KR20100092742A - A communication system for access control during active handover toward a csg cell and a method thereof - Google Patents

Abstract

PURPOSE: A system for controlling access during handover to a CSG base station of a terminal and a method thereof are provided to efficiently determine whether a terminal accesses the CSG base station and whether the terminal receives a service, thereby controlling handover of the terminal. CONSTITUTION: A serving eNB(evolved-NodeB)(302) allows a terminal(301) to handover to a CSG(Closed Subscriber Group) cell. A serving MME(Mobility Management Entity)(303) transfers an allowed CSG list of the terminal to a target MME(304). A target eNB(305) transfers a CSG ID of a target CSG cell to the target MME after handover of the terminal. The target MME checks whether the terminal performing the handover is able to receive a service in the target CSG cell. The target MME continuously performs or stops the handover of the terminal.

Description

A communication system for access control during active handover toward a CSG cell and a method

The present invention relates to a wireless communication system for handover and a method therefor, and more particularly, to a communication system and a handover method for controlling handover of a terminal when the terminal hands over to a CSG base station.

The wireless communication network is based on a cellular system, and a wireless communication network in which macro and CSG cells (closed subscriber group cells) are mixed among these cellular systems will be described. A CSG cell or a femto cell refers to a cell that can cover a very small range in a cellular system, and a base station for managing such a CSG cell is called a tentative CSG base station (or femto base station). Meanwhile, 3GPP Long Term Evolution (LTE) has defined a base station called an evolved NodeB (eNB) and a home evolved NodeB (home eNB). The dual eNB is a macro base station that manages a typical macro cell, and a home eNB is an example of a CSG base station that manages a CSG cell.

1 is a view for explaining a configuration of a wireless communication network in which a macro cell and a CSG cell are mixed.

Referring to FIG. 1, a wireless communication network according to an embodiment of the present invention includes a core network including a mobility management entity (MME) 105 and an evolved NodeB (eNB) 102 connected to the MME 105. ), A Closed Subscriber Group (CSG) base station (HeNB, Home eNB) 103, a macro base station (eNB) 102, and a CSG base station (HeNB), which are connected through an MME 105 and a gateway (HeNB GW) 104. A user terminal (hereinafter abbreviated as " terminal ") 101 that wirelessly connects to 103. At this time, the HeNB GW 104 may not be installed among the network components.

The CSG cell broadcasts its CSG Identity (CSG Identity) to a System Information Block (SIB). The UE has CSG ID information of the CSG cell to which it can access as a UE Allowed CSG list, and if it reads the SIB of the CSG cell, it can determine whether it is a CSG cell to which it can access. The core network including the MME 105 also has such a UE Allowed CSG list.

2 is a diagram illustrating a handover method from a macro base station to a macro base station.

Referring to FIG. 2, in step 206, the terminal 201 detects a signal of the target cell 205 and reports a measurement to the serving cell 202. Then, the serving base station 202 analyzes the measurement report (measurement report) received in step 207 to determine who the target cell of the terminal and based on the Tracking Area ID (TAI), the frequency band used, etc. of the target cell 205 After determining the handover of the UE in step 208, the handover request message is transmitted to the MME 203 in step 208. Then, if necessary, the source MME 203 of the serving base station 202 transmits a handover request message to the target MME 204 connected to the target base station 205 in step 209, and the target MME 204 steps 210. Transmits a handover request message to the target base station 205. However, if the source MME 203 manages the target base station 205, there is no need to re-request a handover to a separate target MME 204, which will apply equally below.

Thereafter, the target base station 205 transmits an Ack that the target MME 204 can receive a handover (HO) in step 211, and the target MME 204 performs handover to the source MME 203 in step 212. Inform them that you can. Then, the source MME 203 commands the handover of the terminal to the serving base station 202 in step 213, and the serving base station 202 instructs the terminal 201 to handover the target cell 205 in step 214.

Thereafter, the terminal 201 performs a handover to the target cell 205 in step 215, and the target base station 205 informs the target MME 204 that the HO is completed in step 216. The target MME 204 informs the source MME 203 that the UE has completed HO in step 217, and the source MME 203 transmits ack information in step 218 and serves to erase all UE-related information in step 219. Commanding the base station 202, the serving base station 202 recovers the terminal information and the resources used by the terminal in step 220 and notifies the source MME (203).

