME 120. In addition, a packet that handovers voice traffic to the packet network of the WCDMA network to provide call continuity when the mobile communication terminal device 300 enters the LTE weak field in consideration of the propagation environment of the LTE network and the WCDMA network during VoLTE calls. The switched handover is determined, and a handover request message including bearer identification information required for bearer relocation is transmitted to the MME 120.

The MME 120 is responsible for signal control between the eNodeB 110 and the SGW 140, and determines routing for transmission data of the mobile communication terminal device 300. The MME 120 performs paging message distribution to the eNodeB 110, non-access spectrum (NAS) signaling, intra-network handover control, and tracking area list management. In addition, the MME 120 selects the SGW 140 and the PGW 150, selects and changes the MME 120 for handover, and performs terminal authentication. The MME 120 processes a control signal when there is an association request or a radio bearer setup request from the mobile communication terminal device 300 or another network node, such as the PGW 150 or the SGW 140. Responsible for various functions of the control plane, and receives subscriber profile information, authentication, and location-related data from the HSS 130 to set up an EPS bearer or an IP tunnel, and mobility It performs functions such as mobility management.

When the packet switched handover request message is received from the eNodeB 110, the MME 120 transmits a bearer forward relocation request message to the SGSN 230. In this case, the bearer forward relocation request message includes bearer identification information (EPS bearer ID) required for bearer relocation.

In particular, the MME 120 may be equipped with a call processing device (reference numeral 500 in FIG. 2) according to an embodiment of the present invention or interlocked with a separately installed call processing device. When relocating the bearer for packet-switched handover, the MME 120 performs relocation processing only for the non-guaranteed bearer from which the dedicated bearer with guaranteed bandwidth is excluded. To this end, the MME 120 transmits a bearer forward relocation request message including bearer identification information of bearers other than the dedicated bearer to the SGSN 230.

The HSS 130 is a network node including a database including subscriber information for an LTE mobile communication network, and stores subscriber profile information, authentication, and location-related data.

The SGW 140 is a user plane node that performs session control processing payload traffic according to a set session. It interlocks with the eNodeB 110 through the S1-U interface, supports handoff within 3GPP, sets the PGW 150 and EPS bearer, and transmits a packet data unit (PDU) using tunneling. The SGW 140 selects the PGW 150 based on a subscriber profile, and in the case of an inbound roaming call, generates billing data for mutual settlement with the PGW of the home network.

The PGW 150 is a user plane node that allocates an IP of the mobile communication terminal device 300 and performs session control interworking with an external Internet network and a non-3GPP network. It maintains routing information with the SGW 140 and the external network for packet service, and performs tunneling and IP routing functions. Also, the PDU is delivered to the SGW 140 and the external network. In the case of a local call, the PGW 150 performs billing processing.

The MSC server 160 provides a session data protocol for audio and video for additional functions by the IP Multimedia Subsystem (IMS) 400.

The PCRF 170 provides dynamic QoS and billing rules according to a service data flow, and performs communication policy and billing processing in a communication network.

NodeB(210), RNC(220), SGSN(230), MSC(Mobile Switching Center)(240), HLR(Home Location Register)(250), CGS(Cellular Gateway Switch)(260), GGSN(Gateway General packet) The radio service support node) 270 may constitute a WCDMA mobile communication network. Here, the NodeB 210 and the RNC 220 correspond to the radio access network area, the MSC 240 and the CGS 260 correspond to the circuit switched core network, and the SGSN 230 and the GGSN 270 correspond to the packet exchange Corresponds to the core network.

The NodeB 210 secures a frequency used for connection with the mobile communication terminal devices 300 and guarantees a stable connection with the mobile communication terminal devices 300.

The RNC 220 controls several NodeBs 210, allocates communication resources to each NodeB 210, and performs functions such as handover. The RNC 220 may be equipped with a call processing device (reference numeral 500 in FIG. 2) according to an embodiment of the present invention or interlocked with a separately installed call processing device.

The RNC 220 receives a bearer relocation request message for packet switched handover from the SGSN 230 and transmits a bearer relocation request response message to the SGSN 230. In this case, the bearer relocation request message and the bearer relocation request response message include bearer identification information necessary for bearer relocation.

In particular, the RNC 220 may be equipped with a call processing device (reference numeral 500 in FIG. 2) according to an embodiment of the present invention or may interwork with a separately installed call processing device. When relocating bearers for packet switched handover, the RNC 220 performs relocation processing only for non-bandwidth-guaranteed bearers excluding dedicated bearers with guaranteed bandwidth. To this end, the RNC 220 transmits a bearer relocation request response message including bearer identification information of bearers other than the dedicated bearer to the SGSN 230.

