KR100602167B1 - Method for hand-off to synchronous mobile network from asynchronous mobile network using paging signal - Google Patents

Abstract

The present invention relates to a handoff method from an asynchronous mobile communication network to a synchronous mobile communication network using a paging signal. According to the present invention, when the dual-mode terminal reports a radio environment measurement result message of a CDMA cell to be handed off to a WCDMA network when a handoff event occurs, the WCDMA network is to be handed off with a radio environment measurement result message of a received CDMA cell. The BS in charge of the cell is determined, and a handoff event message is transmitted to the MSC managing the BS through the MAP converter. Then, the MSC grasps ESN information of the CDMA module to be handed off included in the handoff event message and transmits a paging request signal to the BS requesting a call to the CDMA module, and the BS sends the received paging request signal to the BS. The CDMA module transmits the handoff indication information and the telephone number information of the WCDMA module to the MSC as a paging response message, and the MSC transmits the handoff indication information to the MSC according to the handoff indication information included in the paging response message. After grasping the location information and identifying the CN in charge of the WCDMA module with the obtained location information, a call channel is formed with the CN and a channel is allocated to the CDMA module to complete the handoff.

Description

Method for hand-off to synchronous mobile network from asynchronous mobile network using paging signal}

1 is a block diagram of a dual network in which a CDMA network and a WCDMA network are mixed to achieve the present invention.

2 is a data flow diagram illustrating a handoff process from a WCDMA network to a CDMA network using a method according to an embodiment of the present invention.

The present invention relates to a handoff method from an asynchronous mobile communication network to a synchronous mobile communication network. In particular, when a handoff event occurs from a WCDMA network to a CDMA network, a handoff is performed according to a paging request signal of a CDMA network. A handoff method from an asynchronous mobile communication network to a synchronous mobile communication network.

Mobile communication technology has advanced from unidirectional radio technology, and the analog method of FDMA (Frequency Division Multiple Access), which is represented by the first generation Advanced Mobile Phone System (AMPS), has been developed to provide two-way radio technology, TDMA (Time Division Multiple Access) and CDMA. It has advanced to the second generation digital method represented by (Code Division Multiple Access) and is progressing to the third generation IMT (International Mobile Telecommunication) -2000 which is called the dream mobile communication.

The IMT-2000 can be configured with the same coverage area through global roaming using the same wireless access method in a single frequency band, and supports high speed with high bandwidth to support not only existing voice services but also images, video and video. It was developed to provide wireless multimedia services such as telephony and Internet access. It has been standardized by ATDMA and WCDMA, and some countries are commercializing, and Korea is still in preparation for commercialization.

Briefly describing the domestic mobile communication environment, the second generation mobile communication system using the CDMA method is currently being built and commercialized in Korea, but the third generation mobile communication system using the WCDMA method is still at the level of pilot service.

Currently, the mobile communication environment established in Korea is constructed in the form of local WCDMA network in the widely established CDMA network, but in the future, when the WCDMA network is commercialized, the CDMA network and WCDMA network are nationwide. Will be. However, building a single mobile communication network requires a lot of cost and time. For this reason, it will take a long time for a WCDMA network to be established nationwide like a CDMA network.

As described above, since the WCDMA network is not established nationwide, the WCDMA network has a problem that the user can no longer support a call when the user moves to an area where the WCDMA network is not established. This problem will naturally be solved when the WCDMA network is established nationwide, but until the WCDMA network is established nationwide, it is a big concern for network service providers.

In an effort to solve the above problem, a handoff method has been proposed to enable a user to continue a call by handing off an existing CDMA network when a WCDMA network user leaves the WCDMA network.

However, there are many difficulties in supporting handoff between a WCDMA network and a CDMA network. This is because the radio access method of the CDMA mobile communication system is synchronous and the radio access method of the WCDMA mobile communication system is asynchronous and has different Radio Access Technology (RAT), and the frequency bands used are different. . The synchronous wireless access method is a method of synchronizing timing synchronization between the subsystems and the synchronization between the transceiver and the asynchronous method is a method that does not need to synchronize between the subsystem and the transceiver. WCDMA uses 1.9-2.2GHz frequency band and 5MHz bandwidth, while CDMA uses 1.7-1.8GHz frequency band and 1.25MHz bandwidth.

