KR20050059664A - Method for handover between asynchronous communication network and synchronous communication network - Google Patents

Abstract

The present invention proposes a handover method of a mobile communication terminal in a mobile communication network in which an asynchronous network and a synchronous network overlap.

According to the present invention, an asynchronous exchange instructs a handover to a synchronous exchange in a handover request of a mobile communication terminal so that an omnidirectional channel is allocated between the synchronous mobile communication system and the mobile communication terminal, and the asynchronous exchange performs handover to the mobile communication terminal. Instruct the reverse channel to be allocated between the mobile communication terminal and the synchronous mobile communication system according to the indication.The synchronous mobile communication system reports that the handover is completed to the asynchronous exchange, and after the connection between the asynchronous exchange and the wireless network controller is released, the handover is performed. As the requested mobile communication terminal is in an alerting state and the mobile communication terminal responds to the alerting, the synchronous mobile communication system transmits an inter-system response message to the asynchronous exchange, so that the call path is established, and the mobile communication requesting handover is made. When the terminal is waiting for a response, the called mobile terminal responds The asynchronous send the inter-exchange system, a response message to the synchronous mobile communication system based on, so that a call to set up.

According to the present invention, a call disconnection phenomenon can be prevented during handover.

Description

Handover method between asynchronous mobile communication system and synchronous mobile communication system {Method for Handover Between Asynchronous Communication Network and Synchronous Communication Network}

The present invention relates to a handover method in a mobile communication network, and more particularly, to a handover method of a mobile communication terminal in a mobile communication network in which an asynchronous network and a synchronous network overlap.

With the development of mobile communication technology and the evolution of communication networks, various types of mobile communication systems are being developed. Accordingly, the IMT-2000 system has been developed to solve the global roaming problem between mobile communication systems. IMT-2000 system is divided into CDMA2000 based synchronous system and WCDMA based asynchronous system.

In addition, in order to support global roaming between mobile communication systems, a dual band dual mode terminal (DBDM mobile communication terminal) capable of being used in both a synchronous system and an asynchronous system has been developed. By using, different types of services can be used in each of the asynchronous system domain and the synchronous system domain.

Currently, asynchronous mobile communication systems are being built around regions with high service demands, and accordingly, synchronous mobile communication systems have evolved to include service areas of asynchronous system. When a user moves between an asynchronous mobile communication system and a synchronous mobile communication system, handover between systems is required for continuous service provision.

Handover may occur in various cases, such as when a call is in progress, when an incoming alert is being made, and when a call is waiting for a response from an originating mobile communication terminal. You can also request

However, at present, the handover method between the asynchronous mobile communication system and the synchronous mobile communication system is not defined, and if such a handover method is not defined, there is a problem that a huge cost is required to implement the asynchronous mobile communication system.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and defines a handover method between an asynchronous mobile communication system and a synchronous mobile communication system, thereby reducing the cost required to implement the asynchronous mobile communication system, and asynchronous mobile communication system and synchronous mobile communication. SUMMARY OF THE INVENTION There is a technical problem to provide a handover method capable of preventing a communication disconnection phenomenon caused by movement of a mobile communication terminal in a mobile communication system in which a system coexists.

In addition, the present invention provides a handover method of waiting for a response from the originating mobile communication terminal during alerting of the incoming mobile communication terminal, so that the mobile communication terminal can provide a continuous service in any situation.

In addition, the present invention provides a handover method when the mobile communication terminal moved from the asynchronous mobile communication system area to the synchronous mobile communication system area to the third area and needs handover to use the service without a call disconnection phenomenon. There are other technical challenges to this.

In accordance with an aspect of the present invention, a wireless network controller of an asynchronous mobile communication system is handed over to an asynchronous exchange according to a handover request of a mobile communication terminal moving from the asynchronous mobile communication system area to the synchronous mobile communication system area. A first step of allocating an omni-directional channel between the synchronous mobile communication system and the mobile communication terminal by requesting the handover to the synchronous mobile communication system; A second process of allocating a reverse channel between the mobile communication terminal and the synchronous mobile communication system as the asynchronous exchange 220 instructs handover to the mobile communication terminal; A third step in which the synchronous mobile communication system reports that the handover is completed to the asynchronous exchange, thereby disconnecting the connection between the asynchronous exchange and the wireless network controller; In the first process, when the mobile communication terminal requesting the handover is in an alerting state, the synchronous mobile communication system sends an intersystem response message to the asynchronous exchange as the handovered mobile communication terminal responds to the alerting. A fourth process of transmitting a call to establish a call path; And in the first step, when the mobile communication terminal requesting the handover is in a response waiting state, the incoming mobile communication terminal located in the asynchronous mobile communication system area responds, so that the asynchronous exchange is transferred to the synchronous mobile communication system. And transmitting a system response message to establish a call path.

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

1. System Configuration

1 is a block diagram of a mobile communication network to which the present invention is applied.

