KR101801940B1 - Apparatus and method for managing small cell base station, system - Google Patents

Abstract

The present invention relates to an apparatus and a method for allocating a PCI of a small cell base station. The apparatus according to the present invention collects PCI configuration information and neighboring cell information for the small cell base station from an operation management server that manages information on a plurality of small cells superposed on a macro cell and a macro cell, A determination unit for determining whether or not to collide with the PCI assigned to the small cell base station based on the PCI usage information of the neighboring cells of the neighboring cells, And allocating a PCI of the small cell base station if the PCI assigned to the small cell base station does not collide with the PCI of the neighboring cells according to the determination result of the small cell base station.

Description

Technical Field [0001] The present invention relates to an apparatus, a method, and an operation management system for a small cell base station,

The present invention relates to an apparatus and method for allocating a PCI in a small cell base station, and more particularly, to a technique for allocating a PCI (Physical Cell Identity) of a small cell base station so as to satisfy conditions of collision and confusion.

Recently, a small-sized cell base station such as a femtocell, which is a personal base station installed in a room for a small-sized subscriber, has been proposed. Such a small-sized cell base station is divided into a wide- Located.

Standard specifies that the PCI area for a small cell base station is separately allocated so as to distinguish the cells of the macro cell base station from those of the small cell base station including the closed subscriber group cell. Therefore, there is a need for a PCI allocation method that satisfies the conditions of collision-free and confusion-free in a smaller number of PCI ranges for a small cell base station.

Korean Patent Laid-Open No. 10-2011-0018043

It is an object of the present invention to provide an apparatus, a method, and a system for allocating a PCI of a small cell base station in a collision-free and confusion-free manner.

Another object of the present invention is to provide a small cell base station capable of performing a sniff function of an NMM when a small cell base station supports an NMM (Network Monitoring Mode) function and collecting information on neighboring base stations, And to provide a PCI allocation apparatus, method, and system for a small cell base station that detects a PCI collision and a chaotic situation.

According to an aspect of the present invention, there is provided an apparatus for managing a plurality of small cells superimposed on a macro cell of a macro cell base station and a plurality of small cells superimposed on the macro cell, A PCI information collecting unit for collecting information on neighboring cells and PCI usage information of the neighboring cells, a PCI information collecting unit for collecting PCI usage information for the neighboring cells, And a PCI allocator for allocating a PCI of the small cell base station if the PCI assigned to the small cell base station does not collide with the PCI of the neighboring cells according to the determination result of the determination unit .

The cell information collecting unit collects PCI usage information for a base station of the neighboring cells by performing a sniff function of a network monitoring mode (NMM).

The cell information collecting unit scans the neighboring cells to collect Received Signal Strength Indicator (RSSI), Master Information Block (MIB), System Information Block (SIB), peripheral component interconnect (PCI) UTRAN Cell Global Identifier), a neighbor cell, a base station name, and a reference signal received power (RSRP).

The cell information collecting unit may generate a PCI list of neighboring cells for the small cell base station based on the PCI setting information and information on neighboring cells.

And the cell information collecting unit updates the PCI list of the neighboring cells based on the PCI usage information for the base station of the neighboring cell.

The PCI list of the neighboring cells may include a name, a PCI, an ECGI, a REMOVE, a HANDOVER, and an X2 attribute value for the neighboring small cell base station, a name, PCI, ECGI, REMOVE, HANDOVER, And at least one of them.

Wherein the determination unit determines whether there is the same PCI as the PCI assigned to the small cell base station from the PCI list of the neighboring cell.

The determining unit compares the PCI-specific RSRP value included in the PCI list of the neighboring cell with a predefined upper limit reference value and a lower limit reference value to check whether the RSRP value of each PCI is between the upper limit reference value and the lower limit reference value, Or not.

The determination unit may determine whether a PCI conflict occurs based on whether at least one of MIB information and SIB information is received for each PCI included in the PCI list of the neighboring cell.

The determination unit may determine whether a PCI conflict occurs depending on whether the number of times that the neighboring cell list table exceeds the reference value for each PCI included in the PCI list of the neighboring cell.

And the PCI allocator reports the collision information of the PCI assigned to the small cell base station to the operation management server when it is confirmed that the PCI assigned to the small cell base station conflicts with the PCI of the neighboring cells.

The PCI allocator configures a PCI conflict list including PCI information that conflicts with a PCI of the neighboring cell if it is determined that the PCI assigned to the small cell base station conflicts with the PCI of the neighboring cells.

