KR100810293B1 - Hand-over apparatus and method between mobile communication systems - Google Patents

Abstract

An apparatus and method for handling handover between a first and a second mobile communication network according to a user's movement when making a call with a mobile terminal supporting both the first and second mobile communication services. In a mobile communication network including at least two or more mobile communication systems employing mutually independent communication method and a mobile terminal using the same, a handover device between different mobile communication systems, the first handover notification message to the mobile terminal; A first mobile communication system for generating a second handover notification message upon receipt of a handover preparation message from the mobile terminal, and a second handover notification message for receiving a second handover notification message from the first mobile communication system. And a mobile terminal having a second mobile communication system for transmitting a channel assignment message to form a communication path, and the first and second communication modules communicating with the first and second mobile communication systems, respectively. The first communication module is configured to receive the first handover notification message from the first mobile communication system. The handover preparation message is transmitted to the first mobile communication system when a drive command is generated and a predetermined drive-response is received. When the second communication module receives the drive command from the first module, the first module is transmitted. When the call-path is established by transmitting the drive-response and receiving a call channel establishment message from the second mobile communication system, the call enters the call state without disconnection.

Handover, incoming

Description

Handover device and method between different mobile communication systems {HAND-OVER APPARATUS AND METHOD BETWEEN MOBILE COMMUNICATION SYSTEMS}             

1 is a view showing a schematic configuration of a multi-mode multi-band mobile terminal according to an embodiment of the present invention

2 is a diagram illustrating a handover operation procedure between a first mobile communication network and a second mobile communication network according to an embodiment of the present invention.

3 is a diagram illustrating a handover operation procedure between a first mobile communication network and a second mobile communication network according to another embodiment of the present invention.

The present invention relates to a handover apparatus and method in a mobile communication system, and in particular, between a first mobile communication network and a second mobile communication network according to a user's movement when making a call with a mobile terminal supporting both first and second mobile communication services. An apparatus and method for handling handover of an apparatus are provided.                         

If mobile communication services are classified into two types, an example may be classified into a synchronous method and an asynchronous method. Generally, the asynchronous method is a system in which all base stations are independent of synchronization, such as WCDMA and UMTS, which is adopted as a European standard. The synchronization method adopts a method using GPS satellites, and the synchronization of all base stations is correct. For example, second-generation CDMA systems such as IS-95 and J-STD008, which are provided in Korea and the United States, and CDMA2000, which is adopted as a US standard, are synchronous methods.

Standardization of WCDMA asynchronous mobile services is underway in 3GPP. WCDMA is based on GSM, the European standard. Meanwhile, standardization of CDMA-1X synchronous mobile communication service is underway in 3GPP2. CDMA-1X is an upgrade based on the IS-95B. Therefore, the compatibility between WCDMA and GSM has been thoroughly examined by 3GPP, and compatibility between CDMA-1X and IS-95A / B has already been implemented.

However, when the WCDMA network evolves in the future, when the WCDMA network is built on the CDMA-1X network that is currently being serviced nationwide, there is no standard that specifies communication between the WCDMA network and the CDMA-1X network. Handover is not possible when moving to a network. In other words, handover is impossible because procedures for interworking between independent communication methods (synchronous and asynchronous) are not defined.

In addition, a mobile terminal currently connected to a synchronous mobile communication network to receive a service should continue to receive a synchronous service. If a mobile terminal is connected to an asynchronous mobile communication network, the mobile terminal must receive asynchronous service. In conclusion, the mobile terminal should be able to perform handover from a synchronous network to an asynchronous network or vice versa according to a moving position, but did not have a device or a method capable of performing such handover.

Therefore, when a user connected to an asynchronous mobile communication network moves to an area in which a synchronous mobile communication network is installed, there is no problem that the call is disconnected. For example, assuming that an asynchronous mobile communication network is installed only in a small area such as Seoul, when a user making a call in the corresponding area moves to an area where the asynchronous mobile communication network is not installed, the call is disconnected.

