Method for controlling access of terminal to home (e)NodeB

A method for controlling access of a terminal to a Home (e)NodeB by a network entity, the terminal accessed to the Home (e)NodeB operated in a closed access mode or a hybrid access mode by using a specific closed subscriber group (CSG) ID, the method comprises: recognizing by the network entity, that an allowed access timer of the specific CSG ID with respect to the Home (e)NodeB has expired; transmitting an Update Bearer Request message to other network entity in order to change a membership of the expired CSG ID; transmitting a Bearer Modify Request message to the Home (e)NodeB in order to change a membership of the expired CSG ID; and updating a bearer with said other network entity, and a bearer with the Home (e)NodeB.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a mobile communication system, and particularly, to a Home(e)NodeB system in a mobile communication system.

2. Background of the Invention

In the field of 3GPP that regulates technical standards of the third generation mobile communication system, since the end of 2004, has started researches for Long Term Evolution/System Architecture Evolution (LTE/SAE) techniques to optimize and enhance functions of 3GPP techniques in correspondence to a plurality of forums and new techniques relevant to the 4thgeneration mobile communication.

The SAE based on the 3GPP SA WG2 relates to a network technique for determining a network structure and supporting mobility of a heterogeneous radio network system with cooperating with an LTE operation of the 3GPP TSG RAN. The SAE, one of the most important standardization issues of the 3GPP, is implemented to develop a 3GPP system into a system that supports various wireless access techniques based on IP. More concretely, the SAE has been implemented for an optimized packet-based system capable of minimizing transmission delay with an enhanced data transmission capability.

A conceptual reference model of the SAE, defined by 3GPP SA WG2 includes a non-roaming case, and a roaming case having various scenarios. Details of the conceptual reference model can be referred from TS 23.401 and TS 23.402 which are 3GPP standard documents. This may be schematically reconfigured inFIG. 1.

FIG. 1is a structural view of an evolved mobile communication network.

One of the most representative characteristics of the network ofFIG. 1is that a structure is based on a two-layer model (2 Tier Model), an evolved NodeB (so-called eNodeB) of an Evolved UTRAN and a Gateway of a Core Network. The eNodeB has similar functions to them of both a RNC and a NodeB of the conventional UMTS system. And, the Gateway has a similar function to it of the conventional SGSN/GGSN.

Another important characteristic of the network is that a Control Plane and a User Plane between an Access Network and a Core Network are interchanged to each other through different interfaces. In the conventional UMTS system, one interface (Iu) exists between an RNC and an SGSN. However, since a Mobility Management Entity (MME) which processes a control signal is separated from a Gateway (GW), two interfaces (i.e., S1-MME and S1-U) were respectively used.

FIG. 2shows an (e)NodeB and a Home (e)NodeB.

In the 3rdor 4thgeneration mobile communication system, efforts to increase a cell capacity have been ongoing in order to support high-capacity service such as multimedia contents and streaming, and a bi-directional service.

As various techniques for transmitting a large amount of data in addition to multimedia relating techniques are required, many methods for increasing wireless capacity have been researched. One of the methods include a method for allocating frequency resources as much as possible. However, there have been limitations in allocating limited frequency resources to a plurality of users as much as possible.

In order to increase a cell capacity, there are efforts to use a high frequency bandwidth, and to reduce a cell radius. When cells having a small radius, such as pico cells are used, a frequency bandwidth of the cell can increase highly than that in the conventional cellular system thus to transmit more information. However, in this case, more base stations have to be installed in the same area, which results in high costs.

In order to increase a cell capacity by using a small cell, a Home (e)NodeB30has been proposed.

The Home (e)Node30has been researched based on RAN WG3 of the 3GPP (e)NodeB, and is being intensively applied to SA WG.

Referring toFIG. 2, an (e)NodeB (or NodeB)20may correspond to a macro-base station, whereas a Home (e)NodeB (or Home NodeB)30may correspond to a femto-base station. In the specification, the terms will be explained based on the 3GPP. And, the (e)NodeB20will be used so as to indicate ‘NodeB’ or ‘eNodeB’, and the Home (e)NodeB30will be used so as to indicate ‘Home NodeB’ or ‘Home eNodeB’.

A cell of the Home (e)NodeB20is implemented in an Open Access Mode, a Closed Access Mode, and a Hybrid Access Mode.

In the case of the Open Access mode, the cell of the Home (e)NodeB20provides service to all serviceable terminals without limitations.

In the case of the Closed Access mode, the cell of the Home (e)NodeB20permits access of only allowed terminals.

In UMTS/EPS of the 3GPP standard, it has been proposed that one or more Home (e)NodeBs operated in the Closed Access mode forms one Closed Subscriber Group (CSG). That is, one CSG may be composed of one or more Home (e)NodeBs, and the terminal also receives one a permission (e.g., one CSG membership) to access the cell of the Home (e)NodeB. Here, the terminal may have one or more CSG membership to access one or more CSGs, and may have time information allowed according to each CSG. Information on accessible CSGS is called as an Allowed CSG List. This allowed CSG list is stored in the terminal, and a network entity such as MME, SGSN, MSC, HSS, and HLR.

Access control is performed according to the allowed CSG list. For instance, if accessible time to the CSG has expired or a permission to access the CSG has been deleted (or expired) while the terminal receives service, a handover to a suitable cell is executed. That is, a handover to a peripheral CSG, or to a NodeB (or eNodeB) corresponding to a macro-base station is executed.

In the related art, if accessible time to the CSG has expired or a permission to access the CSG has been deleted, the terminal may execute a handover to a suitable cell. However, concrete methods thereof have not been disclosed.