The SGSN 230 is connected to several RNCs 220 to manage the mobility and packet sessions of the mobile communication terminal device 300, can perform IP routing, and register the location of the mobile communication terminal device 300 and You can do the same interaction.

The SGSN 230 receives a bearer forward relocation request message for packet switched handover from the MME 120, and transmits a bearer relocation request message to the RNC 220. In this case, the bearer forward relocation request message and the bearer relocation request message include bearer identification information necessary for bearer relocation.

In particular, the SGSN 230 may be equipped with a call processing device (reference numeral 500 in FIG. 2) according to an embodiment of the present invention or interlock with a separately installed call processing device. When relocating bearers for packet switched handover, the SGSN 230 performs relocation processing only for non-bandwidth-guaranteed bearers excluding dedicated bearers with guaranteed bandwidth. To this end, the SGSN 230 transmits a bearer relocation request message including bearer identification information of bearers other than the dedicated bearer to the RNC 220.

The GGSN 270 directly accesses the IP network and serves as a gateway connecting the IP network and the PS domain of the WCDMA network, maintaining routing information with the SGSN 230 and external networks, and tunneling and IP routing. Functions.

The MSC 240 stores visitor location information and receives subscriber profile information, authentication and location-related data from the HLR 250 and performs switching control for voice communication.

The CGS 260 serves as a gateway connecting the WCDMA mobile communication network and the general communication network, enabling communication with other communication systems connected to the general communication network, and serves as a gateway between the MSC 240 and the IMS 400.

CSCF(Call Session Control Function)(410), HSS(Home Subscriber Server)(420), MGW(Media Gateway)(430), MGCF(Media Gateway Control Function)(440), AS(Application Server)(450), etc. May configure an IP Multimedia Subsystem (IMS) 400.

The CSCF 410 is an infrastructure system that performs call processing and performs basic functions for controlling a multimedia session based on a Session Initiation Protocol (SIP). The CSCF 410 handles subscriber registration, authentication, billing, triggering and routing for each service, destination location inquiry, and compression and decompression of SIP messages, and can be divided into Proxy_CSCF, Interogating-CSCF, and Serving-CSCF according to roles.

The HSS 420 is a network node including a database including subscriber information for a WCDMA mobile communication network and/or an LTE mobile communication network, and stores subscriber profile information, authentication, and location-related data.

The MGW 430 is a gateway serving as a gateway between the MGCF 440 and the CGS 260, and converts signaling and media for interworking with the LTE mobile communication network connected to the CSCF 410 and the WCDMA mobile communication network.

The MGCF 440 supports conversion of signaling between SIP and ISUP (ISDN User Part) used in the circuit-switched network, and controls the MGW 430.

The AS 450 is a server that provides a telephony service, and provides additional services such as caller identification service, call/call prohibition, and call forwarding.

2 is a block diagram of a call processing apparatus according to an embodiment of the present invention.

As shown, the call processing device 500 includes a message receiving unit 510, a bearer checking unit 520, a message transmitting unit 530, etc., and any one of the RNC 220, MME 120, or SGSN 230 It can be mounted on one node or interlocked with any one node while separately installed.

The message receiving unit 510 constituting the call processing device 500 receives a message requiring relocation of a bearer including a bandwidth guaranteed bearer and a non-bandwidth guaranteed bearer. The message receiving unit 510 may receive a bearer relocation request message from the SGSN 230 belonging to the packet-switching core network of the WCDMA network or may receive a handover request message from the eNodeB 210, which is a base station of the LTE network. Alternatively, a bearer forward relocation request message may be received from the MME 120 belonging to the core network of the LTE network.

The bearer check unit 520 checks bearer support information of the legacy network and provides it to the message transmission unit 530. For example, the bearer checker 520 may check whether the WCDMA network supports a bandwidth guarantee bearer.

The message transmission unit 530 transmits, to the legacy network, a message related to relocation processing for a bandwidth non-guaranteed bearer from which a bandwidth guarantee bearer is excluded, based on the bearer support information checked by the bearer identification unit 520. The message transmission unit 530 may transmit a bearer relocation request response message or a bearer relocation request response message to the SGSN 230 belonging to the packet-switching core network of the WCDMA network. Alternatively, a bearer relocation request message may be transmitted to the RNC 220 belonging to the radio access control network of the WCDMA network.