The mobile communication terminal 10 applied to the present invention is a dual band dual mode (hereinafter, referred to as 'DBDM') mobile communication terminal, which is a form capable of simultaneously providing an asynchronous mobile communication service and a synchronous mobile communication service. Reference will be made to 2 below. The DBDM mobile communication terminal 10 may wirelessly connect to the asynchronous mobile communication system 20 and the synchronous mobile communication system 30 to use voice and data services.

The asynchronous mobile communication system 20 is a wireless network controller (Node B / RNC, 210) for controlling Node B and Node B as a base station for wireless section communication with the mobile communication terminal 10, wireless network controller 210 Short service center connected with the asynchronous exchange (MSC, 220), the asynchronous exchange 220 and the No.7 common signal network 230 to perform a call exchange for providing a service to the mobile communication terminal (10) (SMSC, 240), the intelligent network controller (SCP, 250) and home location register (HLR, 260), the wireless network controller 210 and the GPRS (General Packet Radio Service) network 280 is connected to the mobile communication terminal (10) No.7 common signal connected via Serving GPRS Support Node (SGSN), SGSN (270) and General Packet Radio Service (GPRS) network 280, which maintains a location track and performs access control and security functions. Gateway GPRS Support Node, which is connected to the network 230 and supports interworking with external packets through the Internet 40, 290).

In addition, the synchronous mobile communication system 30 is connected to the mobile communication terminal 10 and the base station controller (BTS / BSC, 310) for controlling the base station and the base station for supporting the wireless section communication, and connected to one or more base station controller to perform a call exchange Short-term service center (SMSC, 340), intelligent network controller (SCP, 350) and home location register (HLR) connected through an exchange (MSC) 320, an exchange 320, and a No. 7 common signaling network 330 to perform 360, a data core network for supporting a connection between a packet data service node (PDSN, 370) and a packet data service node 370 and the Internet 40 to be connected to a base station controller to provide a packet data service to a subscriber ( DCN, 380 is configured.

The switches 220 and 320 of the asynchronous mobile communication system 20 and the synchronous mobile communication system 30 are interconnected by the No. 7 common signal networks 230 and 330, and the handover of the mobile communication terminal 10 is performed. Send and receive the necessary information. In addition, the home location registers 260 and 360 may be implemented as a dual stack home location register. The home location registers 260 and 360 may store and manage subscriber information, additional service usage status, and provide subscriber information according to a request of the exchange 220 or 320. .

In such a system environment, the mobile communication terminal is handed over to the Node B / RNC 210 as the mobile communication terminal in a call, alerting or waiting for a response in the asynchronous mobile communication system area moves to the synchronous mobile communication system area. The RNC requests the asynchronous switch 220 to handle handover of the mobile communication terminal.

Accordingly, the asynchronous switch 220 instructs the handover to the synchronous switch 320, while instructing the mobile terminal 10 to handover to the synchronous mobile communication system area, and the base station / base station of the synchronous mobile communication system. Forward and reverse channels are allocated between the controller 310 and the mobile communication terminal 10 to complete the connection. A detailed handover procedure will be described later.

2. Configuration of mobile communication terminal

2 is a structural diagram of a mobile communication terminal applied to the present invention.

As shown, the DBDM mobile communication terminal 10 applied to the present invention includes an antenna 100, a module 110 for a synchronous mobile communication service, a module 120 and a common module 130 for an asynchronous mobile communication service. It is configured to include.

The antenna 100 has a function of simultaneously processing a frequency band for a synchronous mobile communication service and a frequency band for an asynchronous mobile communication service.

The synchronization module 110 includes a duplexer 111 that operates as a band pass filter for separating and processing respective frequencies, a synchronous wireless transceiver 112 for separating transmission and reception radio waves into a predetermined frequency band, and a wireless section with a synchronous mobile communication system. The asynchronous module 120 includes a synchronous modem unit 113 for processing a protocol, and the asynchronous module 120 divides each frequency into a duplexer 121 that operates as a band pass filter, and asynchronous radios for separating transmission and reception radio waves into predetermined frequency bands. It includes a transmitting and receiving unit 122 and an asynchronous modem unit 123 for processing a wireless section protocol with the asynchronous mobile communication system.

The common module 130 includes an application processor, a memory, an input / output unit, other application processing units, etc. that operate as a central processing unit for controlling the synchronous modem unit 113 and the asynchronous modem unit 123 and perform multimedia functions.

In addition, the DBDM mobile communication terminal 10 is equipped with software for user interface, additional service, mobility management, access / session control, resource control, and protocol processing, so that a user can use various application services and perform handover. Performs protocol conversion according to the mobile communication system.

3. Overall Handover Procedure and Call Release Procedure

3 is a flowchart illustrating a handover method from an asynchronous mobile communication system to a synchronous mobile communication system.

In one mobile communication system, handover (or handoff) refers to a technology that enables a user to communicate without disconnection when a mobile communication terminal moves from one cell to another cell of the mobile communication system.

