WO2015108317A1

WO2015108317A1 - Method and apparatus for cooperation between base stations

Info

Publication number: WO2015108317A1
Application number: PCT/KR2015/000342
Authority: WO
Inventors: 원성환; 조성연
Original assignee: 삼성전자 주식회사
Priority date: 2014-01-16
Filing date: 2015-01-13
Publication date: 2015-07-23

Abstract

The present invention relates to a method and apparatus for eliminating and improving issues that can occur during the execution of the cooperation between base stations in a wireless communication. The method comprises the steps of: identifying whether at least one cell among cells belonging to a counterpart base station is located in the vicinity of a base station; determining, according to a result of the identifying, whether to include information on a neighboring cell in a base station-related message; and transmitting the base station-related message to the counterpart base station according to the determination.

Description

Method and apparatus for cooperation between base stations

The present invention relates to a method and an apparatus for solving and improving an issue that may occur when performing cooperation between base stations in a wireless communication system.

Wireless communication systems have been developed to provide communication services while ensuring user mobility. To this end, the wireless communication system adopts the concept of a cell, divides the actual space into cells, which are virtual zones, and transmits radio waves of appropriate strength so that the base station and the terminal can communicate with each other. Through the telecommunications service provided.

Due to the nature of the propagation, edges of cells relatively far from the source of propagation are exposed to small-wave propagation and are affected by neighboring cells and thus cannot provide an ideal service environment. This phenomenon is called interference of neighboring cells. In addition, as the cell layout becomes more diversified, for example, small cells may be built in a cell having a relatively large size, and the interference environment is gradually diversified.

In order to better handle the diversified interference environment and provide a better service environment to users, a wireless communication system based on cooperation between various cells is introduced. Carrier Aggregation (CA) technology and Coordinated Multi-Point Transmission and Reception (CoMP) technology, covered by the 3rd Generation Partnership Project (3GPP), An example of a technique for implementing a wireless communication system.

In order to cooperate between cells belonging to different base stations, information about cells may need to be exchanged between base stations. The exchange of cell information between base stations may be through an interface that is directly connected between the base stations or through multiple interfaces through at least one other entity.

As the number of cells and base stations participating in cooperation between cells, and also between base stations, increases, one base station may know more information about cells of another base station. Among these, a cell identifier designed to easily identify each cell has a limited allocation range, which may cause confusion when one base station learns more information about a cell of another base station.

In the present specification, the base station includes an evolved Node B (eNB), a Node B (NB), or a Radio Network Subsystem (RNS) including the same, a Base Transceiver Station (BTS). Or a base station subsystem (BSS), a home eNB, a home NB, a home eNB gateway (GW: gateway), or an X2 GW including the same.

In addition, the base station may be composed of one or more cells. The base station means an apparatus for managing and controlling a cell, but in the present specification, a cell and a base station may be used for convenience.

Provided are an apparatus and a method for resolving confusion of a cell identifier when different cells having the same cell identifier are around. Provided are an apparatus and a method for a base station to report resource utilization to a central entity. An apparatus and method are provided for negotiating a Stream Control Transmission Protocol (SCTP) mode between a central entity and a base station that exchange information in a short period.

According to an embodiment of the present invention, a method of transmitting a base station related message to a peer base station by a base station includes: identifying whether at least one cell among cells belonging to the base station is in the vicinity of the base station; And determining whether to include information about the neighbor cell in the base station related message according to the result of the checking, and transmitting the base station related message to the counterpart base station according to the determination.

In the base station for transmitting a base station related message to a peer base station according to an embodiment of the present invention, at least one cell of an interface unit for communicating with the base station and a cell belonging to the base station is located around the base station. And a control unit for determining whether to include information about a neighbor cell in the base station related message according to the identification result, and controlling to transmit the base station related message to the corresponding base station according to the determination. It is characterized by including.

