KR20080026855A - Handover Method and System in Wireless Communication System - Google Patents

Abstract

The present invention relates to a handover method between heterogeneous networks and a system for providing the same. The present invention relates to a handover method in a wireless communication system, comprising: determining a handover of a mobile terminal; and determining a handover of the mobile terminal. Transmitting a ranging request message to a serving base station; transmitting, by the serving base station, a ranging response message including information on neighboring target base stations to the mobile terminal upon receiving the ranging request message; The portable terminal includes a handover to a target base station of a homogeneous or heterogeneous network based on the ranging response message.

Description

METHOD AND SYSTEM FOR HANDOVER IN A WIRELESS COMMUNICATION SYSTEM}

1 is a view schematically showing the configuration of a wireless communication system according to an embodiment of the present invention;

2 is a view schematically showing an example of a configuration of a mobile terminal according to an embodiment of the present disclosure;

3 is a diagram illustrating an example of a handover procedure between heterogeneous manganese according to an embodiment of the present invention;

4 is a diagram illustrating an example of a handover method between heterogeneous networks in a normal mode of a mobile terminal according to an embodiment of the present invention;

5 is a view showing another example of a handover procedure between heterogeneous manganese according to an embodiment of the present invention;

6 illustrates an example of a handover method between heterogeneous manganeses in an idle mode of a mobile terminal according to an embodiment of the present invention;

7 is a diagram illustrating an example of a handover process between heterogeneous networks in a serving base station according to an embodiment of the present invention;

8 is a view showing another example of a handover procedure between heterogeneous manganese according to an embodiment of the present invention;

9 is a view showing an example of a handover method between heterogeneous manganese in a mobile terminal according to an embodiment of the present invention;

10 is a diagram illustrating an example of a handover processing procedure between heterogeneous networks in a target base station according to an embodiment of the present invention.

TECHNICAL FIELD The present invention relates to a broadband wireless access (BWA) communication system, and more particularly, to a system and a method for providing handover between heterogeneous networks in a wireless communication system.

Commonly used technologies to provide data services to users in the current wireless communication environment include CDMA2000 Code Division Multiple Access 2000 1x Evolution Data Optimized (GPDMA), General Packet Radio Services (GPRS), and Universal Mobile Telecommunication Service (UMTS). And third generation or third generation cellular mobile communication technologies such as Global System for Mobile communication (GSM) and Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless local area network (LAN). Technology).

In addition, various short-range wireless access technologies, such as IEEE 802.16 based wireless LAN, have appeared in parallel with the evolution of the mobile communication technologies. The short-range wireless access technologies replace wired communication networks such as cable modems or digital subscriber line (xDSL) in hot spot areas or home network environments such as public places or schools, As an alternative for providing high speed data service in a wireless environment.

However, when providing a high-speed data service over the wireless LAN described above, there are limitations in providing public network services to users due to extremely limited mobility and narrow service area as well as radio wave interference.

Therefore, efforts to overcome the above limitations are being made at various angles. For example, researches on portable Internet technologies that complement the advantages and disadvantages of cellular mobile communication systems and wireless LANs are being actively conducted. As a representative example of the portable Internet technology, researches on a wireless broadband Internet (WiBro) system are actively underway. The WiBro system can provide a high-speed data service in a mobile environment such as a stationary environment, a walking speed, and a medium / low speed (about 60 km / h) by using various types of portable devices.

Various services are currently being developed and provided based on the portable Internet, and as the service area of the portable Internet system overlaps with the service area of the public wireless network (eg, cellular mobile communication system, etc.), the portable Internet providing mobile Internet service is provided. There is a need for an efficient handover scheme between a system and a public wireless communication system.

However, such a portable Internet system (for example, WiBro system) does not specifically present a handover method between heterogeneous networks. In particular, in the portable Internet system, only a handover between portable Internet systems, that is, a handover between homogeneous networks is mentioned, but a handover, that is, heterogeneous manganese, between a portable Internet system and another system (for example, a cellular mobile communication system). There is no specific plan for handover. For this reason, there is a problem in that the mobile terminal cannot provide a continuous service to the mobile terminal when moving to a heterogeneous network.

Therefore, when the portable terminal moves to a heterogeneous network different from the system to which it belongs, an efficient handover scheme between the portable Internet system and the heterogeneous system is required to provide continuous services to the portable terminal.

Accordingly, the present invention has been made to solve the aforementioned problems of the prior art, and an object of the present invention is to provide an efficient handover system and method in a broadband wireless communication system.

Another object of the present invention is to provide an efficient handover system and method between heterogeneous networks in a wireless communication system.

Another object of the present invention is to propose a ranging response (RNG-RSP) message structure for efficient handover between heterogeneous networks in a wireless communication system.

In accordance with another aspect of the present invention, a method for handover in a wireless communication system includes: determining a handover of a mobile terminal; and requesting a ranging request when determining a handover of the mobile terminal. Transmitting a message to a serving base station; when the serving base station receives the ranging request message, transmitting a ranging response message including information about neighboring target base stations to the portable terminal; And handing over to a target base station of a homogeneous or heterogeneous network based on a ranging response message.

In accordance with another aspect of the present invention, a method for handover in a wireless communication system includes: determining a handover of a mobile terminal; and requesting a ranging request when determining a handover of the mobile terminal. Transmitting a message to a serving base station, checking a ranging response message when a ranging response message corresponding to the ranging request message is received from the serving base station, and based on the ranging response message. Handover to a target base station of a heterogeneous network.

The method according to an embodiment of the present invention for achieving the above object, in the handover method in a wireless communication system, the serving base station to collect the information of the surrounding target base station upon receiving a ranging request message from a predetermined mobile terminal Determining whether or not handover is possible in the homogeneous network of the portable terminal based on the information on the collected target base stations; and when the handover in the homogeneous network is possible, including information of target base stations in the homogeneous network. Transmitting a ranging response message to the portable terminal; and transmitting a ranging response message to the portable terminal to add information of target base stations of the heterogeneous network when the handover in the homogeneous network is impossible.

A method according to an embodiment of the present invention for achieving the above object, in the handover method in a wireless communication system, the serving base station determines the handover of the mobile terminal, and when the handover decision of the mobile terminal Determining a handover capable target base station of the portable terminal; and if the portable terminal determines that handover is impossible to a target base station in a homogeneous network, requesting handover of the portable terminal to a corresponding target base station of a heterogeneous network. And transmitting, by the target base station of the heterogeneous network, a handover command of the portable terminal to the serving base station when the portable terminal can accommodate the portable terminal, and the serving base station to the target base station of the heterogeneous network. Instructing a handover, and wherein the portable terminal is the handover name. To include a process of hand-over to the target base station based on.