3 is a flowchart illustrating a call processing method according to an embodiment of the present invention.

As shown, the call processing method according to the embodiment of the present invention includes a bandwidth guarantee bearer and a bandwidth non-guaranteed bearer in a communication environment in which an LTE network supporting a bandwidth guarantee bearer and a legacy network not supporting a bandwidth guarantee bearer are mixed. And a step 610 of receiving a message requiring relocation of a bearer. For example, a bearer relocation request message may be received from an SGSN belonging to a packet-switching core network of a WCDMA network, or a handover request message may be received from an eNodeB, a base station of an LTE network. Alternatively, a bearer forward relocation request message may be received from an MME belonging to the core network of the LTE network.

Further, the step of determining whether the legacy network supports the bandwidth guarantee bearer by checking the bearer support information of the legacy network (S620, S630).

In addition, it further comprises a step (S640) of transmitting a message related to the relocation processing for the bandwidth non-guaranteed bearer is excluded from the bandwidth guarantee bearer based on the confirmed and determined bearer support information to the legacy network. For example, a bearer relocation request response message or a bearer relocation request response message may be transmitted to the SGSN belonging to the packet-switching core network of the WCDMA network. Alternatively, a bearer relocation request message may be transmitted to an RNC belonging to a radio access control network of a WCDMA network.

4 is a flowchart illustrating a packet switched handover call processing process when the call processing apparatus 500 according to an embodiment of the present invention is employed in the RNC 220.

Hereinafter, a packet switched handover call processing process when the call processing apparatus 500 is employed in the RNC 220 will be described with reference to FIGS. 1, 2, and 4.

First, the eNodeB 110 checks whether an intra handover occurs by the mobile communication terminal device 300 located in the service area 111 composed of a plurality of cells (701). In addition, a packet that handovers voice traffic to the packet network of the WCDMA network to provide call continuity when the mobile communication terminal device 300 enters the LTE weak field in consideration of the propagation environment of the LTE network and the WCDMA network during VoLTE calls. Determines the switched handover.

When the packet switched handover is determined, the eNodeB 110 transmits a handover request message including bearer identification information necessary for bearer relocation to the MME 120 (703). In this case, the handover request message includes a plurality of bearer identification information. For example, EBI (EPS bearer ID) 5, 6, 7 may be included. EBI 5 is a bearer for IMS signaling, EBI 6 is a bearer for data only, and EBI 7 is a GBR bearer for VoLTE.

Subsequently, the MME 120 transmits a bearer forward relocation request message including all bearer identification information included in the handover request message to the SGSN 230 to request the execution of packet switched handover (705). For example, if EBIs 5, 6, and 7 were included in the handover request message, EBIs 5, 6, and 7 were all included in the bearer forward relocation request message.

Then, the SGSN 230 transmits a bearer relocation request message including all bearer identification information included in the forward relocation request message to the RNC 220 to inquire whether it is possible to perform packet switched handover (707). For example, if EBI 5, 6, and 7 were included in the forward relocation request message, EBI 5, 6, and 7 were all included in the bearer relocation request message.

Here, the message receiving unit 510 of the call processing apparatus 500 receives a message requiring relocation of a bearer, that is, a bearer relocation request message, from the SGSN 230. At this time, the received bearer relocation request message includes identification information of the bandwidth guarantee bearer, that is, EBI 7.

Subsequently, the bearer verification unit 520 of the call processing device 500 checks the bearer support information of the legacy network when a message related to the relocation request for the bearer is received by the message receiving unit 510 to determine whether a bandwidth guarantee bearer is supported. . That is, it is confirmed and determined that the WCDMA network does not support the bandwidth guarantee bearer. For example, the bearer verification unit 520 may check bearer support information of the RNC 220 or the SGSN 230.

Next, if the message transmission unit 530 of the call processing device 500 determines that the legacy network WCDMA network does not support the bandwidth guarantee bearer by the bearer check unit 520, the bandwidth guarantee bearer is excluded from the bandwidth non-guaranteed bearer. A message related to the relocation process is transmitted to allow the packet switched handover to be performed (709). For example, if EBIs 5, 6, and 7 are included in the relocation request message, a bandwidth guarantee bearer, that is, a bearer relocation request response message including EBIs 5 and 6 excluding EBI 7, may be transmitted to the SGSN 230. Here, when the bandwidth guarantee bearer is excluded from the relocation request response message, it means that the packet switched handover is not permitted for the corresponding VoLTE dedicated GBR bearer.