For these reasons, the telecommunications service provider has not yet provided a technology for supporting handoff between the WCDMA network and the CDMA network. Accordingly, as described above, the user accesses a WCDMA network established in a local area and makes a call. If you move to a CDMA network during the process, you will no longer be able to make calls.

SUMMARY OF THE INVENTION The present invention has been made to solve a conventional problem, and an object thereof is to allow a handoff from a WCDMA network to a CDMA network according to a paging request signal transmitted from a CDMA network when a handoff event occurs.

The present invention for achieving the above technical problem is a MAP converter for converting the standard of the message exchanged to enable the message transfer between the WCDM network and the CDMA network, WCDMA module for processing signals of the WCDMA standard and CDMA standard signal processing In a handoff method from a WCDMA network to a CDMA network using a dual mode terminal having a CDMA module, when a handoff event occurs, a radio environment measurement result message of a CDMA cell to be handed off by the dual mode terminal is reported to the WCDMA network. In the first step, the WCDMA network determines the BS in charge of the CDMA cell to be handed off as a radio environment measurement result message of the received CDMA cell, and sends a handoff event message to the MSC managing the BS through the MAP converter. In a second step of transmitting, the MSC identifies the ESN information of the CDMA module to be handed off included in the handoff event message. A third step of transmitting a paging request signal requesting a call to a CDMA module to the BS, the BS transmitting a received paging request signal to the CDMA module, and the CDMA module is configured to provide handoff indication information. And transmitting the telephone number information of the WCDMA module to the MSC as a paging response message, and the MSC grasps the location information of the WCDMA module according to the handoff indication information included in the paging response message. In the asynchronous mobile communication network using the paging signal comprising the sixth step of identifying the CN in charge of the WCDMA module by using the location information, and forming a call channel with the CN, assigning a channel to the CDMA module to complete the handoff A handoff method to a synchronous mobile communication network is provided.

Preferably, the handoff indication information is preferably a handoff special number, and the handoff special number is preferably recorded in a Calling Party Number of the paging response message.

Hereinafter, a handoff method from an asynchronous mobile communication network to a synchronous mobile communication network using a paging signal according to an embodiment of the present invention will be described with reference to the accompanying drawings. 1 is a block diagram of a dual network in which a CDMA network and a WCDMA network are mixed to achieve the present invention. Since the CDMA network and the WCDMA network applied to the present invention are already commercialized and use the known configurations of the networks, they are briefly shown as shown in FIG. 1.

The CDMA network shown in FIG. 1 includes a base station and a mobile station controller, and the WCDMA network includes a UTRAN (UMTS Terrestrial Radion Access Network) and a CN (Core Network).

Here, it is apparent that the WCDMA network and the CDMA network include HLR (Home Location Register) and VLR (Visitor Location Register). The UTRAN includes a base station (node_B) and a radio network controller (RNC), and if the CN includes an MSC, a Serving GPRS Support Node (SGSN), and a Gateway GPRS Support Node (GGSN), the following description will be facilitated. I can understand.

The dual network for the present invention provides a mobile application protocol (MAP) converter 10 and a dual HLR (Home Location Register) 20 to interwork the WCDMA network and the CDMA network into one network, that is, to support handoff. A dual mode terminal 30 provided on the network side and having a WCDMA module 31 for accessing a WCDMA network to process a WCDMA signal and a CDMA module 32 for accessing a CDMA network to process a CDMA signal. ).