In accordance with another aspect of the present invention, a method for handover in a wireless communication system includes determining a handover of a mobile terminal, and a measurement report message when determining a handover of the mobile terminal. Transmitting to the serving base station, synchronizing with the corresponding target base station of the heterogeneous network when receiving a handover command from the serving base station to the target base station of the heterogeneous network, and handing over to the target base station of the heterogeneous network. It includes the process of doing.

The method according to an embodiment of the present invention for achieving the above object, in the handover method in a wireless communication system, whether the target base station is acceptable for the mobile terminal when receiving the handover request from the serving base station of the heterogeneous network Determining, and transmitting a handover command message indicating a handover to the portable terminal to the serving base station when the portable terminal can accommodate the portable terminal.

The system according to an embodiment of the present invention for achieving the above objects, in the system for providing handover between heterogeneous networks, requests a handover to the base station to which it belongs at the time of handover decision, and from the base station On the basis of the received information, the mobile terminal performs a handover to the target base station of the homogeneous or heterogeneous network, and the handover to the target base station of the homogeneous network to which it belongs or the target base station of the heterogeneous network when the handover request is received. The first base station and the first base station to indicate that the network is different from the first base station, when the handover request of the mobile terminal indicates the handover to the target base station of the homogeneous network to which it belongs or the target base station of the heterogeneous network And a second base station.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, only the parts necessary for understanding the operation according to the embodiment of the present invention will be described, it should be noted that the description of other parts will be omitted so as not to distract from the gist of the present invention.

The terms or words used in the specification and claims described below should not be construed as being limited to the ordinary or dictionary meanings, and the inventors are appropriate to the concept of terms in order to explain their invention in the best way. It should be interpreted as meanings and concepts in accordance with the technical spirit of the present invention based on the principle that it can be defined. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only one of the most preferred embodiments of the present invention, and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

For example, an embodiment using a portable Internet system (for example, a WiBro system) and a public wireless network (for example, a cellular mobile communication system, etc.) will be described. However, the handover method of heterogeneous manganese of the present invention is not limited to such systems. That is, the handover method between heterogeneous networks according to an embodiment of the present invention is based on IEEE 802.1x, IEEE 802.2x similar to the portable Internet system, as well as the portable Internet system and the public wireless network. It includes a network that can provide IP (Internet Protocol) based packet service to subscribers such as wireless LAN, and public wireless network also includes Global System for Mobile communication (GSM), General packet radio service (GPRS), and Enhanced (EDGE). It may include communication networks such as Data GSM Environment, Universal Mobile Telecommunications System (UMTS), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Wi-Fi, and 3rd Generation Partnership Project (3GPP), Various applications may also be applied to the expanded and modified forms of the above-described communication networks.

In addition, in the following description, in order to clarify the gist of the invention and to facilitate the explanation and understanding thereof, the mobile terminal supports at least dual mode that can be connected to a general mobile communication network as well as a communication network such as a wireless LAN or a portable Internet. A terminal can be used.

In addition, the term "serving base station (BS)" or "serving radio access station" (hereinafter referred to as "RAS"), which will be described below, refers to a base station to which the mobile terminal currently belongs or RAS indicates a base station or RAS that currently provides services to the mobile terminal. That is, the serving base station means a base station that currently provides a service to a mobile terminal in a public wireless network, and the serving RAS means a base station that currently provides a service to a mobile terminal in a portable internet network. Hereinafter, for convenience of description, the base station and the RAS will be referred to collectively as a 'base station'.

In addition, the term "target base station" described below means a base station to which the portable terminal is to move from the serving base station, i.e., handover and continuously receive a service.

The handover between heterogeneous networks described below indicates that the mobile terminal handovers from a current network to a network of different types in an overlay network in which two or more types of networks having different characteristics are mixed.

In addition, in the embodiment of the present invention, the mobile terminal is described as an example of a mobile communication terminal supporting dual mode or more, but the present invention is not limited thereto. Therefore, the portable terminal according to an embodiment of the present invention is a terminal supporting the above-described dual mode, preferably, a digital broadcasting terminal, a personal digital assistant (PDA), a smart phone, an IMT- 2000 (International Mobile Telecommunication 2000) terminal, Code Division Multiple Access (CDMA) terminal, Wideband Code Division Multiple Access (WCDMA) terminal, Global System for Mobile communication (GSM) terminal, Universal Mobile Telecommunication Service (UMTS) terminal, Cellular phone, It will be apparent to all telecommunications and multimedia devices such as Palmtop computers and laptops, and applications thereof.

The proposed embodiment of the present invention proposes a handover scheme to a broadband wireless access (BWA) communication system. Specifically, a handover between a representative wireless broadband Internet (WiBro) system of portable Internet technology (hereinafter referred to as WiBro) system and a public wireless network (eg, GSM, CDMA, WCDMA system, etc.) A handover method between heterogeneous manganeses is proposed.

First, an example of a system and a portable terminal to which a function according to an embodiment of the present invention is applied will be described with reference to FIGS. 1 to 2.

1 is a diagram illustrating an example of a structure of a wireless communication system to which a function according to an embodiment of the present invention is applied. In particular, FIG. 1 shows an example of a structure in which the portable Internet system and the public wireless network communication system overlap.

Referring to FIG. 1, the portable Internet system 300 largely controls a plurality of RASs 310 for wirelessly communicating with the portable terminal 100 and functions of the RASs 310. Core Network (CN) 400 relaying service interworking between Access Control Routers (hereinafter referred to as 'ACR') 320 and the portable Internet system 300 and other external systems. ), And the like.

Each of the ACRs 320 is a system located between the Core Network (CN) 400 and the RASs 310, and includes a Convergence Sublayer (CS) function and an Automatic Retransmission (ARQ). Automatically Request) function and handover control function. The ACRs 320 also provide an interface with the core network 400.

The core network 400 identifies the location information between the ACRs 320 and the like, and the location of the surrounding heterogeneous network (for example, the public wireless network 500), and the portable terminal 100. It is responsible for relaying connection related information required for handover from the portable Internet system 300 to the public wireless network 500 or from the public wireless network 500 to the portable internet system 300. .

Each of the RASs 310 is a system located between the ACRs 320 and the mobile terminal 100, and provides a wireless access interface that conforms to a wireless connection standard, for example, the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard. .

Accordingly, the mobile terminal 100 connects to the RASs 310 and performs communication according to the wireless access standard as described above. In addition, although not shown in FIG. 1, the mobile terminal 100 may connect to the public wireless network 500 to perform communication. That is, it is assumed that the portable terminal 100 according to an embodiment of the present invention supports at least dual mode for communicating with different communication systems. An example of the configuration of the portable terminal 100 will be described with reference to FIG. 2 to be described later.

The public wireless network 500 is representative of a network different from the portable Internet system formed by the public wireless network communication system. In the following description, terms of a public wireless network or a public wireless network communication system are mixed and described for convenience of description, but they refer to the same system. In particular, the network of all types of communication systems different from the portable Internet system 300 will be referred to collectively. It should be noted that it is shown.