The present invention provides a handover method of a DBDM mobile communication terminal in a network in which a synchronous mobile communication system and an asynchronous mobile communication system are mixed, where a mobile communication terminal moves from a synchronous area to an asynchronous area, and a mobile communication terminal in an asynchronous area. In the case of moving to the synchronization area, the following description will be made only to the latter.

As the mobile communication terminal using the service in the asynchronous region approaches the synchronous region, the magnitude of the pilot signal received from the node B of the asynchronous mobile communication system to the mobile communication terminal gradually decreases, and the node B of the asynchronous mobile communication system Periodically measures the signal sensitivity (S1) and checks whether the measured signal sensitivity falls below a specified threshold (S2). If the signal sensitivity between the mobile communication terminal and the NodeB is measured below a specified threshold, the NodeB requests a handover to the asynchronous exchange 220 through the RNC (S3).

When requesting a handover to the asynchronous exchange 220, the neighbor cell information, neighbor base station information, and signal sensitivity with the neighbor base station measured by the mobile communication terminal are transmitted together. The asynchronous exchange 220 that has received the handover request checks whether the current state of the mobile communication terminal requesting the handover is busy, alerting, or waiting for a response (S4).

If it is determined that the status of the mobile communication terminal is busy, a handover procedure suitable for the call is performed (S10). In addition, in the case of the alerting state and the response waiting state, respectively, the appropriate handover procedure is performed (S20, S30), and when the incoming mobile communication terminal responds after performing the handover corresponding to the alerting state and the response waiting state, the call is made. It is started (S5). When the mobile communication terminal in the alerting state is handed over, the mobile communication terminal which performed the handover is the called terminal, and when the terminal in the response waiting state is handed over, the mobile communication terminal which performed the handover is the calling terminal. It will be apparent to those skilled in the art to which the invention pertains.

In the present invention, when the mobile communication terminal requesting the handover is in an alerting state, the asynchronous exchange 220 instructs the synchronous exchange 320 to handover to allocate an omnidirectional channel to the mobile communication terminal. Instructing the handover to the mobile communication terminal 220 to allocate a reverse channel to the base station / base station controller 310 so that the mobile communication terminal and the synchronous mobile communication system 30 are connected, and then the mobile communication terminal and the asynchronous exchanger ( The connection between the terminals 220 is released, and as the mobile communication terminal in the alerting state responds to the alerting, the switch 320 transmits an intersystem response message to the asynchronous switch 220, thereby completing the handover.

In addition, when the mobile communication terminal requesting the handover is in a waiting state for response, the asynchronous exchange 220 instructs the handover to the synchronous exchange 320 to allocate an omnidirectional channel to the mobile communication terminal, and the asynchronous exchange 220 ) Instructs the mobile communication terminal to handover and allocates a reverse channel to the base station / base station controller 310 so that the mobile communication terminal and the synchronous mobile communication system 30 are connected, and then the mobile communication terminal and the asynchronous switch 220. The asynchronous exchange 220 transmits an intersystem response message to the exchange 320 as the mobile communication terminal located in the asynchronous mobile communication system area responds, thereby completing the handover.

When a call is initiated in response to a mobile communication terminal in an alert state after a handover, when a call is initiated in response to a call by a terminating mobile terminal after a handover by a mobile terminal in response waiting state The service is provided between the destination mobile communication terminal (S6), and then the asynchronous exchange 220 and the synchronous exchange 320 checks whether a call termination request is received from the originating or incoming mobile communication terminal (S7), and the call termination request is When received, it is checked whether the terminal requesting to release the call is the terminal (terminal a) located in the asynchronous mobile communication system area or the terminal (terminal b) located in the synchronous mobile communication system area (S8), and the call release according to each case. Perform the procedure (S40, S50).

When the mobile communication terminal 10a located in the asynchronous mobile communication system area requests call release, a call release request message is transmitted from the asynchronous exchange 220 to the base station / base station controller 310 through the exchange 320, and the call is The call release procedure is performed by instructing the base station / base station controller 310 which receives the release request message to release the call to the mobile communication terminal 10b.

On the other hand, when the mobile communication terminal 10b located in the area of the synchronous mobile communication system requests call release, the base station / base station controller 310 requests the call release from the switch 320 and calls the mobile communication terminal 10b. A call release procedure is sent, as the exchange 320 requests the asynchronous exchange 220 to release the call.

The handover procedure in the alerting state, the handover procedure in the response waiting state, the call release procedure by the request of the mobile communication terminal located in the asynchronous area, and the call release procedure by the request of the mobile communication terminal located in the synchronization area This will be described in more detail with reference to FIGS. 4 and 5.

4. Handover Procedure (Alert State, Waiting for Response)

4 is a detailed flowchart of the handover procedure shown in FIG. 3.