Looking at the current evolution of asynchronous mobile communication services, it is expected that the service will initially be provided only to a specific region and then to the nationwide service. With this in mind, handover between different mobile networks is essential.

Accordingly, an object of the present invention is to provide an apparatus and method for handling handover between first and second mobile communication networks according to a user's movement when making a call with a mobile terminal supporting both first and second mobile communication services. have.

Another object of the present invention is to provide an apparatus and method for handling handover between a synchronous and asynchronous mobile communication network according to a user's movement when making a call with a mobile terminal supporting both synchronous and asynchronous mobile communication services.                         

The present invention for achieving the above object is a handover device between different mobile communication systems in a mobile communication network including at least two or more mobile communication systems employing mutually independent communication method and a mobile terminal using the same; A first mobile communication system for transmitting a first handover notification message to the mobile terminal and generating a second handover notification message upon receiving a handover preparation message from the mobile terminal; A second mobile communication system for transmitting a channel assignment message to the mobile terminal to form a communication path upon receiving a handover notification message; and first and second communication modules communicating with the first and second mobile communication systems, respectively. Including the mobile terminal having a first communication module, the first communication module from the first mobile communication system When the over notification message is received, a driving command of the second communication module is generated, and when a predetermined drive-response is received, the handover preparation message is transmitted to the first mobile communication system, and the second communication module transmits the first communication message. When the drive command is received from the module, the drive-response is transmitted to the first module, and a call channel establishment message is received from the second mobile communication system. do.

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

The synchronous mobile communication service to which the present invention can be applied is the CDMA method and the IS-95A / B method, and the asynchronous mobile communication service is the GSM method, the WCDMA method, and the PDC (Personal Digital Cellular) method used in Japan. Therefore, according to the present invention, handover from the CDMA or IS-95A / B scheme to the GSM, WCDMA, or PDC scheme is possible. In addition, according to the present invention, handover from the GSM, WCDMA, or PDC scheme to the CDMA or IS-95A / B scheme is possible. In addition, handover between other asynchronous mobile communication services (GSM and WCDMA) is possible.

1 is a view showing a schematic configuration of a multi-mode multi-band mobile terminal according to an embodiment of the present invention.

The mobile terminal to which the present invention is applied is a multi-mode multi-band mobile terminal (hereinafter referred to as an MMMB mobile terminal). In order to support the first and second mobile communication services, an antenna for each mobile communication service, an RF (Radio Frequency) unit, and a corresponding service processing unit are independently provided.

In the illustrated example, it is assumed that the first mobile communication service is implemented using asynchronous WCDMA and the second mobile communication service using a synchronous CDMA-1X.                     

The WCDMA module 20 includes a first antenna 22 and a first RF unit 24 for transmitting or receiving a WCDMA wireless signal, and a WCDMA processing unit for performing coding or decoding according to the WCDMA scheme for transmitted or received data. Has 26. Similarly, the CDMA-1X module 30 has a second antenna 32, a second RF unit 34, and a CDMA-1X processor 36. The WCDMA or CDMA-1X processing units 26 and 36 may be modem chips or DSPs in the chip. The controller 40 controls driving / stopping of the first and second mobile communication service modules 20 and 30, mutual communication, and respective operations.

The MMMB mobile terminal having the above configuration operates as follows to handle handover between different mobile communication networks.

When the MMMB mobile terminal 100 is located in the region providing the first mobile communication service, the second antenna 32 and the second RF unit 34 of the CDMA-1X module 30 capable of processing the second mobile communication service 34 And the CDMA-1X processor 36 is not driven. Instead, the first antenna 22, the first RF unit 24, and the WCDMA processing unit 26 of the WCDMA module 20 are driven. As a result, the MMMB mobile terminal 100 operates as a first mobile communication service mobile terminal.

On the contrary, that is, when the MMMB mobile terminal 100 is located in the region providing the second mobile communication service, the CDMA-1X module 30 is driven, and the WCDMA module 20 is not driven, so that the MMMB mobile terminal 100 is operated. ) Acts as a second mobile communication service mobile terminal.