However, when the above procedure is applied to an active handover of a terminal from a macro base station to another CSG base station, there is no method of determining whether the terminal performing the handover is a terminal accessible to the target CSG base station. Accordingly, in order to solve this problem, the present invention proposes an access control method for examining whether a terminal can access a CSG base station and receive a service when the HO is connected to a CSG base station.

Accordingly, an object of the present invention is to provide a wireless communication network for performing access control in which a core network can check whether a terminal can access a CSG base station and receive a service when the active terminal is connected to the CSG base station. And to provide a system for this.

In a wireless communication network in which a macro base station and a closed subscriber group (CSG) base station are mixed, a system for reporting a measurement of a wireless communication network according to an embodiment of the present invention includes: a serving base station allowing handover to a CSG cell by a terminal; A handover based on the serving MME which delivers the access allowance list of the terminal to the target MME, the target base station which delivers the CSG ID of the target CSG cell to the target MME after performing the handover of the terminal, and the CSG ID reported by the target base station. It is characterized by including the MME to continue or stop the handover by checking whether the terminal that has performed the UE that can be serviced in the target CSG cell.

In addition, the access control method for handover of a wireless communication system in which a macro base station and a CSG base station are mixed according to an embodiment of the present invention, the MME of the serving base station with a handover request message to the target side when the handover is required, Transmitting the access permission list, performing a handover between the terminal and the target base station, transmitting, by the target CSG base station, the CSG ID of the target cell to which the terminal accesses, and the target MME; Checking whether the CSG ID of the target cell is included in the access permission list of the terminal; and if the CSG ID of the target cell is included in the UE allowed access list, the MME completes handover of the UE normally. It is characterized in that it consists of a process of releasing the terminal information and the resources used by the terminal through the serving base station.

If the CSG ID of the target cell is not included in the access permission list of the terminal, the target MME notifies the target CSG base station and the source MME of the handover failure, and the target base station releases the RRC connection with the terminal. Characterized in that the process further comprises.

In addition, according to an embodiment of the present invention, the access control method for handover of a wireless communication system in which a macro base station and a CSG base station are mixed includes a process of requesting a handover from a serving base station to a target base station when a handover of the terminal is required; Performing a handover between the target base station and the target base station, transmitting the CSG ID to the MME by the target CSG base station, and checking whether the MSG includes the CSG ID of the target cell in an access allow list of the terminal; Process, and if the CSG ID of the target cell is included in the UE allowed access list, the MME detects that the handover of the UE is normally completed, and releases UE information and resources used by the UE through the serving base station. Characterized in that made.

According to the present invention, when handover of an active terminal to a CSG base station, it is possible to control the handover of the terminal by efficiently review / determine in the core network whether the terminal can access the CSG base station.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts will be omitted so as not to distract from the gist of the present invention.

A wireless communication network according to an embodiment of the present invention assumes a cellular system in which a macro cell and a CSG cell are mixed. Hereinafter, only an embodiment in which the macro base station is a serving base station will be described, but the present invention also includes a case in which the serving base station is a CSG base station. In the present invention, when there is no great confusion, the base station and the cell are used in parallel with each other.

The first embodiment of the present invention relates to a procedure in which a handover succeeds by a UE attempting a handover through an MME to a CSG cell permitted by a macro base station.

When the serving base station needs handover of the terminal, the serving base station requests a handover without determining whether the target CSG base station is accessible. The source MME transmits an access permission list of the terminal with a handover request message to the target side. Upon handover, the target CSG base station transmits the CSG ID of the cell to which the terminal is connected when the target MME notifies the terminal of the handover completion. Then, the target MME checks whether the target base station includes the CSG ID of the target cell to which the terminal is handed over in the UE Allowed CSG List received from the source MME upon the handover request. At this time, if the CSG ID of the target cell is included in the access allowance list of the terminal, the target MME informs the source MME that the handover of the terminal is normally completed (Forward Relocation Complete), the source MME through the serving base station terminal information and Release the resources used by the terminal.