In response to a handover request of the mobile communication terminal, the RNC 210 requests a handover to the asynchronous switch 220. Accordingly, the asynchronous switch 220 instructs the handover to the synchronous mobile communication system 30 to perform synchronous mobile communication. The omnidirectional channel is allocated between the system 30 and the mobile communication terminal (S101 ˜ S107), and the reverse direction between the mobile communication terminal and the synchronous mobile communication system 30 as the asynchronous switch 220 instructs handover to the mobile communication terminal. The channel is allocated (S108-S113), and the synchronous mobile communication system 30 reports that the handover is completed to the asynchronous switch 220 (S114-S116), and the connection between the asynchronous switch 220 and the RNC 210 is performed. Release (S117-S118).

More specifically, in the asynchronous mobile communication system 20, the mobile communication terminal in communication with the mobile communication terminal also located in the asynchronous mobile communication system region 20, or the terminal in an alerting state, or waiting for a response As the terminal moves to the boundary area between the asynchronous mobile communication system 20 and the synchronous mobile communication system 30, the mobile mobile communication terminal requests a handover to the RNC 210, and the RNC 210 sends an asynchronous switch. A handover is requested to 220 (Relocation Required) (S101).

Accordingly, the asynchronous exchange 220 checks the mobile communication terminal information, neighbor cell information, neighbor base station information, etc., which requested the handover received from the RNC 210, and determines that the handover is in the area of the synchronous mobile communication system 30. When the handover is requested, the synchronization switch 320 transmits information indicating whether the mobile communication terminal is busy, alerting, or waiting for a response (FACDIR2) (S102).

Receiving a handover request from the asynchronous switch 220, the synchronous switch 220 requests a handover to the BSC 310 (Handoff Request) (S103), and receives a response (Handoff Req Ack) (S104). In addition, the BSC 310 transmits a null frame to the synchronous modem unit 113 of the mobile communication terminal to perform the handover (null F-FCH frames) to allocate the omnidirectional channel (S105). .

Thereafter, the synchronous exchange 320 transmits a response message facdir2 for the handover request to the asynchronous exchange 220, and the asynchronous exchange 220 responds to the handover request to the RNC 210 (Relocation Command). (S106, S107). Although not shown, after the step S106 in which the synchronous exchange 320 transmits a response message facdir2 for the handover request to the asynchronous exchange 220, before performing the step S107, the asynchronous exchange 220 receives the synchronous exchange. The IAM (Initial Address Message) is sent to the 320, and the synchronous exchange 320 transmits an address completion message (ACM) as a response thereto so that trunk setup is completed between the asynchronous exchange 220 and the synchronous exchange 320. do. The exchange duration message for trunk establishment is sent and received by the ISUP.

Next, the asynchronous switch 220 instructs a handover to the asynchronous modem unit 123 of the mobile communication terminal (HANDOVER FROM UTRAN COMMAND) (S108). This message includes a message related to the synchronous mobile communication system. Information for assignment will be included. Channel assignment information is transmitted from the asynchronous modem unit 123 to the synchronous modem unit 113 so that the synchronous modem unit 113 may prepare for handover in advance (S109).

As such, as the synchronous modem unit 113 receives the channel assignment message and the handover message, the synchronization module 110 performs a communication preparation process with the synchronous mobile communication system 30 (S110), and the communication preparation process is performed. When it is completed, it is notified to the asynchronous modem unit 123 (call connected, S111). When the synchronization module 110 of the mobile communication terminal completes preparation for communication with the synchronous mobile communication system, mode switching is performed between the asynchronous modem unit 123 and the synchronous modem unit 113 such as vocoder switching (S112). The unit 113 transmits a frame through the reverse channel to the BTS / BSC 310 of the synchronous mobile communication system 30 (R-FCH frames, S113), thereby connecting the mobile communication terminal to the synchronous mobile communication system 30. This is done.

Subsequently, the mobile communication terminal reports that the handover is completed to the BSC 310 (Handoff Complete) (S114), and the BSC 310 hands over the synchronous exchange 320 (Handoff Complete) to the asynchronous exchange 220. It is notified that the over has been completed (MSONCH) (S115, S116).

Accordingly, the asynchronous switch 220 requests the RNC 210 to release the call (Iu Release Command, S117), the RNC 210 terminates the connection with the asynchronous modem unit 220, and the call release is completed. By reporting to the asynchronous switch 220 (IU Rel. Complete) (S118), the connection between the synchronous modem unit 113 and the synchronous mobile communication system 30 of the mobile communication terminal is completed and the asynchronous modem unit 123 and asynchronous The connection between the mobile communication system 20 is completely released.

In the above-described procedure, a communication preparation process (S110) of the synchronous modem unit 113 will be described below. The synchronous modem 113 receiving the channel allocation information from the asynchronous modem 123 is activated through a switch-on and warm-up process, and acquires a pilot channel and a synchronous channel. By acquiring the pilot channel, synchronization between the base station 310 and the terminal of the synchronous mobile communication system 30 is performed. By acquiring the synchronization channel, timing information and other system information are received from the base station 310. Accordingly, the synchronization module 110 of the mobile communication terminal transitions to the traffic state through an idle state, thereby making a connection with the synchronous mobile communication system 30.