The MAP converter 10 converts a signal of the CDMA radio access standard into a signal of the WCDMA radio access standard, and converts a signal of the WCDMA radio access standard into a signal of the CDMA radio access standard. In addition, the MAP converter 10 requests and provides information on the HLR in the CDMA network from the WCDMA network, that is, the electronic serial number (ESN) information for the UE, to the CDMA network for the handoff. Has the function to The MAP converter 10 includes a No. 7 protocol stack and has one No. 7 signal point to process a Transaction Capabilities Application Part (TCAP) message with the HLR.

The dual HLR 20 integrates and manages call processing databases such as location registration for CDMA and CDMA network subscribers, and synchronizes asynchronous protocol and asynchronous to one input signal point according to a synchronous protocol or an asynchronous protocol. By searching for information for generating two output signal points according to the protocol of the scheme, one corresponding output signal point is generated and a corresponding message is transmitted to the corresponding output signal point.

Hereinafter, a handoff method from an asynchronous mobile communication network to a synchronous mobile communication network using a paging signal according to an embodiment of the present invention will be described with reference to FIG. 2.

2 is a data flow diagram illustrating a handoff process from a WCDMA network to a CDMA network using a method according to an embodiment of the present invention.

It is assumed that the dual mode terminal 30 located in the WCDMA network is connected to the WCDMA network N1 through the WCDMA module 21 to make a call. In the WCDMA network, the dual-mode terminal 30 in a call registers the current location of the user in the home location register (HLR) 13 of the WCDMA network through the WCDMA module 21, and the dual mode terminal 30 through the WCDMA module 31. The mode terminal 30 informs the dual HLR 20 that the call is in progress. In addition, the WCDMA module 31 of the dual-mode terminal 30 in the WCDMA network periodically measures the radio environment (i.e., the strength of the pilot signal which is the Radio Signal Strength Indicator (RSSI)) for the neighboring WCDMA cells and measures the result. Reporting to the UTRAN as a Radio Resource Control (RRC) / Measurement Report message (S1).

In this state, when the user moves and arrives at the boundary between the WCDMA cell and the CDMA cell, the radio environment for the currently located WCDMA cell received by the WCDMA module 31 is weakened so that a call can no longer be made. The UTRAN (N11), which has reported the radio environment measurement result for the WCDMA cell, recognizes that there is no more WCDMA cell to continue the call in the vicinity, and instructs the dual mode terminal 30 to radio environment measurement for the neighbor CDMA cell. do. The dual mode terminal 30 instructed to measure the radio environment for the CDMA cell from the UTRAN N11 activates the CDMA module 32 to synchronize with the CDMA network, and the CDMA module 32 transmits the radio for the neighboring CDMA cells. The environment is measured, and among the measured radio environment measurement results of neighboring CDMA cells, a CDMA cell having a large RSSI is determined as a CDMA cell to be handed off, and information (BS offset information, etc.) of the BS (base station) in charge of the CDMA cell is collected (S2).

The BS information of the cell to be handed off collected by the CDMA module 32 is transmitted by the WCDMA module 31 to the UTRAN N11 as an RRC / Measurement Report message of the WCDMA standard (S3). The RRC / Measurement Report message transmitted in this process S3 includes the phone number information of the CDMA module 32, and the phone number of the CDMA module 32 is used by the MSC for handoff by the MSC in charge of the cell to be handed off. It allows you to send a call, ie a paging message.

  The UTRAN N11 determines that it is a handoff situation through the received RRC / Measurement Report message, and transmits the received RRC / Measurement Report message to the CN N12 (S4).

The CN 12 identifies the MSC (Exchange) N22 in charge of the BS (N21) with information of the BS (N21) included in the RRC / Measurement Report message received from the UTRAN (N11). A WCDMA standard IAM (Initial Address Message) including information requesting handoff is transmitted. At this time, the CN 12 transmits the IAM through the MAP converter 10 so that the IC of the WCDMA standard can be received by the MSC N22 using the CDMA standard (S5).

