KR20130074597A - Method for supporting closed subscriber group in wireless communication system - Google Patents

Abstract

PURPOSE: A method for supporting a closed subscriber group (CSG) in a wireless communication system is provided to supply a service according as a base station subscribes to a mode of a CSG cell and a terminal subscribes to the CSG cell. CONSTITUTION: A base station periodically broadcasts system information (SI) including a CSG ID which identifies a CSG mode, which is an operation mode, and a CSG cell to a terminal (S400). The base station receives a call connection request from the terminal. The base station performs communication with the terminal according to the CSG mode of the CSG cell where the terminal is located and whether the terminal is the member of the CSG cell (S440). The SI includes at least one of a frequency band, which is allocated to the CSG cell, and the zone name of the CSG cell. [Reference numerals] (AA) Terminal; (BB) Base station; (EE) Check whether a CSG becomes a member of the terminal; (S400) SI including a CSG mode; (S420) Initial context setup request (CSG information); (S440) Communication depending on the CSG mode and a CSG member; (S450) Initial context modification request (CSG information); (S470) Communication depending on the changed CSG information

Description

METHOD FOR SUPPORTING CLOSED SUBSCRIBER GROUP IN WIRELESS COMMUNICATION SYSTEM BACKGROUND OF THE INVENTION [0001]

The present invention relates to wireless communication systems, and more particularly, to a method for supporting closed subscriber groups in a wireless communication system.

A Closed Subscriber Group (CSG) supports only a specific terminal among terminals subscribed to a service provider to access a specific cell area. That is, when a terminal subscribed to the CSG is located in the corresponding CSG cell, it can be connected via an intranet through its own gateway.

It is necessary to provide a service according to a setting mode of the CSG cell and a method differentiated according to whether the terminal joins the CSG cell.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for supporting a closed subscriber group (CSG) in a wireless communication system.

A method for supporting a Closed Subscriber Group (CSG) in a wireless communication system according to an embodiment of the present invention includes a CSG mode which is an operating mode and a system information including a CSG ID Information, SI), receiving a call connection request from the terminal, communicating with the terminal according to the CSG mode of the CSG cell in which the terminal is located, and whether the terminal is a member of the CSG cell .

The system information may further include at least one of a frequency band allocated to the CSG cell and a zone name of the CSG cell.

At least one of the CSG mode of the CSG cell and the information on whether the UE is a member of the CSG cell may be received from an MME (Mobility Management Entity).

The CSG mode may be at least one of a closed mode for providing a communication service only to a terminal that is a member of the CSG cell and a hybrid mode for providing a communication service for a terminal that is not a member of the CSG cell have.

The step of performing communication may handover or redire the UE to another cell when the CSG mode is the closed mode and the UE is not a member of the CSG cell.

The step of performing communication includes providing a quality of service (QoS) lower than that of a terminal that is a member of the CSG cell when the CSG mode is the hybrid mode and the UE is not a member of the CSG cell can do.

The step of performing communication may provide a zone service through a pre-allocated local gateway IP address when the UE is a member of the CSG cell.

The local gateway IP address may be pre-allocated to the MME for each CSG cell.

A method for a terminal to communicate in a CSG cell in a wireless communication system according to an embodiment of the present invention includes receiving a system information (SI) including a CSG mode identifying a CSG mode and a CSG ID, Periodically receiving the CSG cell list, comparing the CSG cell list of the subscriber station with the CSG ID, and transmitting UE capability information including the CSG cell list to the base station.

The CSG cell list may be stored in a Universal Subscriber Identity Module (USIM) of the UE.

A BS supporting a closed subscriber group (CSG) service according to an embodiment of the present invention includes system information including a CSG mode for operating a CSG cell and a CSG ID for identifying a CSG cell, (Radio Frequency) unit periodically broadcasts a call connection request message and receives a call connection request from the UE, and a CSG mode of the CSG cell in which the UE is located, And a control unit configured to control a service to be provided.

The CSG mode may be at least one of a closed mode for providing a communication service only to a terminal that is a member of the CSG cell and a hybrid mode for providing a communication service for a terminal that is not a member of the CSG cell have.

According to an exemplary embodiment of the present invention, the BS can provide better quality to a UE subscribing to a CSG cell by providing a service according to a mode of the CSG cell and whether the UE subscribes to the CSG cell.

FIG. 1 illustrates a network structure supporting a closed subscriber group (CSG) according to an embodiment of the present invention.
FIG. 2 shows cell-specific gateway information managed by the MME.
3 is a flowchart illustrating a method for supporting a CSG by a base station according to an embodiment of the present invention.
4 is a flowchart illustrating a CSG support method of a wireless communication system according to an embodiment of the present invention.
5 is a diagram illustrating a CSG supporting method of the base station 100 according to an embodiment of the present invention.
6 is a block diagram of a base station supporting a CSG service according to an embodiment of the present invention.