When a message requesting the X2 connection setup or a message informing that the configuration of the adjacent base station is changed is received from the neighboring base station, the PCI allocating unit allocates the neighboring cell information to the neighboring cell based on the result of comparison between the neighboring cell information included in the received message and the PCI list of the neighboring cell And report collision information on the PCI of the neighboring cell to the operation management server.

According to another aspect of the present invention, there is provided a method of allocating a PCI cell in a small cell base station, the method comprising: receiving, from an operation management server that manages information on a plurality of small cells superimposed on macrocells and macrocells of a macrocell base station, Collecting PCI setup information and neighboring cell information for a small cell base station and collecting PCI usage information for a base station of the neighboring cells, and transmitting the PCI setup information, information about the neighboring cells, Generating a PCI list of peripheral cells for the small cell base station based on the PCI usage information for the small cell base station based on the PCI usage information for the small cell base station, And if the PCI assigned to the small cell base station does not collide with the PCI of the neighboring cells according to the determination result, And allocating a PCI of the cell base station.

According to the present invention, when the small cell base station supports the NMM (Network Monitoring Mode) function, it performs a sniff function of the NMM to collect information about neighboring base stations, And a chaotic situation are detected, thereby making it possible to allocate a PCI of a small cell base station as collision-free and confusion-free.

1 is a diagram illustrating a system according to the present invention.
2 is a block diagram showing a configuration of a PCI allocation apparatus for a small cell base station according to the present invention.
FIGS. 3 to 5B are views for explaining the operation of the PCI allocation apparatus of the small cell base station according to the present invention.
6 is a flowchart illustrating an operation flow for a PCI allocation method of a small cell base station according to the present invention.
7A and 7B are flowcharts illustrating a detailed operation flow of the sniff function operation process of FIG.
8 is a flowchart illustrating a flow of a PCI management operation of a small cell base station according to the present invention.
9 is a diagram illustrating a computing system to which an apparatus according to the present invention is applied.

It is noted that the technical terms used in the present invention are used only to describe specific embodiments and are not intended to limit the present invention. In addition, the technical terms used in the present invention should be construed in a sense generally understood by a person having ordinary skill in the art to which the present invention belongs, unless otherwise defined in the present invention, and an overly comprehensive It should not be construed as meaning or overly reduced. In addition, when a technical term used in the present invention is an erroneous technical term that does not accurately express the concept of the present invention, it should be understood that technical terms that can be understood by a person skilled in the art can be properly understood. In addition, the general terms used in the present invention should be interpreted according to a predefined or context, and should not be construed as being excessively reduced.

Furthermore, the singular expressions used in the present invention include plural expressions unless the context clearly dictates otherwise. The term "comprising" or "comprising" or the like in the present invention should not be construed as necessarily including the various elements or steps described in the invention, Or may include additional components or steps.

Furthermore, terms including ordinals such as first, second, etc. used in the present invention can be used to describe elements, but the elements should not be limited by terms. Terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals refer to like or similar elements throughout the several views, and redundant description thereof will be omitted.

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. It is to be noted that the accompanying drawings are only for the purpose of facilitating understanding of the present invention and should not be construed as limiting the scope of the present invention.

1 is a diagram showing a configuration of a system applied to the present invention. 1, an eNB (Evolved NodeB) refers to a base station, and a Home eNB refers to a small cell base station 200.

Referring to FIG. 1, a system according to the present invention includes a macro cell base station (Macro eNB) 100 and a plurality of small cell base stations (HeNBs 1 to 5) 200 having a smaller coverage than a macro cell. Here, the macro cell base station 100 and the plurality of small cell base stations 200 communicate with an operation, administration, maintenance (OAM) server when the power is applied to transmit and receive information. In particular, the newly installed small cell base station 200 automatically establishes the configuration of the small cell base station 200 through the operation management server 300 after communication with the operation management server 300 when the power is applied.

Since the cell coverage of the small cell base station 200 is smaller than the macro cell, it can be used to extend the coverage of the macro cell or to solve the deficient capacity of the macro cell.

The small cell base station 200 according to the present invention has a small cell overlapping with a macro cell and can be installed in a small cell base station 200 within the coverage of a macro cell or a PCI In the case of newly setting the Physical Cell Identity, PCI is set up by using neighboring cell information by other small cell base stations in the coverage of the macro cell.