In a method for allocating resources to a terminal by a base station according to an embodiment of the present invention, exchanging resource allocation information with a central entity, and receiving a channel measurement result from the terminal, the central information includes information that may be considered for scheduling. Reporting to the entity and if the resource for data transmission is allocated from the central entity, performing resource allocation to the terminal for data transmission.

According to an embodiment of the present invention, a base station for allocating resources to a terminal exchanges resource allocation information with an interface unit for communicating with a terminal or a central entity and the central entity, and receives a report of channel measurement results from the terminal for scheduling. And a controller for reporting information that may be considered to the central entity, and if the resource for data transmission is allocated from the central entity, to perform resource allocation to the terminal.

According to an embodiment of the present invention, the peer base station can efficiently perform the PCI confusion mechanism by differently adjusting the information of the cell in the base station and / or information on the neighbor cell of the cell in the base station. According to another embodiment of the present invention, the central entity may receive a report on the resource utilization status from the base station. According to another embodiment of the present invention, when a base station establishes a connection with another base station based on transport layer (TL) information received from a node of a core network, it is based on a certain mode of SCTP or a TL protocol. You can decide whether to make a connection.

1 is a diagram illustrating an entity including a base station for linkage between base stations and connections between the entities.

2 is a diagram illustrating various forms of a connection between a base station and a central entity.

3 is a flowchart illustrating a process of exchanging information between base stations.

4 is a block diagram of modification of a message sent to a counterpart base station.

5 is a flowchart of a message for resource allocation.

6 is a flowchart illustrating information exchange between a base station and an EPC.

7 is a configuration diagram of a base station 100 according to an embodiment of the present invention.

8 is a configuration diagram of a node of a core network according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. At this time, it should be noted that the same components in the accompanying drawings are represented by the same reference numerals as possible. In addition, detailed descriptions of well-known functions and configurations that may blur the gist of the present invention will be omitted.

In addition, in the embodiments of the present invention, 3GPP will mainly target long-term evolution (LTE) and evolved packet core (EPC), which are core wireless access networks and core networks. The main subject matter of the present specification may be applied to other communication systems having a similar technical background with a slight modification without departing from the scope of the present specification, which has a technical skill that is skilled in the art of the present specification. It will be possible in his judgment.

The cooperation between the base stations may be performed by each base station in a distributed way or a centralized way. In order for cooperation between base stations to be meaningful, each base station must operate according to a predetermined rule. If the base station operates according to its own rules and other rules, cooperation may become meaningless. In this respect, centralized collaboration, which is relatively easy to coordinate to work in a set rule, can help to achieve better performance. In this specification, the centralized method will be taken as the main consideration. On the other hand, it will be apparent to those skilled in the art of the present disclosure that reducing the base station participating in the centralized method, and taking the cooperation of the centralized method in multiple ways may be a distributed method.

Referring to FIG. 1, each base station 100 has a unique coverage 105. Here, the coverage 105 may be defined as an area in which one or more cells belonging to the base station 100 may provide a service with a predetermined level or more. The base stations 100 may be connected through the X2-C interface 120. In addition, when the base station 100 cooperates in a centralized manner, the central entity 110 may be connected to various base stations 100 through a specific interface 130. In the present specification, for convenience, the specific interface 130 will be referred to as a C1 interface.

In FIG. 1, for convenience, each base station 100 has coverage 105 having the same size and shape, but each base station 100 may have coverage 105 having various different sizes and shapes. The overlapping coverage 105 of each base station 100 may also vary. For example, the coverage 105 of one base station 100 may all be included in the coverage 105 of another base station 100.

2 is a diagram illustrating various forms of the connection between the base station 100 and the central entity 110.

The connection shown in FIG. 1 follows FIG. 2- (a). In addition, the connection between the central entity 110 and the base station 100 may have various forms, which are illustrated in FIGS. 2- (b) and 2- (c). Since the central entity 110 and the base station 100 are logical entities performing specific functions, various locations may be physically selected.