The second embodiment of the present invention relates to a procedure when the terminal fails to perform a handover through the MME to the CSG cell which is not allowed in the macro base station.

When the serving base station requires handover of the terminal, the serving base station requests handover without determining whether the target CSG base station is accessible, and the source MME transmits an access permission list of the terminal with a handover request message to the target side. Upon handover, the target CSG base station transmits the CSG ID of the cell to which the terminal is connected when the target MME notifies the terminal of the handover completion. Then, the target MME checks whether the target base station includes the CSG ID of the target cell to which the terminal is handed over in the UE Allowed CSG List received from the source MME upon the handover request. At this time, if the CSG ID is not included in the access permission list of the terminal, the target MME informs the source MME that the handover of the terminal is denied, and transmits a terminal access release command to the target CSG base station. The target CSG base station then blocks the terminal's use of the CSG base station and reports it to the target MME. The source MME instructs the serving base station to erase all terminal related information, and the serving base station recovers the terminal information and resources used by the terminal.

The third embodiment of the present invention relates to a procedure in which the handover succeeds by attempting a handover through a direct connection (ie, an X2 interface) to a CSG cell permitted by a macro base station.

When the serving base station needs handover of the terminal, the serving base station requests handover to the target cell side without determining whether the target CSG base station is accessible, and the target cell approves the handover request. Thereafter, a handover procedure is performed between the terminal and the target base station, and the target base station transmits the CSG ID of the CSG cell to which the terminal is connected to the MME. Then, the MME checks whether the target base station includes the CSG ID of the target cell handed over by the terminal in the UE Allowed CSG List. At this time, if the CSG ID of the target cell is included in the access permission list of the terminal, the MME informs the target cell and the serving base station, the target cell to block the access of the terminal, the serving base station terminal information and resources used by the terminal To release it.

In a wireless communication network in which a macro base station and a closed subscriber group (CSG) base station are mixed, a system for measuring and reporting a wireless communication network according to the first to third embodiments of the present invention is handovered to a CSG cell by a terminal. A serving base station that allows the serving base station; The terminal performing the handover based on the CSG ID reported by the base station includes an MME for continuously performing or stopping the handover by checking whether the terminal can be serviced by the target CSG cell.

A mobility control method according to the first embodiment-the third embodiment of the present invention will be described. A system for measurement report of a wireless communication network according to an embodiment of the present invention may use a wireless communication network in which a macro base station and a closed subscriber group (CSG) base station are mixed, and the configuration of the wireless communication network having the above configuration It can be configured as shown in FIG.

First embodiment

FIG. 3 is a diagram illustrating a case where a handover succeeds by attempting a handover through an MME to a CSG cell permitted by a macro base station.

Referring to FIG. 3, the terminal 301 detects a signal of the target cell 305 in step 306 and transmits a measurement report to the serving base station 302. The serving base station 302 then determines the handover of the terminal through the measurement report transmitted from the terminal 301. At this time, the serving base station 302 does not determine whether the terminal 301 is accessible to the target CSG base station 305 or not, and transmits a handover request message to the source MME 303 in step 308. If necessary, the source MME 303 transmits a UE Allowed CSG List with a handover request message to the target MME 304 having a connection with the target CSG base station 305 in step 309. 304 transmits a Handover Request message to the target CSG base station 305 in step 310. As described above, the serving base station 302 requests handover without determining whether the target CSG base station 305 is accessible when the terminal requires handover, and the source MME 303 requests a handover request to the target side. Along with the access permission list of the terminal.

Then, the target base station 305 transmits a response message (Handover request Ack) that can receive a HO to the target MME 304 in step 311, the target MME 304 handover to the source MME 303 in step 312 Forward Relocation Response. The source MME 303 then sends a handover command to the serving base station 302 in step 313, and the serving base station 302 hands over the target cell to the target cell in step 314. command).