Here, PCI is a cell identifier of the physical layer, and PCI is an essential configuration parameter for identifying a cell when a user equipment (UE) performs wireless communication. Therefore, the small cell base station 200 essentially sets PCI for small cells at initial installation or initialization. At this time, the small cell base station 200 sets the PCI within the range where the small cells and the macro cells in the vicinity do not collide with or confuse the PCI. In other words, the small cell base station 200 sets the PCI within a range satisfying the collision-free and confusion-free conditions defined in 3GPP 36.902.

The detailed configuration of the small cell base station 200 will be described in more detail with reference to the embodiment of FIG.

2 is a diagram for explaining a configuration of a PCI allocation apparatus of a small cell base station according to the present invention. In the embodiment of the present invention, a PCI allocation device (hereinafter, referred to as a PCI allocation device) of a small cell base station is a small cell base station, and therefore the same reference numerals as those of the small cell base station are given. However, the PCI allocation apparatus can be separately implemented in the small cell base station. At this time, it may be formed integrally with the internal control units of the small cell base station, or may be implemented as a separate device connected to the internal control units by a connection means such as a cable. Hereinafter, a small cell base station corresponding to the PCI allocation apparatus will be referred to as a 'setup base station'.)

2, the PCI allocation apparatus 200 includes a control unit 210, a communication unit 220, a storage unit 230, a cell information collection unit 240, a determination unit 250, and a PCI allocation unit 260 ). Here, the control unit 210 may process signals transmitted between the respective units of the PCI allocation device 200. [

The communication unit 220 may operate by the control unit 210 when the PCI allocating apparatus 200 is operated and may attempt to establish a communication connection with the operation managing server 300 in this case.

Here, the communication unit 220 may include a communication module for accessing the Internet. The communication module may support a communication interface for communication connection with the small cell base stations and the operation management server that manages the macro cell base station. In addition, the communication module may support a communication interface for communication connection with the macro cell base station and / or the small cell base stations located nearby.

At this time, the communication unit 220 receives from the operation management server the PCI setting information for the cell corresponding to the setting base station (hereinafter, referred to as a 'setting cell'), information about the surrounding small cells and the macro cell, It is possible to transmit the PCI confusion information to neighboring cells to the OAM server. In addition, the communication unit 220 can receive information about surrounding small cells and macrocells. In addition, the communication unit 220 can request or receive the MIB (Master Information Block) / SIB (System Information Block) information for each peripheral cell and receive the X2 setting request or the environment information update request. Also, the communication unit 220 can transmit the PCI confusion information about the neighboring cells to the OAM server.

Also, the communication unit 220 can support wireless Internet communication of the user terminal UE.

Here, the wireless Internet technology includes a wireless LAN (WLAN), a wireless broadband (Wibro), a Wi-Fi, a World Interoperability for Microwave Access (WIMAX), a High Speed Downlink Packet Access ), And the like. The wired communication technology may include USB (Universal Serial Bus) communication, optical cable communication, and the like.

The storage unit 230 may store a set value for operation of the PCI allocating apparatus 200. [ As an example, the storage unit 230 may store information on neighboring small cells and macro cells received from the operation management server, and may store the PCI-specific MIB / SIB information received from neighboring cells.

Also, the storage unit 230 may store an algorithm for performing a sniff function, and may store a result of execution of the sniff function, for example, a neighboring cell list table and the like. The storage unit 230 may store an algorithm for allocating PCI or determining a PCI collision or confusion condition based on information about the received small cells in the vicinity and macro cell information.

The storage unit 230 may be a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (for example, an SD or XD memory A random access memory (SRAM), a read-only memory (ROM), a programmable read-only memory (PROM), an electrically erasable programmable read-only memory (EEPROM) Erasable Programmable Read-Only Memory).

The cell information collection unit 240 requests the OAM server connected through the communication unit 220 to set the cell configuration when power is applied to the setting base station. At this time, the communication unit 220 can receive the configuration information message including the PCI setting information for the set base station and information on the neighboring cells from the OAM server. The cell information collecting unit 240 collects information on the PCI configuration information and neighboring cells included in the configuration information message. Here, the PCI setting information may be information on a single PCI and information on a predetermined range of PCI.