In order to perform a handover from a first CSG to which the terminal is being accessed to a second CSG, a status of wireless resources (i.e. whether the terminal is accessible to the second CSG) has to be considered. However, this has not been disclosed in the related art.

For the consideration, signal transmission between relevant entities is required as much as possible. However, the related art has not disclosed appropriate solutions relating thereto, which causes waste of wireless resources.

Furthermore, even if the terminal has not found a suitable CSG, a handover to a macro-cell (NodeB or eNodeB) has to be executed so as to ensure service continuity. This may depart from the original purpose of the Home (e)Node B for reducing the amount of resources usage by the macro base station.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide a method for allowing a terminal to perform a handover to a cell of a Home (e)NodeB corresponding to another closed subscriber group (CSG) by a Home (e)NodeB.

Another object of the present invention is to provide a method capable of efficiently using wireless resources of a Home (e)NodeB and a macro base station, and capable of minimizing signaling exchange while ensuring service continuity to a terminal when accessible time to a closed subscriber group (CSG) has expired or a permission to access the CSG has been deleted.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a method for controlling access of a terminal to a Home (e)NodeB by a network entity, the terminal accessed to the Home (e)NodeB operated in a closed access mode or a hybrid access mode by using a specific closed subscriber group (CSG) ID, the method comprising: recognizing by the network entity, that a timer, which designates allowable time to access to the Home (e)NodeB by using a specific closed subscriber group (CSG) ID has expired; transmitting a bearer update request message to other network entity in order to change a membership for the expired CSG ID; transmitting a bearer modify request message to the Home (e)NodeB in order to change a membership for the expired CSG ID; and updating a bearer with said other network entity, and a bearer with the Home (e)NodeB.

At least one of the bearer update request message and the bearer modify request message may be a message including information about a new membership and QoS-related information, or may be a message including information about a specific membership and QoS-related information. At least one of the bearer update request message and the bearer modify request message may further include at least one of an indicator indicating membership change (e.g., CSG member, non-CSG member), an indicator indicating membership expiration, an expired_indicator, and a deleted_indicator.

The method may further comprise receiving an Update Bearer Response message by the network entity from said other network entity.

The network entity may be a Mobility Management Entity (MME).

Said other network entity may be a serving gateway (S-GW) or a serving GPRS support node (SGSN).

The step of recognizing may comprise receiving a message notifying that the timer has expired, from a specific entity located in a network and monitoring the allowed access timer.

The step of recognizing may further comprise monitoring the timer by the network entity.

The method may further comprise transmitting, to the Home (e)NodeB, a message notifying membership change of the terminal (S604).

The message notifying membership change of the terminal may be an SI AP UE Context Modification Request message, or a UE Context Update message.

The message notifying membership change of the terminal may be a message including information about a new membership and QoS-related information, or may be a message including information about a specific membership and QoS-related information. At least one of the messages may further include at least one of an indicator indicating membership change, an indicator indicating membership expiration, an expired_indicator, and a deleted_indicator.

The bearer update request message may be an Update Bearer Request Message, and the bearer modify request message may be a Bearer Modify Request.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is also provided a network entity configured to control access of a terminal to a Home (e)NodeB, the terminal accessed to the Home (e)NodeB operated in a closed access mode or a hybrid access mode by using a specific closed subscriber group (CSG) ID, the network entity comprising: a transceiver; and a controller configured to recognize that a timer, which designates allowable time to access to the Home (e)NodeB by using a specific closed subscriber group (CSG) ID has expired, configured to transmit, through the transceiver, an Update Bearer Request Message to other network entity and a Bearer Modify Request Message to the Home (e)NodeB in order to change a membership of the expired CSG ID, and configured to update a bearer with said other network entity and a bearer with the Home (e)NodeB.

In the present invention, access of the terminal to the Home (e)NodeB may be effectively controlled by minimizing signaling exchange in a network, and by reducing the amount of resources usage of a macro base station.

Especially, when accessible time of the terminal to the CSG has expired or a permission of the terminal to access the CSG has been deleted, unnecessary handovers are prevented through suitable access control. This may enhance the efficiency of the network and wireless resources.

DETAILED DESCRIPTION OF THE INVENTION

Description will now be given in detail of the present invention, with reference to the accompanying drawings.

The present invention is applied to a Home (e)NodeB system. However, the present invention is not limited to this, but may be applied to all communication systems and methods to which the techniques of the present invention are applicable.

Unless differently defined, all the terms used herein with including technical or scientific terms have the same meaning as terms generally understood by those skilled in the art relating to the field of the present invention. Terms defined in a general dictionary should be understood so as to have the same meanings as contextual meanings of the related art. Unless definitely defined in the present invention, the terms are not interpreted as ideal or excessively formal meanings. Furthermore, when the technical terms used in the present invention are unsuitable technical terms that do not precisely express the techniques of the present invention, the unsuitable technical terms should be replaced by suitable technical terms that can be understood by those skilled in the art. The general terms used in the present invention should be interpreted based on the previous or next contexts, but should not be interpreted as an excessively narrowed meaning.

A singular expression includes a plural concept unless there is a contextually distinctive difference therebetween. In the present invention, a term of “include” or “have” should not be interpreted as if it absolutely includes a plurality of components or steps of the specification. Rather, the term of “include” or “have” may not include some components or some steps, or may further include additional components.

Though terms of ‘first’, ‘second’, etc. are used to explain various components, the components are not limited to the terms. The terms are used only to distinguish one component from another component. For example, a first component may be referred to as a second component, or similarly, the second component may be referred to as the first component within the scope of the present invention.