Referring to FIG. 2- (b), the central entity 110 may be located inside the base station 100a. In order for the central entity 110 to perform an appropriate function, the base station 100a may transfer information received from the other base station 100b through the X2 interface 120 to the central entity 110. In addition, the central entity 110 may transmit information to the other base station 100b through the base station 100a. The information may have the form of an information element (IE).

Referring to FIG. 2- (c), the central entity 110 may be located inside the base station 100a as shown in FIG. 2- (b). However, the difference is that in FIG. 2- (c), the C1 interface 130 is defined between the central entity 110 and the other base station 100b, so that necessary information can be directly transmitted and received.

The central entity 110 or the base station 100 may perform at least one or more of the following functions:

Collecting information that may be considered for scheduling from one or more base stations;

Resource allocation for data transmission by base station using collected information;

Resource allocation for data transmission by cell using the collected information;

Resource allocation for data transmission for each terminal using the collected information;

Conveying resource allocation information to one or more base stations;

-Selection of base stations and / or cell sets to cooperate;

Resource allocation for transmitting a reference signal (RS: Reference Signal, for example, CRS: Common Reference signal / CSI-RS: Channel State Information RS / DMRS: Demodulation RS / SRS: Sounding RS) to the base station.

When the base station 100 performs at least one or more of the above functions, it may be said that the central entity 110 exists inside the base station 100.

When the central entity 110 exists inside the base station 100a, the base station 100a serving as the central entity 110 may be determined through a network configuration. In addition, the general base station 100b that does not serve as the central entity 110 may also be determined through network configuration. Alternatively, the base station 100a and the general base station 100b serving as the central entity 110 may be set by an operation / administration / maintenance (OAM) responsible entity. In addition, the general base station 100b may acquire transmission address information on the base station 100a serving as the central entity 110 through a method through OAM or network setting.

셀 식별자 혼동 이슈(cell identifier confusion)Cell identifier confusion

3 is a flowchart illustrating a process of exchanging information between base stations 100.

Referring to FIG. 3, the base station 100 may exchange information about each of the base stations 100 by exchanging (transmitting and receiving) messages. Here, it is preferable to understand that the base station 100a and the other base station 100b are not to distinguish whether the central entity 110 is included but to indicate that the base station 100a is different from each other.

In step 310, the base station 100a may send a message to the other base station 100b. The message may be an X2 SETUP REQUEST message and / or an ENB CONFIGURATION UPDATE message. In addition, the message is a cell global identifier (CGI: Cell Global Identifier, ECGI in case of LTE) and a physical identifier (PCI: Physical Cell Identifier) of the cell belonging to the base station (100a), the CGI of the neighbor cell of the cell belonging to the base station (100a) and It may include at least one of the PCI.

In step 320, the base station 100b may send a response message. The message may be an X2 SETUP RESPONSE message or an ENB CONFIGURATION UPDATE ACKNOWLEDGE message. The message may include at least one of CGI and PCI belonging to the base station 100b and CGI and PCI of the neighbor cell of the cell belonging to the base station 100b.

The base station 100 uses a PCI confusion using PCI of a cell belonging to a counterpart base station and / or a neighbor cell of a cell belonging to a counterpart base station obtained through an X2 setup process and / or an eNB configuration update process. Mechanism to solve the

In general, the information collected by the base station 100a through

steps

310 and 320 is information about the base station 100b in the vicinity of the base station 100a. Therefore, a mechanism for resolving PCI confusion may be performed using information obtained through the X2 Setup process and / or the eNB Configuration Update process.

For reference, the PCI may correspond to one of integers from 0 to 503 and may be used to easily identify a cell between the base station 100 and the terminal. Since the PCI may include only 504 types of identifiers, different cells may have the same PCI among cells operated by one operator. If different cells with the same PCI are in the periphery, PCI confusion can arise.