Then, the SGSN 230 provides a bearer forward rearrangement response message for bearers excluding the bandwidth guarantee bearer to the MME 120 (711). For example, if EBI 5 and 6 were included in the relocation request response message, EBI 5 and 6 were also included in the forward relocation response message.

As described above, in the embodiment of the present invention, the eNodeB 210 requests a packet switched handover for all bearers including the bandwidth guarantee bearer, but the handover of the bandwidth guarantee bearer is rejected by the RNC 220. Therefore, the mobile communication terminal device 300 does not wait for the reception of the voice traffic through the GBR bearer, but waits for the reception of the voice traffic in another bearer, for example, the data-only bearer of EBI 6, and the PDN (Packet Data Network) is also the same. Since voice traffic is transmitted using a bearer, silence due to the difference between the transmit bearer and the receive bearer does not occur.

5 is a flowchart illustrating a packet switched handover call processing procedure when the call processing apparatus 500 according to an embodiment of the present invention is employed in the MME 120.

Hereinafter, a packet switched handover call processing process when the call processing apparatus 500 is employed in the MME 120 will be described with reference to FIGS. 1, 2, and 5.

First, the eNodeB 110 checks whether an intra handover occurs by the mobile communication terminal device 300 located in the service area 111 composed of a plurality of cells (801). In addition, a packet that handovers voice traffic to the packet network of the WCDMA network to provide call continuity when the mobile communication terminal device 300 enters the LTE weak field in consideration of the propagation environment of the LTE network and the WCDMA network during VoLTE calls. Determines the switched handover.

When the packet switched handover is determined, the eNodeB 110 transmits a handover request message including bearer identification information necessary for bearer relocation to the MME 120 (803). In this case, the handover request message includes a plurality of bearer identification information. For example, EBI (EPS bearer ID) 5, 6, 7 may be included. EBI 5 is a bearer for IMS signaling, EBI 6 is a bearer for data only, and EBI 7 is a GBR bearer for VoLTE.

Here, the message receiving unit 510 of the packet switched handover call processing apparatus 500 receives a message requiring relocation of a bearer including a bandwidth guaranteed bearer and a non-bandwidth guaranteed bearer, that is, a handover request message from the eNodeB 210 do. At this time, the received handover request message includes identification information of the bandwidth guarantee bearer, that is, EBI 7.

Subsequently, when a handover request message is received by the message receiving unit 510, the bearer checker 520 of the call processing device 500 checks bearer support information of the legacy network to determine whether a bandwidth guarantee bearer is supported. That is, it is confirmed and determined that the WCDMA network does not support the bandwidth guarantee bearer. For example, the bearer verification unit 520 may check bearer support information of the SGSN 230.

Next, if the message transmission unit 530 of the call processing device 500 determines that the legacy network WCDMA network does not support the bandwidth guarantee bearer by the bearer check unit 520, the bandwidth guarantee bearer is excluded from the bandwidth non-guaranteed bearer. A message related to relocation processing is transmitted to request the execution of packet switched handover (805). For example, if EBIs 5, 6, and 7 are included in the handover request message, a bandwidth guarantee bearer, that is, a bearer forward relocation request message including EBIs 5 and 6 excluding EBI 7, may be transmitted to the SGSN 230. Here, when the bandwidth guarantee bearer is excluded from the forward relocation request message, it means that the packet switched handover is not allowed for the corresponding VoLTE dedicated GBR bearer.

Subsequently, the SGSN 230 transmits a bearer relocation request message including all bearer identification information included in the forward relocation request message to the RNC 220 to inquire whether it is possible to perform packet switched handover (807). For example, if EBI 5 and 6 were included in the forward relocation request message, EBI 5 and 6 were all included in the bearer relocation request message.

Next, when the bearer relocation request message is received, the RNC 220 transmits a message related to the relocation process for the bearer to the SGSN 230 to allow the packet switched handover to be performed (809). For example, if EBIs 5 and 6 are included in the relocation request message, a bearer relocation request response message including EBIs 5 and 6 may be transmitted to the SGSN 230 as well.

Then, the SGSN 230 provides a bearer forward rearrangement response message for bearers excluding the bandwidth guarantee bearer to the MME 120 (811). For example, if EBI 5 and 6 were included in the relocation request response message, EBI 5 and 6 were also included in the forward relocation response message.