Then, the terminal 301 performs a handover with the target CSG cell 305 in step 315. At this time, the target CSG base station 305 receives the handover confirm message (Handover confirm) transmitted in step 315 to recognize that the handover of the terminal has been performed, and in step 316 to perform the HO of the terminal to the target MME 304 Upon completion, the UE informs the CSG ID (Handover notify with CSG ID) of the cell to which the UE is connected. Then, the target MME 304 controls the access according to the access permission list of the UE in step 317 (Access Control based on UE Allowed CSG List). That is, the target MME 304 the CSG ID received together when the target base station 305 informs the handover of the terminal in step 316 to the UE Allowed CSG List received in step 309 Check if it is included. In this case, if the CSG ID transmitted in step 315 is included in the access control list received in step 309, the target MME 304 normally completes handover of the terminal to the source MME 303 in step 318 (Forward). Relocation Complete). In step 319, the source MME 303 responds to the target MME 304, and instructs the serving base station 302 to erase all terminal related information. The serving base station 302 recovers the terminal information and the resources used by the terminal in step 321 and informs the source MME 303 of the result. (UE context Release Complete)

Second embodiment

4 is a diagram illustrating a case in which a handover fails due to a UE attempting a handover through an MME to a CSG cell which is not permitted in a macro base station.

Referring to FIG. 4, the terminal 401 detects a signal of the target cell 405 and performs a measurement report to the serving cell 402 in step 406, and the serving base station 402 receives the measurement report in step 407. Determines the handover of the UE. In this case, the serving base station 402 does not determine whether the terminal 401 is connectable to the target CSG base station 405, and transmits a handover request message to the MME 403 in step 408. If necessary, the source MME 403 transmits a UE Allowed CSG List with the handover request message to the target MME 404 connected to the target CSG base station 405 in step 409. The target MME 404 transmits a handover request message to the target CSG base station 405 in step 410.

In step 411, the target base station 405 transmits a message (Handover Request Ack) to approve the handover request to the target MME 404. Then, the target MME 404 notifies the source MME 403 that handover can be performed in step 412, and the source MME 403 commands the handover of the terminal to the serving base station 402 in step 413, and the serving base station. In step 414, the terminal 401 commands the handover to the target base station.

Thereafter, the terminal 401 performs a handover to the target CSG cell 405. In this case, the target CSG base station 405 notifies the target MME 404 of the UE that the UE performs the HO and the CSG ID of the cell to which the UE accesses in step 416. In operation 417, the target MME 404 checks whether the received CSG ID is included in the access permission list. That is, the target MME 404 checks whether the CSG ID of step 415 is included in the access permission list of the terminal received in step 409.

Herein, operation 417 in operation 406 of FIG. 4 may be performed in the same manner as operation 317 in operation 306 of FIG. 3.

In this case, if it is detected in step 417 that the CSG ID of step 415 is not included in the access permission list of the UE, the target MME 404 determines that handover of the UE is denied to the source MME 403 in step 418. Forward Relocation Failure, and in step 419, a UE Context Release Command is transmitted to the target CSG base station 405. Then, the target CSG base station 405 blocks a UE's use of the CSG base station by transmitting a message (UE RRC Release message) for releasing the service of the terminal 401 in step 420, and release completion message of the terminal (step 421) UE Context Release Complete message) is transmitted to the target MME 404. In addition, the source MME 403 transmits a Forward Relocation Failure Ack message to the target MME 404 in step 419, and sends the serving MME 403 to the serving base station 402 to erase all terminal related information in step 422. Command In step 423, the serving base station 402 recovers the terminal information and the resources used by the terminal and reports it to the source MME 403.

FIG. 5 is a diagram illustrating in detail the operation of the target MME in FIGS. 3 and 4.

Referring to FIG. 5, when the CSG base station receives the handover performance completion report of the terminal and the CSG ID of the CSG cell connected to the terminal in step 501, the target MME 404 accesses the CSG cell accessed by the terminal in step 503. It is determined whether the terminal is accessible. That is, the target MME checks whether the CSG ID of the target CSG cell is included in the access permission list of the terminal transmitted from the source MME. If the target CSG ID is included in the access permission list, the target MME proceeds to step 505. If the access to the CSG base station is allowed, and the target CSG ID is not included in the access allow list, the process proceeds to step 507 to deny access to the CSG base station of the terminal.

Third embodiment

FIG. 6 is a diagram illustrating a case where a handover succeeds when a UE attempts handover through a direct connection (ie, an X2 interface) to a CSG cell permitted by a macro base station.