Meanwhile, the central entity 110 may be directly or indirectly connected to a base station 100 located far away from the base station 100 as well as to a geographically neighboring or near base station 100, regardless of whether the central entity 110 is located inside the base station 100. Here, the fact that an entity A is located far from an entity B can be interpreted in various ways. According to an embodiment of the present invention, the fact that an entity A is located far from an entity B means that the terminal serving from the cell / base station to which the entity B belongs does not recognize the entity B and / or the entity A belongs to. This may mean that the terminal serving from the cell / base station is located where the entity A cannot be recognized.

The exchange of information between the base stations 100 and the connection between the central entity 110 and the far-located base station 100 have been described. If the central entity 110 exists inside the base station 100a (FIGS. 2- (b) and 2- (c)) or the central entity 110 exists inside the base station 100a and another base station 100b is present. In the case where the connection between the central entity 110 and the central entity 110 is not made separately (FIG. 2- (c)), the base station 100a is not only information about the base station 100b located nearby but also the base station 100b located far from the base station 100a. You can also collect information about. The collected information may include at least one of CGI and PCI of a cell belonging to the base station 100b, and CGI and PCI of a neighbor cell of a cell belonging to the base station 100b.

Therefore, there may occur a case where the base station 100a attempts to resolve the PCI confusion using information received from another base station 100b not in the vicinity. Resolving the information received from the base station 100b far away from the base station 100a to the PCI confusion may be inefficient in that it considers even a cell that does not need to consider the PCI confusion.

The base station 100b may also receive information from the base station 100a in which the central entity 110 is embedded. Since the base station 100a performs the role of the central entity 110, the base station 100a may establish an X2 connection with a relatively large number of base stations. Therefore, considering the PCI confusion using the information received from the base station 100a, the base station 100b may be PCI. Even cells that do not need to be confused can be considered inefficient. If there are more than hundred base stations connected to the base station 100a, there may be no way to avoid PCI confusion because there are only 504 types of PCI.

In order to solve the above problem, the neighbor base station / cell list management method, the X2 Setup process and / or eNB configuration update process of the base station 100 can be changed as follows.

When the base station 100 transmits information about the neighbor cell, for example, during the X2 Setup process and / or the eNB Configuration Update process, the base station 100 may be determined according to which base station the peer base station is. 100) may be transmitted by adjusting the information about the neighbor cell of the cell in the cell and / or the base station 100 differently. This allows the base station to efficiently perform the PCI confusion mechanism. In other words, it is possible to prevent the base station from applying the PCI confusion mechanism, including unnecessary PCI.

The base station 100 may manage at least one list of the following:

A list of base stations connected via X2;

A list of cells belonging to a base station connected via X2;

A list of cells which have reported (measurement related information) from the terminal;

A list of cells of the other base station from which the base station 100 has received the relevant information;

A list of cells configured by network setup, OAM and / or various other methods;

A list of cells belonging to a neighbor relation table (NRT);

A list of cells generated according to other neighbor management methods performed at the base station 100 without considering the central entity 110.

Two or more of the above items may be managed together.

During the X2 Setup process and / or the eNB Configuration Update process, the base station 100 neighbors the base station 100 with respect to the base station that does not include a cell belonging to the cell list in the vicinity of the base station 100. Information about the cell may not be sent. The base station 100 may transmit information about the cell list in the vicinity of the base station 100 to the base station including a cell belonging to the cell list in the vicinity of the base station 100.

The information about the cell list in the vicinity of the base station 100 may include at least one of a list that can be managed by the base station 100. For example, the information on the cell list in the vicinity of the base station 100, the cell list reported by the base station 100 from the terminal, the cell list of the other base station that the base station 100 heard the related information, and network settings, It may include at least one of a cell list set by OAM and / or various other methods. Alternatively, a new attribute --- for example, Cells nearby --- may be created in a neighbor relationship table (NRT), so that the cell whose attribute is checked may be regarded as a cell around the base station 100. According to the list management method of the base station 100 described above, each base station (manufacturer, release version) can encompass the definition of different "cells around". For example, according to the list management method of the base station 100 described above, the cell list in the vicinity of the base station 100 / cell corresponds to the cell list considered when the base station 100 / cell sets a parameter called NeighCellConfig can do.