When the MAP converter 10 receives an IAM of the WCDMA standard from the CN 12, the MAP converter 10 determines that a handoff situation, and accordingly, the information required to request the HLR in the CDMA network from the WCDMA network for handoff, that is, the CDMA module 32 Electronic Serial Number (ESN) information is requested and received on behalf of the WCDM network to form information for handoff (S6), which is made into an IAM signal of the CDMA standard and transmitted to the MSC (N22) (S7). Here, the MAP converter 10 provides the phone number of the CDMA module 32 included in the received IAM signal to the HLR of the CDMA network to obtain the ESN of the CDMA module 32.

When the MSC N22 receives the IAM from the MAP converter 10, the MSC N22 knows the ESN information of the CDMA module 32 to be handed off from the received IAM signal, and requests a call to the CDMA module 32 using the ESN information. The Page Request message is transmitted (S8). At this time, the page request message transmitted to the CDMA module 32 transmits the content indicating the handoff or the information indicating the information required for the handoff in the Page Response message.

The Page Request message transmitted from the MSC N22 is transferred to the CDMA module 32 through the BS N21 (S9).

The CDMA module 32 receiving the call request reads the received Page Request message, generates a Page Response message corresponding to the ACK message, and calls the calling party number of the Page Response message, that is, the WCDMA module. Telephone number), and the handoff number and the telephone number of the WCDMA module 31 are included and transmitted to the MSC N22 (S10, S11).

The MSC N22 determines that it is a handoff request according to the handoff number included in the page response message, and obtains the WCDMA module from the page response message to request the current position (ie, routing information) of the WCDMA module 31. Include the phone number of the Location Request message and transmits to the dual HLR (20) (S12).

When the dual HLR 20 receives a Location Request (current location request, that is, routing information request) message, the dual HLR 20 recognizes that the WCDMA module is requesting routing information of the WCDMA module currently in communication with the telephone number of the WCDMA module included in the received message. A routing request message requesting routing information of the WCDMA module 31 is transmitted to the calling HLR, that is, the HLR N13 of the WCDMA network (S13).

The WCDMA HLR N13 receives a Routing Request message from the dual HLR 20, and accordingly, provides the routing information of the WCDMA module 31 to the dual HLR 20 as a Routing Request Response message (S14).

After obtaining the routing information of the WCDMA module 31, the dual HLR 20 changes the acquired routing path information into a form conforming to the CDMA protocol, and then requests a location request which is an acknowledgment (ACK) of the location request message of the MSC N22. The response message is provided to the MSC N22 (S15).

The MSC N22 knows the CN to be handed off through the routing information of the WCDMA module 31, that is, the CN N12 that is in charge of the call of the WCDMA module 31, and is currently serving the WCDM module for outgoing exchanges. An IAM (Initial Address Message) indicating that a trunk line (i.e., voice line) of CN (N12) connected to 31 is extended to itself is transmitted to CN (N12) side. At this time, since the IAM transmitted by the MSC N22 is defined in the CDMA standard and cannot be received by the CN N12, the MSC N22 transmits the IAM to the MAP converter 10 (S16).

When the MAP converter 10 receives the IAM of the CDMA standard, the internal message processing protocol is changed from the CDMA protocol to the WCDMA protocol, and then the IDMA of the CDMA standard is made into the IAM of the WCDMA standard so that the CN (N12) can receive it. Transmit to CN (N12) (S17).

When CN (N12) receives an IAM of WCDMA standard, the CN (N12) extends a trunk line connected to a called terminal to MSC (N12), that is, performs a handoff to connect a new trunk line to MSC (N12) (S18). When the trunk line is connected to the MSC N12, an ACM (Address Complete Message) is output to the MAP converter 10 in response to the IAM (S19).

When the MAP converter 10 receives the ACM from the CN (N12), it changes to the CDMA type, and then transfers the ADMA of the CDMA standard to the MSC (N22) of the CDMA network (S20), and the MSC (N22) receives the ACM as the ACM is received. A message requesting channel allocation is transmitted to the BS N21 (S21).