As described above, in the embodiment of the present invention, the eNodeB 210 requests a packet switched handover for all bearers including the bandwidth guarantee bearer, but the handover of the bandwidth guarantee bearer is rejected by the MME 120. Therefore, the mobile communication terminal device 300 does not wait for the reception of the voice traffic through the GBR bearer, but waits for the reception of the voice traffic in another bearer, for example, the data-only bearer of EBI 6, and the PDN (Packet Data Network) is also the same. Since voice traffic is transmitted using a bearer, silence due to the difference between the transmit bearer and the receive bearer does not occur.

6 is a flowchart illustrating a packet switched handover call processing process when the call processing apparatus 500 according to an embodiment of the present invention is employed in the SGSN 230.

Hereinafter, a packet switched handover call processing process when the call processing apparatus 500 is employed in the RNC 220 will be described with reference to FIGS. 1, 2, and 4.

First, the eNodeB 110 checks whether an intra handover occurs by the mobile communication terminal device 300 located in the service area 111 composed of a plurality of cells (901). In addition, a packet that handovers voice traffic to the packet network of the WCDMA network to provide call continuity when the mobile communication terminal device 300 enters the LTE weak field in consideration of the propagation environment of the LTE network and the WCDMA network during VoLTE calls. Determines the switched handover.

When the packet switched handover is determined, the eNodeB 110 transmits a handover request message including bearer identification information required for bearer relocation to the MME 120 (903). In this case, the handover request message includes a plurality of bearer identification information. For example, EBI (EPS bearer ID) 5, 6, 7 may be included. EBI 5 is a bearer for IMS signaling, EBI 6 is a bearer for data only, and EBI 7 is a GBR bearer for VoLTE.

Subsequently, the MME 120 transmits a bearer forward relocation request message including all bearer identification information included in the handover request message to the SGSN 230 to request the execution of packet switched handover (905). For example, if EBIs 5, 6, and 7 were included in the handover request message, EBIs 5, 6, and 7 were all included in the bearer forward relocation request message.

Here, the message receiving unit 510 of the call processing device 500 receives a message requiring relocation of a bearer including a bandwidth guarantee bearer, that is, a bearer forward relocation request message from the MME 120. In this case, the received forward relocation request message includes identification information of the bandwidth guarantee bearer, that is, EBI 7.

Subsequently, when the bearer forward rearrangement request message is received by the message receiving unit 510, the bearer verification unit 520 of the call processing device 500 checks bearer support information of the legacy network to determine whether a bandwidth guarantee bearer is supported. That is, it is confirmed and determined that the WCDMA network does not support the bandwidth guarantee bearer. For example, the bearer verification unit 520 may check bearer support information of the SGSN 230 or RNC 220.

Next, if the message transmission unit 530 of the call processing device 500 determines that the legacy network WCDMA network does not support the bandwidth guarantee bearer by the bearer check unit 520, the bandwidth guarantee bearer is excluded from the bandwidth non-guaranteed bearer. A message related to relocation processing is transmitted to inquire whether it is possible to perform packet switched handover (907). For example, if EBIs 5, 6, and 7 are included in the bearer forward relocation request message, a bandwidth guarantee bearer, that is, a bearer relocation request message including EBIs 5 and 6 excluding EBI 7, may be transmitted to the RNC 220. Here, when the bandwidth guarantee bearer is excluded from the relocation request message, it means that the packet switched handover is not permitted for the corresponding VoLTE dedicated GBR bearer.

Next, when the bearer relocation request message is received, the RNC 220 transmits a message related to the relocation process for the bearer to the SGSN 230 to allow the packet switched handover to be performed (909). For example, if EBIs 5 and 6 are included in the relocation request message, a bearer relocation request response message including EBIs 5 and 6 may be transmitted to the SGSN 230 as well.

Then, the SGSN 230 provides a bearer forward relocation response message for bearers excluding the bandwidth guarantee bearer to the MME 120 (911). For example, if EBI 5 and 6 were included in the relocation request response message, EBI 5 and 6 were also included in the forward relocation response message.

As described above, in the embodiment of the present invention, the eNodeB 210 requests a packet switched handover for all bearers including the bandwidth guarantee bearer, but the handover of the bandwidth guarantee bearer is rejected by the SGSN 230. Therefore, the mobile communication terminal device 300 does not wait for the reception of the voice traffic through the GBR bearer, but waits for the reception of the voice traffic in another bearer, for example, the data-only bearer of EBI 6, and the PDN (Packet Data Network) is also the same. Since voice traffic is transmitted using a bearer, silence due to the difference between the transmit bearer and the receive bearer does not occur.