In step 400, the base station 100 may be in a situation in which neighboring cell information may be sent to another base station. The situation may mean a situation in which at least one of an X2 SETUP REQUEST message, an X2 SETUP RESPONSE message, and an ENB CONFIGURAION UPDATE message are sent. In the present specification and claims, the messages may be referred to as a base station related message or an eNB related message. The process may proceed to step 410.

In step 410, the base station 100 may check whether at least one cell among the cells belonging to the peer base station is included in the cell list around the base station 100. If at least one of the cells belonging to the other base station is included in the cell list around the base station 100, the process may proceed to step 430, and if not, to step 420.

In step 420, if the base station 100 determines that the other base station is not in the vicinity of the base station 100, the base station 100 may not include information about the neighbor cell in the message sent to the other base station. In other words, the neighbor information IE may be left empty. The process may then proceed to step 440.

In step 430, if the base station 100 determines that the other base station is in the vicinity of the base station 100, the base station 100 may include information about the neighbor cell in the message sent to the other base station. In this case, the information on the neighbor cell may include at least one of CGI, PCI, frequency band information, and tracking area code of a cell belonging to a cell list in the vicinity of the base station 100. Information on the neighboring cells may be communicated by including the surrounding information (Neighbour Information) IE. The process may then proceed to step 440.

In step 440, the base station 100 may send at least one of an X2 SETUP REQUEST message, an X2 SETUP RESPONSE message, and an ENB CONFIGURAION UPDATE message to the counterpart base station. .

자원 활용 현황 미보고 이슈(reporting status of resource utilization)Reporting status of resource utilization

The central entity 110 may receive information that may be considered for scheduling from the base station 100 and allocate a resource for data transmission to the base station 100.

Information that may be considered for scheduling may include the channel situation of each terminal. To this end, the base station 100 may allocate a resource for transmitting the RS. When the resource is allocated to transmit the RS, the UE can measure the RS or transmit the RS (in the case of SRS) in the corresponding resource. In order for the central entity 110 to allocate a resource for RS and / or data transmission, information about whether the resource is suitable for use may be needed.

Not all resources may be available for RS and / or data transmission. In this case, it may be necessary to inform the central entity 110 which resources are used or how less detailed, and which resources can be used.

5 is a flowchart of a message for resource allocation.

In step 510, the base station 100 and the central entity 110 may exchange resource utilization status information. In the present specification and claims, resource utilization status information may be used as the same as resource allocation information. The information can be exchanged via the X2 interface or the C1 interface, for example, according to the various schemes shown in FIG. The base station 100 may inform the central entity 110 through the X2 or C1 message of information on what purpose a particular resource is being used. The information may have a form for notifying which purpose is used for at least one of a specific resource block (RB), an RB group (RBG), a subframe, and a radio frame. have. The use includes at least one of broadcasting (MBMS: Multimedia Broadcast / Multicast Service), relay, time domain inter-cell interference coordination (TD-ICIC), and frequency domain inter-cell interference coordination (FD-ICIC). It may refer to one. In addition, the information notified by the base station 100 to the central entity 110 may include information related to semi-persistent scheduling (SPS) when the base station 100 allocates resources semi-permanently to the terminal.

MBMS related resource utilization status information can be provided according to Table 1. The base station 100 may send information on whether or not the corresponding subframe is in use together with information indicating subframe information configured for MBMS. For example, it can send information indicating whether or not each MBMS Single Frequency Network (MBSFN) subframe allocation setting is in use, or send MBSFN region identifier allocated for each MBSFN subframe allocation setting to indicate whether or not it is used. have.