2 is a diagram illustrating a handover operation procedure between a first mobile communication network and a second mobile communication network according to an embodiment of the present invention. FIG. 2 illustrates a case in which a user moves to a second mobile communication network, for example, a synchronous CDMA-1X mobile communication network while talking on a first mobile communication network, for example, an asynchronous WCDMA mobile communication network.

When a user makes a call by connecting to a WCDMA mobile communication network, only the WCDMA module 20 of the MMMB mobile terminal 100 is driven and the CDMA-1X module 30 is not driven. After that, if the user moves to a location where handover should be performed, that is, a CDMA-1X mobile communication service area, a first predefined predefined WCDMA base station 500 to the WCDMA module 20 of the MMMB mobile terminal 100. A first handover notification message indicating a handover between the mobile communication network and the second mobile communication network is sent (step S70).

The WCDMA module 20 of the MMMB mobile terminal 100 drives the CDMA-1X module 30 in the off state after receiving the first handover notification message (step S72).

In this case, as if two independent phones were powered on, the MMMB mobile terminal 100 is in a call state in a WCDMA mobile communication network, but is in a call waiting state (idle) in a CDMA-1X mobile communication network. At this time, both the WCDMA module 20 and the CDMA-1X module 30 of the MMMB mobile terminal 100 are temporarily driven.

The CDMA-1X module 30 notifies the WCDMA module 20 that the drive has been driven by the drive-response signal, and the WCDMA module 20 that has recognized this transmits a handover preparation message to the WCDMA base station 500 by wireless ( Step S74, step S76).

The CDMA-1X mobile communication network recognizes that the CDMA-1X module 30 of the MMMB mobile terminal 100 is driven as follows.                     

First, when the WCDMA module 20 of the MMMB mobile terminal 100 informs the WCDMA base station 500, the WCDMA base station 500 informs the CDMA-1X base station 600.

Second, when the CDMA-1X module 30 is driven, it will attempt to register with the CDMA-1X base station 600. The CDMA-1X base station 600 knows through the registration procedure.

Third, when a predetermined time elapses, the CDMA-1X base station 600 or the WCDMA base station 500 unconditionally determines that the CDMA-1X module 30 is driven.

In this embodiment, the first method is applied. Therefore, in FIG. 2, the WCDMA base station 500 transmits and receives the received second handover notification message to the CDMA-1X base station 600 (step S78).

Upon receiving the second handover notification message, the CDMA-1X base station 600 transmits a channel assignment message to the CDMA-1X module 30 of the MMMB mobile terminal 100 to establish a channel (step). S80).

As a result, the call is handed over from the first mobile communication network to the second mobile communication network, and the CDMA-1X base station 600 sends a handover completion message to the WCDMA base station 500 to notify that the call is handed over (step S82). The WCDMA base station 500 transmits a release message to the WCDMA module 20 of the MMMB mobile terminal 100 to release the call (step S84).

After handover, a call is made to the CDMA-1X module 30.

On the other hand, there are three ways to disconnect the old channel and connect the new channel for handover.

First, the WCDMA module 20 is first blocked and then connected to the CDMA-1X module 30.                     

Second, the CDMA-1X module 30 is connected first and the WCDMA module 20 is disconnected.

Third, the connection of the CDMA-1X module 30 and the blocking of the WCDMA module 20 are simultaneously performed.

The first method has the advantage of catching one of the first or second mobile communication network at a specific moment, but if the handover fails, the call is disconnected. The second method is simultaneously connected to the WCDMA module 20 and the CDMA-1X module 30 at a specific moment, even if the paging fails in the CDMA-1X module 30 can still hold the WCDMA module 20 to improve the handover success rate It can increase. The third method has similar characteristics to the first method.

