KR20050091160A - Handover method using interworking interoperability function for minimization of mute interval in mixed mobile communication system of asynchronous network and synchronous network - Google Patents

Abstract

The present invention provides a handover method using an interoperation operation unit for minimizing the silence period of a mobile communication terminal in a mobile communication system in which asynchronous and synchronous networks are mixed.

In the handover method of the present invention, when the asynchronous mobile communication system requests handover to the synchronous mobile communication system through the interoperation operation unit, the synchronous mobile communication system allocates traffic, and after the relay line between the asynchronous exchange and the synchronous exchange is established, the asynchronous exchange Instructing handover to a mobile communication terminal through a wireless network controller, connecting the mobile communication terminal to a synchronous mobile communication system, transmitting a reverse traffic by the mobile communication terminal, driving a timer by the mobile communication terminal, As the base station / base station controller notifies the interoperation operation unit that the handover is completed, the mobile communication terminal expires the timer operation and switches the vocoder, switching the vocoder between the asynchronous exchange and the synchronous exchange period, and asynchronous Between mobile communication system and synchronous mobile communication system And a step of releasing the connection.

According to the present invention, the quality of service can be improved by minimizing the silence period during the handover during the voice call from the asynchronous network to the synchronous network.

Description

Handover method using interworking interoperability function for minimization of mute interval in mixed mobile communication system of asynchronous network in mobile communication system with asynchronous network and synchronous network and Synchronous 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 for minimizing a silent section of a mobile communication terminal in a call in a mobile communication system in which an asynchronous network and a synchronous network are mixed. It is about.

Currently, a mobile communication network has a form in which a synchronous mobile communication system (CDMA mobile communication system) called a second generation or 2.5 generation network and a asynchronous mobile communication system (WCDMA mobile communication system) called a third generation network coexist.

With the development of mobile communication network technology, 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. This allows different types of services to be used in each of the asynchronous system domain and the synchronous system domain. The DBDM mobile communication terminal includes an antenna, a synchronous modem unit which is a module for synchronous mobile communication service, an asynchronous modem unit which is a module for asynchronous mobile communication service, and a common module.

The asynchronous mobile communication system is in the early stage of service, and because a huge investment cost is required to implement the system, it cannot be serviced in a large area, and thus, the asynchronous mobile communication system is superimposed on the synchronous mobile communication system. Accordingly, since the service area of the asynchronous mobile communication system is limited, a hand for providing a continuous service when the subscriber of the asynchronous mobile communication system moves to a synchronous area where the asynchronous mobile communication service is not provided while using the service in the asynchronous area. Over is needed.

Recently, various handover methods for terminals moving from an asynchronous mobile communication system to a synchronous mobile communication system have been studied. During the handover of the mobile communication terminal, the mobile communication terminal should switch the asynchronous vocoder used for the voice call with the asynchronous mobile communication system to the synchronous vocoder used for the voice call with the synchronous mobile communication system. Similarly, a vocoder switching process is required. Then, both the mobile communication terminal and the mobile communication system are able to make a voice call after the vocoder is switched.

However, since there is a time difference between the vocoder switching time point of the mobile communication terminal and the vocoder switching time point of the mobile communication system, a silent section occurs during the handover of the mobile communication terminal, and thus there is a problem that the service quality is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and is a synchronous mobile communication system area in which a mobile communication terminal using a voice call service in an asynchronous mobile communication system area is connected by an asynchronous mobile communication system and an interoperation unit. As a result, there is a technical problem to provide a handover method that can minimize the silent period by making the vocoder switching time of the mobile communication terminal and the mobile communication system the same.