Example of configuring resource utilization information

Table 1

■ IE / Group Name	Presence	Range	IE type and reference	Criticality	Assigned Criticality
■ MBSFN Subframe Info		0 .. < maxnoofMBSFN >		GLOBAL	ignore
■ > Radioframe Allocation Period	M		ENUMERATED (n1, n2, n4, n8, n16, n32, ...)	-	-
■ > Radioframe Allocation Offset	M		INTEGER (0..7, ...)	-	-
■ > Subframe Allocation	M			-	-
■ > MBSFN Subframe Under Use	O		ENUMERATED (Under Use, Not Under Use, ...)
■> MBSFN Area ID	0		INTEGER (0..255)

The central entity 110 may exchange resource utilization status information with the MBMS-GW or the multi-cell / multicast coordination entity (MCE) as well as the base station 100. For example, the information notified by the base station 100 to the central entity 110 may be informed by the MBMS-GW or the multi-cell / multicast coordination entity (MCE) to the central entity 110. .

In operation 520, the central entity 110 may send a message for allocating RS resources to the base station 100. In step 525, the base station 100 may actually allocate RS resources to the terminal 500. In

operation

520 or 525, at least one of the central entity 110 and the base station 100 may consider resource utilization status information exchanged in operation 510. For example, a subframe used as an MBMS may not be allocated to an RS resource.

In step 530, the terminal 500 may measure RS or transmit RS (in case of SRS) through the allocated resources. In addition, the terminal 500 may report the result of measuring the RS to the base station 100. In step 540, the base station 100 may report to the central entity 110 information that may be considered for scheduling, including the measurement result reported from the terminal 500.

In operation 550, the central entity 110 may allocate a resource for data transmission based on the information collected from the base station 100. In this case, the central entity 110 may perform resource allocation in consideration of resource utilization status information. For example, a subframe used as an MBMS can be prevented from being allocated as a resource for data transmission.

In operation 560, the central entity 110 notifies the base station 100 of the resource allocation result for data transmission, and the base station 100 may additionally perform resource allocation for the data transmission to the terminal 500. The resource allocation result for data transmission may correspond to a coordinated multi-point hypothesis.

Due to the change in the MBMS scheduling information, the base station 100 may change the resource utilization status information related to MBMS at once, and as a result, the information may be transmitted to the central entity 110 at once. In this case, since a heavy load may be applied to the central entity 110, only some base stations 100 / cells in one MBSFN region and / or MBMS service region may be configured to send MBMS related resource utilization status information to prevent this. have.

잦은 데이터 전송 이슈(frequent data transmission)Frequent Data Transmission

Since the scheduling needs to take into account the channel situation of the terminal 500 that changes momentarily, the central entity 110 and the base station 100 may exchange information with a short period. For example, the messages used in

steps

540 and 560 may have to be sent at intervals of 1 ms to several ms.

The X2 interface uses the Stream Control Transmission Protocol (SCTP) in the Transport Layer (TL). A typical SCTP is appropriate for accuracy but may not be suitable for data transmission over short time intervals. Therefore, when data exchange is performed between the base station 100 and the central entity 110 through the X2 interface, it may be necessary to use a special mode of SCTP.

With normal SCTP, data is retransmitted when it is not sent correctly. However, it may be appropriate to use an unreliable data transmission mode that does not perform retransmission even when there is a problem in data transmission between the base station 100 and the central entity 110.

Accordingly, the base station 100 uses a general SCTP with a certain base station, and an unreliable data mode SCTP (unreliable data mode SCTP) with another base station (for example, a base station in which the central entity 110 is embedded). Can be used. To this end, a procedure for negotiating an SCTP mode between base stations may be required.

In operation 610, the base station 100a may request information from the EPC 600 to establish a connection with another base station 100b through the X2 interface 120. The information request may mean a message for requesting TL information for another base station 100b. At this time, an eNB CONFIGURATION TRANSFER message may be used. More specifically, the EPC 600 may refer to a mobile management entity (MME). The request message may also be transferred between MMEs.