Referring to FIG. 6, in step 605, the terminal 601 detects a signal of the target cell 603 and posts a measurement report to the serving cell 602. Then, the serving base station 602 determines the handover of the terminal through the measurement report in step 606. In this case, the serving base station 602 does not determine whether the terminal 601 is accessible to the target CSG cell 603 in step 607, and delivers a handover request message to the target CSG cell 603. The target CSG cell 603 then informs the serving base station 602 that it can perform a handover in step 608. The serving base station 602 then instructs the terminal 601 to handover to the target cell in step 609.

Thereafter, the terminal 601 performs a handover to the target CSG cell 603 in step 610, and notifies the target CSG base station 603 of the result (Handover Confirm). At this time, the target CSG base station 603 informs the MME 604 of the handover of the terminal to the MME 604 and the CSG ID of the target cell to which the terminal is connected in step 611. Then, the MME 604 checks whether the CSG ID received in step 612 is included in the UE Allowed CSG List. In this case, if the CSG ID received in step 611 is included in the access allow list of the UE, the MME 604 notifies the target CSG base station 604 that the UE's HO is normally completed in step 613, and serves in step 614. The base station 602 is instructed to recover terminal information of the serving base station 602 and resources used by the terminal. The serving base station 602 then retrieves the terminal information and the user sources of the terminal and notifies the MME 604 of the UE Context Release Complete.

Embodiments of the present invention disclosed in the specification and drawings are only specific examples to easily explain the technical contents of the present invention and aid the understanding of the present invention, and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention can be carried out in addition to the embodiments disclosed herein.

1 is a view for explaining the configuration of a wireless communication network in which a macro cell and a CSG cell are mixed;

2 is a diagram illustrating a handover method from a macro base station to a macro base station;

3 is a diagram illustrating a case in which a handover succeeds when a UE attempts handover through an MME to a CSG cell permitted by a macro base station.

4 is a diagram illustrating a case in which a handover fails due to a UE attempting handover through an MME to a CSG cell not allowed in a macro base station;

FIG. 5 is a diagram illustrating details of an operation of a target MME in FIGS. 3 and 4.

FIG. 6 is a diagram illustrating a case where a handover succeeds by attempting a handover through a direct connection from a macro base station to a CSG cell permitted in FIG.

Claims (4)

In a wireless communication system in which a macro base station and a CSG base station are mixed, A serving base station which allows the terminal to handover to the CSG cell; A serving MME for delivering the allowed CSG list of the UE to the target MME; A target base station for delivering the CSG ID of the target CSG cell to the target MME after the UE performs handover; And a MME for continuously performing or stopping the handover by checking whether the terminal performing the handover based on the CSG ID reported by the target base station is a terminal that can be serviced in the target CSG cell. A method for controlling access during handover of a wireless communication system in which a macro base station and a CSG base station are mixed, Transmitting, by the MME of the serving base station, a handover request message with the handover request message to the target side when the handover of the terminal is required; Performing a handover between the terminal and the target base station; Transmitting, by the target CSG base station, a CSG ID of a target cell to which the terminal is connected to a target MME; Checking, by the target MME, whether a CSG ID of the target cell is included in an access permission list of the terminal; If the CSG ID of the target cell is included in the terminal allowed access list, the MME detects that the handover of the terminal is normally completed and releases the terminal information and resources used by the terminal through the serving base station. And said access control method. The method according to claim 2, wherein if the CSG ID of the target cell is not included in the access list of the terminal, the target MME notifies the target CSG base station and the source MME of the handover failure, and the target base station communicates with the terminal. The access control method further comprising the step of releasing the RRC connection. A method for controlling access during handover of a wireless communication system in which a macro base station and a CSG base station are mixed, Requesting a handover from the serving base station to the target base station when handover of the terminal is required; Performing a handover between the terminal and a target base station; Transmitting, by the target CSG base station, a CSG ID to an MME; Checking, by the MME, whether the CSG ID of the target cell is included in the access permission list of the terminal; If the CSG ID of the target cell is included in the terminal allowed access list, the MME detects that the handover of the terminal is normally completed and releases the terminal information and resources used by the terminal through the serving base station. And said access control method.

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