The present invention for achieving the above technical problem is a mobile communication system in which an asynchronous mobile communication system and a synchronous mobile communication system are mixed, and the asynchronous mobile communication system and the synchronous mobile communication system are connected by an interlocking operation unit. A handover method for minimizing a silent period during a voice call of a dual band dual mode mobile communication terminal capable of communicating with an asynchronous mobile communication system and a synchronous mobile communication system, wherein the asynchronous exchange transmits a handover request message to the interoperation unit. Requesting and receiving the subscriber information transmission of the mobile communication terminal from the dual stack home location register to the dual stack home location register; The interoperation operator instructing a handover to the synchronous exchange, and the synchronous exchange requesting a handover to the base station controller / base station; Assigning, by the base station / base station controller, an omnidirectional traffic channel to the mobile communication terminal, and transmitting a response message to the handover request to the synchronous exchange; The synchronous exchange transmits a response message for a handover instruction to the interoperation operator, and the interoperation operator transmits a response message for a handover request to the asynchronous exchange, thereby establishing a relay line between the asynchronous exchange and the synchronous exchange. Becoming; Reporting, by the asynchronous exchange, that resource allocation for handover has been completed to the radio network controller; Instructing the wireless network controller to handover to the mobile communication terminal through the node B, such that the mobile communication terminal switches to a synchronous mobile communication system connected mode; Transmitting, by the interoperation operator, an access signal to the asynchronous exchange; Sending, by the mobile communication terminal, a frame and a preamble through a reverse traffic channel to the base station / base station controller and reporting that handover is completed; Driving a timer as the mobile communication terminal completes the connection with the synchronous mobile communication system; Reporting, by the base station / base station controller, that the handover is complete to the exchange, and notifying the interoperation operator that the handover is complete; The mobile communication terminal expiring timer driving and switching a vocoder; Switching a vocoder between the asynchronous exchange and a synchronous exchange period; And releasing a connection between the asynchronous mobile communication system and the synchronous mobile communication system.

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

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, and is a type capable of simultaneously providing an asynchronous mobile communication service and a synchronous mobile communication service. It comprises a synchronous modem unit which is a module for, asynchronous modem unit which is a module for asynchronous mobile communication service and a common module, and wirelessly connected to the asynchronous mobile communication system 20 and the synchronous mobile communication system 30, respectively, Data service is available.

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 Is connected between the asynchronous exchange (MSC, 220), the radio network controller (RNC) and the GPRS (General Packet Radio Service) network 240 to perform a call exchange for providing a service to the mobile communication terminal (10) It is connected through a Serving GPRS Support Node (SGSN) 230, a SGSN 230, and a General Packet Radio Service (GPRS) network 240 that maintains a location track of the mobile communication terminal 10 and performs access control and security functions. And a Gateway GPRS Support Node (GGSN) 250 connected to the IP network 70 to support interworking with external packets.

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 A packet data service node (PDSN, 330), a packet data service node (330), and an IP network (70), which are connected to an exchange (MSC) 320, a base station controller (BSC), to provide a packet data service to a subscriber. It is configured to include a data core network (DCN, 340) to support the connection between.

In addition, the switch 220 and 320 of the asynchronous mobile communication system 20 and the synchronous mobile communication system 30 are interconnected by an interworking interoperability function (IFF) 60, and the interoperable operating unit ( 60 converts an asynchronous message transmitted from the asynchronous exchange 220 into a synchronous message, and transmits the asynchronous message to the synchronous exchange 320.

The asynchronous exchanger 220 and the synchronous exchange 320 are also interconnected to the No. 7 common signal network 40 and thereby connected to the dual stack home position register (D-HLR) 50, and the dual stack home position. The register 50 stores and manages asynchronous mobile communication system subscription information of the DBDM mobile communication terminal 10 and corresponding synchronous mobile communication system subscription information, and the asynchronous and synchronous exchanges 220 and 320 provide services such as handover. It can be referred to when executing.

In such a network configuration, the mobile communication terminal 10 using the voice call located in the asynchronous mobile communication system 20 area periodically measures the signal strength of the Node B and the signal strength of the neighboring base station, If the signal strength with the node B falls below a specified threshold, the node B reports that the handover event has occurred to the asynchronous exchange 220 through the RNC. In this case, the Node B / RNC 210 transmits the neighbor cell information, the base station ID, etc. detected by the mobile communication terminal 10 to the asynchronous switch 220.