The public wireless network 500 includes a base station supporting wireless section communication with the portable terminal 100, a base station controller (BSC) for controlling the base station and at least one base station controller when the data network service includes the data network service. And a switch (MSC, Mobile Switching Center) for performing a call exchange.

2 is a diagram schematically illustrating an example of a configuration of a portable terminal according to an exemplary embodiment of the present invention.

Referring to FIG. 2, the portable terminal 100 to which a function according to an exemplary embodiment of the present invention is applied includes an antenna 110 and a portable Internet as shown in FIG. 2 to support a dual mode or more. A first module 120 for a service, a second module 130 for a public wireless network communication service, and a common module 140 are included.

The antenna 110 may simultaneously process a frequency band for a public wireless network communication service and a frequency band for a portable Internet service. In FIG. 2, the antenna 110 is illustrated in one configuration. However, the antenna 110 may be configured as a dual antenna or more corresponding to each system.

The first module 120 for providing a portable Internet service includes a duplexer 122 that operates as a band pass filter for processing each frequency and a first wireless transceiver 124 for separating transmission and reception radio waves into a predetermined frequency band. And a first modem unit 126 for processing a wireless section protocol with the portable Internet system 300.

The second module 130 for providing a public wireless network communication service includes a duplexer 132 that operates as a band pass filter for processing different frequencies, and a second wireless transceiver for separating transmission and reception radio waves into predetermined frequency bands. 134 and a second modem unit 136 for processing a radio section protocol with the public wireless network communication system 400.

The common module 140 operates as a central processing unit for controlling the first modem unit 126 and the second modem unit 136 and performs a multimedia function. An application processor, a memory, an input / output unit, other application processing units, and the It includes a control unit for performing the signal flow and control between each component.

As described above, the portable terminal 100 supports two or more communication connection modes.

On the other hand, the portable terminal 100 according to an embodiment of the present invention varies the handover method according to the state of the portable terminal 100, respectively. In detail, the portable terminal 100 may have an idle mode and a normal mode according to a situation, and perform a handover procedure according to the idle mode and the normal mode, respectively.

The idle mode is a deregistration request (DREG-REQ) between the mobile terminal 100 and the base station to which the mobile terminal 100 currently belongs in order to save power and save idle radio resources of the mobile terminal 100. Paging Group, Paging Cycle, Paging Offset, etc. approved by the BS through the signaling of a message and a De-Registration Command (DREG-CMD) message Indicates the mode to

The normal mode indicates a mode in which the mobile terminal 100 performs a service provided by the base station by establishing a resource and session with the base station through a network entry procedure. The handover method according to the idle mode and the normal mode will be described later with reference to FIGS. 3 to 6.

In the above, the configuration for handover between heterogeneous manganese according to an embodiment of the present invention has been described. Hereinafter, exemplary embodiments of a handover method of heterogeneous manganese of the present invention will be described with reference to FIGS. 3 to 8. However, the present invention is not limited to the contents described below, it should be noted that it can be applied to various embodiments based on the following embodiments.

3 is a diagram illustrating a handover procedure between heterogeneous networks according to an embodiment of the present invention. In particular, FIG. 3 illustrates a handover procedure performed by the mobile terminal in a normal mode during handover from the portable Internet system to the public wireless network communication system.

Before describing FIG. 3, the mobile terminal 100 may move from the serving base station 300 to the target base station 500. Therefore, in order to facilitate the connection establishment with the target base station 500, the base station currently connected to the mobile terminal 100, that is, the serving base station 300, the mobile terminal 100 is moved adjacent to a new connection possibility Information about neighbor base stations is provided to the mobile terminal 100 through a neighbor base station information advertisement (MOB_NBR-ADV, Mobile_Neighbor-Advertisement) message.

Therefore, in order for the mobile terminal 100 to move and handover to a neighbor cell, first, the portable terminal 100 needs to know information of neighbor cells, that is, information of neighbor BSs. Accordingly, the mobile terminal 100 may receive periodic broadcast messages from the serving base station 300 that is currently receiving a service and collect information of neighbor base stations.

Accordingly, the portable terminal 100 described below supports two or more access modes, and a serving base station (eg, a serving RAS of a portable Internet system) and an ACR serving the same include a location for a heterogeneous network through a core network. Assume that you have enough connection-related information.

In addition, hereinafter, the messages used for handover for convenience of description are not directly related to the operation of the present invention, so a detailed description thereof will be omitted. That is, an embodiment of the present invention relates to a ranging procedure during a handover procedure. Messages used in a handover procedure before or after the ranging procedure may vary according to a handover provision type of a corresponding system. . Therefore, in the embodiment of the present invention, since the ranging procedure is characterized as described above, only the ranging procedure will be described below.

For example, the above-described neighbor base station information advertisement (MOB_NBR-ADV) message, a handover request (HO-REQ) message requesting a serving base station to perform a handover from a mobile terminal, and a handover request from a serving base station Handover Response (HO-RSP) message transmitted to the mobile terminal in response to the message, a handover indication (HO-IND, Handover Indication) used to inform that the mobile terminal finally performs a handover Message, a handover acknowledgment message (HO Confirm) indicating that the portable terminal will be handed over to a target base station when the serving base station receives the handover indication message, and a portable terminal necessary for performing an optimized handover (Optimized HO). Information such as Subscriber Station's Basic Capability Negotiation (SBC) information, encryption key management (PKM, Privac) Note that a transmission / reception procedure such as a HO Optimization message including key management information, registration information, and provisioned service flow (SF) information is omitted.

Referring to FIG. 3, first, the mobile terminal 100 is referred to as a received signal strength indicator (RSSI) with a serving base station (eg, serving RAS) 300 that currently provides a service to itself. Measure) (S301).

In step S301, the portable terminal 100 measures the RSSI with the serving base station 300 at a predetermined period. If the RSSI is less than or equal to a preset reference value, the portable terminal 100 performs the serving base station 300. A ranging request (hereinafter, referred to as 'RNG-REQ') message is transmitted (S303).

That is, in steps S301 and S303, the portable terminal 100 measures the RSSI with the serving base station 300, and determines that a handover will occur when the RSSI is less than or equal to a preset reference value. Send an RNG-REQ message to inform the user. In this case, the portable terminal 100 attempts to perform handover between homogeneous networks. Hereinafter, although the handover occurs due to the determination of the portable terminal 100, the case in which handover to target base stations existing in the same network is impossible will be described.

The serving base station 300 receiving the RNG-REQ message from the mobile terminal 100 includes a ranging response including a handover process optimization field in response to the RNG-REQ message. A response, hereinafter referred to as an 'RNG-RSP' message, is transmitted to the mobile terminal 100 (S305).