DETAILED DESCRIPTION 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 may easily implement 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 the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts 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.

Also, the term "part" in the description means a unit for processing at least one function or operation, which may be implemented by hardware, software, or a combination of hardware and software.

In this specification, a terminal includes a mobile station (MS), a mobile terminal (MT), a subscriber station (SS), a portable subscriber station (PSS), a user equipment , An access terminal (AT), an access terminal (AT), and the like, and may include all or some of functions of a terminal, a mobile station, a mobile terminal, a subscriber station, a mobile subscriber station, a user equipment, .

FIG. 1 illustrates a network structure supporting a closed subscriber group (CSG) according to an embodiment of the present invention.

Referring to FIG. 1, a base station 100 includes a plurality of radio units 110 and 120. Each of the radio units 110 and 120 performs communication with a terminal in the cell using radio resources of the corresponding cell. Here, the radio unit 110 performs communication with a terminal in a CSG cell, and the radio unit 120 performs communication with a terminal of a general cell.

When the UE 200 is located in the CSG cell and is subscribed to the CSG cell and the UE 200 requests the BS 100 to establish a call connection through the radio unit 110, , GW, 300).

When the terminal 200 is located in a general cell and the terminal 200 requests a call connection to the base station 100, the base station 100 provides the Internet service through the general gateway 400.

To this end, when the base station 100 receives a call connection request from the UE 200, the BS 100 determines whether the cell where the UE 200 is located is a CSG cell and the UE 200 is a UE subscribed to the CSG cell. Mobility Management Entity, 500). The MME 500 can know whether or not it has subscribed to the CSG cell for each terminal through the Home Subscriber Service (HSS) 600. [ The MME 500 can also manage information on an IP address of a gateway used for each cell. FIG. 2 shows cell-specific gateway information managed by the MME. As shown in FIG. 2, a local gateway IP address may be allocated to each CSG cell, and a general gateway IP address may be allocated to each general cell. When the terminal 200 requests the call connection, the base station 100 can transmit information on the cell where the terminal 200 is located and information on the terminal 200 to the MME 500. The MME 500 may provide the gateway IP address to the BS 100 according to whether the cell where the UE 200 is located is a CSG cell and the UE 200 is subscribed to the CSG cell.

3 is a flowchart illustrating a method for supporting a CSG by a base station according to an embodiment of the present invention.

3, when the base station 100 receives a call connection request from the terminal 200 (S300), the base station 100 determines whether the terminal 200 has attempted to access the subscribed CSG cell (S310 ). To this end, the BS must know whether the cell where the UE 200 is located is a CSG cell or whether the UE is subscribed to the CSG cell if the cell is a CSG cell. The UE 200 or the MME 500 can know whether the cell where the UE 200 is located is a CSG cell. It can be known from the MME 500 or the HSS 600 whether the terminal 200 is subscribed to the corresponding CSG cell.

When the UE 200 attempts to connect to the CSG cell, the BS 100 provides the intranet service through the local gateway assigned to the CSG cell (S320). When the terminal 200 does not attempt to connect to the CSG cell to which the subscriber station 200 is connected, that is, when the subscriber station 200 attempts to access the subscriber station 200 or when the subscriber station 200 is not subscribed to the corresponding CSG cell, The service is provided through the general gateway assigned to the general cell (S330). To this end, the base station 100 may receive the gateway IP address allocated for each cell from the MME 500.

In this manner, when a terminal subscribed to a CSG cell requests connection from the corresponding CSG cell, an intranet service is provided through the local gateway, thereby ensuring a good quality service.

Hereinafter, a CSG supporting method according to an embodiment of the present invention will be described in more detail.

4 is a flowchart illustrating a CSG support method of a wireless communication system according to an embodiment of the present invention.

4, the base station 100 periodically transmits system information (SI) including at least one of a CSG mode, a CSG ID, a frequency band allocated to a CSG cell, and a name of a CSG zone (S400). For example, the CSG mode and the CSG ID can be transmitted through the system information block type 1, the frequency band allocated to the CSG cell can be transmitted through the system information block type 4, May be transmitted via system information block type 9.

Table 1 is an example of the system block type 1.

As shown in Table 1, the CSG mode can be transmitted through the CSG Indication, and the CSG ID can be transmitted through the CSG Identity. CSG Indication can be set to a value of TRUE or FALSE. When the CSG Indication is set to TRUE, it means that the terminal, which is a member of the corresponding CSG, can access only the closed mode. On the other hand, when the CSG Indication is set to FALSE, it means that the terminal which is a member of the corresponding CSG and the terminal which is not a member can be connected but it is a hybrid mode that provides a differentiated service.