When the asynchronous switch 220 receives the handover request message from the RNC, the synchronous mobile communication system 30 determines whether it is a handover between adjacent cells in the asynchronous mobile communication system 20 with reference to neighbor cell information, base station ID, and the like received from the RNC. It is determined whether or not the handover is performed.

In the case of handover between adjacent cells in the asynchronous mobile communication system 20, the asynchronous exchange 220 performs handover to the adjacent cell, and in the case of handover to the synchronous mobile communication system 30, through the IIF 60. Handover is made to the synchronous exchange 320. To this end, the IIF 60 converts an asynchronous message into a synchronous message and transmits it to the synchronous exchange 320, and pre-configures and manages synchronous mobile communication system information as a database. The database contains exchange information, signaling points, and trunk line information for the dedicated channel. The IIF 60 selects the handover target exchange 320 according to the handover request from the asynchronous exchange 220 and the synchronous mobile communication system information, and generates a billing ID including a handover target exchange ID and the like. It is used in the subsequent handover process.

This handover procedure will be described in more detail with reference to FIG. 2 as follows.

2 is a flowchart illustrating a handover method between an asynchronous network and a synchronous network for minimizing a silent section according to the present invention.

As the mobile communication terminal 10 using the voice call in the asynchronous mobile communication system 20 moves to the synchronous mobile communication system 30, the mobile communication terminal 10 is moved from the synchronous mobile communication system 30. Signal is detected from the Node B of the asynchronous mobile communication system 20 and the signal strength with the neighboring base station (or Node B) periodically measured and reported to the Node B. Accordingly, when the Node B currently connected to the mobile communication terminal 10 confirms that the signal strength between the mobile communication terminal and the Node B is less than or equal to a specified value, the handover is requested to the asynchronous exchanger 220 through the RNC (IU Reloc). Required) (S101).

This handover request message (IU Reloc Required) includes a handover related message used in a synchronous mobile communication system. In addition, the RNC transmits neighbor base station information (base station ID), neighbor cell information, etc. received from the mobile communication terminal 10 together, and the asynchronous switch 220 according to the information indicates whether handover between neighbor cells in the asynchronous mobile communication system. Or, it is determined whether the handover is made to the synchronous mobile communication system 30. The handover request message (IU Reloc Required) that the RNC sends to the asynchronous switch 220 includes the message type, handover type, handover cause, source base station controller ID, target base station controller ID, radio access bearer (RAB) information, and radio. It includes parameters such as section related information.

Upon receiving the handover request message, the asynchronous exchange 220 transmits an asynchronous message requesting a handover to the interoperation operation unit 60 (MAP Prep Handover Req) (S102). In this case, the expansion container is added to the asynchronous message to transmit the asynchronous identification number (MSISDN) of the mobile communication terminal 10, and the message includes parameters such as an invoke ID, a target cell ID, a target radio network controller ID, and an MSISDN. It includes.

Subsequently, the interoperation operation unit 60 refers to the asynchronous subscriber information (MSISDN) received from the asynchronous exchange 220, and requests to transmit subscriber information to the dual stack home location register 50 (Call Data Request). (S103). That is, to request the synchronization network identifier (MIN, ESN) of the mobile communication terminal 10. In operation S103, the interoperation operation unit 60 may request the subscriber's synchronization network identifier information using the asynchronous message MAP_SEND_IMSI to the dual stack home location register 50.