In step S305, when the serving base station 300 receives the RNG-REQ message from the mobile terminal 100 confirms that the mobile terminal 100 will be handed over, the mobile terminal 100 is to be handed over Collect information about neighboring base stations. In this case, when the mobile terminal 100 determines that handover between homogeneous networks is impossible, the serving base station 300 adds information for handover between heterogeneous networks to the RNG-RSP message and transmits the information.

That is, when the serving base station 300 determines that handover between homogeneous networks is impossible based on the information on the neighbor base stations when the RNG-REQ message is received, the serving base station 300 checks the existence of the base stations of the neighboring heterogeneous networks. do. Thereafter, the serving base station 300 generates an RNG-RSP message in which information about base stations of the heterogeneous network is added and transmits the generated RNG-RSP message to the mobile terminal 100. Information about the base stations of the heterogeneous network is included in the handover processing optimization field in the RNG-RSP message.

Hereinafter, the general RNG-RSP message format including the handover processing optimization field and the RNG-RSP message format including the handover processing optimization field proposed by the present invention will be described with the following <Table 1> and <Table 2>. Let's look at it.

The format of a general RNG-RSP message including the handover processing optimization field may be represented as shown in Table 1 below.

As shown in Table 1, the handover processing optimization field in the RNG-RSP message is optimized for optimal handover such as SBC information, PKM information, and REG information of the mobile terminal 100 requested in the handover signaling process. Information necessary to perform HO) is included.

Accordingly, the RNG-RSP message according to an embodiment of the present invention may include a handover processing optimization field for the mobile terminal 100 to handover to the heterogeneous service network when the mobile terminal 100 fails in the same service network. Include. That is, the RNG-RSP message proposed in the embodiment of the present invention performs handover to a heterogeneous service network using reserved bits (eg, 14th bit and 15th bit) in the handover processing optimization field. Configure by adding information to support. Looking at the format of the RNG-RSP message including the handover processing optimization field can be represented as shown in the following Table 2.

As shown in Table 2, the RNG-RSP message according to an embodiment of the present invention is assigned to the reserved bits of the handover processing optimization field, that is, the 14th bit and the 15th bit as shown in the <Table 2>. Contains information for handover between heterogeneous networks. Accordingly, the portable terminal 100 may determine handover between heterogeneous networks according to the setting of the 14th bit and the 15th bit among the information added to the handover processing optimization field.

That is, the mobile terminal 100 checks the handover processing optimization field when receiving the RNG-RSP message from the serving base station 300. In this case, when the 14th bit or the 15th bit is set to '1', the portable terminal 100 performs handover between heterogeneous networks.

In Table 2, a case of including heterogeneous network information of an 802.11x system and a 3GPP system is illustrated as an example, but the present invention is not limited thereto. That is, the information of the 14th bit and the 15th bit illustrated in Table 2 may be added to the heterogeneous network information for the corresponding systems according to the system type provided.

For example, when the 14th bit or the 15th bit is set to '1', the handover processing optimization field may be set by the mobile terminal 100 in a public Internet system (eg, IEEE 802.16 system, WiBro system, etc.). It represents a handover to a wireless network (eg, 3GPP, CDMA, GSM, WiFi, cellular communication system, IEEE 802.11x system, etc.). Accordingly, when the mobile terminal 100 receives the RNG-RSP message including heterogeneous network information, the mobile terminal 100 currently belongs to the mobile terminal 100 based on a setting value of 14th bit or 15th bit of the handover processing optimization field. Deregistration with the existing mobile Internet system.

Next, when receiving the RNG-RSP message from the serving base station 300, the portable terminal 100 measures the RSSI with the target base station 500 (S307).

When the mobile terminal 100 receives the RNG-RSP message from the serving base station 300 in step S307, the handover processing optimization field in the RNG-RSP message includes information for handover between heterogeneous networks. Determine if there is.

In this case, when heterogeneous network handover information is included in the handover processing optimization field in the RNG-RSP message, the portable terminal 100 stops the handover procedure between homogeneous networks. The handover to the heterogeneous network is determined based on handover optimization field information in the RNG-RSP message, that is, 14th bit or 15th bit information. To this end, the portable terminal 100 measures the RSSI for the target base station 500 of the heterogeneous network capable of handover based on the handover processing optimization field.

3 illustrates a case where there is only one target base station, preferably, the target base station may include a plurality of neighbor base stations searched by the mobile terminal 100 or the serving base station 300. Accordingly, the portable terminal 100 measures RSSIs for the neighbor base stations, and selects the neighbor base station having the highest RSSI as a target base station to perform stable handover.

Next, when the RSSI with the target base station 500 is greater than or equal to a predetermined reference value, the portable terminal 100 performs a handover to the target base station 500 (S309). Thereafter, the mobile terminal 100 and the target base station 500 perform a network entry process.

In the network entry process, the target base station 500 transmits a network entry completion response (Network_Entry_Done_Ack) message indicating that the network entry to the portable terminal 100 is normally completed (S311).

When the mobile terminal 100 receives the network entry complete response message from the target base station 500, the mobile terminal 100 completes the handover to the heterogeneous network (S313), and the serving base station 300 to which the mobile terminal 100 is currently belonging. De-Registration with DE) is performed (S315). Thereafter, the mobile terminal 100 may receive a service from the target base station 500 to perform a communication service.

4 is a diagram illustrating a handover method in a mobile terminal according to an exemplary embodiment of the present invention. In particular, FIG. 4 illustrates a handover process from the portable Internet system to a public wireless network communication system when the portable terminal is in a normal mode.

Referring to FIG. 4, first, the mobile terminal periodically measures RSSI with the serving base station to which it belongs (S401) and compares the measured RSSI with a preset reference value (S403).

If it is determined in step S403 that the RSSI with the serving base station is equal to or less than the reference value, the mobile terminal transmits an RNG-REQ message to the serving base station (S405). Subsequently, the portable terminal determines whether a response message to the RNG-REQ message, that is, an RNG-RSP message, is received from the serving base station (S407).

In step S407, when receiving the RNG-RSP message, the portable terminal checks a handover processing optimization field included in the RNG-RSP message (S409). The portable terminal determines whether information on a heterogeneous network is included in the handover processing optimization field, that is, information on a target base station of a heterogeneous network different from a serving base station currently being served by the portable terminal itself (S411). . A detailed description of the RNG-RSP message and the handover processing optimization field is as described in the description with reference to Tables 1 and 2.

If the RNG-RSP message does not include the information on the target base station of the heterogeneous network as a result of the determination in step S411, the portable terminal determines a target base station in the homogeneous network based on a handover processing optimization field of the RNG-RSP message. In step S413, handover is performed. If the RNG-RSP message includes information on the target base station of the heterogeneous network, the portable terminal handovers to the heterogeneous network based on a handover processing optimization field of the RNG-RSP message. Perform (S415).

