KR102127759B1 - Method and femto base station for detecting change of location - Google Patents

Abstract

A method for detecting a location change and a femto base station performing the same are provided. This method is a method in which a femto base station detects a location change. After rebooting, acquiring at least one neighbor base station information adjacent to the femto base station through network listening, and a neighbor list in which at least one neighbor base station information obtained is already generated. Determining whether it is included, and detecting the location change of the femto base station, if not included, and the neighbor list includes the at least one neighbor base station information obtained through network listening before the reboot. And, the neighboring base station includes at least one macro base station adjacent to the femto base station.

Description

METHOD AND FEMTO BASE STATION FOR DETECTING CHANGE OF LOCATION

The present invention relates to a method for detecting a location change and a femto base station performing the same.

Currently, a broadband wireless communication system is considering a method of expanding a femto base station to complement a macro base station. The femto base station is located in the area of the macro base station of a wide radius or is installed outside the area of the macro base station, and provides a specific communication service with femto cell coverage for a small number of subscribers.

In the case of the femto base station, which is an ultra-small base station, a Global Positioning System (GPS) module is generally not embedded in order to lower a product price. Even if the GPS module is installed, GPS reception is not easy due to the fact that the femto base station is installed indoors.

Due to the nature of the femto base station, it is small and light, and is mainly installed indoors, such as homes and offices, so the location of the femto base station can be changed when moving and moving the office.

However, in the absence of GPS information, it is difficult for an operator to know the location change of the femto base station. In this case, the original purpose for radio quality improvement and data offloading of the macro base station may be lost and may act as interference to neighboring subscribers.

In order to prevent this phenomenon, when the location of the femto base station is changed, the operator must detect it and recover the femto base station or relocate it for cost reduction.

The problem to be solved by the present invention is to provide a method for detecting a location change of a femto base station using a neighbor list collected by the femto base station and a femto base station performing the same.

According to one feature of the present invention, a method for detecting a location change by a femto base station, obtaining at least one neighbor base station information adjacent to the femto base station through network listening after rebooting, and obtaining at least one neighbor base station information Determining whether is included in the pre-generated neighbor list, and if not, detecting a location change of the femto base station, the neighbor base station comprising: at least one macro base station adjacent to the femto base station. Includes.

The neighboring base station information includes a cell identifier, and the detecting step includes changing the location of the femto base station when the cell identifier of the neighboring base station obtained through network listening after the reboot is not included in the neighbor list. Can be detected.

The neighboring base station information includes a tracking area code (TAC), and the detecting step includes: if the TAC of the neighboring base station obtained through network listening after the reboot is not included in the neighbor list, the femto base station information Change of position can be detected.

After the determining step, further comprising determining whether a media access control (MAC) address of the upper network equipment connected to the femto base station is changed, and the detecting step comprises neighboring acquired through network listening after the rebooting. When the base station information is not included in the neighbor list and the MAC address is changed, the location change of the femto base station can be detected.

The neighboring base station information includes a cell identifier and a Tracking Area Code (TAC), and the detecting step includes when the cell identifier of a neighboring base station obtained through network listening after the reboot is not included in the neighbor list, The step of detecting the position change may be further included, and if the TAC of the neighboring base station acquired through the network listening is not included in the neighbor list, the step 2 of detecting the position change may be further included.

After the step of determining, further comprising determining whether a media access control (MAC) address of a higher-level network equipment connected to the femto base station is changed, and the detecting step comprises: when the MAC address is changed, the femto base station It may further include the step of detecting the position change of step 3.

After the detecting step, the step 1 of the position change alarm, the step 2 of the position change alarm and the step 3 of the position change alarm may further include the step of sequentially transmitting to the femto base station management system.

According to another aspect of the present invention, the location change detection method is a method for detecting a location change by a femto base station, a first neighbor list including at least one macro base station information adjacent to the femto base station obtained through network listening, and Generating a second neighbor list, storing the first neighbor list in a non-volatile memory, storing the second neighbor list in a volatile memory, and deleting the second neighbor list when power is off; Re-generating the second neighbor list by acquiring at least one macro base station information adjacent to the femto base station through network listening upon rebooting, comparing the first neighbor list with the second neighbor list, and comparing the at least one neighbor base station information Determining whether is consistent, and if it is inconsistent, detecting a location change of the femto base station.

