WO2011005019A2

WO2011005019A2 - Method and apparatus for transmission of neighbor base station information performed by macro base station in wireless communication system

Info

Publication number: WO2011005019A2
Application number: PCT/KR2010/004408
Authority: WO
Inventors: 정수정; 김주희; 김은경; 차재선; 임광재; 이현; 윤철식; 김원익; 김성경; 김남기
Original assignee: 한국전자통신연구원
Priority date: 2009-07-06
Filing date: 2010-07-06
Publication date: 2011-01-13
Also published as: WO2011005019A3

Abstract

Provided is a method in which a terminal makes a request for neighbor base station information in a wireless communication system. The method comprises: a step of searching for neighbor base stations as an object for the handover of the terminal; a step of transmitting, to a serving base station, preamble information on the base station searched for by the terminal from among the neighbor base stations and a list request message containing a neighbor base station list request indicator for indicating a request for information on neighbor base stations; and a step of receiving, from the serving base station, a response list message containing neighbor base station identification information and system information.

Description

Method and apparatus for transmitting neighbor base station information performed by macro base station in wireless communication system

The present invention relates to wireless communication, and more particularly, to a method and apparatus for transmitting neighbor base station information performed by a macro base station in a wireless communication system.

The Institute of Electrical and Electronics Engineers (IEEE) 802.16e standard is the sixth standard for the International Mobile Telecommunications (IMT-2000) in the ITU-Radiocommunication Sector (ITU-R) under the International Telecommunication Union (ITU) in 2007. It was adopted under the name OFDMA TDD '. ITU-R is preparing the IMT-Advanced system as the next generation 4G mobile communication standard after IMT-2000. The IEEE 802.16 Working Group (WG) decided to implement the IEEE 802.16m project in late 2006 with the aim of creating an amendment specification for the existing IEEE 802.16e as a standard for IMT-Advanced systems. As can be seen from the above objectives, the IEEE 802.16m standard implies two aspects: the past continuity of modification of the IEEE 802.16e standard and the future continuity of the specification for next generation IMT-Advanced systems. Therefore, the IEEE 802.16m standard is required to satisfy all the advanced requirements for the IMT-Advanced system while maintaining compatibility with the Mobile WiMAX system based on the IEEE 802.16e standard.

In the 802.16m system, femto cell technology can be applied, and active research is being conducted on this recently. A femto cell is a base station having a small power and can be installed by a user. A femto base station supporting a femto cell uses the same frequency as the macro base station or a different frequency, and the backbone network uses a public internet network used in a wired internet network. It is done. The femtocell may allow access only to limited user groups (closed group of users) or open access of all users without user restriction (open group of user). In addition, femto cells need to support seamless handover between macro cells or other femto cells. The location information of the femto base station should be able to be grasped, and there should be no problem in operation even if a plurality of femto cells are installed densely.

Femto cells also support Low Duty Operation (LDO) mode to reduce the amount of interference with neighboring cells. The femto base station entering the LDO mode repeats an AI (Availability Interval) section and an UAI (Unavailability Interval) section. The femto base station entering the AI section may transmit information between the terminal and the base station for synchronization and signal transmission for paging or ranging and data transmission of the terminal, similarly to a general macro base station. On the other hand, the femto base station entering the UAI interval does not exchange any information with the terminal over the radio to minimize the amount of interference. The AI section and the UAI section may be set differently for each femto base station according to the situation of the base station.

In a conventional wireless communication system before a femto cell is introduced, information about neighbor base stations is broadcasted from each macro base station to all terminals in order to support handover between macro cells. This may be done by the NBR-ADV message of the IEEE 802.16 system. The information included in the message includes identifiers (BSID) information of each neighboring base station and uplink / downlink related parameter (DL / UL parameter) information. This is to select a proper target base station and to reduce synchronization and re-entry time to the target base station. Is provided. However, in general, since a large number of femto cells are densely installed in a macro cell, it is inefficient to broadcast information on a neighboring femto base station from the macro base station to the terminal. On the contrary, if the macro base station does not provide any information about the neighboring femto base station to the terminal, it may take a long time for the terminal to recognize the neighboring femto base station and perform a search procedure for obtaining the information.

There is a need for a new method for the macro base station to efficiently provide information on neighboring base stations to the terminal.

An object of the present invention is to provide a method and apparatus for transmitting neighbor base station information performed by a macro base station in a wireless communication system.