The dual stack home location register 50 receiving the subscriber information request from the interlocking operation unit 60 searches the database, extracts the subscriber's synchronization network identifier information (MIN, ESN), and transmits the information to the interoperation operation unit 60. (Call Data Req Ack) (S104), and the interlocking operation unit 60 that receives this instructs the handover to the synchronous exchange 320 (Facilities Directive2) (S105), and the synchronous exchange 320 is a base station controller / A handover request is made to the base station 310 (Handoff Request) (S106). Here, the call data request for the subscriber's sync network identifier information includes a parameter such as a billing ID, a digit (ie, MSISDN), and the response message (Call Data Req Ack) is an ESN, MIN. , Parameters such as MSCID.

On the other hand, when the asynchronous message (MAP_SEND_IMSI) is used to request the subscriber's synchronization network identifier information, the parameters included in the asynchronous message include an Invoke ID, MSISDN, IMSI, ESN, and the like.

As described above, the interlocking operation unit 60 generates a billing ID and includes the billing ID in the handover instructions message (Facilities Directive2) before transmitting the handover instructions message (Facilities Directive2) to the synchronization exchanger 320. The switch includes an internal exchange circuit ID (InterMSCCircuitID) for each handover section. Here, the billing ID includes ID information of the synchronous exchange 320 to be connected to the asynchronous exchange 220.

The base station / base station controller 310 receiving the handover request from the switch 320 transmits a null frame to the synchronous modem unit of the mobile communication terminal through the forward traffic channel. The base station / base station controller 310 transmits a response message (Handoff Request Ack) to the switch 320 (S108). In addition, the exchange 320 transmits a response message (Facilities Directive2 Ack) to the handover instruction to the interoperation operation unit 60 (S109), and the interoperation operation unit 60 transmits the step S102 to the asynchronous exchange unit 220. In step S110, a response message (MAP Prep Handover Resp) for a handover request is transmitted. Accordingly, the relay line between the asynchronous exchange 220 and the synchronous exchange 320 is set.

In more detail, the interoperation operation unit 60 establishes a mapping relationship between a date channel, which is a logical trunk line setting identifier, and a physical trunk line, and sets this information to an internal exchange circuit of a handover request message (Facilities Directive2). It is set to ID (InterMSCCircuitID) and transmitted to the synchronous exchange 320. When a response message (Facilities Directive2 Ack) is transmitted from the synchronous exchange 320, a relay line is established between the asynchronous exchange 220 and the synchronous exchange 320. . The handover request message (Facilities Directive2) transmitted / received between the interoperation operation unit 60 and the synchronization exchanger 320 includes parameters such as billing ID, ESN, internal exchange circuit ID, MIN, and the like, and the response message (Facilities Directive2 Ack). ) Includes parameters such as CDMA channel data, CDMA channel list, and the like.

As such, after the exchange period relay line is established, the asynchronous exchange 220 reports to the node B / RNC 210 that resource allocation for handover is completed (IU Relocation Command) (S111), and receives the node B / The RNC 210 requests to perform handover to the asynchronous modem unit of the mobile communication terminal 10 (Handover from UTRAN Command) (S112). Here, the message (IU Relocation Command) reporting that resource allocation is completed includes parameters such as message type, RRC container, RAB list to release, and the like.

Subsequently, the asynchronous modem unit of the mobile communication terminal transmits channel assignment information to the synchronous modem unit (Channel Assignment) (S113), and the interoperation operation unit 60 requests an access signal to the asynchronous exchange unit 220 (MAP Process Access). Signaling Req (S114), the access signal includes an invoke ID, an application protocol data unit (APDU), selected radio resource information and the like.

In addition, the synchronous modem unit of the mobile communication terminal transmits a frame and a preamble to the base station / base station controller 310 of the synchronous mobile communication system through the reverse traffic channel (Reverse Traffic Channel Frames or Traffic Channel Preamble) (S115), handover Report that the process has been completed (Handoff Completion Message) (S116), the base station / base station controller 310 that receives this will transmit a response signal for this (BS Ack Order) (S117). Accordingly, the connection between the synchronous modem unit of the mobile communication terminal and the synchronous mobile communication system is completed, and the synchronous modem unit of the mobile communication terminal notifies the asynchronous modem unit that the connection with the synchronous mobile communication system is completed (Call Connection) (S118). ).