In operation 615, the EPC 600 may transmit an MME CONFIGURATION TRANSFER message to the other base station 100b to inform the other base station 100b that the base station 100a requests TL information. In response, the base station 100b may transmit the TL information to the EPC 600 in step 620 by putting the TL information in an eNB CONFIGURATION TRANSFER message. The TL information may include at least one selected from a TL address, an SCTP mode, and a TL protocol (SCTP, User Datagram Protocol (UDP)). The TL information may be transferred from one MME to another MME in the EPC 600. Table 2 shows an example of TL information configuration.

TABLE 2

■ IE / Group Name	Presence	Range	IE type and reference	Criticality	Assigned Criticality
■ eNB X2 Transport Layer Addresses		1 .. <maxnoofeNBX2TLAs>
■ > Transport Layer Address	M		BIT STRING (1..160, ...)
■ eNB X2 Extended Transport Layer Addresses		1 .. <maxnoofeNBX2ExtTLAs>		YES	ignore
■ > IP-Sec Transport Layer Address	O		BIT STRING (1..160, ...)	-	-
■> eNB GTP Transport Layer Addresses		1 .. <maxnoofeNBX2GTPTLAs>		-	-
■ >> GTPTransport Layer Address	M		BIT STRING (1..160, ...)	-	-
■ eNB X2 Transport Layer Protocol Mode	O		ENUMERATED (Reliable, Unreliable, ...)
■ eNB X2 Transport Layer Protocol	O		ENUMERATED (SCTP, UDP, ...)

In step 625, the EPC 600 may send an MME CONFIGURATION TRANSFER message to the base station 100a. The message may include TL information.

When the base station 100a makes a connection with another base station 100b based on the TL information received from the EPC 600, the base station 100a may determine which mode of SCTP or which TL protocol to make a connection with. In step 650, the base station 100a may send the selected TL information through the X2 Setup and / or eNB Configuration Update process.

Referring to FIG. 7, the base station 100 may include a configuration of an interface unit 710, a controller 720, and a storage unit 730.

The interface unit 710 may communicate with another base station, a central entity, or a terminal under the control of the controller 720. The communication may include both wired communication and wireless communication. The interface unit 710 may include an X2 interface 120 or a C1 interface.

The controller 720 identifies whether at least one cell among the cells belonging to the peer base station is in the vicinity of the base station, and determines whether to include information about the neighbor cell in the base station related message according to the result of the checking. The base station may control the base station related message to be transmitted to the counter base station according to the determination. The controller 720 may determine whether at least one cell among the cells belonging to the counterpart base station is included in the neighbor cell list held by the base station. If the controller 720 determines that at least one of the cells belonging to the counterpart base station is around the base station, the controller 720 may include information about the neighbor cell in the base station related message. If the controller 720 determines that at least one of the cells belonging to the counterpart base station is not around the base station, the controller 720 may not include information about the neighbor cell in the base station related message. The base station related message may include at least one of an X2 SETUP REQUEST message, an X2 SETUP RESPONSE message, and an ENB CONFIGURAION UPDATE message.

When the controller 720 exchanges resource allocation information with the central entity, reports the channel measurement result from the terminal, reports the information that may be considered for scheduling to the central entity, and when the resource for data transmission is allocated from the central entity. It may be controlled to perform resource allocation for data transmission to the terminal. Before receiving the channel measurement result from the terminal, the controller 720 may allocate an RS resource to the terminal based on the allocation information of the RS resource received from the central entity. The controller 720 may request information from the central entity through a node of the core network in order to exchange data with the central entity through the X2 interface.

The storage unit 730 may store information received from another base station, a central entity, a terminal, or a node of the core network.

Referring to FIG. 7, the base station 100 may include a central entity 110. For example, as shown in FIG. 2 (b) or FIG. 2 (c), a device that performs a central entity function may be included in the base station, or may be implemented in software so that the base station performs the central entity function.

The node may include a mobile management entity (MME). Referring to FIG. 8, the node may include a configuration of an interface unit 810, a controller 820, and a storage unit 830.

The interface unit 810 may communicate with another node (eg, MME), a base station, or a central entity of the core network under the control of the controller 720.