In one aspect, a method for requesting neighbor base station information by a terminal in a wireless communication system is provided. The method may include searching for neighbor base stations targeted for handover of the terminal, requesting preamble information about the base station found by the terminal among the neighbor base stations, and requesting information on the neighbor base station. And transmitting a list request message including a neighbor base station list request indicator to a serving base station, and receiving a list response message including identification information and system information about the neighbor base station from the serving base station.

The list response message may be a unicast message transmitted to the terminal through a dedicated channel.

The list request message may be a MAC message for requesting identification information and system information about the neighbor base station.

The list request message may be a MAC message for reporting a search result of the neighboring base station to the serving base station.

The serving base station may be a macro base station.

The method may further include receiving, from the serving base station, a broadcast message including the type, frequency of use, and location information of the neighboring base station.

The terminal may perform a handover to any one of the neighbor base stations.

In another aspect, a method of transmitting neighbor base station information by a serving base station in a wireless communication system is provided. The method may further include receiving, from the terminal, a list request message including preamble information about a base station searched by a terminal among neighboring base stations of the serving base station, and a neighbor base station list request indicator indicating that the neighbor base station is requested. And transmitting a list response message including identification information and system information about the neighboring base station to the terminal.

When the terminal handovers from the macro cell to the femto cell (HO; hand-over), information about the neighbor base station for handover can be efficiently transmitted.

1 shows an embodiment of the proposed neighbor base station transmission method.

2 shows another embodiment of the proposed neighbor base station transmission method.

3 shows another embodiment of the proposed neighbor base station transmission method.

4 shows an embodiment of the proposed handover method.

5 is a block diagram illustrating a base station in which an embodiment of the present invention is implemented.

In step S100, the macro base station 110, which is a serving base station providing a service to the terminal, generates a broadcast message including a plurality of fragment broadcast messages, and transmits the broadcast message to the plurality of terminals. The method of transmitting to the plurality of terminals may be broadcast.

Each divided broadcast message included in the plurality of divided broadcast messages may include information about different neighbor base stations according to types of neighbor base stations, locations of neighbor base stations, or operating frequencies of neighbor base stations.

The information on the neighbor base station includes the same degree of information as the macro base station 110. When the neighbor base station is a femto base station, the broadcast message may include a parameter regarding a pattern of repeating the AI section and the UAI section when the femto base station operates in the LDO mode or the LDO mode. Since each divided broadcast message can be classified according to the type of neighboring base station, when the type of neighboring base station is divided into macro base station, micro base station, relay station, femto base station, etc. Can be generated. Therefore, when the neighbor base station includes the macro base station and the femto base station together, the neighbor base station information about the macro base station and the neighbor base station information about the femto base station may be included in different fragment broadcast messages in a broadcast message. Alternatively, each fragment broadcast message may be classified based on operating frequency or location information of neighboring base stations. For example, even if the type of the neighbor base station is the same as the femto base station, the information about the neighbor base station may be included in different fragment broadcast messages in the broadcast message according to the operating frequency or the location information.

Meanwhile, the broadcast message may be periodically transmitted by the macro base station. The plurality of split broadcast messages included in the broadcast message may be transmitted in a certain order. That is, all of the fragment broadcast messages included in the broadcast message are transmitted once within a predetermined period, and accordingly, a transmission period of the broadcast message may be set. Alternatively, a period may be set for each fragment broadcast message, and each fragment broadcast message may be transmitted to the terminal 120.

The terminal 120 receives at least one fragment broadcast message of the plurality of fragment broadcast messages transmitted by the macro base station. The at least one fragment broadcast message may include index information of the fragment broadcast message in the broadcast message. In addition, the broadcast message may include information on the number of split broadcast messages included in the broadcast message. Therefore, even when the terminal 120 fails to receive the broadcast message according to a channel environment in receiving the broadcast message, when the terminal 120 receives the divided broadcast message for the neighboring base station, it is possible to handover to the corresponding neighbor base station. . In addition, when the number of fragment broadcast messages is one, index information of the fragment broadcast message may be an ID of a corresponding neighbor base station.

In operation S110, the terminal 120 receiving at least one fragment broadcast message included in the broadcast message searches for a neighbor base station based on the information included in the fragment broadcast message.

The terminal 120 may search for neighboring base stations at a frequency at which the macro base station 110 operates. If the search for the neighbor base station fails at the corresponding frequency or if the search for the neighbor base station using a different frequency band is necessary, the terminal 120 may transmit a scanning request message requesting scanning for another specific frequency to the macro base station 110. have. The macro base station 110 may transmit a scanning response message in response to the scanning request of the terminal 120, and the terminal may search for neighbor base stations again based on information included in the scanning response message. The selection of a frequency for searching for a neighbor base station included in the scanning response message may be determined according to the information provided in the broadcast message.