In detail, step S415, the portable terminal measures the RSSI for the corresponding target base station of the heterogeneous network based on the handover processing optimization field. In this case, the target base station may be a specific target base station designated by the serving base station or all neighbor base stations to which the portable terminal can be handed over. Therefore, the portable terminal can measure the RSSI of all of the neighboring base stations capable of handover or the RSSI measurement with a specific target base station. When the RSSI is equal to or larger than a predetermined reference value, the portable terminal stops the handover procedure between homogeneous networks and performs handover to the heterogeneous network target base station. In this case, the portable terminal may perform a deregistration process with the serving base station when the handover is completed.

5 is a diagram illustrating a handover procedure of heterogeneous manganese according to an embodiment of the present invention. In particular, FIG. 5 illustrates a handover procedure performed by the portable terminal in idle mode during handover from the portable Internet system to the public wireless network communication system.

Before describing FIG. 5, the mobile terminal 100 may move from the serving base station 300 to the target base station 500. Therefore, in order to facilitate the connection establishment with the target base station 500, the base station currently connected to the mobile terminal 100, that is, the serving base station 300, the mobile terminal 100 is moved adjacent to a new connection possibility Information about neighbor base stations is provided to the mobile terminal 100 through a neighbor base station information advertisement (MOB_NBR-ADV) message.

Therefore, in order for the mobile terminal 100 to move and handover to a neighbor cell, first, the portable terminal 100 needs to know information of neighbor cells, that is, information of neighbor BSs. Accordingly, the mobile terminal 100 may receive periodic broadcast messages from the serving base station 300 that is currently receiving a service and collect information of neighbor base stations.

Accordingly, the portable terminal 100 described below supports two or more access modes, and a serving base station (eg, a serving RAS of a portable Internet system) and an ACR serving the same include a location for a heterogeneous network through a core network. Assume that you have enough connection-related information.

In addition, hereinafter, the messages used for handover for convenience of description are not directly related to the operation of the present invention, so a detailed description thereof will be omitted. That is, an embodiment of the present invention relates to a ranging procedure during a handover procedure. Messages used in a handover procedure before or after the ranging procedure may vary according to a handover provision type of a corresponding system. . Therefore, in the embodiment of the present invention, since the ranging procedure is characterized as described above, only the ranging procedure will be described below. A detailed description of examples of the message omitted as described above is as described in the description with reference to FIG. 3.

Referring to FIG. 5, first, the mobile terminal 100 performs an RNG to the serving base station 300 to perform a location update process between the serving base stations 300 in an idle mode state S501. -REQ message is transmitted (S503).

In step S503, the mobile terminal 100 sets the TLV (Type Length Variable) value of a ranging purpose indication field in the RNG-REQ message to '1' to locate the serving base station 300. Request for Update (Location Update Request). That is, when the value of the TLV of the ranging purpose indication field is set to '1', this indicates the operation of the mobile terminal 100 for the idle mode location update process in the idle mode. The format of the RNG-REQ message can be represented as shown in Table 3 below.

As shown in Table 3, the ranging purpose indication field in the RNG-REQ message includes information indicating handover or location update in the idle mode state of the mobile terminal 100 and the mobile terminal 100 accordingly. Information indicating the operation of the).

Next, the serving base station 300 receiving the RNG-REQ message from the mobile terminal 100 includes an RNG-RSP including a handover process optimization field in response to the RNG-REQ message. The message is transmitted to the mobile terminal 100 (S505).

In step S505, when the serving base station 300 receives the RNG-REQ message from the mobile terminal 100 confirms that the mobile terminal 100 will be handed over in the idle mode, and the mobile terminal 100 Collects information about neighboring base stations that can be handed over. In this case, when the mobile terminal 100 determines that handover between homogeneous networks is impossible, the serving base station 300 adds information for handover between heterogeneous networks to the RNG-RSP message and transmits the information.

That is, when the serving base station 300 determines that handover between homogeneous networks is impossible based on the information on the neighbor base stations when the RNG-REQ message is received, the serving base station 300 checks the existence of the base stations of the neighboring heterogeneous networks. do. Thereafter, the serving base station 300 generates an RNG-RSP message in which information about base stations of the heterogeneous network is added and transmits the generated RNG-RSP message to the mobile terminal 100. Information about the base stations of the heterogeneous network is included in the handover processing optimization field in the RNG-RSP message. As described above, the RNG-RSP message includes a handover processing optimization field describing a handover method according to the setting of the 14th bit or the 15th bit. A detailed description of the RNG-RSP message is as described in the description with reference to FIG. 3.

Next, when the mobile terminal 100 receives the RNG-RSP message from the serving base station 300, the mobile terminal 100 performs an RSSI measurement (S507) and a network re-entry procedure for the corresponding target base station 500. (S509).

When the mobile terminal 100 receives the RNG-RSP message from the serving base station 300 in steps S507 and S509, information for handover between heterogeneous networks in the handover processing optimization field in the RNG-RSP message is received. Determine whether or not is included.

In this case, when heterogeneous network handover information is included in the handover processing optimization field in the RNG-RSP message, the portable terminal 100 stops a location update procedure between homogeneous networks. The handover to the heterogeneous network is determined based on handover optimization field information in the RNG-RSP message, that is, 14th bit or 15th bit information. To this end, the portable terminal 100 performs RSSI measurement and network reentry procedure with the target base station 500 of the heterogeneous network capable of handover based on the handover processing optimization field.

That is, the mobile terminal 100 extracts the information on the target base station 500 from the information of the neighbor heterogeneous network included in the RNG-RSP message, and transmits the information to the target base station 500 based on the extracted information. After the RSSI measurement, if the RSSI is greater than or equal to a predetermined reference value, the network re-entry procedure is performed to the target base station 500.

5 illustrates a case where there is only one target base station, but preferably, the target base station may include a plurality of neighbor base stations searched by the mobile terminal 100 or the serving base station 300. Accordingly, the portable terminal 100 measures RSSIs for the neighbor base stations, and selects the neighbor base station having the highest RSSI as a target base station to perform stable handover.

Next, as described above, when the RSSI with the target base station 500 is equal to or larger than a predetermined reference value, the portable terminal 100 performs a handover to the target base station 500 (S511).

Next, the target base station 500 transmits a network entry complete response (Network_Entry_Done_Ack) message indicating that network re-entry to the portable terminal 100 is normally completed (S513).

When the mobile terminal 100 receives the network entry complete response message from the target base station 500, the mobile terminal 100 completes a handover to a heterogeneous network (S515), and then, in the heterogeneous network supported by the target base station 500. Enter Idle mode. Subsequently, the portable terminal 100 performs deregistration (DE-REG) with the serving base station 300 to which the portable terminal 100 itself belongs (S517). Thereafter, the mobile terminal 100 may receive a service from the target base station 500 to perform a communication service.