Currently, the synchronous modem unit of the mobile communication terminal switches the vocoder after the step of completing the connection with the synchronous mobile communication system (S118), so that a silent section occurs until the mobile communication system switches the vocoder. Therefore, in the present invention, in order to be able to switch the vocoder of the mobile communication terminal at the vocoder switching time of the mobile communication system, the mobile communication terminal to drive a timer set to a specified time (S119).

Meanwhile, the base station / base station controller 310 reports that the handover is completed to the switch 320 (Handoff Complete) (S120), and the switch 320 notifies the interoperation operation unit 60 that the handover is completed. (Mobile On Channel) (S121).

Vocoder switching time of the mobile communication system is made after the step (S121) that the asynchronous switch 220 is reported that the handover is completed from the interlocking operation unit 60, in the present invention, the synchronous modem unit of the mobile communication terminal to the asynchronous modem unit After reporting the completion of the connection with the synchronous mobile communication system, the asynchronous exchange causes the timer of the mobile communication terminal to run for a time reporting that the handover is completed from the synchronous exchange, and when the timer is completed, the vocoder of the mobile communication terminal switches. At the same time (S122), the vocoder of the mobile communication system is also switched (S123).

In this way, the mobile communication terminal and the vocoder of the mobile communication system are simultaneously switched and the occurrence of the silent section can be minimized.

Next, the interlocking operation unit 60 requests the asynchronous exchange 220 to release the connection (MAP Send End Signal Req) (S124), so that the connection between the asynchronous exchange 220 and the node B / RNC is released. (IU Release Command, IU Release Complete) (S125, S126).

After the handover from the asynchronous mobile communication system to the synchronous mobile communication system is completed by the procedure described above, the call is released by the request of one of the two mobile communication terminals. (S127). The call release may be requested first from the subscriber's mobile communication terminal in the asynchronous mobile communication system area or from the subscriber's mobile communication terminal handing over to the synchronous mobile communication system area.

If the mobile communication terminal located in the asynchronous mobile communication system area releases the call, the asynchronous exchange 220 transmits a call release request message (Facilities Release) to the interoperation operation unit 60, and the interoperation operation unit. As the 60 responds (Facilities Ack), the relay line that was set during the exchange period is released. Here, the call release request message (Facilities Release) includes parameters such as internal MSC circuit ID, release reason, billing ID, MIN, etc., and the response message (Facilities Ack) includes parameters such as billing ID.

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.

As described above, according to the present invention, when the asynchronous mobile communication system is superimposed on the synchronous mobile communication system, and the exchanges of the two mobile communication systems are connected by the interlocking operation unit, the dual band dual mode mobile communication terminal is used during the voice call. When moving from the asynchronous mobile communication system area to the synchronous mobile communication system area, the quality of service during handover can be improved by minimizing the silent period.

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

2 is a flowchart illustrating a handover method between an asynchronous network and a synchronous network for minimizing a silent section according to the present invention.

<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: No.7 common signal network

50: dual stack home position register 60: interlocking operation unit

70: IP network 210: Node B / wireless network controller

220: asynchronous exchange 230: SGSN

240: GPRS network 250: GGSN

310: base station / base station controller 320: switchboard

330: packet data service node 340: data core network

Claims (12)