Combinations of each block of the block diagram attached to the present specification and each step of the flowchart may be performed by computer program instructions. Since these computer program instructions can be mounted on a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, the instructions executed by the processor of the computer or other programmable data processing equipment are shown in each block or flow chart of the block diagram. Each step creates a means to perform the functions described. These computer program instructions can also be stored in computer-usable or computer-readable memory that can be directed to a computer or other programmable data processing equipment to implement a function in a particular way, so that the computer-usable or computer-readable memory It is also possible to produce an article of manufacture in which the instructions stored in the block diagram contain instruction means for performing the functions described in each block or flow chart. Computer program instructions can also be mounted on a computer or other programmable data processing equipment, so that a series of operating steps are performed on a computer or other programmable data processing equipment to create a computer-executable process to create a computer or other programmable data processing equipment. It is also possible for the instructions to perform the processing equipment to provide steps for performing the functions described in each block of the block diagram and each step of the flowchart.

In addition, each block or each step may represent a module, segment, or part of code comprising one or more executable instructions for executing the specified logical function(s). In addition, it should be noted that in some alternative embodiments, functions mentioned in blocks or steps may occur out of order. For example, two blocks or steps shown in succession may in fact be performed substantially simultaneously, or the blocks or steps may sometimes be performed in the reverse order depending on the corresponding function.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains will be able to make various modifications and variations without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

According to an embodiment of the present invention, when a bearer is relocated for packet switched handover, since a dedicated bearer with guaranteed bandwidth is relocated only to a non-guaranteed bearer, silence due to the difference between the transmit bearer and the receive bearer is reduced. It does not occur, and silence time is minimized during packet switched handover call processing.

The present invention can be used in a heterogeneous mobile communication system in which an LTE mobile communication network is operated together with various legacy networks.

120: MME 220: RNC 230: SGSN
500: call processing device
510: message receiving unit 520: bearer checking unit 530: message transmitting unit

Claims (7)

A call processing method in a communication environment in which a first network supporting a bandwidth guarantee bearer and a second network not supporting the bandwidth guarantee bearer are mixed,
Receiving a message requiring relocation of the bandwidth guarantee bearer and the bearer that does not support the bandwidth guarantee,
Checking bearer support information of the second network,
And transmitting, to the second network, a relocation processing related message for a bearer that does not support the bandwidth guarantee from which the bandwidth guarantee bearer is excluded from the received message based on the confirmed bearer support information,
The message requiring relocation includes identification information for the bandwidth guarantee bearer.
Call processing method. The method of claim 1,
The receiving step includes receiving a bearer relocation request message from the packet-switching core network of the second network,
The transmitting may include transmitting a bearer relocation request response message to the packet-switched core network of the second network.
Call processing method. The method of claim 1,
The receiving step includes receiving a bearer forward relocation request message from the core network of the first network,
The transmitting may include transmitting a bearer relocation request message to the radio access control network of the second network.
Call processing method. A call processing method in a communication environment in which a first network supporting a bandwidth guarantee bearer and a second network not supporting the bandwidth guarantee bearer are mixed,
Receiving a handover request message including the bandwidth guarantee bearer and the bearer not supporting the bandwidth guarantee from the base station of the first network,
Checking bearer support information of the second network,
Based on the confirmed bearer support information, a bearer forward relocation request message for a bearer that does not support the bandwidth guarantee from which the bandwidth guarantee bearer is excluded from the received handover request message is sent to the packet-switching core network of the second network. Including the step of transmitting,
The handover request message includes identification information on the bandwidth guarantee bearer.
Call processing method. A call processing device in a communication environment in which a first network supporting a bandwidth guaranteed bearer and a second network not supporting the bandwidth guaranteed bearer are mixed,
A message receiving unit for receiving a message related to a relocation request for the bandwidth guarantee bearer and the bearer not supporting the bandwidth guarantee;
A bearer confirmation unit that checks bearer support information of the second network,
A message transmission unit for transmitting a relocation processing-related message to the second network for a bearer that does not support the bandwidth guarantee in which the bandwidth guarantee bearer is excluded from the received message based on the confirmed bearer support information,
The relocation request-related message includes identification information on the bandwidth guarantee bearer.
Call processing device. The method of claim 5,
The message receiving unit receives a bearer relocation request message from the packet-switching core network of the second network,
The message transmission unit transmits a bearer relocation request response message to the packet-switching core network of the second network.
Call processing device. The method of claim 5,
The message receiving unit receives a bearer forward relocation request message from the core network of the first network,
The message transmission unit transmits a bearer relocation request message to the radio access control network of the second network.
Call processing device.

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