Unlike the above, the terminal 120 may not receive the fragment broadcast message included in the broadcast message. In this case, as in the case where the neighbor base station search fails or when the search for another frequency band is necessary, the steps of transmitting the scanning request message and receiving the scanning response message are performed. In addition, the selection of a frequency to search may be determined according to the information provided in the broadcast message.

The search request message may include information on whether to receive the fragment broadcast message. In this case, the search request message may include index information of the received fragment broadcast message. If the broadcast message consists of one fragment broadcast message, the ID of the neighboring base station corresponding to the fragment broadcast message may be used as index information of the fragment broadcast message.

Even after transmitting / receiving a scanning request / response message, the procedure after performing neighbor base station search is the same as the general procedure of the present embodiment described below.

In step S120, the terminal 120 transmits the searched information of the femto base station and the neighbor BS list request indicator to the macro base station 110. Here, the neighbor base station list request indicator indicates that the terminal 120 requests list information about neighbor base stations located near the searched femto base station.

The searched femto base station information and neighbor base station list request indicator transmitted by the terminal 120 transmits a neighbor base station information request message (AAI_NBR-REQ) transmitted to request information about the neighbor base station, and the serving cell to scan the neighbor base station. A scanning request message AAI_SCN-REQ and a scanning report message AAI_SCN-REP transmitted to report the scanning result to the serving cell may be transmitted. In addition, when included in the message and transmitted, whether to receive part or all of the broadcast message may be additionally included in the message.

The transmitted femto base station information transmitted includes information on the type of the neighboring base station requesting, identifier information (preamble or BSID) of the retrieved femto base station, operating frequency (FA) information of the retrieved femto base station, and the downlink signal received from the retrieved femto base station. Quality and the like. The information about the type of the neighboring base station may be represented in the form of a bitmap indicating the type or type-specific information of the neighboring base station.

In step S130, the macro base station 110 transmits femto cell information around the terminal 120 in response to the searched femto base station information transmitted from the terminal 120 and the neighbor base station list request indicator. In this case, a list and a base station identifier (BSID) for neighboring femto base stations present in the neighboring femtocell may be included, and system information of the corresponding femto base station may also be included. In addition, when the neighboring base station operates in the LDO mode, it may include information about the LDO operation parameters of the base station.

Information of neighboring femtocells may be included in a broadcast message and transmitted, and in some cases, may be included in a fragment broadcast fragment message and transmitted. However, while the broadcast message transmitted in step S100 is transmitted by the broadcast method, the broadcast message of this step is transmitted to the terminal 120 by the unicast method. In addition, since the message is a message that is configured separately from the broadcast message of S100, index information indicating a specific fragment broadcast message included in S100 is not included.

The neighbor femto base station list of the surrounding femtocell information to be provided to the terminal 120 may be determined based on the location information of the terminal 120. The location information of the terminal 120 includes information on the femto base station searched by the terminal 120 (information on the type of neighboring base station requested, identifier information (preamble or BSID) of the searched femto base station, and the searched femto base station). Operating frequency (FA) information and downlink signal quality received from the searched femto base station, etc.) to the macro base station 110 upon request of a list of neighboring femto base stations can be obtained through the geographic information of the femtocell base stations known to the macro base station. have.

In step S140, the terminal 120 scans an appropriate femto base station to perform a handover of the neighbor femto base station based on the received peripheral femtocell information.

In step S150, when the appropriate femto base station is scanned, the terminal 120 transmits a handover request message requesting handover to the corresponding femto base station to the macro base station 110.

In step S160, the terminal 120 receives a handover instruction message according to the handover request message from the macro base station 110. The terminal 120 receiving the handover indication message performs a handover to the corresponding femto base station.

2 shows another embodiment of the proposed neighbor base station information transmission method.

In step S200, the macro base station 110 generates a broadcast message including a plurality of fragment broadcast messages, and transmits the broadcast messages to a plurality of terminals. Since this is the same as S100 of FIG. 1, a detailed description thereof will be omitted.

However, the terminal 220 may not receive the broadcast message according to the channel environment. In addition, the divided parts of the broadcast message including the information about the neighboring base station searched around may not be received yet. In this case, the terminal may request information on the neighboring base station from the macro base station 210. In this case, the terminal may directly search for a base station existing in the vicinity (S210) may provide information to the macro base station 120.