On the other hand, when the mobile communication terminal is in a call state in step S102 described above, the voice call continues after step S118.

However, when the mobile communication terminal is in an alerting state in step S102, the following procedure is further required. That is, according to the handover of the terminating mobile communication terminal (Connect Order) (S201), the BSC 310 notifies (Connect) that the terminating terminal has responded to the switch 320 (S202), 320 transmits the intersystem response message ISANSWER to the asynchronous exchange 220 (S203).

In addition, the asynchronous exchange 220 turns off the ringback tone transmitted to the calling terminal in the asynchronous mobile communication system 30 area (S204), and responds to the intersystem response message to the synchronous exchange 320. By transmitting the answer (S205), the call is started between the calling terminal located in the asynchronous mobile communication system 20 area and the called terminal handing over to the synchronous mobile communication system 30 area.

In addition, when the mobile communication terminal is waiting for a response in step 102, the procedure after step S118 is further required. That is, as the called mobile terminal located in the asynchronous mobile communication system 20 after the calling mobile communication terminal moves to the synchronous mobile communication system area (called party answer) (S301), the asynchronous exchange 220 While transmitting the intersystem response message ISANSWER to the synchronization exchanger 320 (S302), the synchronization exchanger 320 receiving the notification informs the BSC 310 of the response of the called terminal (S303), The asynchronous exchange 220 transmits an answer to the intersystem response message (S304).

In addition, the BSC 310 starts a call by notifying that the called terminal has responded to the mobile communication terminal (synchronous modem unit) handed over to the synchronous mobile communication system 30 (S305) (S305).

5. Call Release Procedure

5A and 5B are detailed flowcharts of the call release procedure shown in FIG.

The call release procedure after the handover of the mobile communication terminal does not distinguish between the calling terminal and the called terminal when the mobile communication terminal located in the asynchronous mobile communication system area requests call release (FIG. 5A), that is, located in the synchronous mobile communication system area. In the case of handover request by the mobile communication terminal for call release (FIG. 5B), the description will be given.

This call release procedure may be applied to all of the cases where the mobile communication terminal is busy at the time of handover, when the call is initiated in response to an alerting state, or when the call is initiated by the called terminal in response waiting state.

In addition, for convenience of description, a mobile communication terminal located in the asynchronous mobile communication system area will be described as a terminal a and a mobile communication terminal located in the synchronous mobile communication system area as a terminal b.

5-1. Call Release Procedures for Call Release Requests in the Asynchronous Zone

FIG. 5A is a diagram illustrating a procedure in which terminal a requests call release and releases a connection after terminal a located in an asynchronous mobile communication system area and terminal b handing over to a synchronous mobile communication system area complete a call.

As shown, according to the call release request of the terminal a (S401), the RNC 210 requests to release the call to the asynchronous exchange 220 (S402), the asynchronous exchange 220 is in a call with the terminal a A request is made to release the call to the exchange 320 to which the terminal b is connected (FACREL) (S403).

Accordingly, when the exchange 320 requests the call release to the BSC 310 (Clear Command), the BSC 310 receiving the call transmits a call release command to the terminal b (Release Order) (S405). In addition, it reports to the exchange 320 that call release is completed (Clear Complete) (S406). Subsequently, the exchange 320 reports the completion of the call release to the asynchronous exchange 220 (facrel) (S407) so that the call path established between the terminal a and the terminal b is released.

5-2. Call Release Procedure When Call Release Request in Synchronous Area

FIG. 5B is a diagram illustrating a procedure in which terminal b requests call release to release a connection after terminal a located in an asynchronous mobile communication system area and terminal b handed over to a synchronous mobile communication system area complete a call.

As shown, according to the terminal b call release request (Release Order) (S501), the BSC 310 requests the exchange 320 to release the call (Clear Request) (S502) and the synchronization exchange 220 The response message is transmitted (Clear Command) (S503).

Thereafter, the BSC 310 transmits a call release command to the terminal b (Release Order) (S504), and reports that the call release is completed to the exchange 320 (Clear Complete) (S505). Accordingly, the switch 320 requests the asynchronous switch 220 to release the call (FACREL) (S506), and the asynchronous switch 220 sends a disconnection command to the terminal a (disconnect) (S507). In step S508, it transmits to the exchange 320 that call release is completed.

6. Procedure for handover to a third area by a terminal handing over to a synchronization area

6 is a conceptual diagram illustrating a handover method of a mobile communication terminal handed over to a synchronous mobile communication system to a third region, and FIG. 7 is a handover method of the mobile communication terminal illustrated in FIG. 6. This is a flowchart for explaining.

In the asynchronous mobile communication system area, the mobile communication terminal during a call, alerting or waiting for a response moves to the synchronous mobile communication system area and performs a handover, and this mobile communication terminal may request handover again. May occur.