When it is mentioned that one component is “connected” or “accessed” to another component, it may be understood that the one component is directly connected or accessed to the another component or that still other component is interposed between the two components. In the meantime, when it is mentioned that one component is “directly connected” or “directly accessed” to another component, it may be understood that no component is interposed therebetween.

Hereinafter, preferred embodiments of the present invention will be explained in more detail with reference to the attached drawings. The same or similar components of one embodiment as or to those of another embodiment will be provided with the same or similar reference numerals, and their detailed explanations will be omitted. And, if it is judged that detailed descriptions of the related art are not within the range of the present invention, the detailed descriptions will be omitted.

Hereinafter, the term of a ‘mobile terminal’ will be used. The mobile terminal may be also referred to as a user equipment (UE), a mobile equipment (ME), and a mobile station (MS). The UE may be a mobile device having a communication function, such as a portable phone, a PDA, a smart phone, and a notebook. Also, the UE may be an immobile device such as a PC and a vehicle mounted device.

And, the term of a ‘Home (e)NodeB will be used hereinafter. The ‘Home (e)NodeB may be referred to as a ‘femto-cell’, a ‘home NodeB’, and a ‘home eNodeB’.

Definition of Terms

Hereinafter, the terms used in the present invention will be briefly defined for understanding.

UMTS: An abbreviation of a Universal Mobile Telecommunication System, which signifies the 3rdgeneration mobile communication network.

EPS: An abbreviation of an Evolved Packet System, which signifies a core network that supports a long term evolution (LTE) network, and a network evolved from the UMTS.

NodeB: A base station of a UMTS network, which is installed outdoors and has a cell coverage size corresponding to a macro cell.

eNodeB: A base station of an EPS network, which is installed outdoors and has a cell coverage size corresponding to a macro cell.

(e)NodeB: A term indicating a NodeB and an eNodeB.

Home NodeB: A base station of a UMTS network, which is installed indoors and has a cell coverage size corresponding to a femto cell.

Home eNodeB: A base station of an EPS network, which is installed indoors and has a cell coverage size corresponding to a femto cell.

Home (e)NodeB: A term indicating a Home NodeB and a Home eNodeB.

Home (e)NodeB gateway: A gateway performing an interfacing with a core network by being connected to one or more Home(e)NodeBs.

Home (e)NodeB sub-system: A sub-system that manages a wireless network by combing a Home (e)NodeB and a Home (e)NodeB gateway as one set. The Home (e)NodeB sub-system and the Home (e)NodeB manage a wireless network, and are interworked with a core network. Therefore, the Home (e)NodeB sub-system and the Home (e)NodeB may be considered as one set. Accordingly, the terms of the Home (e)NodeB and the Home (e)NodeB sub-system will be used together.

Access control: An operation to allow access of a terminal to a system such as a Home (e)NodeB, or to handover the terminal to other access system.

Service continuity: A function to maintain the current service even if a service direction in a mobile communication system is changed to other cell or access system.

Closed Subscriber Group (CSG): A term indicating one or more Home to (e)NodeB groups. The Home (e)NodeB groups that belong to the CSG have the same CSG identifier (ID). And, each user receives a permission message according to each CSG.

PCC (Policy and Charging Control): An operation for an operator's policy and charging.

PCRF (Policy and Charging Rule Function): A network element for performing the PCC, and provides an operator policy and a charging rule to another entity.

The Concept of the Method Disclosed in the Specification

In the present invention, even if accessible time to the CSG has expired or a permission to access the CSG has been deleted, the frequency of handovers is reduced as much as possible. Accordingly, the efficiency of the access control is enhanced. That is, it is determined whether or not a cell of the Home (e)NodeB to which a terminal is being accessed can continuously provide service to the terminal. This may allow unnecessary handovers to be reduced, thereby enhancing management of a network and wireless resources.

Hereinafter, the method for controlling access in a Home (e)NodeB will be explained in more detail with reference to the attached drawings.

FIG. 3is conceptual views of access modes for explanation of preferred embodiments of the present invention.

The Home (e)NodeB300may operate in a Closed Access Mode, an Open Access Mode, and a Hybrid Access Mode. In the closed access mode (or limited access mode), only terminals having CSG membership (or accounts) are accessible to the Home (e)NodeB300. In the open access mode, the Home (e)NodeB300operates in the same manner as a normal cell having no concept of a CSG. In this case, general all UEs are accessible to the Home (e)NodeB300. In the hybrid access mode, the Home (e)NodeB300operates in both the closed access mode and the open access mode.

The open access mode is not within the range of the present invention. Accordingly,FIG. 3shows an access control method in the closed access mode and the hybrid access mode.

FIG. 3Ashows an example of the closed access mode. In the closed access mode, the Home (e)NodeB300operates as a closed subscriber group (CSG). The Home (e)NodeB300stores an ID list of CSGs. For instance, the Home (e)NodeB supports a first CSG (a CSG ID is “CSG1”), a second CSG (a CSG ID is “CSG2”), and a third CSG (a CSG ID is “CSG3”).

Referring toFIG. 3A, the terminal (or UE100) has memberships (or accounts) to the first CSG (“CSG1”) and the second CSG (“CSG2”) of the Home (e)NodeB300and is connected to the Home (e)NodeB300by using a membership to the first CSG (“CSG1”) thus to receive a service.