The macro base station information includes a cell identifier of the macro base station, and the determining step includes determining whether at least one of the cell identifiers of the macro base stations included in the first neighbor list and the second neighbor list matches each other. can do.

The macro base station information includes a tracking area code (TAC) of the macro base station, and the determining step includes at least one of the TACs of the macro base station included in the first neighbor list and the second neighbor list, respectively. You can judge if they match.

After the determining step, if it is inconsistent, further comprising determining whether a media access control (MAC) address of an upper network equipment connected to the femto base station is changed, and the detecting step comprises: detecting the first neighbor list and When the second neighbor list is inconsistent with each other and the MAC address is changed, the location change of the femto base station can be detected.

After the detecting step, the step of transmitting a position change detection alarm to the femto base station management system may further include.

After the sensing step, the non-volatile memory and the step of synchronizing the volatile memory according to the instructions of the femto base station management system may further include.

According to another feature of the present invention, the femto base station comprises a communication unit that receives at least one macro base station information adjacent to the femto base station through network listening, a program for performing location change detection, and the at least one macro base station information. A storage unit for storing a neighbor list, a temporary memory for storing a second neighbor list including the at least one macro base station information, and a processor for executing the program, wherein the program comprises: Delete the neighbor list, regenerate the second neighbor list including at least one macro base station information obtained by performing the network listening upon reboot, and at least one macro base station information included in the second neighbor list is If it is not included in the first neighbor list, it includes instructions for detecting a position change.

The program may include instructions for detecting a location change if at least one of the cell identifiers included in the second neighbor list is not included in the first neighbor list.

If at least one of the cell identifiers included in the second neighbor list is not included in the first neighbor list, the program may include at least one of the tracking area codes (TACs) included in the second neighbor list. If it is not included in the list, it may include commands for detecting a position change.

The program, if the cell identifier and the TAC included in the second neighbor list are not included in the first neighbor list, and the MAC (media access control) address of the upper network equipment connected to the communication unit is changed, the location change It may include instructions for detecting the.

According to an embodiment of the present invention, it can be seen that the location of an actual femto base station has been changed by detecting macro base station information adjacent to the femto base station, and it is possible to prevent interference in unnecessary places and to collect and relocate a small femto base station. Can be reduced.

1 is a network configuration diagram according to an embodiment of the present invention.
2 is an exemplary diagram of a femto base station detecting a new macro base station according to an embodiment of the present invention.
3 is an exemplary diagram in which a femto base station detects a new macro base station according to another embodiment of the present invention.
4 is a block diagram showing the configuration of a femto base station according to an embodiment of the present invention.
5 is a flowchart illustrating a method for detecting a position change of a femto base station 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 so that those skilled in the art to which the present invention pertains can easily practice. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. In addition, in order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and like reference numerals are assigned to similar parts throughout the specification.

Throughout the specification, when a part “includes” a certain component, this means that other components may be further included rather than excluding other components unless specifically stated to the contrary. In addition, terms such as “…unit”, “…group”, and “module” described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. have.

In this specification, a terminal is a mobile station (MS), a mobile terminal (MT), a subscriber station (SS), a portable subscriber station (PSS), and a user equipment (User Equipment). , UE), an access terminal (AT), or the like, or may include all or part of functions such as a terminal, a mobile station, a mobile terminal, a subscriber station, a mobile subscriber station, a user device, and an access terminal. .

In this specification, the base station (Base Station, BS) is an access node (Access Point, AP), a radio access station (Radio Access Station, RAS), Node B (Node B), advanced Node B (evolved NodeB, eNodeB), a transmitting and receiving base station (Base Transceiver Station, BTS), MMR (Mobile Multihop Relay), may also refer to BS, access node, base station, radio access station, Node B, eNodeB, transmitting/receiving base station, MMR-BS, etc. It may include.

Now, a method for detecting a position change according to an embodiment of the present invention and a femto base station performing the same will be described with reference to the drawings.

1 is a configuration diagram of a wireless communication system according to an embodiment of the present invention, FIG. 2 is an exemplary view of a femto base station detecting a new macro base station according to an embodiment of the present invention, and FIG. 3 is another embodiment of the present invention This is an example diagram in which a femto base station according to an example detects a new macro base station.