In a mobile communication system in which an asynchronous mobile communication system and a synchronous mobile communication system are mixed, and wherein the asynchronous mobile communication system and the synchronous mobile communication system are connected by an interlocking operation unit, the asynchronous mobile communication system and the synchronous mobile communication system communicate with each other. As a handover method for minimizing a silent period during a voice call of a possible dual band dual mode mobile communication terminal, Sending, by the asynchronous exchange, a handover request message to the interoperation unit, and the interoperation unit requesting and receiving subscriber information of the mobile communication terminal to the dual stack home location register; The interoperation operator instructing a handover to the synchronous exchange, and the synchronous exchange requesting a handover to the base station controller / base station; Assigning, by the base station / base station controller, an omnidirectional traffic channel to the mobile communication terminal, and transmitting a response message to the handover request to the synchronous exchange; The synchronous exchange transmits a response message for a handover instruction to the interoperation operator, and the interoperation operator transmits a response message for a handover request to the asynchronous exchange, thereby establishing a relay line between the asynchronous exchange and the synchronous exchange. Becoming; Reporting, by the asynchronous exchange, that resource allocation for handover has been completed to the radio network controller; Instructing the wireless network controller to handover to the mobile communication terminal through the node B, such that the mobile communication terminal switches to a synchronous mobile communication system connected mode; Transmitting, by the interoperation operator, an access signal to the asynchronous exchange; Sending, by the mobile communication terminal, a frame and a preamble through a reverse traffic channel to the base station / base station controller and reporting that handover is completed; Driving a timer as the mobile communication terminal completes the connection with the synchronous mobile communication system; Reporting, by the base station / base station controller, that the handover is complete to the exchange, and notifying the interoperation operator that the handover is complete; The mobile communication terminal expiring timer driving and switching a vocoder; Switching a vocoder between the asynchronous exchange and a synchronous exchange period; And Releasing the connection between the asynchronous switch and the NodeB / wireless controller; Handover method comprising a. The method of claim 1, The step of transmitting a handover request message to the asynchronous exchange by the wireless network controller may include a handover related message used in the synchronous mobile communication system, neighbor cell information of the mobile communication terminal, neighbor base station information, handover type, And a parameter including a handover cause, a source base station controller ID, a target base station controller ID, RAB information, and radio section related information. The method of claim 2, The asynchronous exchange further comprises determining whether the handover in the asynchronous mobile communication system or the handover to the synchronous mobile communication system by referring to the neighbor cell information and the neighbor base station information of the mobile communication terminal. The method of claim 1, In the step of the asynchronous exchange to send a handover request message to the interoperation operation unit, handover method characterized in that it also transmits asynchronous identification number (MSISDN) of the mobile communication terminal. The method of claim 1, The subscriber information received by the interoperation manager from the dual stack home location register includes a synchronization network identifier (MIN, ESN) of the mobile communication terminal. The method of claim 1, And requesting subscriber information of the mobile communication terminal to the dual stack home location register by the interoperation manager using one of a synchronous message and an asynchronous message. The method of claim 1, The interlocking operation unit generates a billing ID including the ID information of the synchronous exchange to be connected to the asynchronous exchange before transmitting the handover instruction message to the synchronous exchange, and transmits the generated billing ID in the handover instruction message. A handover method comprising transmitting with an internal exchange circuit ID (InterMSCCircuitID) for each over interval. The method of claim 1, The handover request message transmitted by the interoperation manager to the synchronous exchange includes a parameter including a billing ID, an ESN, an internal exchange circuit ID, and a MIN, and the response message sent by the synchronous exchange to the interoperation manager is CDMA. And a parameter including a channel data and a CDMA channel list. The method of claim 1, In the step of the asynchronous exchange transmitting a resource allocation complete message to the radio network controller, the resource allocation complete message further comprises a parameter including a message type, an RRC container, and a list of RABs to be released. . The method of claim 1, The access signal includes an invoke ID, an application protocol data unit (APDU), and selected radio resource information. The method of claim 1, After the step of disconnecting the connection between the asynchronous exchange and the Node B / wireless network controller, When a call release request is received from an incoming or outgoing mobile communication terminal, the exchange receiving the call release request transmits a call release request message to the interoperation operation unit, and the interoperation operation unit responds to the asynchronous exchange and synchronization. A handover method, wherein the relay line set during the exchange period is released. The method of claim 11, And the call release request message includes a parameter including an internal MSC circuit ID, a release reason, a billing ID, and a MIN, and the response message includes a parameter including a billing ID.