6 is a diagram illustrating a handover method in a mobile terminal according to an embodiment of the present invention. In particular, FIG. 6 illustrates a handover process from the portable Internet system to the public wireless network communication system in the idle mode.

Referring to FIG. 6, first, the mobile terminal transmits an RNG-REQ message to a serving base station to which it belongs to for location update, which is a handover process in idle mode (S601). A detailed description of the RNG-REQ message is as described in the description with reference to Table 3 above.

Subsequently, the portable terminal determines whether a response message to the RNG-REQ message, that is, an RNG-RSP message, is received from the serving base station (S605). In step S605, when the mobile terminal receives the RNG-RSP message, the portable terminal checks a handover processing optimization field included in the RNG-RSP message (S607). The portable terminal determines whether information on a heterogeneous network is included in the handover processing optimization field, that is, information on a target base station of a heterogeneous network different from a serving base station currently being served by the portable terminal itself (S609). . A detailed description of the RNG-RSP message and the handover processing optimization field is as described in the description with reference to FIG. 3.

If the RNG-RSP message does not include information on the target base station of the heterogeneous network as a result of the determination in step S609, the portable terminal determines a target base station in the homogeneous network based on a handover processing optimization field of the RNG-RSP message. In step S611, handover is performed. After the handover is performed, the portable terminal enters an idle mode in the target base station (S613).

If the RNG-RSP message includes information on the target base station of the heterogeneous network, the portable terminal performs handover to the heterogeneous network based on a handover processing optimization field of the RNG-RSP message. Perform (S615). After the handover is performed, the portable terminal transitions to the idle mode in the target base station of the heterogeneous network (S617).

In step S615 and step S617 in detail, the portable terminal measures the RSSI for the target base station of the heterogeneous network based on the handover processing optimization field. In this case, the target base station may be a specific target base station designated by the serving base station or all neighbor base stations to which the portable terminal can be handed over. Therefore, the portable terminal can measure the RSSI of all of the neighboring base stations capable of handover or the RSSI measurement with a specific target base station. When the RSSI is equal to or larger than a predetermined reference value, the portable terminal stops the location update procedure between homogeneous networks and performs a handover to the heterogeneous network target base station. When the handover to the target base station is completed, the portable terminal performs a state transition for maintaining a mode corresponding to an idle mode in the serving base station. In this case, the portable terminal may perform a deregistration process with the serving base station when the handover is completed.

7 is a diagram illustrating an example of a handover process between heterogeneous networks in a serving base station according to an embodiment of the present invention. In particular, FIG. 10 illustrates an example of a handover processing procedure from the serving base station of the portable Internet system to the public wireless network communication system for the portable terminal.

Referring to FIG. 7, the serving base station first collects information on neighbor target base stations to which the portable terminal can be handed over when the RNG-REQ message is received from a predetermined portable terminal (S701). In this case, the serving base station may check the state of the mobile terminal, for example, a normal mode or an idle mode, through the RNG-REQ message. A detailed description of the structure of the RNG-REQ message is as described in the description with reference to Table 3.

Next, the serving base station determines the information to be collected to determine whether the portable terminal is capable of handover to the same network (S705).

If it is determined in step S705 that the portable terminal is capable of handover to a homogeneous network, the serving base station creates an RNG-RSP message including information on the corresponding target base stations to which the portable terminal can be handed over. S707 Transmits to the mobile terminal (S711).

If the mobile terminal determines that handover to the homogeneous network is impossible, in step S705, the serving base station includes an RNG-RSP message including information on corresponding target base stations of the heterogeneous network to which the mobile terminal can handover. Is generated (S709) and transmitted to the mobile terminal (S711).

A detailed description of the RNG-RSP message is as described in the description with reference to FIG. 3.

In the above, the handover method from the portable Internet system to the public wireless network communication system of the handover method between heterogeneous networks according to an embodiment of the present invention has been described. Next, a handover method from a public wireless network communication system to a portable internet system among handover methods between heterogeneous networks according to an embodiment of the present invention will be described.

8 is a diagram illustrating a handover procedure between heterogeneous networks according to an embodiment of the present invention. In particular, FIG. 8 illustrates a handover procedure from the public wireless network communication system to the portable Internet system.

Referring to FIG. 8, first, when the mobile terminal 100 receives a measurement information message from a serving base station 500 that currently provides a service to itself (S801), the mobile terminal 100 based on the measurement information message. Measure the RSSI for target base stations in the. That is, the mobile terminal 100 collects information on network characteristics of the mobile terminal 100 such as RSSI for neighboring base stations according to the measurement information message, creates a measurement report message, and generates the measured report. A report message is transmitted to the serving base station 500 (S803).

Next, when the serving base station 500 receives the measurement report message from the mobile terminal 100, based on the RSSI information measured by the mobile terminal 100 for neighbor base stations in the measurement report message, The portable terminal 100 determines whether handover between homogeneous networks is possible. At this time, if the serving base station 500 determines that the portable terminal 100 is unable to perform handover between homogeneous networks, the serving base station 500 transmits to the portable terminal 100 as a core network (CN) 400 of the portable Internet system. A handover request message for requesting handover is transmitted (S805).

When the core network 400 receives the Handover Required message from a base station of a heterogeneous network, for example, the serving base station 500, a relocation request for handover support of the portable terminal 100 is performed. ) Transmits the message to one or more target base stations (eg, target RASs or ACRs) belonging to the core network 400 (S807). That is, the core network 400 of the portable internet system transmits a relocation request message related to the location of the portable terminal 100 to the target base station 300 in the portable internet system.

Next, when the target base station 300 receives the relocation request message from the core network 400, the target base station 300 determines whether it is acceptable to the mobile terminal 100. At this time, if the target base station 300 can accommodate the portable terminal 100, a handover to the heterogeneous network of the portable terminal 100, that is, the portable Internet service provided by the target base station 300 itself. A Relocation Request Acknowledge message for handover to the system is transmitted to the core network 400 (S809).

Next, when the core network 400 receives the relocation request acknowledgment message from the target base station 300, it determines that handover to the heterogeneous network with respect to the mobile terminal 100 is possible. In operation S811, the mobile terminal 100 transmits a handover command message for instructing handover to the heterogeneous network of the portable terminal 100, that is, a handover command to the portable Internet system.

Next, when the serving base station 500 receives the Handover Command message in response to a Handover Required message requested by the Core Network 400 of the heterogeneous network, Then, the mobile terminal 100 commands a handover to a heterogeneous network, for example, a portable internet system (S813).