In such situation, even if accessible time (or allowed time) of the current membership (or account) to the first CSG (“CSG1”) has expired, the Home (e)NodeB300can not handover the terminal (or UE100) to other base station such as other home (e)NodeB, Instead, the Home (e)NodeB300can change the current CSG ID (“CSG1”) for the terminal (or UE100) into another CSG ID (or a different CSG ID or new CSG ID) (e.g., “CSG2”) to maintain a provision of the service to the UE100.

To do this, the Home (e)NodeB300compares its CSG ID list with an allowed CSG list for the UE100. The allowed CSG list includes information on CSGs to which the terminal (or UE100) has a membership. As illustrated inFIG. 3A, the allowed CSG list includes information on the first CSG (“CSG1”) and the second CSG (“CSG2”).

As results from the comparison, it is determined that at least one CSG ID in the CSG list of the Home (e)NodeB300is matched with it in the allowed CSG list for the UE100(or there is at least one matched CSG ID in both the lists), and the matched CSG ID has not expired yet, a membership to matched the CSG ID having not expired yet can be used.

As shown inFIGS. 4 to 6, there area various method for changing the current CSG ID for the UE100to another CSG ID for service continuity to the UE100. For example, the various methods may be performed between the UE100and the Home (e)NodeB300, or between the Home (e)NodeB300and a network entity, or by the network entity500, exclusively. This will be explained in more detail with reference toFIGS. 4 to 6. Here, the network entity may also indicate a Home Subscriber Server (HSS), an Application Server (AS), a Home Location Register (HLR), a User Repository, etc. The network entity to be explained hereinafter signifies at least one of the aforementioned entities, or the combination thereof.

FIG. 3Bshows an example of the hybrid access mode.

The Home (e)NodeB300operated in the hybrid access mode provides service to both UEs having a CSG membership, and UE having not the CSG membership (or UEs of a non-CSG). In other words, the UEs of a non-CSG may use the Home (e)NodeB without any membership (or permission). However, the UEs in the non-CSG may access to the Home (e)NodeB with a service quality lower than that in the CSG.

The terminal (or UE100) has a membership (or accounts) to the first CSG (“CSG1”) of the Home (e)NodeB300and a membership to “CSG5” of other Home (e)NodeB and is connected to the Home (e)NodeB300by using the membership to the first CSG (“CSG1”) thus to receive a service.

In such situation, even If an accessible time (or allowed time) of the current membership of the terminal to the first CSG (“CSG1”) has expired, the Home (e)NodeB300checks whether the membership of a specific ID of the UE100can be changed to a non-CSG member. According to a result of the check, the membership of the UE100is changed to a non-CSG member. Then, the current service is continuously maintained.

FIG. 4is a flowchart showing a method for controlling access in a Home (e)NodeB operated in a closed access mode according to a first embodiment of the present invention.

FIG. 4shows a UE100, a Home (e)NodeB (e.g., femto-base station), a core network (CN)500, and a target cell200.

The core network500may include a Mobility Management Entity (MME), a serving GPRS support node (SGSN), a Mobile-services Switching Centre (MSC), a Home Subscriber Server (HSS), a Home Location Register (HLR), a User Repository, etc. The target cell200may be a femto-base station such as the Home (e)NodeB300, or a macro-base station such as an (e)NodeB.

According to the first embodiment of the present invention, if accessible time (or allowed time) of the current membership of the terminal to a current (or specific) CSG ID of the Home (e)NodeB300has expired while the UE100is receiving a service from the Home (e)NodeB300, the Home (e)NodeB300compares a CSG ID list stored therein with an allowed CSG ID list for the UE100. As results from the comparison, it is determined that at least one CSG ID in the CSG ID list for the UE100is matched with it in the CSG ID list of the Home (e)NodeB300, the Home (e)NodeB300changes the current (or specific) CSG ID for the UE100to another CSG ID (or new CSG ID) (i.e., the matched CSG ID) without any handover. Accordingly, the Home (e)NodeB300may continuously provide service to the UE100. Once the current (or specific) CSG ID for the UE100is changed to the another CSG ID, the Home (e)NodeB300informs the changed status to the core network500, thereby updating the changed status.

This will be explained in more detail with reference toFIG. 4.

1) While the Home (e)NodeB300provides service to the UE100, the Home (e)NodeB300recognizes that a timer to a membership of the UE100(e.g., a CSG timer) has expired (S110). The timer may be operated by the Home (e)NodeB300, or by an external entity (e.g., a specific entity of the core network500). In the case that the timer is operated by a specific entity of the core network500, the Home (e)NodeB300may acquire information about the expiration of the timer from the specific entity.

2) Then, the Home (e)NodeB300requests and receives an allowed CSG ID list for the UE100from the UE100(S120˜S130). Then, the Home (e)NodeB300compares its CSG ID list stored therein, with the allowed CSG ID list received from the UE100(S140). Based on a result of the comparison, the Home (e)NodeB300determines whether to maintain the UE100in the current cell, or to handover the UE100to other cell.

Alternatively, the Home (e)NodeB300may transmit its CSG ID list to the UE100. Then, the UE100compares its allowed CSG ID list stored therein, with the CSG ID list received from the Home (e)NodeB300. Based on a result of the comparison, the UE100determines whether to stay in the Home (e)NodeB300, or to perform a handover to other cell.

3) If it is determined in S140that at least one CSG ID of the allowed CSG ID list of the UE100is matched with it in the CSG ID list of the Home (e)NodeB300, the Home (e)NodeB300exchanges information about the matched CSG ID(s) with the core network500(S150). The core network500or the Home (e)NodeB300updates a bearer according to the changed status.