Table 2 is an example of system information block type 4.

As shown in Table 2, the frequency band allocated to the CSG cell can be transmitted through the PhysicalCellID Range. This represents the PCI assigned to the zone service or femtocell. This value can be valid for 24 hours after the terminal 200 receives it.

Table 3 is an example of system information block type 9.

As shown in Table 3, the name of the CSG zone can be transmitted via hnb-name. Through this, the terminal 200 can know the name of the zone service area.

The UE 200 can determine whether it is located in the CSG cell to which it belongs and in the cell in which it is located based on the system information received from the base station 100. [ For example, the terminal 200 can compare the CSG whitelist stored in the terminal 200 with the system information received from the base station, so that the terminal 200 can know whether the cell in which the terminal 200 is currently located is the CSG cell to which the terminal 200 belongs. Also, when the CSG mode included in the system information received from the base station is in the hybrid mode, it can be understood that the CSG cell can receive the service even if it is not the CSG cell to which it belongs. The CSG whitelist may be stored in a Universal Subscriber Identity Module (USIM) of the terminal.

When the UE 200 desires to access the network, the UE 200 transmits UE capacity information including the CSG ID of the UE 200 to the MME 500 through the BS 100 (S410) . The CSG whitelist is stored in the terminal 200, and the terminal 200 can transmit the CSG ID to the MME 500 through the CSG whitelist.

The MME 500 transmits the CSG information about the UE 200 to the BS 100 through an initial context setup request (S420). The CSG information may include a CSG mode and whether the UE 200 is a member of a CSG cell. For this purpose, the HSS 600 can inform the MME 500 of whether or not to join the CSG for each terminal.

The base station 100 transmits an initial context setup response to the MME 500 in step S430 and communicates with the terminal 200 according to the CSG information received from the MME 500 in step S440. A detailed description thereof will be described later.

Thereafter, when the CSG information is changed, the MME 500 transmits an initial context modification request including the changed CSG information to the base station 100 (S450). The base station 100 transmits an initial context modification response to the MME 500 in step S460 and communicates with the terminal 200 according to the changed CSG information received from the MME 500 in step S470 ).

Meanwhile, an RRC Connection Reconfiguration Message may be exchanged between the MS 200 and the BS 100 when establishing a RRC connection. Table 4 shows an example of an RRC connection reset message.

As shown in Table 4, the RRC connection re-establishment message may include otherConfig-r9 for checking whether there is a CSG cell in the adjacent area.

otherConfig-r9 can be expressed as shown in Table 5.

In this manner, when the base station 100 receives the proximity indication message in the RRC connection reset procedure, it can confirm that the CSG cell exists in the neighboring area and can support the handover function to the CSG cell. If the base station 100 does not support the handover to the CSG cell, the interference of the CSG cell due to the handover non-support should be minimized by redirecting the E-UTRAN or UTRAN to another frequency.

Hereinafter, a method (step S440 of FIG. 4) in which the base station 100 communicates with the terminal 200 according to the CSG mode and whether the terminal 200 is a member of the CSG cell will be described in detail.

5 is a diagram illustrating a CSG supporting method of the base station 100 according to an embodiment of the present invention.

5, when the base station 100 receives a call connection request from the terminal 200 in step S500, the base station 100 confirms the CSG mode of the CSG cell in which the terminal 200 is located (step S510) . If the CSG mode is the closed mode, the BS 100 determines whether the UE 200 is a member of the CSG cell (S520). If the CSG mode is the closed mode and the UE 200 is a member of the CSG, the BS 100 performs a normal call operation to the UE 200 (S530). On the other hand, when the CSG mode is the closed mode and the UE 200 is not a member of the corresponding CSG, the Node B 100 transmits the E-UTRAN, the UTRAN, Over (S540). In an initial connection, the base station 100 may redirect the UE 200 to an E-UTRAN or UTRAN of a different frequency.

If the CSG mode is not the closed mode, i.e., the hybrid mode, the base station 100 determines whether the terminal 200 is a member of the CSG cell (S550). When the CSG mode is the hybrid mode and the UE 200 is a member of the corresponding cell, the Node B 100 provides QoS (Quality of Service) requested by the MME 500 to the UE 200 (S560). On the other hand, when the CSG mode is the hybrid mode and the UE 200 is not a member of the corresponding CSG cell, the BS 100 provides a service to the UE 200, (S570). To this end, the base station 100 controls a data transmission rate for the terminal 200. The data transmission rate can be set to an aggregated maximum bit rate (AMBR). If a predetermined load is exceeded in the base station 100, that is, if a predetermined number of users is exceeded, the mobile station can be handed over or transited to a terminal that is not a member of the CSG cell even in the hybrid mode.