Next, the mobile terminal 100 is a handover command to the heterogeneous network from the serving base station 500 which is currently being serviced (for example, an Inter-system to WiBro Handover Command) When receiving a message, a synchronization (eg, physical layer synchronization) for handover of the portable Internet system, which is a heterogeneous network, to the target base station 300 is performed (S815). For example, the portable terminal 100 de-activates a modem for communication with the serving base station 100 of a public wireless network communication system and deactivates the target base station 300 of the portable internet system. The modem is activated to communicate with the portable internet system through physical layer synchronization, that is, a network entry procedure is performed (S819).

In this case, the target base station 300 performs relocation detection of the mobile terminal 100 and includes the result thereof in a relocation detection message to the core network 400 of the mobile Internet system. It passes (S817). In step S817, when the target base station 300 synchronizes with the mobile terminal 100, the target base station 300 performs a relocation detection on the location of the mobile terminal 100 and transmits the result to the core network 400. do.

Meanwhile, in step S819, the portable terminal 100 performs a network entry process after synchronization with the target base station 300 of the portable internet system in step S815. For example, the portable terminal 100 performs a handover procedure (eg, ranging procedure) related to handover with the target base station 300. Thereafter, the mobile terminal 100 needs information of the mobile terminal 100 necessary to perform an optimized handover with the target base station 300, for example, basic capacity negotiation (SBC) information. The network entry process is performed by transmitting and receiving encryption key management (PKM) information and registration (REG, Registration) information.

Next, when the handover to the target base station 300 is completed through the above procedure, the portable terminal 100 indicates a handover to WiBro Complete message indicating completion of handover to the portable Internet system. It is transmitted to the target base station 300 (S821).

Next, when the target base station 300 receives the Handover to WiBro Complete message from the mobile terminal 100, the relocation completion (Relocation) indicating that the location relocation to the mobile terminal 100 is completed. Complete) message is transmitted to the core network 400 (S823).

When the core network 400 receives the relocation complete message from the target base station 300, the heterogeneous network handover for the mobile terminal 100 is completed to the serving base station 500 of the heterogeneous network. The serving base station 500 transmits a clear command message to command the termination of the service for the mobile terminal 100 (S825).

When the serving base station 500 receives the clear command message from the core network 400, the serving base station 500 stops the service for the mobile terminal 100 and terminates the service for the mobile terminal 100. A Clear Complete message indicating completion is transmitted (S827). Thereafter, the portable terminal 100 terminates the service provided by the public wireless network communication system and performs a service with the portable internet system.

9 is a diagram illustrating a handover method in a mobile terminal according to an embodiment of the present invention. In particular, FIG. 9 illustrates a handover process of the portable terminal from the public wireless network communication system to the portable internet system.

Referring to FIG. 9, first, a mobile terminal transmits measurement information about neighbor base stations to a serving base station (S901). In step S901, the portable terminal measures RSSI with respect to neighboring base stations, and transmits the measured information to the serving base station that provides the current service to the serving base station by including the measurement information in a measurement report message.

Next, when the portable terminal receives a handover command message from the serving base station after transmitting the measurement report message (S903), the handover command information in the handover command message is received. Determine (S905).

If it is determined in step S905 that the handover command from the serving base station is a handover command between homogeneous networks, the mobile terminal performs a handover process to a target base station in the homogeneous network (S907). If the handover command from the serving base station is a handover command between heterogeneous networks, the portable terminal performs a synchronization process with a target base station in the heterogeneous network for handover between heterogeneous networks (S909). ).

In this case, it is preferable that the target base station is designated by the mobile terminal or the serving base station based on measurement information of the mobile terminal, for example, RSSI measurement information. For example, the mobile terminal can designate a target base station based on the RSSI measurement information. In addition, the serving base station may designate a specific target base station based on the RSSI measurement information, or may provide information on a plurality of neighbor base stations to which the portable terminal can handover.

Next, when the synchronization with the target base station of the heterogeneous network is completed in step S909, the portable terminal performs a handover process to the target base station of the heterogeneous network (S911).

10 is a diagram illustrating an example of a handover process between heterogeneous networks in a target base station according to an embodiment of the present invention. In particular, FIG. 10 illustrates an example of a handover process for a portable terminal in a target base station of the portable internet system.

Referring to FIG. 10, first, the target base station determines whether the portable terminal can accept the mobile terminal when receiving a handover request for a predetermined mobile terminal from a serving base station of a heterogeneous network (S1011) (S1015).

As a result of the determination in the steps S1013 and S1015, if it is impossible to accept the portable terminal, the target base station may reject the handover to the portable terminal (S1017). Therefore, the target base station preferably transmits a message for rejecting handover of the mobile terminal to a serving base station of a heterogeneous network.

As a result of the determination in steps S1013 and S1015, when the portable terminal is accommodated, the target base station may command a handover to the portable terminal (S1019). Therefore, the target base station preferably transmits a message instructing handover of the mobile terminal to a serving base station of a heterogeneous network.

As described above, in the detailed description of the present invention has been described with respect to specific embodiments, various modifications are possible without departing from the scope of the invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below, but also by the equivalents of the claims.

As described above, according to the handover method and system in the wireless communication system of the present invention proposed by the present invention, handover between heterogeneous networks can be efficiently performed in a portable terminal supporting multiple access modes. As a result, the portable terminal can be continuously provided with a service without interruption when handing over to a heterogeneous network, which can improve the quality of service for the portable terminal.

In addition, according to the present invention, information of the mobile terminal stored in the target base station and the backbone network can be reused for handover. In addition, by using a reserved bit of a previously defined field for a message defined for handover between heterogeneous networks, message overhead can be reduced.

In addition, according to the present invention can be achieved by complementing the existing existing public wireless network resources and complementary with the mobile Internet system, the advantages of the existing public public wireless network services with relatively large network coverage and All of these have the advantage of being available to the user.

Claims (34)