3 is a diagram illustrating a handover operation procedure using an incoming call between a synchronous mobile communication network and an asynchronous mobile communication network according to another embodiment of the present invention. 3 illustrates a case where a user moves to a first mobile communication network, for example, an asynchronous WCDMA mobile communication network while making a call on a second mobile communication network, for example, a synchronous CDMA-1X mobile communication network.

When a user makes a call by accessing a CDMA-1X mobile communication network, only the CDMA-1X module 30 of the MMMB mobile terminal 100 is driven and the WCDMA module 20 is not driven.

After that, if the user moves to a location where handover should be performed, that is, a WCDMA mobile communication service, the first mobile communication network-second move predefined from the CDMA-1X base station 600 to the MMMB mobile terminal 100. A first handover notification message is sent to notify handover between the communication networks (step S90).

The CDMA-1X module 30 of the MMMB mobile terminal 100 transmits a drive command to drive the WCDMA module 20 in the off state after receiving the first handover notification message, and the WCDMA module 20 Transmits a drive-response signal to the CDMA-1X module 30 (steps S92 and S94).

In this case, as if two independent telephones were powered on, the MMMB mobile terminal 100 is in a call state in a CDMA-1X mobile communication network, but is in a call waiting state in a WCDMA mobile communication service. At this time, both the CDMA-1X module 30 and the WCDMA module 20 of the MMMB mobile terminal 100 are temporarily driven.

The CDMA-1X module 30 wirelessly transmits a handover preparation message indicating that the CDMA-1X base station 600 is ready for handover (step S96).

The WCDMA mobile communication network recognizes that the WCDMA module 20 of the MMMB mobile terminal 100 is driven as follows.

First, when the CDMA-1X module 30 of the MMMB mobile terminal 100 informs the CDMA-1X base station 600, the CDMA-1X base station 600 informs the WCDMA base station 500.

Secondly, when the WCDMA module 20 is driven, it will attempt to register with the WCDMA base station 500. The WCDMA base station 500 knows through the registration procedure.

Third, when a predetermined time elapses, the WCDMA base station 500 or the CDMA-1X base station 600 determines that the WCDMA module 20 is unconditionally driven.

This embodiment is an example in which the first method is applied. Therefore, in FIG. 3, the CDMA-1X base station 600 transmits and notifies the second handover notification message to the WCDMA base station 500 (step S98).

Upon receiving the second handover notification message, the WCDMA base station 500 establishes a call path by transmitting a radio resource control (RRC) connection setup message and a radio bearer setup message, which are a channel allocation message. (Step S100).

As a result, the call is handed over from the CDMA-1X mobile communication network to the WCDMA mobile communication network, and the WCDMA base station 500 notifies the CDMA-1X base station 600 that the handover is completed (step S102).

The CDMA-1X base station 600 transmits a release message to the CDMA-1X module 30 of the MMMB mobile terminal 100 to release the call (step S104).

After handover, a call is made to the WCDMA module 20.

On the other hand, there are three ways to disconnect the old channel and connect the new channel for handover.

First, the CDMA-1X module 30 is blocked first and then connected to the WCDMA module 20.

Second, the WCDMA module 20 is connected first and the CDMA-1X module 30 is disconnected.

Third, the connection of the WCDMA module 20 and the blocking of the CDMA-1X module 30 are simultaneously performed.

The first method has the advantage of catching one of the second or the first mobile communication network at a specific moment, but if the handover fails, the call is disconnected. The second method is simultaneously connected to the CDMA-1X module 30 and the WCDMA module 20 at a specific moment, so that even if the paging fails in the WCDMA module 20, the CDMA-1X module 30 can still be held to achieve a handover success rate. It can increase. The third method has similar characteristics to the first method.

As described above, the present invention enables the user to efficiently handle handover between different mobile communication networks, so that the user does not feel uncomfortable because the call is not disconnected even when the user moves to another mobile communication service area while making a call. There is.