First, referring to FIG. 1, a wireless communication system includes at least one femto base station 100 and at least one macro base station 200 having different cell sizes. At least one femto base station 100 is connected to the femto base station management system 300.

The femto base station 100 is an ultra-small base station that provides wireless communication services to a narrow range (for example, a 30m range). The femto base station 100 manages the femto cell, and is installed in a shaded area where radio waves of other cells deteriorate, such as inside a home or building, to ensure the quality of mobile communication services. The femto base station 100 is connected to a mobile communication core network (EPC, Evolved Packet Core) by using a public network such as a digital subscriber line (DSL) and Ethernet installed indoors, such as a home or an office. Service.

The femto base station 100 is used in various terms such as a small base station, a pico base station, and a 3GPP standard term, such as HeNodeB, and is not limited to a dictionary definition of femto, and is a name of a larger unit or a smaller unit. It includes a range of a small base station and a small cell.

The femto base station 100 is located in a macro cell served by the macro base station 200. At this time, there is at least one macro base station that is a neighbor base station adjacent to the femto base station 100. The femto base station 100 periodically performs network listening at boot-up and after boot-up to receive base station information broadcast by at least one adjacent macro base station 200.

In this case, the obtained base station information may include a cell ID of a neighboring base station located near the femto base station 100, a tracking area code (TAC), and a physical cell identity (PCI).

The cell identifier is a cell-specific value, and the TAC is a minimum unit for paging and is generally a unit including several cells. The telecommunications carriers group several adjacent macro base stations 200 into groups and define them as one TA, and each macro base station 200 knows in advance which TA it belongs to. For example, the macro base stations 200 located in Samsung-dong may be set to TA1, the macro base stations 200 located in Yeoksam-dong to TA2, and the macro base stations 200 located in Nonhyeon-dong to TA3. The TAC represents a unique value assigned to each TA by the communication service provider, and may be set to, for example, TA1=0x0001 in Samsung-dong and TA2=0x0002 in Yeoksam-dong.

The femto base station 100 generates, changes, and deletes a neighbor list consisting of neighbor base station information obtained through network listening, and reports it to the femto base station management system 300. Here, the neighbor list is used for handover processing.

The femto base station 100 may update the neighbor list by performing an Automatic Neighbor Relation (ANR) operation. The femto base station 100 may perform the ANR operation specified in 3GPP when a PCI (Physical Cell Identity) unknown by the terminal (not shown) is detected.

The macro base station 200 manages a macro cell. Here, the macro cell means a cell having a larger area than the femto cell, and is not limited to the dictionary definition of the term macro. The macro base station 200 may be a base station of a mobile communication network such as a long term evolution (LTE) network, a wideband code division multiple access (WCDMA) network, a code division multiple access (CDMA) network, or a wireless broadband internet (Wibro) network. have.

The femto base station 100 and the macro base station 200 may be operated by generating a plurality of thin and precise beams using beam forming technology.

The base station management system 300 is a system that operates and manages the femto base station 100, and manages a neighbor list received from at least one femto base station 100.

In the case of the femto base station 100 without a global positioning system (GPS), a method of recognizing that the surrounding environment has changed is a method of recognizing that the information of the peripheral macro base station 200 having a fixed location has changed. .

Referring to FIG. 2, in a state in which macro base station #1 and macro base station #2 exist as neighboring base stations of the femto base station 100, the femto base station 100 may generate a new macro base station #3 due to additional cell generation or antenna adjustment. It corresponds to the case of detection. In this case, the neighbor list is updated to include the new macro base station #3.

Referring to FIG. 3, when the femto base station 100 moves to a new region, the femto base station 100 relocated to the new region acquires neighboring macro base station #3 information through network listening to update the neighbor list.

However, although macro base station #3 information has been newly added, it is difficult to distinguish whether this is due to a base station environment change such as additional cell creation or antenna adjustment as shown in FIG. 2 or a location change as shown in FIG. 3. This is because in both cases, the new macro base station #3 information is additionally generated while the existing neighbor list remains intact.

Therefore, in the embodiment of the present invention, the femto base station 100 is the case where the macro base station #3 information is added to the neighbor list, when the macro base station 200 is simply detected due to additional cell generation or antenna adjustment, and in fact the femto base station The case where the macro base station 200 in the new area is detected because the location of the 100 is changed is distinguished.

