KR101883995B1 - System and method for PCI allocation and PCI collision detection of femto-cell method using the same - Google Patents

Abstract

To allocate physical cell identity (PCI) to a first femto-cell, a device to allocate PCI to the first femto-cell allocates temporary PCI to the first femto-cell, and then, broadcasts a femto-cell message including the temporary PCI and femto-cell information about the first femto-cell in an amplified signal output mode which is able to transmit the message in wider coverage than the femto-cell coverage of a normal mode. Depending on whether a PCI reallocation request signal is transmitted from HeMS within a preset time, the temporary PCI or PCI different from the temporary PCI is determined as the final PCI for the first femto-cell.

Description

[0001] The present invention relates to a femtocell PCI allocation system, an allocation method, and a PCI collision detection method using the femtocell.

The present invention relates to a PCI allocation system, an allocation method of a femtocell, and a PCI collision detection method using the same.

When the femtocell is installed, the neighbor base station signal is searched through sniffing, and the detected neighbor base station signal is used as a signal source for frequency synchronization, or a neighbor cell is added. In particular, in the case of an LTE femtocell, an ID assigned to a neighboring cell is searched to add a neighboring cell through sniffing.

To this end, the LTE femtocell must successfully decode the primary synchronization signal (PSS), the secondary synchronization signal (SSS), the physical broadcast channel (PBCH), and the physical downlink shared channel (PDSCH). This is because it can synchronize with neighboring cells through the corresponding physical channels, or know the PCI (Physical Cell Identity), Cell ID and TAC (Tracking Area Code) of the neighboring cell.

In particular, PSS, SSS, and PBCH are specified to be allocated to the middle band, 1.4MHz regardless of the LTE frequency bandwidth. The 1.4 MHz band corresponds to 6 RB when converted into an RB (Resource Block) which is the minimum unit of resource allocation in LTE.

Sniffing to add neighboring cells is also very important because it also involves PCI allocations. Generally, in the case of a femtocell, there is a separately allocatable PCI range in order to distinguish it from neighboring macro cells and handover with a macro cell, and allocate PCI within this range.

In order for a femtocell to successfully perform sniffing, it is necessary to decode physical channels such as PSS, SSS, PBCH, and PDSCH. However, the strength of a signal level and a signal to interference and noise ratio (SINR) Therefore, in the femtocell where the current sniffing is to be performed, the signal level of the adjacent femtocell is low and the sniffing in the cell center area can not be performed. On the other hand, a handover in the boundary area of the cell is possible.

In this case, in the boundary interval between the femtocell and the adjacent femtocell in which the same PCI is allocated and the sniffing fails, the UE fails to perform the handover and the call disconnection occurs. Also, in the case of macrocells adjacent to both femtocells, PCI is confused at the time of handover.

Accordingly, the present invention provides a system and method for allocating a PCI of a femtocell, and a method of detecting a PCI collision of a femtocell by sniffing a broadcast message through output amplification.

According to an aspect of the present invention, there is provided a femtocell network in which a first femtocell and a home eNodeB Management Server (HeMS) are connected, a physical cell identity (PCI) The method for allocating PCI to the first femtocell by the allocating device includes:

Allocating a temporary PCI to the first femtocell that has been booted; transmitting the femtocell message including the temporary PCI and the femtocell information on the first femtocell to an amplified And outputting a PCI to the first femtocell according to whether a PCI relocation request signal is transmitted within a predetermined time from the HeMS, PCI. ≪ / RTI >

Wherein the determining of the final PCI comprises: maintaining a cell barred state such that terminals entering the first femtocell region can not access the first femtocell; driving a timer for the predetermined time; And if the PCI reallocation request signal is received from the HeMS before the driven timer expires, allocating another PCI different from the temporary PCI to determine the final PCI.

If the PCI reallocation request signal is not received from the HeMS while the timer is being driven after the step of driving the timer, determining the temporary PCI to be the final PCI.

According to another aspect of the present invention, there is provided a femtocell system including a first femtocell and a second femtocell forming a femtocell, and a Home eNodeB Management Server (HeMS) managing the first femtocell and the second femtocell, The method of detecting PCI for the first femtocell in which the second femtocell is booted,

The method comprising the steps of: sniffing a femtocell message broadcasted from the first femtocell and including a PCI of the first femtocell and a cell ID of the first femtocell; comparing the PCI allocated to the second femtocell and the PCI of the first femtocell And transmitting the PCI collision notification signal including the cell ID of the first femtocell and the PCI to the HeMS when the two PCIs coincide with each other.