At this time, the cell information collecting unit 240 generates a neighboring cell list for the set base station based on the PCI setting information and the neighboring cell information received from the OAM server. The neighboring cell list may be implemented in the form of a Neighbor Relation Table (NRT). The neighboring cell list table may include information on neighboring small cell base stations and / or information on macro cell base stations. As an example, the neighboring cell list table includes neighboring cell base station names, peripheral component interconnect (PCI) for surrounding small cell base stations, ECRI (E-UTRAN Cell Global Identifier), REMOVE, HANDOVER and X2 attribute values, A base station name, a PCI, an ECGI, a REMOVE, a HANDOVER, and an X2 property value for a macro cell base station. Here, EGCI denotes cell identification information broadcast from base stations located in the vicinity of the set base station. Also, the neighbor cell list table stores attribute values for REMOVE, HANDOVER, and X2 interface connection to peripheral cells, and these attribute values can be managed by the OAM server.

In addition, the cell information collecting unit 240 may check whether the setting base station supports a sniff function of a network monitoring mode (NMM), and may scan information from surrounding cells when the sniff function is supported. Here, the cell information collecting unit 240 may receive a sniff scan result, a Received Signal Strength Indicator (RSSI), a Master Information Block (MIB), a System Information Block (SIB), a PCI, an ECGI, , A base station name, and a reference signal received power (RSRP). Here, RSRP represents the signal reception strength of surrounding cells, and the size of the RSRP value can be a reference for determining the distance between the cell of the set base station and the surrounding cell. An embodiment of a sniff scan result for neighboring cells of the cell information collecting unit 240 will be described with reference to FIG.

At this time, the cell information collecting unit 240 may update the pre-generated neighboring cell list table using the information obtained as the sniff scan result. For example, the cell information collecting unit 240 may include only peripheral cells whose RSRP values exceed a preset reference value in the neighboring cell list table, and may exclude neighboring cells whose RSRP value is below the reference value from the neighboring cell list table. Here, an embodiment of the neighboring cell list table generated by the cell information collecting unit 240 will be described with reference to FIGS. 5A and 5B.

The determination unit 250 determines whether or not the base station conflicts with the PCI assigned to the set base station based on the PCI usage information of the base stations of neighboring cells.

For example, the determination unit 250 compares the PCI-specific RSRP value on the neighbor cell list table with a predefined upper limit reference value (RSRP_H) and a lower limit reference value (RSRP_L), and determines whether the RSRP value of each PCI is between the upper limit reference value and the lower limit reference value And judges whether or not there is a conflict between the PCI assigned to the setting base station and the PCI on the neighboring cell list table based on the result.

In addition, the determination unit 250 may determine whether there is a conflict between the PCI assigned to the setting base station and the PCI on the neighbor cell list table according to whether the MIB information and / or the SIB information is received for each PCI on the neighbor cell list table.

Also, the determination unit 250 determines whether the number of times that the number of appearing in the neighboring cell list table per PCI on the neighboring cell list table exceeds the reference value, and determines whether there is a conflict between the PCI granted to the setting base station and PCI on the neighboring cell list table Can be determined.

Here, when a single PCI is assigned to the setting cell, the determination unit 250 compares the PCI on the neighbor cell list table with the PCI assigned to the setting base station. At this time, the determination unit 250 determines whether there is a PCI corresponding to the PCI assigned to the set base station on the neighbor cell list table. The determination unit 250 transmits the determination result to the PCI allocation unit 260. [

On the other hand, when a predetermined range of PCI is assigned to the setting cell, the determination unit 250 compares the PCI on the neighbor cell list table with the PCI range assigned to the setting base station. At this time, the determination unit 250 determines whether there is a PCI corresponding to the PCI on the neighbor cell list table among the PCIs in the range given to the setting base station. The determination unit 250 transmits the determination result to the PCI allocation unit 260. [ For example, the determination unit 250 may provide the PCI allocation unit 260 with PCI information that is inconsistent with the PCI on the neighbor cell list table among the PCIs in the range given to the setting base station.

If the PCI assigned to the set base station does not collide with the PCI of peripheral cells according to the determination result of the determination unit 250, the PCI allocator 260 allocates the PCI to the set base station.

For example, when it is determined that there is no PCI that matches the PCI assigned to the setting base station in the neighboring cell list table, the PCI allocating unit 260 allocates the PCI to the setting base station. If it is determined that at least one PCI that does not match the PCI on the neighbor cell list table among the PCIs in the range given to the setting base station exists, the PCI allocator 260 allocates the PCI to the set base station. In this case, if there are two or more PCIs in a range that does not match the PCI on the neighboring cell list table, the PCI allocator 260 may allocate PCIs arbitrarily selected in the PCI range to the setting base station.