4) If the changed status is updated by the core network500, the Home (e)NodeB300and the UE100exchange information about the matched CSG ID(s) with each other (S160). Then, the Home (e)NodeB300and the UE100update a bearer according to the changed CSG ID. And, the Home (e)NodeB300and the UE100execute service by using the changed CSG ID.

5) On the contrary, if it is determined in S140that at least one CSG ID of the allowed CSG ID list of the UE100is not matched with it in the CSG ID list of the Home (e)NodeB300, the UE100performs a handover to other suitable CSG cell or macro cell (S170).

FIG. 5is a flowchart showing a method for controlling access in a Home (e)NodeB operated in a closed access mode according to a second embodiment of the present invention.

According to the second embodiment, the allowed CSG ID list of the UE100may be also stored in the core network500. Accordingly, the Home (e)NodeB300acquires the allowed CSG ID list of the UE by request from the core network500, and then compares the allowed CSG ID list of the UE with its CSG ID list.

This will be explained in more detail with reference toFIG. 5.

1) While the Home (e)NodeB300provides service to the UE100, the Home (e)NodeB300recognizes that a timer for for a membership of the UE100to a specific CSG ID (current CSG ID) of the Home (e)NodeB(e.g., a CSG timer) has expired (S210). The timer may be operated by the Home (e)NodeB300, or by an external entity (e.g., a specific entity of the core network500). In the case that the timer is operated by a specific entity of the core network500, the Home (e)NodeB300may acquire information about the expiration of the timer from the specific entity.

2) Then, the Home (e)NodeB300request and receives the allowed CSG ID list of the UE100from the UE100from the core network500(S220˜S230). Then, the Home (e)NodeB300compares its CSG ID list stored therein, with the allowed CSG ID list of the UE100(S240). Based on a result of the comparison, the Home (e)NodeB300determines whether to maintain the UE100in the current cell, or to handover the UE100to other cell.

Alternatively, the Home (e)NodeB300may transmit its CSG ID list to the core network500. Then, the core network500compares an allowed CSG ID list of the UE stored therein with the CSG ID list received from the Home (e)NodeB300. Based on a result of the comparison, the core network500determines whether to allow the UE100to stay in the Home (e)NodeB300, or to handover the UE100to other cell.

3) If it is determined in S240that at least one CSG ID of the allowed CSG ID list of the UE100is matched with any one in to the CSG ID list of the Home (e)NodeB300, the Home (e)NodeB300changes the current ID into the matched CSG ID for the UE100and exchanges information about the matched CSG ID(s) with the core network500(S250). The core network500updates a bearer according to the changed status.

4) If the changed status is updated by the core network500, the Home (e)NodeB300and the UE100exchange information about the identical CSG ID(s) with each other (S260). Then, the Home (e)NodeB300and the UE100update a bearer according to the changed CSG ID. And, the Home (e)NodeB300and the UE100execute service by using the changed CSG ID.

5) On the contrary, if it is determined in5240that at least one CSG ID of the allowed CSG ID list of the UE100is not matched with it to the CSG ID list of the Home (e)NodeB300, the UE100executes a handover to other suitable CSG cell or macro cell (S270).

FIG. 6is a flowchart showing a method for controlling access in a Home (e)NodeB operated in a closed access mode according to a third embodiment of the present invention.

According to the third embodiment, the allowed CSG ID list of the UE100and the CSG ID list of the Home (e)NodeB300may be also stored in the core network500. The third embodiment is different form the first and second embodiments in that a specific entity of the core network500directly determines whether to change the CSG ID.

This will be explained in more detail with reference toFIG. 5.

1) While the Home (e)NodeB300provides service to the UE100, a specific entity of the core network500recognizes that a timer for a membership of the UE100to a specific CSG ID (or current CSG ID) of the Home (e)NodeB300(e.g., a CSG timer) has expired (S310). The timer may be operated by the Home (e)NodeB300, or by other entity of the core network500. Here, the specific entity of the core network500acquires information about the expiration of the timer, from said other entity or the Home (e)NodeB300.

2) Then, the specific entity of the core network500compares the allowed CSG ID list for the UE100stored therein, with the CSG ID list of the Home (e)NodeB300stored therein (S320). Based on a result of the comparison, the specific entity of the core network500determines whether to maintain the UE100in the current cell, or to handover the UE100to other cell. The specific entity of the core network500may include a Mobility Management Entity (MME), a serving GPRS support node (SGSN), a Mobile-services Switching Centre (MSC), a Home Subscriber Server (HSS), a Home Location Register (HLR), a User Repository, etc.

3) If it is determined in S320that at least one CSG ID in the allowed CSG ID list for the UE100is matched with any one in the CSG ID list of the Home (e)NodeB300, the specific entity of the core network500updates a bearer according to the identical CSG ID(s). Then, the specific entity of the core network500transmits, to the Home (e)NodeB300, a request message requesting change of the CSG ID of the UE, and receives a response message with respect to the request message (S330).

4) If the changed status is updated by the specific entity of the core network500, the Home (e)NodeB300and the UE100exchange information about the matched CSG ID(s) with each other (S340). Then, the Home (e)NodeB300and the UE100change the current CSG ID into the matched CSG ID for the UE100and update a bearer according to the changed CSG ID. And, the Home (e)NodeB300and the UE100execute service by using the matched CSG ID.

5) On the contrary, if it is determined in S320that at least one CSG ID of the allowed CSG ID list for the UE100is not matched with any one in the CSG ID list of the Home (e)NodeB300, the specific entity of the core network500handovers the UE to other suitable CSG cell or macro cell (S350).