Wherein the femtocell message broadcasted from the first femtocell is a message broadcast in an amplified signal output mode capable of transmitting a message with a wider coverage than the normal mode femtocell coverage, PBCH, and PDSCH, to a 6RB bandwidth of 1.4MHz.

According to another aspect of the present invention, there is provided a method for providing a physical cell identity (PCI) to a first femtocell that is booted in a femtocell network environment in which a first femtocell and a home eNodeB Management Server (HeMS) Lt; RTI ID = 0.0 >

A PCI allocation unit allocating a temporary PCI to the first femtocell that is booted and generating a femtocell message including the temporary PCI and the femtocell information about the first femtocell when the signal output mode is wider than the femtocell coverage in the normal mode And a message transmission / reception unit for broadcasting the femtocell message in accordance with the signal output mode converted by the output mode conversion unit.

When the femtocell message is broadcast according to the converted signal output mode, the output mode conversion unit drives a timer function to maintain a cell barred state until a final PCI is allocated to the first femtocell .

When the PCI reassignment request signal transmitted from the HeMS is received from the message transmission / reception unit, the PCI allocation unit may allocate another PCI different from the already allocated temporary PCI to the final PCI.

The neighbor cell search unit may transmit a PCI collision notification signal including the cell ID and the PCI of the neighbor femtocell to the HeMS when the PCI included in the neighbor femtocell message matches the PCI assigned to the neighbor femtocell message.

According to the present invention, when the PCI is selected in the femtocell, it is detected that the same PCI as the adjacent femtocell is selected and avoiding the same PCI is selected, thereby preventing the handover failure and the quality deterioration in the cell boundary.

1 is a diagram illustrating an example of PCI allocation in a general femtocell installation environment.
2 is an exemplary diagram of PCI confusion in a typical femtocell installation environment.
FIG. 3 is a diagram illustrating an example of failure of PCI detection in a general femtocell installation environment.
4 is an exemplary diagram illustrating an environment in which a PCI allocation system according to an embodiment of the present invention is applied.
5 is a structural diagram of a PCI allocation system according to an embodiment of the present invention.
6 is a flowchart of a PCI allocation and collision detection method according to an embodiment of the present invention.
FIG. 7 is a diagram illustrating allocation of resources for amplifying an output in a femtocell according to an embodiment of the present invention. Referring to FIG.
8 is a structural diagram of a femtocell base station apparatus according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

In this specification, a base station (BS) is an access point (AP), a radio access station (RAS), a node B, a base transceiver station (BTS) Mobile Multihop Relay) -BS, and may include all or some of the functions of an access point, a radio access station, a Node B, a base transceiver station, and an MMR-BS.

Hereinafter, a PCI allocation system and a PCI allocation method for a femtocell according to an embodiment of the present invention and a collision detection method using the same will be described in detail with reference to the drawings. Before describing the embodiment of the present invention, a case where a PCI is allocated and a PCI is not detected in a general femtocell installation environment will be described with reference to FIGS.

1 is a diagram illustrating an example of PCI allocation in a general femtocell installation environment.

It is assumed that the femtocell 1 10 and the femtocell 2 20 are already operating and the femtocell 3 30 is preparing for operation as shown in FIG. Then, the femtocell 3 (30) sniffs neighboring cells and adds neighboring cells.

If there is a femtocell among the added neighbor cells, the neighboring femtocell (femtocell 1 10, femtocell 2 20) of the PCI range possessed by the femtocell 3 (30) Gt; PCI < / RTI > For example, assuming that the PCI of the femtocell 1 10 is assigned 1 and the PCI of the femtocell 2 20 is assigned 2, the PCI range of the newly installed femtocell 3 30 is 1, 2, 3.

Then, the femtocell 3 (30) checks the PCI allocated to neighboring cells through sniffing, and allocates the PCI to 3 for use.