When the controller 820 receives the information request from the first base station, the controller 820 may request the information from the second base station. When the controller 820 receives the information from the second base station, the controller 820 may transfer the received information to the first base station. The information may include transport layer (TL) information.

The storage unit 830 may store information received from another node, a base station, or a central entity of the core network.

All steps and messages described above may optionally be subject to execution or may be subject to omission. Also, the steps do not necessarily have to occur in order, and can be reversed. Message delivery doesn't necessarily have to happen in order, but can be reversed.

In the embodiments of the present invention, it is obvious that the consideration regarding the message exchange between the base station 100 and the central entity 110 may also be used for message exchange between two general base stations.

Claims

In the base station transmits the base station-related message to the peer base station,

Identifying whether at least one of the cells belonging to the counterpart base station is in the vicinity of the base station;

Determining whether to include information about a neighbor cell in the base station related message according to the checking result; And

And transmitting the base station related message to the counterpart base station according to the determination.
The method of claim 1,

And the checking step includes determining whether at least one cell among the cells belonging to the counterpart base station is included in the neighbor cell list held by the base station.
The method of claim 2,

The neighbor cell list may include a list of base stations connected to the base station through X2, a list of cells belonging to a base station connected through X2 with the base station, a list of cells that have received measurement related information from the terminal, and the base station heard the related information. the air) at least one of a cell list of another base station, a network list and / or a cell list set to OAM, and a cell list belonging to a neighbor relation table (NRT).
The method of claim 1,

And determining that at least one of the cells belonging to the counterpart base station is around the base station, including the information on the neighboring cell in the base station related message.
The method of claim 1,

If it is determined that at least one cell among the cells belonging to the other base station is not around the base station, the base station-related message transmission method, characterized in that the information on the neighbor cell is not included in the base station-related message.
The method of claim 1,

The information on the neighboring cell includes a base station-related message transmission method comprising at least one of CGI, PCI, frequency band information, and tracking area code of a cell belonging to a neighboring cell list held by the base station.
The method of claim 1,

And information about the neighbor cell is included in a neighbor information IE.
The method of claim 1,

The base station related message,

And at least one of an X2 SETUP REQUEST message, an X2 SETUP RESPONSE message, and an ENB CONFIGURAION UPDATE message.
A base station for transmitting a base station related message to a peer base station,

An interface unit for communicating with the counterpart base station; And

Identify whether at least one of the cells belonging to the counterpart base station is in the vicinity of the base station, and determine whether to include information about the neighboring cell in the base station related message according to the result of the checking; And a control unit controlling to transmit the base station related message to the counter base station.
The method of claim 9,

And the controller determines whether at least one cell among cells belonging to the counterpart base station is included in the neighbor cell list held by the base station.
The method of claim 10,

The neighbor cell list may include a list of base stations connected to the base station through X2, a list of cells belonging to a base station connected through X2 with the base station, a list of cells that have received measurement related information from the terminal, and the base station heard the related information. the air) a base station comprising at least one of a cell list of another base station, a network list configured for network setting and / or an OAM, and a cell list belonging to a neighbor relation table (NRT).
The method of claim 9,

The controller, if it is determined that at least one of the cells belonging to the counterpart base station is around the base station, the base station, characterized in that to include the information on the neighboring cell in the base station related message.
The method of claim 9,

The controller, if it is determined that at least one of the cells belonging to the counterpart base station is not around the base station, the base station, characterized in that it does not include information about the neighbor cell in the base station related message.
The method of claim 9,

And the information on the neighbor cell includes at least one of CGI, PCI, frequency band information, and tracking area code of a cell belonging to the neighbor cell list held by the base station.
The method of claim 9,

And information on the neighbor cell is included in a neighbor information IE.
The method of claim 9,

The base station related message,

And at least one of an X2 SETUP REQUEST message, an X2 SETUP RESPONSE message, and an ENB CONFIGURAION UPDATE message.