If it is determined that there is a PCI corresponding to the PCI assigned to the setting base station in the neighbor cell list table, the PCI allocator 260 transmits the PCI conflict information to the operation management server through the communication unit 220 To be transmitted. Here, the PCI allocator 260 may generate a PCI conflict list for the PCI that is predicted to have a conflict, and report the created PCI conflict list to the operation management server.

If all the PCIs assigned to the set base station exist in the neighbor cell list table, the PCI allocator 260 adds the PCI in the range to the PCI conflict list, and transmits the PCI to the operation management server through the communication unit 220 Report.

Meanwhile, the PCI allocating apparatus 200 according to the present invention may further include an input unit (not shown) and an output unit (not shown).

Here, the input unit is a means for receiving a control command from a user, and can receive a control command from an installer who installs a small-sized cell base station and / or an intermediate manager. The input unit may correspond to a key button, and a soft key implemented on the display may correspond to the input unit. In addition, the input unit may be an input means such as a mouse, a joystick, a jog shuttle, or a stylus pen.

The output unit may include a display for displaying the operation status and results of the PCI allocating apparatus 200, and may include a speaker for voice guidance.

Here, the display may be used as an input device in addition to an output device when a sensor for sensing a touch operation is provided. That is, when a touch sensor such as a touch film, a touch sheet, or a touch pad is provided on the display, the display operates as a touch screen, and the input unit and the output unit may be integrated.

The display may be a liquid crystal display (LCD), a thin film transistor liquid crystal display (TFT LCD), an organic light-emitting diode (OLED), a flexible display, , A field emission display (FED), and a 3D display (3D display).

In addition, the display may be a device separately implemented from the PCI allocating device 200, and may be a device connected to the PCI allocating device 200 by connecting means such as a cable.

FIGS. 3 to 5B are views for explaining the operation of the PCI allocation apparatus of the small cell base station according to the present invention.

3 is an exemplary diagram for explaining an operation of assigning a PCI to a configuration cell.

Referring to FIG. 3, reference numeral 150 denotes a macro cell, and there are 20 small cells in the macro cell, for example, HeNB 1 to HeNB 20 (205). HeNB 1 to HeNB 20 (205) are assigned 1 to 20 PCIs in sequence. Also, the HeNB 1 to HeNB 20 (205) are sequentially assigned 10 to 200 ECGIs.

Here, when the new base station New HeNB 21 (201) is installed, the ECGI which is the cell identifier of the New HeNB 21 (201) can be assigned by the operation management server. As an example, the New HeNB 21 (201) may be granted ECGI = 210 by the operation management server.

On the other hand, the PCI allocation device is given PCI to the New HeNB 21 (201) from the operation management server. However, if the PCI allocation device determines that the PCI is not collided by sniffing the information allocated to the neighboring cells before setting the PCI assigned from the operation management server, the PCI allocation device checks the PCI to the New HeNB 21 .

Here, the result of sniffing the information of the neighboring cells based on the New HeNB 21 (201) can be shown in FIG.

As shown in FIG. 4, the PCI allocation device sniffs the neighbor cells and generates PCI information 410, ECGI information 420, HeNB 1 through HeNB 20 for peripheral cells, i.e., HeNB 1 through HeNB 20 The neighbor cell information 430, the RSRP information 440, and the name information 450 of the neighboring cell. Here, neighbor cell information 430 of each of HeNB 1 to HeNB 20 is assumed to be included in SIB4, SIB5, and SIB9 received from HeNB1 to HeNB 20, respectively.

Here, the result of sniffing the neighbor cells is obtained by searching neighboring cells using the NMM function of the set base station, measuring the RSSI of neighboring cells, and obtaining SIB information from neighboring cells.