On the other hand, FIG. 1 (b) shows a case where sniffing fails even though there is a femtocell among adjacent cells. When the femtocell 3 30 has confirmed the femtocell 1 10 through the sniffing but misses the femtocell 2 20, the femtocell 3 30 receives 2 and 3 excluding the 1 allocated to the femtocell 1 10 in the PCI range PCI will be chosen randomly in triple. At this time, if the femtocell 3 (30) selects 2 as the PCI, it allocates the same PCI as the femtocell 2 (20). In this case, handover with the adjacent femtocell is impossible.

2 is an exemplary diagram of PCI confusion in a typical femtocell installation environment.

As shown in FIG. 2, macrocells 40 exist in two femtocells (femtocell 1 10, femtocell 2 20) in which the same PCI is allocated. In this case, when receiving the PCI for handover from the terminal in the macro cell area, the macro cell can not know to which femtocell of the two femtocells 10 and 20 the terminal should be handed over, do.

FIG. 3 is a diagram illustrating an example of failure of PCI detection in a general femtocell installation environment.

FIG. 3 shows the difference between the sniffing area of the femtocell and the handover area, which is considered as the coverage of the femtocell. Since sniffing is basically performed through a separate circuit in the femtocell equipment, it can be seen that sniffing is performed in the central area of the femtocell. On the other hand, since the handover is performed in the boundary area with the adjacent cell, it can be regarded as the boundary area of the cell.

3, if the femtocell 1 10 and the femtocell 2 20 fail to sniff and can not add each other as neighboring cells, the femtocell 1 10 and the femtocell 2 20 transmit the femtocell 2 PCI will not be detected.

Therefore, in the embodiment of the present invention, a PCI allocation system, a PCI allocation method, and a collision avoiding method using the same will be described in which a femtocell detects that a femtocell has allocated the same PCI as neighboring cells and detects a PCI collision. In the embodiment of the present invention, it is described that the femtocell base station apparatus is implemented in a form including the PCI allocation system 100, but it is not necessarily limited thereto. In the embodiment of the present invention, the femtocell base station apparatus is referred to as a 'femtocell' for convenience of explanation.

4 is an exemplary diagram illustrating an environment in which a PCI allocation system according to an embodiment of the present invention is applied.

4, the first femtocell 10 'and the second femtocell 20' form a femto network with adjacent cells, and the first femtocell 10 'and the second femtocell 20' (Home eNodeB Management Server) 50, which is a server for managing a femtocell.

Then, the first femtocell 10 'and the second femtocell 20' sniff the femtocell message (for example, SystemInformationBlcok) broadcast to provide system information for each femtocell, And collects the femtocell information for the adjacent cell. At this time, each femtocell senses whether or not there is a PCI collision with a neighbor cell, and if a PCI collision is detected, the HeMS 50 generates an alert to notify that the neighboring cell should reallocate the PCI.

At this time, when the femtocell is first installed and rebooted, the femtocell message broadcasted by each femtocell amplifies and broadcasts only the femtocell message broadcasted first after booting so as to be farther than the normal femtocell coverage. That is, as shown in FIG. 4, since the sniffing is basically performed through a separate circuit in the femtocell, the sniffing is performed in the center area a of the coverage area of the femtocell. On the other hand, since the handover is performed in the boundary area with the adjacent cell, it can be regarded as the boundary area (b) of the cell.

Therefore, as shown in FIG. 4, when the first femtocell 10 'and the second femtocell 20' fail to sniff and fail to add each other as neighboring cells, the first femtocell 10 'and the second femtocell 20' ') Are assigned the same PCI. This can obstruct the determination of which femtocell area the terminal located at the boundary between the first femtocell 10 'and the second femtocell 20' handover to.

Therefore, in the embodiment of the present invention, in order to detect that the femtocell has allocated the same PCI as the adjacent cell and to avoid the PCI conflict, when broadcasting the femtocell message after booting, the femtocell message whose output is amplified is broadcast (c )do. Then, neighboring cells sniff the femtocell message whose output is amplified to check the PCI for the neighboring cell, and the same PCI as its own PCI is allocated to detect whether a collision occurs.

The structure of the PCI allocation system 100 installed in the femtocell base station apparatus in this environment will be described with reference to FIG.

5 is a structural diagram of a PCI allocation system according to an embodiment of the present invention.