The terminal 220 transmits the found information of the femto base station and the neighbor BS list request indicator to the macro base station 210 (S220). In step S230, the macro base station 210 transmits femto cell information around the terminal 220 in response to the searched femto base station information transmitted from the terminal 220 and the neighbor base station list request indicator. In step S240, the terminal 220 scans an appropriate femto base station to perform a handover of the neighbor femto base station based on the received peripheral femtocell information. In step S250, when the appropriate femto base station is scanned, the terminal 220 transmits a handover request message requesting handover to the corresponding femto base station to the macro base station 210. In step S260, the terminal 220 receives a handover indication message according to the handover request message from the macro base station 210. The terminal 220 receiving the handover indication message performs a handover to the corresponding femto base station. Since S220 to S260 of the present embodiment are the same as S110 to S160 described above with reference to FIG. 1, detailed descriptions thereof will be omitted.

3 shows another embodiment of the proposed neighbor base station information transmission method.

In step S300, the macro base station 310 generates a broadcast message including a plurality of split broadcast messages, and transmits the broadcast message to a plurality of terminals. Each divided broadcast message included in the plurality of divided broadcast messages may include information about different neighbor base stations according to types of neighbor base stations, locations of neighbor base stations, or operating frequencies of neighbor base stations.

Unlike the embodiment of FIG. 1, the neighbor base station information includes limited information such as whether there is a neighbor base station in the frequency band in which the macro base station 310 operates and / or the number of neighbor base stations. The type of the neighboring base station, the operating frequency or the location information of the neighboring base station may be used as a reference for generating the fragment broadcast message. In addition, the broadcast message may be periodically transmitted. The plurality of split broadcast messages included in the broadcast message may be transmitted in a certain order.

In operation S310, the terminal 320 receives at least one fragment broadcast message included in the broadcast message and searches for a neighbor base station accordingly.

In step S320, the terminal 120 transmits the retrieved information of the femto base station and the neighbor BS list request indicator to the macro base station 310. Here, the neighbor base station list request indicator indicates that the terminal 320 requests list information about neighbor base stations existing near the searched femto base station.

The transmitted femto base station information transmitted includes information on the type of neighboring base station requesting, identifier information (preamble or BSID) of the retrieved femto base station, operating frequency (FA) information of the retrieved femto base station, and the downlink signal received from the retrieved femto base station. Quality and the like. The information about the type of the neighboring base station may be represented in the form of a bitmap indicating the type or type-specific information of the neighboring base station.

The searched femto base station information and neighbor base station list request indicator transmitted by the terminal 320 are included in a neighbor base station information request message (AAI_NBR-REQ), a scanning request message (AAI_SCN-REQ), and a scanning report message (AAI_SCN-REP). Can be sent. In addition, when included in the message and transmitted, whether to receive part or all of the broadcast message may be additionally included in the message.

In operation S330, the macro base station 310 transmits femto cell information around the terminal 120 in response to the searched femto base station information transmitted by the terminal 320 and the neighbor base station list request indicator. However, according to the message type transmitted from the terminal 320 to the macro base station 310 in S320, the method of transmitting the surrounding femtocell information may be different.

If the message transmitted by the terminal 320 is the neighbor base station information request message (AAI_NBR-REQ), the macro base station 310 first checks the neighbor base station type requested by the terminal 320 and then optimizes the neighboring base station around the terminal 320. Transmits femtocell information including the information. In this case, the neighbor femtocell information may be transmitted in a neighbor base station information response message (AAI_NBR-RSP).

If the message transmitted from the terminal 320 is a scanning request message (AAI_SCN-REQ), it is first checked whether a neighbor base station list request indicator exists in the scanning request message. If there is an indicator, the scanning response message (AAI_NBR-RSP) may be transmitted to the neighboring base station corresponding to the requested neighbor base station type as the scanning target base station.

If the message transmitted from the terminal 320 is a scanning report message (AAI_SCN-REP), the handover may be instructed to the femto base station searched immediately according to the report information of the terminal. In this case, the peripheral femtocell information is not provided. However, when the neighbor base station list request indicator exists, the neighbor femtocell information may be transmitted. The information of the neighbor femtocell may be included in the broadcast message or the broadcast split message and transmitted. However, while the broadcast message transmitted in step S300 is transmitted by the broadcast method, the broadcast message of this step is transmitted to the terminal 320 by the unicast method.