6 and 7 illustrate a handover method in such a case. Referring first to FIG. 6, a mobile communication terminal 10d that is in a call, alerting, or waiting for a response in the asynchronous mobile communication system 20 region is illustrated. ) Is handed over to the area of the synchronous mobile communication system 30 and the call setup with the mobile communication terminal 10c located in the asynchronous mobile communication system area 20 is completed. Report handover to the base station controller 310. The third area 50 may be a synchronous mobile communication system area or an asynchronous mobile communication system area.

In response to the handover request of the mobile communication terminal 10d, the base station controller 310 requests a handover to the switch 320, and the switch 320 informs the asynchronous switch 220 of the handover. The target exchange 520 of the three regions 50, that is, the exchange to be handed over, can be connected. To this end, the asynchronous exchange 220 requests a handover to the target exchange 520 according to the handover request of the exchange 320, informs the switch 320, and then the base station of the synchronous mobile communication system 30 The base station controller 310 instructs the mobile communication terminal 10d to handover, so that the mobile communication terminal 10d can be connected to the target BTS / BSC 510 of the third region 50.

A more detailed description with reference to FIG. 7 is as follows.

First, the mobile communication terminal 10d handed over to the area of the synchronous mobile communication system 30 moves through the BTS / BSC 310-the synchronous exchange 320-the asynchronous exchange 220-the RNC / node B 210. It is connected with the communication terminal 10c. In this state, when the mobile communication terminal 10d gradually moves to the third region 50 to request a handover, the final connection relationship is the target BTS / BSC 512, 514 of the mobile communication terminal 10d-the third region. It should be switched to be a target MSC 520-asynchronous exchange 220-RNC / node B 210-mobile communication terminal 10c.

To this end, according to the handover request of the mobile communication terminal 10d, the BTS / BSC (serving BTS / BSC, 310) of the synchronous mobile communication system requests a handover to the synchronous exchange (serving MSC) 320 (Handoff Requires). (S601), the serving MSC 320 reports that handover should be performed to the asynchronous exchange 220 (HANDTHIRD) (S602). At this time, the serving MSC 320 transmits the information of the third region 50 adjacent to the mobile communication terminal 10d to the asynchronous switch 220.

The asynchronous exchange 220 requests a handover to the target MSC 520 according to the request of the serving MSC 320 (FACDIR) (S603), and the target MSC 520 hands over to the target BTS / BSC 514. Request (Handoff Req.) (S604), and receives a response thereto (Handoff Req. Ack.) (S605).

Next, when the target MSC 520 sends a response message for the handover request to the asynchronous exchange 220 (facdir) (S606), the asynchronous exchange 220 responds to the handover request to the serving MSC 320. The message is transmitted (handthird) (S607). Subsequently, the serving MSC 320 commands to perform a handover to the serving BTS / BSC 310 (Handoff Command) (S608), whereby the serving BTS / BSC 310 hands the mobile communication terminal 10d. Command to perform over (UHDM) (S609).

The mobile communication terminal 10d receiving the handover execution command transmits a frame to the target BTS / BSC 514 through the reverse channel (R-FCH frames) (S610), and then reports that the handover is completed ( HCML Handoff Completion Message) (S611).

In addition, the target BTS / BSC 514 reports that the handover is completed to the target MSC 520 (Handoff Complete) (S612), the target MSC 520 reports it to the asynchronous exchange 220 (MSONCH) ( S613), the handover to the third area 50 is completed.

The call release process after the handover to the third region 30 may be performed by applying the processes of FIGS. 5A and 5B described above.

The present invention described above, those skilled in the art will understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. Therefore, the above-described embodiments are to be understood as illustrative in all respects and not as restrictive. The scope of the present invention is shown by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

According to the present invention as described above, in a mobile communication network in which an asynchronous mobile communication system and a synchronous mobile communication system are mixed, the mobile communication is being connected during the handover of the dual band dual mode mobile communication terminal during call, alerting, or waiting for response. After the connection with the mobile communication system to be handed over while maintaining the connection with the system is terminated, the call disconnection phenomenon can be prevented during handover by ending the connection with the previously connected mobile communication system. It will be possible to improve.

In addition, even when the mobile terminal handovered to the synchronous mobile communication system requires handover to the third area again, it is possible to provide a high quality service to the subscriber by facilitating the connection between the asynchronous mobile communication system and the third area. This has the effect of minimizing the cost required for the design.

1 is a configuration diagram of a mobile communication network to which the present invention is applied;

2 is a structural diagram of a mobile communication terminal applied to the present invention;

3 is a flowchart illustrating a handover method from an asynchronous mobile communication system to a synchronous mobile communication system;

4 is a detailed flowchart of the handover procedure shown in FIG. 3;

5a and 5b are detailed flow charts of the call release procedure shown in FIG.

6 is a conceptual diagram illustrating a handover method of a mobile communication terminal handed over to a synchronous mobile communication system to a third region;

FIG. 7 is a flowchart illustrating a handover method for a third area of the mobile communication terminal illustrated in FIG. 6.