5, the PCI allocation system 100 includes a neighbor cell search unit 110, a PCI allocation unit 120, an output mode conversion unit 130, and a message transmission / reception unit 140.

When the femtocell is first installed and booted, or when the femtocell power is changed from the off-state to the on-state and rebooted, the neighboring cell search unit 110 sniffs the femtocell message broadcasted from the adjacent cell according to a predetermined period. In an embodiment of the present invention, a femtocell to be initially installed and booted or a femtocell to be rebooted is referred to as a 'target femtocell' for convenience of explanation. The femtocell or macrocell located in the vicinity of the target femtocell is referred to as an 'adjacent cell'.

Here, it is assumed that the PCI, the cell ID, and the TAC broadcasted from the adjacent cell are included, but the present invention is not limited thereto. The neighbor cell search unit 110 compares the PCI included in the sniffed femtocell message with the PCI allocated to the femtocell itself in which the PCI allocation system 100 is implemented. If the PCI included in the femtocell message coincides with the PCI assigned to the femtocell message, the cell ID of the neighbor cell broadcasting the femtocell message to the HeMS 50, which is a server for managing the femtocell, And transmits a PCI conflict notification message.

The PCI allocator 120 allocates a temporary PCI to the target femtocell. At this time, the temporary PCI allocated to the target femtocell is used as the final PCI for the femtocell if the reassignment instruction of the PCI is not transmitted from the HeMS 50. [

The PCI allocator 120 generates a femtocell message including the temporary PCI and the cell ID and the TAC allocated to the target femtocell. Here, the femtocell message is allocated at 1.4 MHz, which is the middle of the resources allocated to the femtocell. That is, the information to be broadcasted through the femtocell message includes the cell ID, the TAC, and the temporary PCI.

The cell ID and the TAC are transmitted through the PDSCH physical channel included in SIB1 (System Information Block Type 1), and the temporary PCI is transmitted through the PSS or SSS physical channel. And another physical channel, PBCH, is basically assigned to 1.4MHz, which is the center of the resource.

When the PCI allocation unit 120 receives a PCI reassignment instruction from the HeMS 50, the PCI allocation unit 120 reassigns the PCI to the target femtocell different from the preliminarily allocated temporary PCI.

When the PCI allocator 120 allocates the temporary PCI to generate the femtocell message, the output mode converter 130 converts the output mode so that the femtocell message is broadcast in the amplification mode. Herein, the amplification mode refers to a mode in which a signal containing a message is amplified and transmitted so as to exhibit a wider femtocell coverage than the normal mode femtocell coverage shown in FIG. In the embodiment of the present invention, the femtocell message is amplified and transmitted after the target femtocell is booted, and the amplification mode can be repeated when the HeMS 50 instructs the PCI reallocation.

The output mode conversion unit 130 drives the timer function provided in the output mode conversion unit 130 for a predetermined time during which the femtocell message is broadcast in the amplification mode. At this time, the time of the timer to be activated is controlled so that the femtocell base station apparatus implementing the PCI allocation system 100 can not transmit the RF signal to the terminals located in the femtocell region, and whether or not the PCI reassignment instruction is transmitted from the HeMS 50 It is time to wait to confirm.

For this, the output mode conversion unit 130 performs a timer function to maintain a cell barrier state until a final PCI is assigned to a target femtocell by successfully sniffing a femtocell message broadcasted by the target femtocell by neighbor cells . In the embodiment of the present invention, the output mode conversion unit 130 adjusts a parameter (for example, CellBarred) to prevent the terminal from connecting to the base station.

The message transmission / reception unit 140 broadcasts the femtocell message generated by the PCI allocation unit 120 into the femtocell region according to the amplification mode converted by the output mode conversion unit 130. Upon receiving the PCI relocation request signal from the HeMS 50, the PCI relocation request signal is transmitted to the PCI allocating unit 120.

A method of allocating PCI based on the PCI allocation system 100 described above and detecting a collision of PCI will be described with reference to FIG.

6 is a flowchart of a PCI allocation and collision detection method according to an embodiment of the present invention.

6, the target femtocell 10 'sniffs the femtocell message broadcasted from the neighbor cell (step S100), and the target femtocell 10' , And when the sniffing succeeds, the neighboring cell is added as a neighboring cell.