When the neighbor femtocell information is transmitted in step S330, the list and the base station identifier (BSID) for the neighbor femto base station existing in the neighbor femtocell may be included, and may also include the system information (system information) of the corresponding femto base station. In addition, when the neighboring base station operates in the LDO mode, it may include information about the LDO operation parameters of the base station.

The list of neighbor femto base stations of the neighbor femtocell to be provided to the terminal 320 may be determined based on the location information of the terminal 320. The location information of the terminal 320 is information on the femto base station searched for by the terminal 320 (information on the type of the neighboring base station requested, the identifier information (preamble or BSID) of the found femto base station, and the searched femto base station). Operating frequency (FA) information and downlink signal quality received from the searched femto base station, etc.) when providing a list of neighboring femto base stations to the macro base station 310, the geographic information of the femtocell base stations already known to the macro base station 310 You can get it through

In operation S340, the terminal 320 scans an appropriate femto base station to perform handover among neighbor base stations based on the received neighbor femtocell information.

In step S350, when the appropriate femto base station is scanned, the terminal 320 transmits a handover request message for requesting handover to the corresponding femto base station to the macro base station 310.

In step S360, the terminal 320 receives a handover indication message according to the handover request message from the macro base station 310. Upon receiving the handover indication message, the terminal 320 performs a handover to the corresponding femto base station.

In the above-described embodiment with reference to FIGS. 1 to 3, the closed subscriber group in which the femto base station found in steps S110, S210, and S310 searches for neighboring base stations by the terminal is permitted to access only to a limited user. If the CSG is a Closed Subscriber Group and the requested UE is included in the group, the UE changes the serving base station to the corresponding searched femto base station through a handover procedure and receives neighboring femtocell information from the searched femto base station serving as a serving base station. You can do that. On the other hand, if the searched femto base station is included in the open subscriber group (OSG; Open Subscriber Group) without the access restriction of the terminal, the information about the neighbor base station can be requested through a message including the searched femto base station information and the neighbor base station list request indicator have. The serving base station may check the neighbor base station information request through the presence of the neighbor base station list request indicator and provide the neighbor femtocell information to the terminal. The peripheral femtocell information may include information provided in the above-described embodiment of FIGS. 1 to 3.

4 shows an embodiment of the proposed handover method.

In step S400, the terminal receives at least one fragment broadcast message included in the broadcast message from the macro base station. The at least one fragment broadcast message includes information about a neighbor base station. In addition, each fragment broadcast message included in the at least one fragment broadcast message includes information about neighbor stations different from each other according to the type of the neighbor base station, the location of the neighbor base station, or the operating frequency of the neighbor base station.

In step S401, the terminal searches for neighbor base stations based on the information included in the fragment broadcast message included in the received fragment broadcast message.

If the neighboring base station exists (402a), the searched femto base station determines whether the femto base station belonging to the CSG to which only the restricted terminal is accessible and accessible (S408).

If there is no neighbor femto base station as a result of the search (S402b) and there is a neighbor base station of a band different from the operating frequency at which the macro base station operates (S403a), the UE transmits a search request message to the macro base station in step S404, and the frequency band The scanning request message, which is a message requesting scanning of another neighboring base station, is transmitted (S404). The scanning response message may be received in response to the scanning request (S405), and the neighboring base stations may be searched again based on the information included in the scanning response message (S406). If there is a neighboring base station, it is determined whether the searched femto base station is a femto base station belonging to the accessible CSG (S408). If the neighbor base station does not exist, the process returns to the step of searching whether there is a neighbor base station using the frequency of the macro base station (S407b).

If the retrieved femto base station is a femto base station belonging to the accessible CSG and is accessible (S408a), the process proceeds to determining a target base station to be handed over (S412).

If the searched femto base station is not a femto base station belonging to the accessible CSG (S408b), and the terminal transmits a message including an indicator requesting a list of neighbor base stations to the macro base station, the terminal receives information on the surrounding femtocell from the macro base station; (S410) The appropriate target base station to be handed over is scanned (S411).

When the terminal transmits a message including an indicator for requesting a list of neighboring base stations, the information of the femto base station and the reception of some or all of the broadcast message may be additionally included in the message.

A list and base station identifier (BSID) for neighboring femto base stations present in the neighboring femtocell may be included, and system information of the corresponding femto base station may also be included. In addition, when the neighboring base station operates in the LDO mode, it may include information about the LDO operation parameters of the base station.