<Description of the symbols for the main parts of the drawings>

10: DBDM mobile communication terminal 20: asynchronous mobile communication system

30: synchronous mobile communication system 40: Internet

100: antenna 110: synchronization module

111, 121: duplexer 112: synchronous radio transceiver

113: synchronous modem unit 122: asynchronous wireless transceiver

123: asynchronous modem unit 130: common module

210: Node B / wireless network controller 220: asynchronous switch

230, 330: No.7 common signal network 240, 340: Short service center

250, 350: intelligent network controller 260, 360: home location register

270: SGSN 280: GPRS network

290: GGSN 310: base station / base station controller

320: switch 370: packet data service node

380 data core network

Claims (12)

In a mobile communication network in which an asynchronous mobile communication system and a synchronous mobile communication system overlap, a handover method of a dual band dual mode mobile communication terminal having an asynchronous modem unit and a synchronous modem unit, A wireless network controller of an asynchronous mobile communication system requests a handover to an asynchronous exchange according to a handover request of a mobile communication terminal moving from the asynchronous mobile communication system area to the synchronous mobile communication system area, and the asynchronous exchange communicates with the synchronous mobile communication. Instructing a handover to a system so that an omnidirectional channel is allocated between the synchronous mobile communication system and the mobile communication terminal; A second process of allocating a reverse channel between the mobile communication terminal and the synchronous mobile communication system as the asynchronous exchange instructs handover to the mobile communication terminal; A third step in which the synchronous mobile communication system reports that the handover is completed to the asynchronous exchange, thereby disconnecting the connection between the asynchronous exchange and the wireless network controller; In the first process, when the mobile communication terminal requesting the handover is in an alerting state, the synchronous mobile communication system sends an intersystem response message to the asynchronous exchange as the handovered mobile communication terminal responds to the alerting. A fourth process of transmitting a call to establish a call path; And In the first process, when the mobile communication terminal requesting the handover is in a response waiting state, the asynchronous exchange intercoms with the synchronous mobile communication system as the incoming mobile communication terminal located in the asynchronous mobile communication system area responds. A fifth step of transmitting a system response message to establish a call path; Handover method comprising a. The method of claim 1, The first process may include: requesting a handover to an asynchronous exchange by a wireless network controller of an asynchronous mobile communication system according to a handover request of a mobile communication terminal moving from the asynchronous mobile communication system area to the synchronous mobile communication system area; Requesting a handover to a synchronous exchange of the synchronous mobile communication system by the asynchronous exchange, and transmitting whether the state of the mobile communication terminal is busy, alerting or waiting for response; Requesting, by the synchronous exchange, a handover to a base station controller of the synchronous mobile communication system, and receiving a response thereto; Allocating an omnidirectional channel by the base station controller transmitting a null frame through an omnidirectional traffic channel to a synchronous modem unit of the mobile communication terminal; And Sending, by the synchronous exchange, a response message for a handover request to the asynchronous exchange, and sending the response message for the handover request to the radio network controller by the asynchronous exchange; Handover method comprising a. The method of claim 1, The second process includes the step of instructing the handover to the asynchronous modem unit of the mobile communication terminal by the asynchronous exchange and transmitting channel allocation information; The asynchronous modem unit transmitting a handover instruction message including the channel allocation information to the synchronous modem unit to prepare for a handover; Performing a communication preparation process with the synchronous mobile communication system when the synchronous modem unit receives a channel assignment message and a handover instruction message, and notifying the asynchronous modem unit when the communication preparation process is completed; Performing mode switching between the asynchronous modem unit and the synchronous modem unit of the mobile communication terminal; And Transmitting, by the synchronous modem unit, a frame to a base station controller of the synchronous mobile communication system through a reverse channel so that the mobile communication terminal and the synchronous mobile communication system are connected; Handover method comprising a. The method of claim 3, wherein The communication preparation process performed by the synchronous modem unit of the mobile communication terminal may include performing switch-on and warm-up of the synchronous modem unit; Obtaining a pilot channel and a synchronization channel from the synchronous mobile communication system; Translating the synchronous modem unit to an idle state; And Translating the idle synchronous modem unit to a traffic state; Handover method comprising a. The method of claim 1, The third process includes: reporting that the mobile communication terminal has completed handover to a base station controller of the synchronous mobile communication system; Notifying, by the base station controller, that the handover has been completed to the asynchronous exchange via the exchange of the synchronous mobile communication system; Requesting the asynchronous exchange to release a call to the radio network controller; And The wireless network controller terminating the connection with the asynchronous modem unit of the mobile communication terminal and reporting to the asynchronous exchange that call release is completed; Handover method comprising a. The method of claim 1, In the fourth process, as the terminating mobile communication terminal performing the first to third processes responds to alerting, the base station controller of the synchronous mobile communication system responds to the exchange of the synchronous mobile communication system. Notifying; Sending, by the synchronous exchange, an inter system response message to the asynchronous exchange; And Turning off the ringback tone transmitted to the originating mobile communication terminal located in the asynchronous mobile communication system area by the asynchronous exchange, and transmitting a response message to the intersystem response message to the synchronous exchange; Handover method comprising a. The method of claim 1, In the fifth process, after