Then, in step S101, temporary PCI is allocated to the target femtocell 10 'except for the PCIs of the neighboring cells within the range where the target femtocell 10' can allocate the PCI. Here, if the target femtocell 10 'is initially installed and booted, a procedure for acquiring the cell ID and the TAC for the target femtocell is performed before performing the adjacent cell sniffing procedure according to step S101, The detailed description will be omitted in the embodiment of the present invention.

Meanwhile, in the process of performing the sniffing procedure in which the target femtocell 10 'is booted up, the neighboring cell 20' to which the PCI is assigned as X is normally operating (S102) It is assumed that the femtocell message is sniffed (S103). At this time, if the target femtocell 10 'fails to sniff the neighboring cell 20', or if the sniffing range of the target femtocell 10 'and the adjacent cell 20' does not overlap each other, The target femtocell 10 'can not confirm the PCI of the neighboring cell 20'. Accordingly, the temporary PCI allocated to the target femtocell 10 'in step S101 may be the same as the PCI of the neighboring cell 20'.

Therefore, the target femtocell 10 'converts the signal output mode to the output amplification mode (S104), and broadcasts the femtocell message to the amplified output (S105). Here, the femtocell message is broadcast according to a predetermined period, and the amplification mode may be repeated when there is an instruction to reallocate the PCI.

In order to broadcast the femtocell message with the amplified output, the target femtocell 10 'includes the cell ID, the TAC, and the provisional PCI allocated in step S101 in the 1.4-MHz bandwidth of the existing bandwidth. That is, the PDSCH physical channel, the SSS, the PSS physical channel, and the PBCH physical channel are allocated to the 1.4 MHz bandwidth. Then, the timer is driven for a preset time so that the output amplification mode is maintained only while the timer expires.

The target femtocell 10 'broadcasting the femtocell message with the amplified output keeps the cell blocking state so that the terminals entering the femtocell region formed by the target femtocell 10' can not access the target femtocell 10 ' do. At the same time, the timer is driven for a preset time (S106).

Here, an example of allocating resources to amplify the output of a broadcast femtocell message in order to increase the sniffing success rate according to an embodiment of the present invention will be described with reference to FIG.

FIG. 7 is a diagram illustrating allocation of resources for amplifying an output in a femtocell according to an embodiment of the present invention. Referring to FIG.

As shown in FIG. 7A, in the LTE, the downlink physical channels (PSS / SSS / PBCH) including the cell synchronization and frequency, PCI, bandwidth, (6RB). As shown in FIG. 7 (b), if the PDSCH, which is a physical channel having additional cell ID and TAC information, can be allocated to the downlink physical channels, it is possible to allocate the LTE minimum The cell can be configured with only the bandwidth of 1.4MHz.

When the PDSCH is to be allocated to 1.4 MHz, the PCI allocation system 100 adjusts the Modulation and Coding Scheme (MCS) of the PDSCH and allocates the PDSCH to the 1.4 MHz bandwidth. This is a normal LTE cell that can be serviced, and can be added as a neighbor cell by sniffing it in a femtocell. Here, the method of adjusting the MCS of the PDSCH can be performed by various methods, and the embodiments of the present invention are not described in detail by any one method.

If a femtocell provides a service with a bandwidth of 20 MHz (100 RB) as shown in FIG. 7 (a), when the service is provided at 1.4 MHz (6 RB) as shown in (b), the output per RB is at least 12 dB (100/6)). This has the same effect as increasing the coverage of the femtocell by more than 12dB.

Thus, the output amplification mode for sniffing is limited to operate in the output amplification mode only when the femtocell is first installed and booted, or when the femtocell is first rebooted, when it broadcasts the femtocell message for the first time. This is to increase the sniffing success rate so that the femtocell is sniffed in the adjacent cell to determine whether the same PCI is used.

6, the parameter is adjusted so that the terminal does not actually receive the service from the cell that maintains the output amplification mode according to the step S106, thereby maintaining the cell cutoff state and driving the timer. Then, the adjacent cell 20 'sniffs the femtocell message broadcasted from the target femtocell 10' with the amplified output, and transmits the cell ID of the target femtocell 10 ', the cell ID of the target femtocell 10' The femtocell setting information such as the cell synchronization, the frequency, and the like of the mobile station 100 are collected (S107).