When the location of the femto base station 100 is moved, it is inevitably rebooted. Accordingly, the femto base station 100 divides the space storing the neighbor list into two types according to whether or not it is deleted upon reboot, and compares the newly created neighbor list through the network listening after reboot and the previous neighbor list that has not changed after rebooting. It is detected whether the location of the femto base station 100 is changed. In this way, when the neighbor list storage area is divided, it is possible to distinguish when a new neighbor base station is opened around the femto base station and when the femto base station 100 is moved to a new area.

In the case of FIG. 2, the neighbor lists of the two areas will be identical to each other. However, as shown in FIG. 3, when the location of the femto base station 100 is changed, the neighbor list generated before reboot and the neighbor list generated after reboot will not match each other. As described above, when the neighbor list is inconsistent with each other, it is possible to determine the location change of the femto base station 100.

The femto base station 100 may check whether a media access control (MAC) address for an upper network device is changed, thereby increasing the probability of detecting a location change.

When the femto base station 100 detects a location change, it transmits a location change alarm to the femto base station management system 300. The femto base station 100 compares the cell identifiers and TACs included in the neighbor list, and additionally, checks whether the MAC address of the upper device of the femto base station 100 is changed, thereby generating a location change alarm step by step. To detect the change of position.

If the location of the femto base station 100 has not changed, the base station information for the new macro base station 200 is obtained to update the neighbor list, and then the two types of neighbor list storage spaces are synchronized.

When the femto base station management system 300 receives a location change alarm from the femto base station 100, it manages the location information of the femto base station 100. The femto base station management system 300 is connected to the femto base stations 100 installed in various regions to manage them.

4 is a block diagram showing the configuration of a femto base station according to an embodiment of the present invention.

Referring to FIG. 4, the femto base station 100 includes a storage unit 101 storing a first neighbor list, a temporary memory 103 storing a second neighbor list, a base station control unit 105 and a communication unit 107 do. The storage unit 101, the temporary memory 103, and the communication unit 107 operate in connection with the base station control unit 105.

The storage unit 101 is a non-volatile memory, and stored data is not deleted even when the power is turned off. That is, even if the femto base station 100 reboots, the first neighbor list stored in the storage 101 is not changed.

In addition, the storage unit 101 stores the location change detection program of the femto base station 100. The location change detection program may be implemented in a form that is built-in by a device manufacturer by default, an application type installed by a user or an operator, or an application type installed and executed by a remote server.

The temporary memory 103 is a volatile memory, and when the power is turned off, stored data is deleted. That is, when the femto base station 100 reboots, the second neighbor list stored in the temporary memory 103 is changed. The temporary memory 103 may be a memory included in the base station controller 105.

The neighbor list used by the femto base station 100 for management and handover is a second neighbor list stored in the temporary memory 103.

The base station control unit 105 is a processor, and executes a position change detection program stored in the storage unit 101. Here, the location change detection program deletes the second neighbor list when the power is turned off, and regenerates a second neighbor list including at least one macro base station information obtained by performing network listening according to a reboot, and to the second neighbor list. If the included at least one macro base station information is not included in the first neighbor list, it may include instructions for detecting a location change.

In addition, if at least one of the cell identifiers included in the second neighbor list is not included in the first neighbor list, the position change detection program may include instructions for detecting the position change.

In addition, if at least one of the cell identifiers included in the second neighbor list is not included in the first neighbor list and at least one of the TACs included in the second neighbor list is not included in the first neighbor list, the location change detection program It may include instructions for detecting a position change.

Further, the location change detection program is a command for detecting a location change when the cell identifier and TAC included in the second neighbor list are not included in the first neighbor list and the MAC address of the upper network equipment connected to the communication unit 107 is changed. It may include.

The communication unit 107 may be connected to the base station control unit 105 to receive radio signals of at least one neighboring base station, that is, the macro base station 200, and to transmit and receive radio signals with the femto base station management system 300. do. Transmit and/or receive wireless signals. Transmit and receive information.

The communication unit 107 receives base station information broadcast from the neighboring macro base station 200 through network listening and transmits it to the base station control unit 105. The communication unit 107 may receive neighbor base station information through booting due to the initial installation of the femto base station 100, or rebooting due to reinstallation by moving the location, or periodically, through network listening.

5 is a flowchart illustrating a method for detecting a location change of a femto base station according to an embodiment of the present invention, and shows the operation of the femto base station 100.