FIG. 7is a flowchart showing a method for controlling access in a Home (e)NodeB operated in a hybrid access mode according to a fourth embodiment of the present invention.

In the hybrid access mode, the Home (e)NodeB300is operated both in the closed access mode and in the open access mode. The UE100may access as a non-CSG member without any permission. However, in this case, the UE100corresponding to the non-CSG member may be provided with lower-quality service than that of the CSG.

If the accessible time (or allowed time) for a membership of UE100to the Home (e)NodeB has expired while the UE100receives service from the Home (e)NodeB300by using the membership, the Home (e)NodeB300or the specific entity of the core network500changes the UE's membership to a non-CSG member from the CSG member. Accordingly, the UE100may be continuously provided with the current service.

For this, it may be checked whether service conditions of the UE such as a bandwidth can be supported even in the non-CSG member. Here, a bandwidth of service required by the UE100may be compared with a resource capability of the non-CSG member.

If the resource capability which the Home (e)NodeB provides to the non-CSG member is high enough to allow the bandwidth of service required by the UE100, information about a session (or bearer) being used by the UE is changed. Then, the changed information is transmitted to the UE100, the Home (e)NodeB300, the network entity, etc. And, the UE100is changed to a non-CSG member from the CSG member.

On the contrary, if the resource capability which Home (e)NodeB300provides to the non-CSG member is deficient, the UE100performs a handover to other suitable CSG cell or macro cell.

Alternatively, if the accessible time has expired while the UE100as a CSG member receives service from the Home (e)NodeB300, it may be determined whether the UE100can be changed to a member of other CSG ID before determining whether the UE100can be changed to a non-CSG member. If it is determined that the UE100can not be changed to other CSG ID, the UE100is changed to a non-CSG member for service continuity. This may enhance flexibility of access control.

This will be explained in more detail with reference toFIG. 7.

1) While the Home (e)NodeB300provides service to the UE100, the Home (e)NodeB(300) or the specific entity of the core network500recognizes that a timer for a membership of the UE100to a specific CSG ID of the Home (e)NodeB (e.g., a CSG timer) has expired (S410). The timer may be operated by the Home (e)NodeB300.

2) At least one of the Home (e)NodeB300and the specific entity of the core network500checks whether the UE100can be changed to a member of other CSG ID according to a network operator policy, and changes the UE100to a member of other CSG ID if so. Then, said at least one of the Home (e)NodeB300and the specific entity of the core network500transmits a notification message to relevant entities to complete the change operation (S420). Whether the UE100can be changed to a member of other CSG ID or not may be selectively determined according to a network operator policy or a network management policy. This is similar to the first to third embodiments shown inFIGS. 4 to 6.

3) If the UE100can not be changed to a member of other CSG ID or the change is not allowed under a policy, at least one of the Home (e)NodeB300and the specific entity of the core network500compares a bandwidth of service being provided to the UE100with resources capability which the Home (e)NodeB provides to a non-CSG member. Based on a result of the comparison, it is checked whether the UE100can operate in a non-CSG member (S430). Here, the checking may be performed based on an additional operator policy. In a similar manner as S440, the UE100may be operated as a non-CSG member by the specific entity of the core network500. Alternatively, in a similar manner as S450, the UE100may be operated as a non-CSG member by the Home (e)NodeB (300.

4) Firstly, the specific entity of the core network500changes the UE100into a non-CSG member (S440). More concretely, the specific entity of the core network500changes a session (or bearer) with the UE, and changes a CSG ID or membership, QoS, etc. (S441). Then, the specific entity of the core network500informs, to the Home (e)NodeB300, that the UE has been changed to a non-CSG member (S442). Subsequently, the Home (e)NodeB300informs, to the UE100, that the UE has been changed to a non-CSG member (S443).

5) Alternatively, if the UE100can be operated as a non-CSG member, the Home (e)NodeB300changes the UE100into a non-CSG member (S450).

More concretely, the Home (e)NodeB300changes the UE100to a non-CSG member (S451), and informs, to the specific entity of the core network500, that the UE100has been changed to a non-CSG member (S452). Then, the specific entity of the core network500changes a session (or bearer) with the UE, and transmits a response message to the Home (e)NodeB300(S454). Once the response message is received, the Home (e)NodeB300informs, to the UE100, that the UE100has been changed to a non-CSG member (S455). The Home (e)NodeB300may receive accessible time information of the UE to the CSG by request from the core network500, or may use the existing information stored therein after being received from the core network500.

If the UE100can not be changed to a non-CSG member, the UE100may perform a handover to other CSG cell or macro cell.

FIG. 8is a flowchart showing the fourth embodiment of the present invention with details, andFIG. 9is a modification example ofFIG. 8.

FIGS. 8 and 9show the fourth embodiment ofFIG. 7according to an EUTRAN/EPC system with details. And,FIGS. 8 and 9may be also applied to the first to third embodiments.FIG. 8shows the fourth embodiment ofFIG. 7according to an EUTRAN/EPC system. However, the fourth embodiment may be extended to be also used in a 3GPP system. A core network500ofFIG. 8comprises a Mobility Management Entity (MME)510, a Serving Gateway (S-GW)520, a Packet Data Network Gateway or PDN Gateway (P-GW)530, a Policy and Charging Rule Function (PCRF) system540, a Home Subscriber Server (HSS)550.

The present invention will be explained in more detail with reference toFIGS. 8 and 9.