In the handover method in a wireless communication system, Determining a handover of the mobile terminal; Transmitting a ranging request message to a serving base station when the portable terminal determines handover; When the serving base station receives the ranging request message, transmitting a ranging response message including information on neighboring target base stations to the mobile terminal; And the mobile terminal handovers to a target base station of a homogeneous or heterogeneous network based on the ranging response message. The method of claim 1, Determining, by the serving base station, whether handover is possible in the same network of the mobile terminal when the ranging request message is received; If the portable terminal determines that handover in the homogeneous network is impossible, the mobile terminal includes transmitting heterogeneous network information capable of handover by the portable terminal in the ranging response message. The method of claim 2, The ranging response message is a handover method in a wireless communication system including an information field indicating a handover to a homogeneous or heterogeneous network. The method of claim 3, The information field is a handover process optimization (HO Process Optimization) field, characterized in that the handover method in a wireless communication system. The method of claim 2, The portable terminal is a handover method in a wireless communication system, characterized in that for determining the handover according to the strength of the transmission and reception signal with the serving base station in the normal mode. The method of claim 2, The portable terminal transmits the ranging request message including the location update request information according to the idle mode state when the handover is determined in the idle mode state. The method of claim 1, The ranging response message includes neighbor target base station information of a homogeneous network and neighbor target base station information of a heterogeneous network. In the handover method in a wireless communication system, Determining a handover of the mobile terminal; Transmitting a ranging request message to a serving base station when the portable terminal determines handover; Checking the ranging response message upon receiving a ranging response message corresponding to the ranging request message from the serving base station; And performing a handover to a target base station of a homogeneous network or a heterogeneous network based on the ranging response message. The portable terminal of claim 8, wherein the portable terminal comprises: Determining information on neighboring target base stations that can be handed over from the handover information field of the ranging response message when the ranging response message is received; If the handover information field of the ranging response message includes information on neighboring target base stations in the homogeneous network, handover to a corresponding target base station capable of handover; If the handover information field of the ranging response message includes information on neighboring target base stations of the heterogeneous network, the handover to the target base station of the heterogeneous network capable of handover is performed. Over way. The method of claim 9, The handover information field is a handover process optimization (HO Process Optimization) field, characterized in that the handover method in a wireless communication system. The method of claim 9, The portable terminal further comprises the step of determining the handover according to the strength of the signal transmitted and received with the serving base station in the normal mode (handover mode). The method of claim 9, The mobile terminal further comprises the step of transmitting the location request information including the location update request information according to the idle mode in the ranging request message when the handover decision in the idle mode (Idle mode) state. The method of claim 12, The mobile terminal further comprises the step of transitioning to the corresponding mode corresponding to the idle mode after completion of the handover to the target base station in the idle mode. In the handover method in a wireless communication system, The serving base station collects information of neighboring target base stations upon receiving a ranging request message from a predetermined mobile terminal; Determining whether handover is possible in a homogeneous network of the portable terminal based on the collected target base stations; Transmitting a ranging response message including information on target base stations in the homogeneous network to the portable terminal when handover in the homogeneous network is possible; And transmitting a ranging response message to the portable terminal to add information of target base stations of the heterogeneous network when the handover in the homogeneous network is impossible. The method of claim 14, The ranging response message includes a handover information field indicating a handover to a homogeneous or heterogeneous network of the portable terminal. The method of claim 15, The handover information field is a handover process optimization (HO Process Optimization) field, characterized in that the handover method in a wireless communication system. In the handover method in a wireless communication system, The serving base station determines the handover of the mobile terminal; Determining a target base station capable of handover of the mobile terminal when determining the handover of the mobile terminal; If the portable terminal determines that handover is impossible to a target base station in a homogeneous network, requesting handover of the portable terminal to a corresponding target base station of a heterogeneous network; Transmitting, by the target base station of the heterogeneous network, a handover command of the portable terminal to the serving base station when the portable terminal can be accommodated; The serving base station instructing the portable terminal to handover to a target base station of a heterogeneous network; And the portable terminal performs a handover to the target base station based on the handover command. The method of claim 17, wherein the serving base station Collecting information on neighboring target base stations when determining a handover of the mobile terminal; And determining a handover capable target base station of the portable terminal based on the collected target base station information. 18. The method of claim 17, wherein the heterogeneous target base station is Determining whether the portable terminal is acceptable when the handover request is received from the serving base station; And transmitting a handover command message including command information to the serving base station for handover to a heterogeneous network with respect to the portable terminal when the portable terminal can be accommodated. The method of claim 17, wherein the portable terminal Synchronizing with a target base station of the heterogeneous network based on a handover command from the serving base station; And completing a handover to a target base station of the heterogeneous network after a network entry to the target base station after the synchronization. In the handover method in a wireless communication system, Determining a handover of the mobile terminal; Transmitting a measurement report message to a serving base station when determining a handover of the mobile terminal; Performing synchronization with the corresponding target base station of the heterogeneous network when receiving a handover command from the serving base station to the target base station of the heterogeneous network; Handover method in a wireless communication system comprising the step of handover to the target base station of the heterogeneous network. The method of claim 21, The measurement report message is a handover method in a wireless communication system including information on the surrounding target base stations collected by the mobile terminal. The method of claim 21, The portable terminal further comprises the step of network entry (Network Entry) to the target base station of the heterogeneous network after the synchronization. In the handover method in a wireless communication system, Determining, by the target base station, whether the portable base station is acceptable when the handover request is received from a serving base station of a heterogeneous network; And transmitting a handover command message indicating a handover to the portable terminal to the serving base station when the portable terminal can accommodate the portable terminal. The method of claim 24, And transmitting a handover rejection message to the serving base station to reject the handover for the portable terminal when the portable terminal cannot be accommodated. In the handover providing system of heterogeneous manganese, A mobile terminal requesting a handover to a corresponding base station to which it belongs at the time of handover determination, and handing over to a target base station of a homogeneous or heterogeneous network based on the received information from the base station; A first base station for instructing handover to a target base station of a homogeneous network to which the mobile terminal belongs or a target base station of a heterogeneous network when the portable terminal receives a handover request; A second base station exists in a network different from the first base station, and includes a second base station indicating handover to a target base station of a homogeneous network to which the mobile terminal belongs or a target base station of a heterogeneous network when the handover request of the mobile terminal is received. Handover providing system of heterogeneous manganese. The terminal of claim 26, wherein the portable terminal is And a handover to a target base station of a homogeneous or heterogeneous network based on a ranging response message received from the first base station. The method of claim 27, The ranging response message is a handover providing system between heterogeneous networks including a handover process optimization (HO Process Optimization) field indicating a handover to the homogeneous or heterogeneous network. The terminal of claim 26, wherein the portable terminal is And a handover to a target base station of a heterogeneous network based on a handover command received from the first base station. The method of claim 26, The portable terminal is a handover providing system of heterogeneous manganese, characterized in that for determining the handover according to the strength of the signal transmitted and received with the first base station in the normal mode (Normal mode). The method of claim 26, The mobile terminal is a handover providing system of heterogeneous manganese, characterized in that when the handover determination in the idle mode (Idle mode), including the location update request information according to the idle mode state in the ranging request message. 27. The system of claim 26, wherein the first base station is And a ranging response message including information on neighbor target base stations of a homogeneous network or a heterogeneous network, to the portable terminal when the handover request is received from the portable terminal. 27. The system of claim 26, wherein the second base station is Request handover to a target base station of a heterogeneous network when handover in the homogeneous network of the portable terminal is impossible; and instructing the mobile terminal to handover to a target base station of a heterogeneous network when a handover command is received from the target base station; Handover providing system of heterogeneous manganese. 27. The system of claim 26, wherein the second base station is The serving base station determines whether the portable terminal is acceptable when a handover request is made from the serving base station of the heterogeneous network, and in response to the result, the serving base station provides information indicating a handover command to the heterogeneous network. Handover providing system between heterogeneous networks, characterized in that for transmitting to.

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