Referring to FIG. 5, the base station control unit 105 receives neighbor base station information through network listening (S101). Here, step S101 may be a process during initial installation.

The base station control unit 105 stores the first neighbor list and the second neighbor list including neighbor base station information in the storage unit 101 and the temporary memory 103, respectively (S103, S105). At this time, the first neighbor list and the second neighbor list are the same.

Thereafter, when the power is turned off, the second neighbor list stored in the temporary memory 103 is deleted (S107). Then, upon rebooting (S109), the base station controller 105 receives neighbor base station information through network listening (S111) and regenerates the second neighbor list (S113).

The base station control unit 105 compares the first neighbor list generated before the reboot with the second neighbor list regenerated in step S113 (S115).

The base station controller 105 determines whether at least one cell identifier included in the second neighbor list is included in the first neighbor list (S117). That is, since the second neighbor list includes the newly generated cell identifier, it is checked whether there is at least one previously generated cell identifier.

As a result of the determination, if it exists, the process is terminated, and if it does not exist, the first stage position change detection alarm is transmitted to the femto base station management system 300 (S119).

The base station controller 105 determines whether at least one TAC included in the second neighbor list is included in the first neighbor list (S121). The TAC has a wider radius than the cell, and the fact that the same TAC does not exist in the existing neighbor list is predicted to have a high probability of detecting a location change beyond the TAC radius.

As a result of the determination, if it exists, the process is terminated. If not, a two-step position change detection alarm is transmitted to the femto base station management system 300 (S123).

The base station control unit 105 determines whether the MAC address of the upper network equipment (not shown) connected to the communication unit 107 has been changed (S125). If the MAC address is changed while the second stage position change detection alarm has occurred, it means that it is interlocked with other higher-level network equipment, so the probability of position change becomes higher.

As a result of the determination, if it has not been changed, the process is terminated, and if the MAC address of the upper network equipment (not shown) is changed, a 3-step location change detection alarm is transmitted to the femto base station management system 300 (S123).

At this time, the position change detection alarm for each step indicates that the higher the level, the higher the probability of position change.

Meanwhile, the base station control unit 105 maintains the corresponding alarm state until the position change detection alarm is cleared by the operator in the femto base station management system 300, and synchronizes the storage unit 101 and the temporary memory 103 Do not order. Then, when a clear, that is, a synchronization instruction is received in the femto base station management system 300, the storage unit 101 and the temporary memory 103 are synchronized. When synchronization is performed, the first neighbor list and the second neighbor list are the same as each other.

As described above, when the newly created neighbor list is compared with the newly created neighbor list after rebooting and the neighbor list created before rebooting, if at least one cell identifier and TAC that match each other do not exist, the location change of the femto base station 100 is primarily detected If an alarm is generated and the MAC address of the upper network equipment is also changed, it is easy to remotely manage whether the location of the femto base station 100 is changed by secondly generating a location change detection alarm of the femto base station 100.

The embodiment of the present invention described above is not implemented only through an apparatus and method, and may be implemented through a program that realizes a function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (17)