1) Referring toFIG. 8, while the Home (e)NodeB300provides service to the UE100, the MME510of the core network500recognizes that a timer for a membership of the UE100(e.g., a CSG timer) has expired (S501). In the case that the Home (e)NodeB300is operated in a closed access mode or in a hybrid access mode, the MME510compares a CSG ID List of the Home (e)NodeB300stored therein, with an allowed CSG ID list of the UE100stored therein. The CSG ID List of the Home (e)NodeB300and the allowed CSG ID list of the UE100may be stored in the HSS550. In this case, the MME510receives the CSG ID lists from the HSS550by request, and then compares the CSG ID lists with each other.

Alternatively, referring toFIG. 9, the HSS550of the core network500recognizes that the CSG timer has expired (S601). In the case that the Home (e)NodeB300is operated in a closed access mode or in a hybrid access mode, the HSS550compares a CSG ID List of the Home (e)NodeB300stored therein, with an allowed CSG ID list for the UE100. The CSG ID List of the Home (e)NodeB300and the allowed CSG ID list may be stored in other entity. In this case, the HSS550requests and receives the CSG ID lists from said other entity, and then compares the CSG ID lists with each other.

Although not shown, other entity of the core network500may recognize that the CSG timer has expired.

2) As shown inFIG. 8, in the case that the MME510recognizes expiration of the CSG timer, the MME510goes to S504.

Alternatively, as shown inFIG. 9, in the case that the HSS550recognizes expiration of the CSG timer, the HSS550informs the MME510that the UE100has a changed membership (S602). The informing method may be different according to whether the Home (e)NodeB300is operated in a closed access mode or in a hybrid access mode.

In the case that the Home (e)NodeB300is operated in a closed access mode, the HSS550transmits, to the MME510, a message such as an S1 Application Protocol (S1 AP) message or a message notifying change of a membership of the UE100. The message may include a CSG membership indicator. The message (or the CSG membership indicator) may include other CSG ID supported by the Home (e)NodeB300.

However, in the case that the Home (e)NodeB300is operated in a hybrid access mode, the HSS550transmits, to the MME510, a message notifying change of a membership of the UE100. The message may include a CSG membership indicator. When there is other CSG ID that can be supported by the Home (e)NodeB300, the message (or the CSG membership indicator) may include a specific CSG ID rather than said other CSG ID.

The specific CSG ID may indicate a non-CSG member, or may indicate the expired CSG ID. Once the specific CSG ID is received, it can be recognized that the corresponding CSG ID has expired.

The HSS550may further include, in the message (or the CSG membership indicator), an indicator informing an expired status of the current CSG ID, or informing that the specific CSG ID (or a current CSG ID) of the UE has changed to a non-CSG member, e.g., an expired_indicator or a deleted_indicator. Then, the MME510transmits a response message with respect to the message to the HSS (S603).

3) The MME510transmits, to the Home (e)NodeB300, a message notifying change of a membership of the UE100, e.g., a UE Context Update message or an S1 AP UE Context Modification Request message (S504, S604). The message may include other CSG ID supported by the Home (e)NodeB300, or a specific ID or indicator which indicates a non-CSG member rather than said other CSG ID. The message may also include an indicator indicating an expired status of the UE100, such as an expired_indicator or a deleted_indicator. In the case that a current membership of the UE100is changed to other CSG ID or a non-CSG member, the Home (e)NodeB300modifies (updates) a radio period (bearer) with the UE100according to an operator policy (S504, S604). That is, the Home (e)NodeB300may differently establish the bearer according to whether the UE has been changed to other CSG ID or to a non-CSG member. More concretely, in the case that the membership of the UE is changed to a non-CSG member from a CSG member, or to a CSG member from a non-CSG member, the Home (e)NodeB300may differently setup the bearer according to whether the UE is a CSG member or not.

4) In the case that QoS of the bearer has modified (updated) due to change of the membership of the UE100, e.g., due to an operator policy or other reasons, the MME510transmits, to the S-GW520, a bearer update request message (e.g., Update Bearer Request message) according to information (e.g., other CSG ID or non-closed access mode) modified due to the membership change (S505, S605). Here, the Update Bearer Request message may be different according to whether the Home (e)NodeB300is operated in a closed access mode or in a hybrid access mode.

In the case that the Home (e)NodeB300is operated in a closed access mode, the MME510may include, in the Update Bearer Request message, a new CSG ID parameter (1), and a modified QoS parameter (2) which is QoS related information modified according to the new CSG ID parameter. This is shown in the following table 1.

TABLE 1Updated Bearer Request Message = (1) New CSG ID parameter, (2)modified QoS parameter

In the case that the Home (e)NodeB300is operated in a hybrid access mode, the MME510may include, in the Update Bearer Request message, a new CSG ID parameter (1), and a modified QoS parameter (2) which is QoS related information modified according to the new CSG ID parameter. This is shown in the following table 2.

TABLE 2Updated Bearer Request Message = (1) New CSG ID parameter, (2)modified QoS parameter

Alternatively, the MME510may include, in the Update Bearer Request message, a specific CSG ID parameter (1) rather than the new CSG ID, and a modified QoS parameter (2) which is QoS related information. This is shown in the following table 3. The specific CSG ID may indicate a non-CSG member, or the expired CSG ID. Once the specific CSG ID is received, it can be recognized that the corresponding CSG ID has expired.

Alternatively, the MME510may include, in the Update Bearer Request message, an indicator indicating an expired status of the current CSG ID or an indicator indicating that a membership (or the specific ID) of the UE has been changed to a non-CSG member, such as an expired_indicator or a deleted_indicator (1), and a modified QoS parameter (2) which is QoS related information.