As an example, PCI of HeNB 1 is 1, EVGI is 10, neighboring cells are HeNB 2, HeNB 7, HeNB 8, HeNB 9, HeNB 10, and RSRP is -9. HeNB 2's PCI is 2, ECGI is 20, neighboring cells are HeNB 1, HeNB 3, HeNB 4, HeNB 10, HeNB 11, and RSRP is -10. In addition, the PCI of HeNB 3 is 3, the ECGI is 30, and the neighboring cells are HeNB 2, HeNB 4, HeNB 11, HeNB 12, HeNB 13, HeNB 14, and RSRP is -10. HeNB 4 has PCI of 4, ECGI of 40, neighboring cells of HeNB 2, HeNB 3, HeNB 5, HeNB 13, HeNB 14 and HeNB 15, and RSRP is -10. In addition, the PCI of HeNB 5 is 5, the ECGI is 50, the neighboring cells are HeNB 4, HeNB 6, HeNB 15, HeNB 16, HeNB 17, and RSRP is -11. The PCI of HeNB 6 is 6, the ECGI is 60, the neighboring cells are HeNB 5, HeNB 7, HeNB 17, HeNB 18, HeNB 19, and RSRP is -11. Also, the PCI of HeNB 7 is 7, the ECGI is 70, and the neighboring cells are HeNB 1, HeNB 6, HeNB 8, HeNB 19, HeNB 20, and RSRP is -12. On the other hand, HeNB 8 to HeNB 20 have an RSRP of -20 or less.

The neighboring cell information shown in FIG. 4 is sorted based on the RSRP value. Here, if the reference value for RSRP is greater than -20 and less than -12, the PCI allocating apparatus allocates only the surrounding cell list table (for example, HeNB 1 to HeNB 7 460) whose RSRP exceeds the reference value, NRT) can be created. Here, the neighboring cell list table can be created for the setting base station, i.e., the small cell base station around the New HeNB 21. Further, the neighboring cell list table can be created for the macro cell base station around the set base station.

Here, the peripheral cell list table created for the HeNB 1 through HeNB 7 (460) based on the New HeNB 21 can be represented as shown in FIG. 5A.

5A is a diagram illustrating a neighbor cell list table for a small cell base station in the vicinity of a set base station. 5A, the peripheral cell list table for the neighboring small cell base stations includes PCI information 511, ECGI information 512, No RM information 513, No HO information 514, No X2 information 515 and small cell base station name information 516. Here, the No RM information 530 may include information corresponding to whether or not to prohibit removal of the corresponding cell. In addition, the No HO information 540 may include information corresponding to whether or not the HANDOVER to the corresponding cell is prohibited. Also, the No X2 information 550 may include information corresponding to whether or not to prohibit connection establishment through the X2 interface with the corresponding cell.

Therefore, in the case of New HeNB 21 of FIG. 3, when PCI = 21 is given from the operation management server, there is no value corresponding to 21 of PCI on the neighbor cell list table of FIG. 5A, so that PCI = 21 can be allocated.

On the other hand, when New HeNB 21 receives a PCI from 1 to 7 from the operation management server, since there is a PCI among the PCIs on the neighbor cell list table of FIG. 5A, Can be reported to the management server. As an example, when PCI = 4 is assigned to the New HeNB 21 from the operation management server, it is possible to report the conflict information for PCI 4 to the operation management server because it matches the PCI of the HeNB 4 on the neighbor cell list table.

5B is a diagram illustrating a neighbor cell list table for a macro cell base station in the vicinity of a set base station. 5A, the neighbor cell list table for the macro cell base station includes macro cell base station name information 531, PCI information 532, ECGI information 533, No RM information 534, No HO information 535, and No X2 information 536. The information included in the neighbor cell list table for the macro cell BS is the same as the item shown in FIG. 5A except for the name information of the BS. Therefore, redundant description thereof will be omitted.

The operation flow of the apparatus according to the present invention will be described in more detail as follows.

6 is a flowchart illustrating an operation flow for a PCI allocation method of a small cell base station according to the present invention.

As shown in FIG. 6, when the newly set up base station is driven, the PCI allocation apparatus can receive a message including the PCI setting information and neighboring cell information from the operation management server (OOAM) (S110).

At this time, the PCI allocation device configures a PCI list of neighboring cells based on the PCI setting information and neighboring cell information received in step 'S110' (S120). If the setting base station supports the sniff function of the NMM (S130), the PCI allocation apparatus operates the sniff function of the set base station (S140) The PCI list is updated (S150).

Here, the detailed operation flow for the process 'S140' is referred to the embodiment of FIGS. 7A and 7B.

As illustrated in FIG. 7A, the PCI allocation apparatus sets an RF at a frequency of a neighboring cell (S300), and adjusts an Automatic Gain Control (AGC) value of RF (S310). In step S320, the PCI allocation device measures RSSI (Received Signal Strength Indicator) for each frequency to be measured for neighboring cells, and configures a cell search frequency list according to the RSSI value measured in step S320 (S330) . At this time, the PCI allocation apparatus starts cell search for each frequency based on the cell search frequency list of step 'S330' (S340). Here, the PCI allocation apparatus temporarily stores information of the searched cell in step 'S340', for example, RSRP information.