Meanwhile, the base station 100 may receive the changed CSG information from the MME 500 as in step S450 of FIG. For example, when the base station 100 is providing the service to the terminal 200 that is a member of the CSG cell in the hybrid mode, when the MME 500 is notified that the terminal 200 is no longer a member of the CSG cell The base station 100 can provide a lower level of QoS by adjusting the data transmission rate for the terminal 200. [

6 is a block diagram of a base station supporting a CSG service according to an embodiment of the present invention.

6, the base station 100 includes a radio signal processor (RU) 100-1, a digital signal processor (DU) 100-2, and a controller 100-3.

The radio signal processing unit 100-1 includes a radio frequency (RF) module as a unit for transmitting and receiving radio signals. The RF module periodically broadcasts system information (SI) including a CSG ID for identifying a CSG mode and a CSG mode, which is an operation mode of the CSG cell, to the terminal 200, and transmits a call connection request .

The digital signal processor 100-2 processes a digital signal.

The plurality of wireless signal processing units 100-1 may be remotely installed in the service area, and the digital signal processing unit 100-2 may be concentrated in the national company.

The control unit 100-3 is configured to control a CSG mode of a CSG cell in which the UE is located and a service to be provided to the UE according to whether the UE is a member of the CSG cell. Here, the CSG mode may be at least one of a closed mode for providing a communication service only to a terminal that is a member of the CSG cell and a hybrid mode for providing a communication service for a terminal that is not a member of the CSG cell have.

As described above, by providing a different level of service according to the mode of the CSG cell and whether the UE is a member of the CSG cell, it is possible to provide an excellent quality of service (QoS) to the member of the CSG cell.

The embodiments of the present invention described above are not implemented only by the apparatus and method, but may be implemented through a program for realizing the function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded.

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 supporting a Closed Subscriber Group (CSG) in a wireless communication system,
Periodically broadcasting system information (SI) including a CSG mode that is an operating mode and a CSG ID that identifies a CSG cell to the terminal,
Receiving a call connection request from the terminal, and
Communicating with the terminal according to the CSG mode of the CSG cell in which the terminal is located and whether the terminal is a member of the CSG cell;
≪ / RTI > The method of claim 1,
Wherein the system information further comprises at least one of a frequency band allocated to the CSG cell and a zone name of the CSG cell. The method of claim 1,
At least one of a CSG mode of the CSG cell and information on whether the UE is a member of the CSG cell is received from a mobility management entity (MME). The method of claim 1,
The CSG mode includes at least one of a closed mode for providing a communication service only to a terminal that is a member of the CSG cell and a hybrid mode for providing a communication service for a terminal that is not a member of the CSG cell Way. 5. The method of claim 4,
Performing the communication,
Wherein the CSG mode is the closed mode and if the UE is not a member of the CSG cell, the UE is handed over to another cell or is redirected. 5. The method of claim 4,
Performing the communication,
Wherein the CSG mode is the hybrid mode and the UE is not a member of the CSG cell, providing a lower quality of service (QoS) than a terminal that is a member of the CSG cell. The method of claim 1,
Performing the communication,
And if the UE is a member of the CSG cell, providing a zone service through a pre-allocated local gateway IP address. The method of claim 7, wherein
Wherein the local gateway IP address is pre-assigned to the MME for each CSG cell. In the wireless communication system, a method in which a terminal communicates in a CSG cell,
Periodically receiving system information (SI) including a CSG mode which is an operation mode of the CSG cell and a CSG ID identifying the CSG cell, from the base station;
Comparing the CSG cell list with the CSG ID subscribed to the terminal, and
Transmitting UE capability information including the CSG cell list to the base station;
≪ / RTI > 10. The method of claim 9,
The CSG cell list is stored in the Universal Subscriber Identity Module (USIM) of the terminal. A base station supporting a Closed Subscriber Group (CSG)
An RF (Radio Frequency) unit for periodically broadcasting system information (SI) including a CSG ID for identifying a CSG cell and a CSG mode for operating a CSG cell to the UE and receiving a call connection request from the UE , And
A control unit configured to control a CSG mode of the CSG cell in which the UE is located and a service provided to the UE according to whether the UE is a member of the CSG cell,
/ RTI > The method of claim 11,
The CSG mode includes at least one of a closed mode for providing a communication service only to a terminal that is a member of the CSG cell and a hybrid mode for providing a communication service for a terminal that is not a member of the CSG cell Base station.

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