The expired_indicator or deleted_indicator may be further included in the aforementioned Update Bearer Request message shown the tables 1 to 3.

5) The S-GW520transmits the Update Bearer Request message to the P-GW530(S506, S606).

6) Then, in the case that a Policy and Charging Control (PCC), etc. are used according to an operator policy, the P-GW530exchanges the current QoS-related parameters with the modified (updated) QoS-related parameters through a PCRF interaction with the PCRF540(S507, S608).

7) Then, the P-GW530applies the modified QoS parameters thereto, and transmits a bearer update response message (e.g., Update Bearer Response message) to the S-GW520(S508, S608). Here, the Update Bearer Response message may include the modified QoS parameters.

8) The S-GW520transmits the received Update Bearer Response message to the MME510(S509, S609). And, the S-GW520updates its QoS parameter according to a QoS parameter included in the received Update Bearer Response message.

9) Once the Update Bearer Response message has been received, the MME510transmits, to the Home (e)NodeB300, a Bearer Modify Request message, or a Session Management Request message, or an Update Bearer Request message (S510, S610). Here, the Bearer Modify Request message may be different according to whether the Home (e)NodeB300is operated in a closed access mode or in a hybrid access mode.

In the case that the Home (e)NodeB300is operated in a closed access mode, the MME510may include, in the Bearer Modify Request message, a new CSG ID parameter (1), and a modified QoS parameter (2) which is QoS related information modified according to the new CSG ID parameter. This is shown in the following table 5.

TABLE 5Bearer Modify Request Message = (1) New CSG ID parameter, (2)modified QoS parameter

In the case that the Home (e)NodeB300is operated in a hybrid access mode, the MME510may include, in the Bearer Modify Request message, a new CSG ID parameter (1), and a modified QoS parameter (2) which is QoS related information modified according to the new CSG ID parameter. This is shown in the following table 6.

TABLE 6Bearer Modify Request Message = (1) New CSG ID parameter, (2)modified QoS parameter

Alternatively, the MME510may include, in the Bearer Modify Request message, a specific CSG ID parameter (1) rather than the new CSG ID, and a modified QoS parameter (2) which is QoS related information. This is shown in the following table 7. The specific CSG ID may indicate a non-CSG member, or the expired CSG ID. Once the specific CSG ID is received by the Home (e)NodeB300, it can be recognized that the corresponding CSG ID has expired.

TABLE 7Bearer Modify Request Message = (1) specific CSG ID parameter,(2) modified QoS parameter

Alternatively, the MME510may include, in the Bearer Modify Request message, an indicator indicating an expired status of the current CSG ID or an indicator which indicates that the specific ID of the UE has been changed to a non-CSG member, such as an expired_indicator or a deleted_indicator (1), and a modified QoS parameter (2) which is QoS related information.

The expired_indicator or deleted_indicator may be further included in the aforementioned Bearer Modify Request message shown the tables 5 to 7.

10) Then, the Home (e)NodeB300may modify (update) a radio period (bearer) with the UE100based on the QoS parameter. And, the Home (e)NodeB300transmits, to the UE100, an RRC Connection Reconfiguration Request message (S511, S611). The RRC Connection Reconfiguration Request message may include other CSG ID, or a specific ID indicating that the UE is a non-CSG member. Alternatively, the RRC Connection Reconfiguration Request message may further include an expired_indicator. In another alternative manner, the RRC Connection Reconfiguration Request message may further include the modified (update) QoS parameter.

Then, the UE100changes to other CSG ID or a non-CSG member, and modifies (or updates) the bearer with the Home (e)NodeB300according to the QoS parameter. Then, the UE100transmits an RRC Connection Reconfiguration Response message to the MME510(S512, S612).

11) Once the RRC Connection Reconfiguration Response message has been received by the MME510, the MME510transmits a Bearer Modify Response message to the S-GW520(S513, S613).

12) As a response message with respect to the Session Management Request message, the UE100transmits a Session Management Response message, to the Home (e)NodeB300, with including in a Direct Transfer message (S514, S614). Then, the Home (e)NodeB300transmits the Session Management Response message to the MME510(S515, S615).

13) Once both the Bearer Modify Response message and the Session Management Response message have completely received, the MME510determines the membership change of the UE100to be normal. Then, the MME510transmits an Update Bearer Response message to the S-GW520, in response to the received Update Bearer Request message (S516, S616).

14) Once the Update Bearer Response message has been received by the S-GW520, the S-GW520transmits the received Update Bearer Response message to the P-GW530(S517, S617).

In addition, the above various embodiments may be implemented by using, computer software, hardware, or some combination thereof. For instance, the method of the present invention may be stored in the storage medium (e.g., internal memory, flash memory, hard disc, etc.), or may be implemented in codes or commands inside a software program that can be executed by a processor such as a microprocessor, a controller, a micro-controller, an application specific integrated circuit (ASIC), etc. This will be explained in more detail with reference toFIG. 10.

FIG. 10is a block diagram showing the UE100, the Home (e)NodeB300, and the core network500according to the present invention.

Referring toFIG. 10, the UE100includes a storage means101, a controller102, and a transceiver103.

The Home (e)NodeB300and each entity of the core network500include storage means301/501, controllers302/502, and transceivers303/503, respectively.

The storage means301/501store software programs including the method shown inFIGS. 4 to 9.

Each of the controllers controls the storage means and the transceivers. More concretely, the controllers execute software programs including the method and stored in the storage means. And, each of the controllers transmits the aforementioned signals through the transceivers.