If the RSRP of the cell found in the process of 'S340' exceeds the upper threshold value (RSRP_H) (S350), the PCI allocation apparatus can determine that the same PCI as the PCI allocated to the corresponding cell is allocated to another cell. Accordingly, the PCI information is added to the PCI conflict list (S380), and the PCI conflict information is reported to the operation management server (S390).

Meanwhile, if the RSRP of the cell found in the process 'S350' does not exceed the upper threshold RSRP_H but is lower than the lower threshold RSRP_L (S360), the PCI allocation device may not recognize the searched cell as a neighboring cell.

If the RSRP of the cell found in step 'S360' exceeds the lower limit threshold value (RSRP_L), the PCI allocation device adds the discovered cell to the PCI list of the neighboring cell (S370) Perform the following steps.

As shown in FIG. 7B, the PCI allocation device requests and receives MIB and / or SIB information for each PCI included in the PCI list of neighboring cells (S400). At this time, if there is a PCI which fails to receive the MIB and / or the SIB information in the process of 'S400', the collision information for the corresponding PCI is reported through 'S380' and 'S390' of FIG.

On the other hand, if the MIB and / or SIB information is received in step S400, peripheral cell information corresponding to the PCI is acquired (S420), and based on the neighboring cell information acquired in step S420, (NRT) (S430). Here, if the number of times that the PCI allocation device is present in the neighboring cell list table per PCI included in the neighboring cell list table (NRT) exceeds the reference value (S440), the PCI allocation device Report conflict information for PCI.

If the number of times that the neighboring cell list table for each of the PCIs included in the neighboring cell list table (NRT) is less than the reference value in step S440, the PCI allocator configures the RF in the service mode of the set base station (S450) The process after 'S150' of FIG. 6 is performed.

8 is a flowchart illustrating a flow of a PCI management operation of a small cell base station according to the present invention.

Referring to FIG. 8, the PCI allocation apparatus can confirm whether or not the PCI is collided even after allocating PCI to the setting base station. As an example, the PCI allocation apparatus can confirm whether or not the PCI conflict occurs by using the information received from the X2 interface.

At this time, the PCI allocation apparatus can receive an X2 setup request message requesting an X2 connection setup from an adjacent base station or an eNB configuration update message informing that the configuration of the base station is changed (S500).

In this case, the PCI allocation unit stores neighbor information included in the received message in step 'S500' (S510). If the number of neighboring cells stored in step S510 is greater than 0, the PCI allocation apparatus sequentially compares the stored neighboring cells with the PCIs included in the neighboring cell list table (S530). If it is determined that there is the same PCI as the PCI included in the neighbor cell list table among the neighboring cells as a comparison result in step S530, the ECGI of the PCI is compared with the ECGI of the same PCI in the neighbor cell list table at step S550. If the ECGI of the two PCIs is the same (S560), the PCI allocation device deletes neighboring cell information of the corresponding neighboring cell information (S570). If not, the PCI information is added to the PCI conflict list (S580), the PCI conflict information is reported to the operation management server (S590), and the process ends.

9 is a diagram illustrating a computing system to which an apparatus according to the present invention is applied.

9, a computing system 1000 includes at least one processor 2100, a memory 1300, a user interface input device 2200, a user interface output device 2300, (1600), and a network interface (1700).

The processor 2100 may be a central processing unit (CPU) or a semiconductor device that performs processing on the memory 1300 and / or instructions stored in the storage 1600. Memory 1300 and storage 1600 may include various types of volatile or non-volatile storage media. For example, the memory 1300 may include a ROM (Read Only Memory) and a RAM (Random Access Memory).

Thus, the steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by processor 2100, or in a combination of the two. The software module may reside in a storage medium (i.e., memory 1300 and / or storage 1600) such as a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, You may. An exemplary storage medium is coupled to the processor 2100, which is capable of reading information from, and writing information to, the storage medium. Alternatively, the storage medium may be integral with the processor 2100. [ The processor and the storage medium may reside within an application specific integrated circuit (ASIC). The ASIC may reside within the user terminal. Alternatively, the processor and the storage medium may reside as discrete components in a user terminal.