the mobile communication terminal performs the first to third processes to hand over to the synchronous mobile communication system, the incoming mobile communication terminal located in the asynchronous mobile communication system area responds. Sending, by an asynchronous exchange, an inter system response message to the exchange of the synchronous mobile communication system; Notifying, by the synchronous exchange, a base station controller of the synchronous mobile communication system of a response of the called terminal; Sending, by the synchronous exchange, a response message to an intersystem response message to the asynchronous exchange; And Notifying, by the base station controller, that the called terminal has responded to the handed over mobile communication terminal; Handover method comprising a. The method of claim 1, Call paths are formed between the first mobile communication terminal located in the asynchronous mobile communication system region and the second mobile communication terminal handed over to the synchronous mobile communication system region by the first to fifth processes, and the fourth process or the fifth process. 5 After the course, Requesting, by the radio network controller, to release a call to the asynchronous exchange according to a call release request of the first mobile communication terminal; Requesting the asynchronous exchange to release a call to an exchange of a synchronous mobile communication system to which the second mobile communication terminal is connected; Requesting the synchronous exchange to release a call to a base station controller of the synchronous mobile communication system; Sending, by the base station controller, a call release command to the second mobile communication terminal and reporting that call release is completed to the synchronization exchanger; And Reporting that the synchronous exchange has completed a call release to the asynchronous exchange; Handover method, characterized in that further performing. The method of claim 1, Call paths are formed between the first mobile communication terminal located in the asynchronous mobile communication system region and the second mobile communication terminal handed over to the synchronous mobile communication system region by the first to fifth processes, and the fourth process or the fifth process. 5 After the course, Requesting the base station controller of the synchronous mobile communication system to release a call to an exchange of the synchronous mobile communication system according to a call release request of the second mobile communication terminal, and receiving a response message thereto; Sending, by the base station controller, a call release command to the second mobile communication terminal and reporting that call release is completed to the synchronization exchanger; And Requesting the synchronous exchange to release a call to the asynchronous exchange; Reporting that the asynchronous exchange has completed a call release to the synchronous exchange after transmitting a connection release command to the first mobile communication terminal; Handover method, characterized in that further performing. In a mobile communication network in which an asynchronous mobile communication system and a synchronous mobile communication system overlap, a dual band dual mode mobile communication terminal having an asynchronous modem unit and a synchronous modem unit is handed over from the asynchronous mobile communication system area to the synchronous mobile communication system area. In the state, a method for handover to the third region, Requesting handover by a serving base station controller of the synchronous mobile communication system to a serving exchange of the synchronous mobile communication system as the mobile communication terminal moves to the third area and requests a handover; The serving exchange requesting a handover to an exchange of the asynchronous mobile communication system and transmitting information of the third region; The asynchronous exchange requesting handover to a target exchange of a third region; The target exchange requesting a handover to a target base station controller of the third region and receiving a response; The target exchange sending a response message for a handover request to the asynchronous exchange, and the asynchronous exchange sending a response message for the handover request to a serving exchange; Instructing the serving exchange to perform a handover to a serving base station controller; Instructing the serving base station controller to perform a handover to the mobile communication terminal; Receiving, by the mobile communication terminal, receiving the handover command, transmitting a frame through a reverse channel to the target base station controller and reporting that the handover is completed; The target base station controller reporting that the handover is complete to the target exchange, and the target exchange reporting that the handover is complete to the asynchronous exchange; Handover method comprising a. The method of claim 10, After the target exchange reports that the handover is complete to the asynchronous exchange, After a call path is formed between a first mobile communication terminal located in an asynchronous mobile communication system area and a second mobile communication terminal handed over to the third area, the wireless network according to a call release request of the first mobile communication terminal. Requesting a controller to release a call to the asynchronous exchange; Requesting the asynchronous exchange to release the call to a target exchange to which the second mobile communication terminal is connected; Requesting, by the target exchange, to release a call to the target base station controller; Sending, by the target base station controller, a call release command to the second mobile communication terminal and reporting that call release is completed to the target exchange; And Reporting that the target exchange has completed a call release to the asynchronous exchange; Handover method, characterized in that further performing. The method of claim 10, After the target exchange reports that the handover is complete to the asynchronous exchange, After the call path is formed between the first mobile communication terminal located in the asynchronous mobile communication system area and the second mobile communication terminal handed over to the third area, the target base station according to the call release request of the second mobile communication terminal. Requesting a controller to release a call to the target exchange, and receiving a response message thereto; Sending, by the target base station controller, a call release command to the second mobile communication terminal and reporting that call release is completed to the target exchange; And Requesting, by the target exchange, to release a call to the asynchronous exchange; Reporting that the asynchronous exchange has completed a call release to the target exchange after transmitting a connection release command to the first mobile communication terminal; Handover method, characterized in that further performing.