When the BS N21 receives the channel allocation request signal from the MSC N22, the BS N21 allocates CDMA resources and transmits the CDMA resources to the CDMA module 32 of the dual mode terminal 30 (S22). Accordingly, the CDMA module 32 sets up a traffic channel through the allocated CDMA resources and performs service negotiation with the BS N21 (S23).

The BS that performs service negotiation with the CDMA module 32 of the dual mode terminal 30 transmits a channel allocation success message to the MSC N22 (S24), and the MSC receiving the channel allocation success message is a hand to be performed by the BS. You will know that you have completed the off process.

Meanwhile, the dual mode terminal 30 allocated the communication channel from the BS N21 of the CDMA releases the radio resource allocated to the WCDMA module 31 and deactivates the WCDMA module 31. CN (N12) transfers the communication channel (Traffic Channel) with the WCDMA module 31 and performs the operation of connecting to the MAP converter (10).

Thus, the dual mode terminal 30 is handed off from the WCDMA cell to the CDMA cell, and continues the call through the communication channel connected with the destination terminal by the CDMA module 32 (S25). That is, the CDMA module 32 of the hand-off dual mode terminal 30 transmits call data to the MSC N22, and when the MSC N22 transmits to the CN N12 through the MAP converter 10, the CN ( N12 transmits the call data in the routing path with the called terminal set at the time of communication with the WCDMA module 31.

The technical spirit of the present invention has been described above with reference to the accompanying drawings, but this is by way of example only and not intended to limit the present invention. In addition, it is obvious that any person skilled in the art can make various modifications and imitations without departing from the scope of the technical idea of the present invention.

In the present invention, when a mobile communication terminal that is busy in a WCDMA network can no longer make a call in the WCDMA network, the user can handoff the call to the CDMA network so that the user can talk without interruption.

Claims (5)

Using a dual-mode terminal equipped with a MAP converter for converting the specification of messages exchanged to enable message transfer between a WCDMA network and a CDMA network, a WCDMA module for processing a WCDMA standard signal and a CDMA module for processing a CDMA standard signal In a handoff method from a WCDMA network to a CDMA network, A first step of reporting, by the dual mode terminal, a radio environment measurement result message of a CDMA cell to be handed off to a WCDMA network when a handoff event occurs; A second step of determining, by the WCDMA network, a BS in charge of a CDMA cell to be handed off with a radio environment measurement result message of a received CDMA cell, and delivering a handoff event message to the MSC managing the BS through the MAP converter; The MSC identifying the ESN information of the CDMA module to be handed off included in the handoff event message and transmitting a paging request signal to the BS requesting a call to the CDMA module; The BS transmitting a received paging request signal to the CDMA module; Transmitting, by the CDMA module, the handoff indication information and the telephone number information of the WCDMA module as a paging response message to the MSC; And The MSC grasps the location information of the WCDMA module according to the handoff indication information included in the paging response message, identifies the CN that is in charge of the WCDMA module with the location information, and then establishes a call channel with the CN. A method for handoff from an asynchronous mobile communication network to a synchronous mobile communication network using a paging signal, comprising the step of completing a handoff by allocating a channel to a CDMA module. The method according to claim 1, In the first step, the wireless environment measurement result message of the CDMA cell including the base station information of the CDMA cell to be handed off and the telephone number of the CDMA module to be handed off is transmitted. Handoff method to synchronous mobile network. The method according to claim 1, The handoff indication information included in the paging response message is a handoff method, characterized in that the handoff from the asynchronous mobile communication network using a paging signal to a synchronous mobile communication network. The method according to claim 3, The handoff number and the telephone number information of the WCDMA module are recorded in a calling party number of the paging response message. The handoff method of an asynchronous mobile communication network using a paging signal to a synchronous mobile communication network. The method according to claim 1, In the second step, the MAP converter receives ESN information of the CDMA module to be handed off from the HLR of the CDMA network to the MSC, and includes the ESAP information in the handoff event message to be transmitted to the BS. A handoff method from an asynchronous mobile communication network to a synchronous mobile communication network using a paging signal.

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