As described above, the present invention has been described with reference to particular embodiments, such as specific elements, and specific embodiments and drawings. However, it should be understood that the present invention is not limited to the above- Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the essential characteristics of the invention. Therefore, the spirit of the present invention should not be construed as being limited to the embodiments described, and all technical ideas which are equivalent to or equivalent to the claims of the present invention are included in the scope of the present invention .

100: macro cell base station (eNB) 150: macro cell
200: small cell base station (HeNB) 210:
220: communication unit 230: storage unit
240: Cell information collecting unit 250:
260: PCI allocation unit 300: Operation management server (OAM)

Claims (18)

1. A PCI allocation apparatus for a small cell base station,
Collects PCI configuration information and neighboring cell information for the small cell base station from an operation management server that manages information on a macro cell and a plurality of small cells superimposed on the macro cell, A cell information collecting unit for collecting PCI usage information for a base station of the neighboring cells by executing a sniff function of a network monitoring mode;
A determination unit for determining whether a collision with the PCI assigned to the small cell base station is based on the PCI usage information of the neighboring cells; And
And a PCI allocator for allocating a PCI of the small cell base station if the PCI assigned to the small cell base station does not collide with the PCI of the neighbor cells according to the determination result of the determination unit,
The cell information collecting unit collects information on neighboring cells including MIB (Master Information Block) and SIB (System Information Block) for neighboring cells and PCI Create a list,
Wherein the determination unit determines whether a PCI conflict occurs based on whether at least one of MIB information and SIB information is received for each PCI included in the PCI list of the neighboring cell. The method according to claim 1,
The cell information collecting unit,
(SIB), a peripheral component interconnect (PCI), an E-UTRAN cell global identifier (ECGI), a neighbor cell, and a base station name And a reference signal received power (RSRP). The apparatus of claim 1, delete The method according to claim 1,
The cell information collecting unit,
And updates the PCI list of the neighboring cell based on the PCI usage information for the base station of the neighboring cell. The method according to claim 1,
The PCI list of the neighboring cells includes:
PCI, ECGI, REMOVE, HANDOVER, and X2 property values for neighboring small cell base stations, and names, PCI, ECGI, REMOVE, HANDOVER, and X2 property values for surrounding macro cell base stations To the small cell base station. The method according to claim 1,
Wherein,
And determines whether there is a PCI same as PCI assigned to the small cell base station from the PCI list of the neighboring cell. delete delete delete The method according to claim 1,
The PCI allocating unit allocates,
And reporting, to the operation management server, the collision information of the PCI assigned to the small cell base station if it is confirmed that the PCI assigned to the small cell base station conflicts with the PCI of the neighboring cells. Device. The method according to claim 1,
The PCI allocating unit allocates,
Wherein the PCI collision list includes conflicting PCI information if it is determined that the PCI assigned to the small cell base station conflicts with the PCI of the neighboring cells. The method according to claim 1,
The PCI allocating unit allocates,
When a message requesting the X2 connection setup or a message informing that the configuration of the neighboring base station is changed is received from the neighboring base station, based on the comparison result between the neighboring cell information included in the received message and the PCI list of the neighboring cell, And reports the collision information to the operation management server. A method of allocating a PCI of a small cell base station,
Collects information on the PCI configuration information and neighboring cells for the small cell base station from an operation management server that manages information on a plurality of small cells superimposed on macro cells and macro cells of the macro cell base station, Performing a sniff function of a Network Monitoring Mode (NMM) supported by the neighboring cells to collect PCI usage information for the base stations of neighboring cells;
Generating a PCI list of peripheral cells for the small cell base station based on the PCI configuration information, information on the neighboring cells, and PCI usage information of the neighboring cells;
Determining whether the PCI assigned to the small cell base station collides with the PCI based on the PCI information included in the PCI list of the neighboring cell; And
And allocating the PCI of the small cell base station if the PCI assigned to the small cell base station does not collide with the PCI of the neighboring cells according to the determination result,
The method of claim 1,
And determining whether a PCI conflict occurs depending on whether at least one of MIB information and SIB information is received for each PCI included in the PCI list of the neighboring cell. 14. The method of claim 13,
The method of claim 1,
Further comprising the step of determining whether there is the same PCI as the PCI assigned to the small cell base station from the PCI list of the neighboring cell. delete delete delete 14. The method of claim 13,
The method of claim 1,
Further comprising the step of reporting, to the operation management server, the collision information of the PCI assigned to the small cell base station if it is confirmed that the PCI assigned to the small cell base station conflicts with the PCI of the neighboring cells. A method of assigning a PCI to a base station.

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