The information of the neighbor femtocell may be included in the broadcast message or the broadcast split message and transmitted. However, while the broadcast message received at S400 is transmitted by the broadcast method, the broadcast message of this step is transmitted to the terminal by the unicast method. In addition, since the corresponding message is a message configured separately from the broadcast message of S400, index information indicating a specific fragment broadcast message included in S400 is not included.

On the other hand, if the terminal does not request the neighbor base station list, and performs the step of determining the target base station for handover (S412).

After determining the handover target base station, a handover request message for requesting handover to the corresponding femto base station is transmitted to the macro base station (S413), and a handover instruction message according to the handover request message is received from the macro base station (S415). . Thereafter, the terminal performs handover to the corresponding femto base station (S415).

In the above, various embodiments of the present invention have been described with reference to FIGS. 1 to 4. In the description, the macro base station (110, 210, 310) as a serving base station for providing a service to the terminal, but the scope of the present invention is not limited to this, for example, may be a femto base station. In addition, the terminals 120, 220, and 320 may search for neighboring femto base stations as well as neighboring macro base stations as handover targets (S110, S210, S310) or scan (S140, S240, S340).

5 is a block diagram illustrating a base station in which an embodiment of the present invention is implemented. The base station 500 includes a processor 510, a memory 520, and a radio frequency unit 530.

Referring to FIG. 5, the processor 510 implements the proposed functions, processes, and / or methods. The processor 510 generates a broadcast message including a plurality of fragment broadcast messages, and transmits the broadcast message to a plurality of terminals, wherein each fragment broadcast message included in the plurality of fragment broadcast messages is a type of a neighboring base station. The information about the neighboring base station may be included according to the location of the neighboring base station or the operating frequency of the neighboring base station. Layers of the air interface protocol may be implemented by the processor 510. The memory 520 is connected to the processor 510 and stores various information for driving the processor 510. The RF unit 530 is connected to the processor 510 to transmit and / or receive a radio signal.

The processor 510 may include an application-specific integrated circuit (ASIC), another chipset, a logic circuit, and / or a data processing device. The memory 520 may include a read-only memory (ROM), a random access memory (RAM), a flash memory, a memory card, a storage medium, and / or another storage device. The RF unit 530 may include a baseband circuit for processing a radio signal. When the embodiment is implemented in software, the above-described technique may be implemented as a module (process, function, etc.) for performing the above-described function. The module may be stored in the memory 520 and executed by the processor 510. The memory 520 may be inside or outside the processor 510 and may be connected to the processor 510 by various well-known means.

All of the above functions may be performed by a processor such as a microprocessor, a controller, a microcontroller, an application specific integrated circuit (ASIC), or the like according to software or program code coded to perform the function. The design, development and implementation of the code will be apparent to those skilled in the art based on the description of the present invention.

Although the present invention has been described above with reference to the embodiments, it will be understood by those skilled in the art that the present invention may be modified and changed in various ways without departing from the spirit and scope of the present invention. I can understand. Therefore, the present invention is not limited to the above-described embodiment, and the present invention will include all embodiments within the scope of the following claims.

Claims

A method for requesting neighboring base station information by a terminal in a wireless communication system, the method comprising: searching for neighboring base stations targeted for handover of the terminal; preamble information about the base station found by the terminal among the neighboring base stations; Transmitting a list request message including a neighbor base station list request indicator indicating a request for information on the neighbor base station, to a serving base station; And receiving, from the serving base station, a list response message including identification information and system information about the neighbor base station.
The method of claim 1, wherein the list response message is a unicast message transmitted to the terminal through a dedicated channel.
The method of claim 1, wherein the list request message is a MAC message for requesting the serving base station to search for the neighbor base station.
The method of claim 1, wherein the list request message is a MAC message for requesting identification information and system information about the neighbor base station.
The method of claim 1, wherein the list request message is a MAC message for reporting a search result of the neighbor base station to the serving base station.
The method of claim 1, wherein the serving base station is a macro base station.
The method of claim 1, further comprising receiving a broadcast message from the serving base station including the type, frequency of use, and location information of the neighboring base station before searching for the neighboring base station. How to request.
The method of claim 1, wherein the terminal performs a handover to any one of the neighbor base stations.
A method of transmitting neighbor base station information by a serving base station in a wireless communication system, the neighbor base station list indicating preamble information about a base station retrieved by a terminal among neighbor base stations of the serving base station and requesting information about the neighbor base station Receiving a list request message including a request indicator from the terminal; And transmitting a list response message including identification information and system information about the neighbor base station to the terminal.