The neighboring cell 20 'can confirm that the PCI of the target femtocell 10' is the same as the PCI of the neighboring cell based on the femtocell setting information collected in step S107. Accordingly, the adjacent cell 20 'generates a PCI collision detection alarm signal and transmits it to the HeMS 50 (S108, S109). Here, the PCI collision detection alarm signal includes the cell ID of the PCI and the target femtocell of the neighboring cell 20 'itself.

The HeMS 50 searches for the target femtocell based on the cell ID included in the PCI collision notification signal received in step S109, and instructs the target femtocell to relocate the PCI to the target femtocell (S110, S113).

Meanwhile, in step S106, the target femtocell 10 'that has driven the timer continuously checks whether the timer is ended (S111). If the timer has not been terminated, it is checked whether there is a PCI reassignment instruction signal transmitted from the HeMS 50 (S112). If the PCI reassignment indication signal is not transmitted, the target femtocell 10 'waits until the timer expires.

However, if it is determined in step S111 that the timer has expired, the target 00 femtocell 10 'checks whether the PCI reallocation instruction is received from the HeMS 50 (S114). If the timer is terminated and the PCI relocation instruction signal is not transmitted from the HeMS 50, the target femtocell 10 'determines the provisional PCI temporarily allocated in step S102 as its own PCI. After the cell cutoff state set in step S106 is canceled, a service is provided to the terminals entering the cell area of the target femtocell 10 '(S116).

However, if the PCI reallocation instruction signal is received from the HeMS 50 before the timer ends, the target femtocell 10 'is reallocated except for the PCI in step S115. Then, in step S104, it is converted into the output amplification mode to check again whether the reassigned PCI is collided. This procedure is repeated until the PCI reassignment indication is not received from the HeMS 50. [

After terminating the cell blocking state set in step S106, the mobile station starts to provide services to the terminals that have entered the cell area of the target femtocell 10 '(S116). In the embodiment of the present invention, it is explained that the PCI collision on the reassigned PCI is not immediately detected, but it is not necessarily limited thereto.

Next, a structure of a femtocell base station apparatus to which the PCI allocation system 100 is applied will be described with reference to FIG. 8 according to an embodiment of the present invention.

8 is a structural diagram of a femtocell base station apparatus according to an embodiment of the present invention.

The functions of the neighbor cell search unit 110, the PCI allocation unit 120, and the output mode conversion unit 130 described with reference to FIG. 5 are performed by the control unit 11 shown in FIG. The control unit 11 performs different functions according to whether the femtocell base station apparatus is a target femtocell or an adjacent femtocell.

That is, when the femtocell is first installed or booted, or when the power of the femtocell is changed from the off-state to the on-state and rebooted, the control unit 11 sniffs the message broadcast in the neighboring cell.

The control unit 11 allocates a temporary PCI to the target femtocell, and converts the output mode so that the femtocell message can be amplified and broadcast in the amplification mode. In addition, when the femtocell message is broadcast in the amplification mode, the controller 11 controls the communication unit 12 to maintain the cell cutoff state. Then, the control unit 11 waits for a check to see whether the PCI reassignment instruction is transmitted from the HeMS 50 The timer 13 is driven for a predetermined time.

If the femtocell base station apparatus is the target femtocell, the controller 11 successfully sniffs the femtocell message broadcasted by the target femtocell by the adjacent cells, and maintains the cell blocking state until the PCI is finally allocated to the target femtocell. 12).

If the femtocell base station apparatus is an adjacent femtocell, the control unit 11 checks the PCI of the target femtocell that has sniffed and compares the PCI of the target femtocell with its own PCI. When the PCI of the neighbor cell coincides with the PCI of the neighboring cell, the HeMS 50 generates a collision notification signal for notifying the collision of the PCI, and transmits the collision notification signal through the communication unit 12.