Claims (13)

A mobile terminal having a first communication module and a second communication module; A first mobile communication system for transmitting a first handover notification message to the mobile terminal and generating a second handover notification message upon receiving a handover preparation message from the mobile terminal; A second mobile communication system for receiving a second handover notification message from the first mobile communication system and transmitting a channel assignment message to the mobile terminal to form a call path; The first and second mobile communication system is a mutually independent communication method, When the first communication module receives the first handover notification message from the first mobile communication system, the first communication module generates a driving command of the second communication module, and when receiving a predetermined drive-response, the first mobile communication system sends the message to the first mobile communication system. Send a handover ready message, When the second communication module receives the drive command from the first module, the second communication module transmits the drive-response to the first module and receives a call channel establishment message from the second mobile communication system. Handover device between different mobile communication systems, characterized in that entering the call state without. The method of claim 1, The second mobile communication system transmits the call channel establishment message and then sends a handover completion message to the first mobile communication system to inform the mobile terminal of the connection, and the first mobile communication system transmits the call terminal establishment message of the mobile terminal. Handover device between different mobile communication systems, characterized in that to terminate the call with the mobile terminal by sending a release message to the first module. The method of claim 1, Different mobile communication systems characterized in that the termination of the call between the first mobile communication system and the first module of the mobile terminal occurs before the second mobile communication system and the second module of the mobile terminal are brought into a call state. Handover between devices. The method of claim 1, Different mobile communication systems characterized in that the termination of the call between the first mobile communication system and the first module of the mobile terminal occurs after the second mobile communication system and the second module of the mobile terminal are in a call state. Handover between devices. The method of claim 1, The end of the call between the first mobile communication system and the first module of the mobile terminal is simultaneously made when the second mobile communication system and the second module of the mobile terminal are in a call state. Handover between devices. Multi-mode multiband mobile having a first module for accessing a first mobile communication network and a second module for processing a call connected to a second mobile communication network that is independent of the first mobile communication network. A handover method between different mobile communication systems, comprising a terminal, and for maintaining a communication state when the mobile terminal moves between the first mobile communication network area and the second mobile communication network area. Receiving a first handover notification message from the first mobile communication network by the first module to command driving for handover to the second module; A second process of notifying the first module that the second module has been driven; A third step of transmitting, by the first module, a handover preparation message to the first mobile communication network; A fourth process of transmitting, by the first mobile communication network, a second handover notification message to the second mobile communication network; And a fifth process, wherein the second mobile communication network transmits a call channel establishment message to the second module to hand over the second mobile communication network. The method of claim 6, wherein the sixth process, A method for handover between different mobile communication systems, characterized in that the first mobile communication network and the communication path of the first module is first blocked, and the second mobile communication network and the communication path of the second module are connected. . The method of claim 6, wherein the sixth process, A handover method between different mobile communication systems, characterized in that handover is performed by simultaneously disconnecting the call path of the first mobile communication network and the first module and connecting the call path of the second mobile communication network and the second module. . The method of claim 6, wherein the sixth process,  Handover method between different mobile communication systems, characterized in that the first mobile communication network and the first communication path of the first module connection first, and then the second mobile communication network and the second module communication path is disconnected and handed over . The method according to any one of claims 6 to 9, Wherein the first mobile communication network is an asynchronous mobile communication network, the first module is an asynchronous mobile communication module, the second mobile communication network is a synchronous mobile communication network, and the second module is a synchronous mobile communication module. Method of handover between them. The method according to any one of claims 6 to 9, Wherein the first mobile communication network is an asynchronous mobile communication network, the first module is an asynchronous mobile communication module, the second mobile communication network is a synchronous mobile communication network, and the second module is a synchronous mobile communication module. Method of handover between them. The method of claim 10, The asynchronous mobile communication system is a GSM, WCDMA, PDC mobile communication system, the synchronous mobile communication system is a CDMA, IS-95A / B mobile communication system characterized in that the handover between different mobile communication systems. The method of claim 11, The asynchronous mobile communication system is a GSM, WCDMA, PDC mobile communication system, the synchronous mobile communication system is a CDMA, IS-95A / B mobile communication system characterized in that the handover between different mobile communication systems.

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