As a method for the femto base station to detect the location change,
After rebooting, acquiring at least one neighboring base station information adjacent to the femto base station through network listening,
Determining whether the obtained at least one neighbor base station information is included in a pre-generated neighbor list,
If not included, detecting the location change of the femto base station, And
If included, updating the pre-generated neighbor list to include the obtained at least one neighbor base station information,
The neighboring base station,
And at least one macro base station adjacent to the femto base station,
The obtained at least one neighbor base station information,
It is stored in volatile memory where data is deleted when the power is turned off.
The previously generated neighbor list,
A method for detecting a position change in which data is stored in a non-volatile memory that is not deleted even when the power is turned off. In claim 1,
The neighbor base station information includes a cell identifier,
The detecting step,
If the cell identifier of the neighboring base station obtained through the network listening after the reboot is not included in the neighbor list, detecting the location change of the femto base station, location change detection method. In claim 1,
The neighboring base station information includes a Tracking Area Code (TAC),
The detecting step,
If the TAC of the neighboring base station obtained through the network listening after the reboot is not included in the neighbor list, detecting the location change of the femto base station, location change detection method. In claim 1,
After the determining step,
Further comprising the step of determining whether the MAC (media access control) address of the upper network equipment connected to the femto base station is changed,
The detecting step,
If the neighbor base station information obtained through the network listening after the reboot is not included in the neighbor list, and the MAC address is changed, the location change detection method of the femto base station is detected. In claim 1,
The neighbor base station information includes a cell identifier and a tracking area code (TAC),
The detecting step,
If the cell identifier of the neighboring base station obtained through the network listening after the reboot is not included in the neighbor list, detecting the step 1 location change, and
If the TAC of the neighboring base station obtained through the network listening is not included in the neighbor list, the step 2 of detecting the location change
Further comprising, a method for detecting a position change. In claim 5,
After the determining step,
Further comprising the step of determining whether the MAC (media access control) address of the upper network equipment connected to the femto base station is changed,
The detecting step,
If the MAC address is changed, detecting a step 3 position change of the femto base station
Further comprising, a method for detecting a position change. In claim 6,
After the detecting step,
Step 1, location change alarm, step 2 location change alarm and step 3 location change alarm are sequentially transmitted to the femto base station management system
Further comprising, a method for detecting a position change. As a method for the femto base station to detect the location change,
Acquiring at least one macro base station information adjacent to the femto base station through network listening,
Generating a first neighbor list and a second neighbor list each including the obtained at least one macro base station information,
Storing the first neighbor list in a non-volatile memory, and storing the second neighbor list in a volatile memory,
When the power is off, deleting the second neighbor list,
Re-generating the second neighbor list by acquiring at least one macro base station information adjacent to the femto base station through network listening upon reboot,
Comparing the first neighbor list and the second neighbor list to determine whether at least one neighbor base station information matches;
If there is a discrepancy, detecting a location change of the femto base station, and
If they match, synchronizing the nonvolatile memory and the volatile memory such that the first neighbor list includes the same neighbor base station information as the second neighbor list.
A method of detecting a position change, comprising: In claim 8,
The macro base station information includes a cell identifier of the macro base station,
The determining step,
A method for detecting position change, determining whether at least one of cell identifiers of the macro base station included in the first neighbor list and the second neighbor list matches each other. In claim 8,
The macro base station information includes a tracking area code (TAC) of the macro base station,
The determining step,
A method for detecting position change, determining whether at least one of the TACs of the macro base station included in the first neighbor list and the second neighbor list matches each other. In claim 8,
After the determining step,
If there is a mismatch, further comprising determining whether a media access control (MAC) address of the upper network equipment connected to the femto base station is changed,
The detecting step,
If the first neighbor list and the second neighbor list are inconsistent with each other, and the MAC address is changed, the location change detection method of the femto base station is detected. In claim 8,
After the detecting step,
Transmitting the location change detection alarm to the femto base station management system
Further comprising, a method for detecting a position change. In claim 12,
The step of synchronizing,
A method for detecting position change of synchronizing the nonvolatile memory with the volatile memory according to the instruction of the femto base station management system. Communication unit for receiving at least one macro base station information adjacent to the femto base station through the network listening,
A storage unit for storing a program for performing location change detection and a first neighbor list including the at least one macro base station information;
A temporary memory storing a second neighbor list including the at least one macro base station information, and
It includes a processor for executing the program,
The above program,
When the power is turned off, the second neighbor list is deleted, and the second neighbor list including at least one macro base station information obtained by performing the network listening according to reboot is regenerated, and at least included in the second neighbor list If one macro base station information is not included in the first neighbor list, a location change is detected, and if at least one macro base station information included in the second neighbor list is included in the first neighbor list, the first neighbor The femto base station includes instructions for synchronizing the first neighbor list and the second neighbor list so that the list includes the same macro base station information as the second neighbor list. In claim 14,
The above program,
If at least one of the cell identifiers included in the second neighbor list is not included in the first neighbor list, the femto base station includes instructions for detecting a location change. In claim 15,
The above program,
If at least one of the cell identifiers included in the second neighbor list is not included in the first neighbor list, at least one of the tracking area codes (TACs) included in the second neighbor list is not included in the first neighbor list. Otherwise, comprising instructions for detecting a location change. In claim 16,
The above program,
Command for detecting a location change when the cell identifier and the TAC included in the second neighbor list are not included in the first neighbor list and a media access control (MAC) address of an upper network device connected to the communication unit is changed Femto base station comprising a.

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