The storage unit 14 stores a program for sniffing a message broadcast in a neighboring cell, temporarily allocated PCI information, and various programs for driving the femtocell base station apparatus.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

Claims (12)

A method for allocating a PCI to a first femtocell in a femtocell network environment in which a first femtocell and a home eNodeB management server are connected, wherein a PCI (Physical Cell Identity) allocating device included in the first femtocell allocates PCI to the first femtocell,
Allocating a temporary PCI to the first femtocell that has been booted,
Broadcasting the femtocell message including the temporary PCI and the femtocell information for the first femtocell in an amplified signal output mode capable of transmitting a message with coverage larger than the femtocell coverage in the normal mode,
Determining, as a last PCI of the first femtocell, any of PCIs different from the temporary PCI or the temporary PCI according to whether a PCI relocation request signal is transmitted within a predetermined time from the HeMS
/ RTI > The method according to claim 1,
Wherein the step of determining the final PCI comprises:
Maintaining a cell blocking state such that terminals entering the first femtocell region can not access the first femtocell;
Driving the timer for the predetermined time, and
When receiving a PCI reassignment request signal from the HeMS before the driven timer expires, allocating another PCI different from the temporary PCI to determine a final PCI
/ RTI > 3. The method of claim 2,
After the step of driving the timer,
If the PCI reallocation request signal is not received from the HeMS while the timer is being driven, determining the temporary PCI to be the final PCI
/ RTI > The method according to claim 1,
Wherein the femtocell message includes a temporary PCI of the first femtocell, a cell ID of the first femtocell, and a TAC for the first femtocell,
Wherein the femtocell message is allocated to a 6-RB (Resource Block) bandwidth of 1.4 MHz such that the femtocell message is transmitted through physical channels PSS, SSS, PBCH, and PDSCH. The first femtocell and the second femtocell form a femtocell, and in an environment where the first femtocell and the home eNodeB management server (HeMS) managing the second femtocell are connected, the first femtocell A method for detecting PCI for a processor,
A femtocell message including a cell ID of the first femtocell and a PCI of the first femtocell is broadcast in an amplified signal output mode capable of transmitting a message from the first femtocell to a wider coverage than the femtocell coverage in the normal mode, ,
Comparing the PCI allocated to the second femtocell with the PCI of the first femtocell included in the femtocell message, and
If the two PCIs match, transmitting a PCI conflict notification signal including the cell ID of the first femtocell and PCI to the HeMS
/ RTI > 6. The method of claim 5,
Wherein the femtocell message is allocated to a 6-RB bandwidth of 1.4 MHz such that the femtocell message is transmitted through physical channels PSS, SSS, PBCH, and PDSCH. A system for allocating a PCI (Physical Cell Identity) to a first femtocell that is booted in a femtone network environment in which a first femtocell and a home eNodeB Management Server (HeMS) are connected,
A PCI allocating unit allocating a temporary PCI to the first femtocell that is booted and generating a femtocell message including the temporary PCI and the femtocell information about the first femtocell,
The signal output mode is switched to an amplified signal output mode capable of transmitting a message with a wider coverage than the femtocell coverage in the normal mode and if the femtocell message is broadcast according to the converted signal output mode, An output mode conversion unit for driving a timer function to maintain a cell barred state until a final PCI is allocated, and
A message transmission / reception unit for broadcasting the femtocell message according to the signal output mode converted by the output mode conversion unit,
/ RTI > delete 8. The method of claim 7,
The PCI allocating unit allocates,
Receiving a PCI reassignment request signal transmitted from the HeMS from the message transmission / reception unit, allocating another PCI different from the already allocated temporary PCI to the final PCI. 8. The method of claim 7,
A neighbor femtocell message broadcasted from an adjacent femtocell connected to the HeMS is sniffed and a neighbor cell search unit for checking whether a PCI included in an adjacent femtocell message matches a PCI allocated to the first femtocell,
Further comprising: 11. The method of claim 10,
Wherein the neighboring cell searching unit comprises:
And transmits a PCI collision notification signal including the cell ID and the PCI of the neighbor femtocell to the HeMS when the PCI included in the neighbor femtocell message matches the PCI assigned to the neighbor femtocell message. 8. The method of claim 7,
The femtocell message is transmitted at a frequency of 6 RBs (1.4 MHz) to be transmitted through the PSS, the SSS, the PBCH, and the PDSCH including the temporary PCI of the first femtocell, the cell ID of the first femtocell, and the TAC for the first femtocell, (PCI) allocation system assigned to a resource block bandwidth.

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