KR20100119349A - Method and apparatus for supporting local internet protocol access at wireless communication network comprising femto cell - Google Patents

Abstract

PURPOSE: A method and an apparatus for supporting a local internet protocol access in a wireless communication network including a femto cell are provided to directly transmit data to a data network, thereby efficiently transmitting data. CONSTITUTION: A femto base station(103) or a femto base station gateway(104) is connected with an MME(Mobility Management Entity)(105). The MME transmits an initial context setup request to the femto base station gateway. A terminal(100) transmits a PDN(Packet Data Network) connectivity request to the femto base station. The MME directly transmits a bearer create session request to a local serving gateway(102). The MME transmits a bearer setup request and a PDN connectivity accept to the femto base station.

Description

METHOD AND APPARATUS FOR SUPPORTING LOCAL INTERNET PROTOCOL ACCESS AT WIRELESS COMMUNICATION NETWORK COMPRISING FEMTO CELL}

According to the present invention, when a femto base station in a wireless communication network including a femto base station and a femto base station gateway is extended to include a function of a local gateway (either a PDN gateway alone, or both a PDN gateway and a serving gateway), an extension function of a femto base station is provided. The present invention relates to a method and apparatus for forming a PDN connection by processing a service request for local IP access.

Femto cell (Femto cell) is a small mobile communication base station connected to the mobile communication core network through a broadband network installed indoors, such as home or office. The femto base station has various advantages such as expanding indoor coverage, improving call quality, and efficiently providing various wired and wireless convergence services.

3GPP LTE (Long Term Evolution) has defined a base station called an evolved NodeB (eNB) and a home evolved NodeB (HeNB). The dual eNB is a macro base station that manages a typical macro cell, and the home eNB is a femto base station that manages a femto cell.

That is, 3GPP considers an environment in which a femto base station that can be accessed only by a specific user is installed separately from the existing macro base station. In this case, the femto base station may be installed by the user or the operator for the purpose of increasing coverage, increasing capacity, or providing other differentiated services. The service coverage of a femto base station can be considered from a few meters up to a maximum degree of macro service coverage.

However, although the femto base station can be directly connected to the data network in the related art, the terminal connected to the femto base station is connected to the data network using a transmission path via a femto base station, a serving gateway, a PDN (Packet Data Network) gateway, or the like. There was a problem that it was necessary to connect.

In a network structure in which a femto base station gateway and a femto base station extended to have a function of a local gateway (either a PDN gateway alone or both a serving gateway and a PDN gateway) coexist, a serving gateway, a PDN gateway, and an MME on an extended femto base station It is impossible to use a method of transmitting and receiving control messages between the macro serving gateway, the macro PDN gateway, and the MME when transmitting control messages between the MMEs. The first reason is that the number of femto base stations can be tens of millions of times the number of macro serving gateways. Therefore, after registering the information of the local serving gateway and the local PDN gateway on the femto base station together with the registered macro serving gate information, Obtaining information for searching and accessing the registered information is inefficient and practically unavailable. Secondly, when a femto base station gateway is introduced to efficiently manage a large number of femto base stations, since each femto base station managed by the femto base station gateway is operated to appear to the MME as one femto base station, each femto base station There is currently no way for an MME to separately distinguish between local Serving Gateways and PDN Gateways present on the network. Third, the control message between the serving gateway and the MME distinguishes information for each terminal user using an ID of IMSI. The control message between the base station and MME distinguishes information for each terminal user using only an ID of S-TMSI. If the MME transmits a message using the IMSI ID to the local serving gateway or the local PDN gateway existing on the base station, it is impossible to find the base station where the user exists.

Accordingly, an object of the present invention is to provide a local IP Access service in which a terminal connected to a femto base station transmits data directly to a data network without passing through an operator's network.

In the local IP access support method of the present invention for solving the above problems, the formation of the PDN connection is the first step of establishing a connection with the MME after the femto base station establishes IP using DHCP or static configuration, A terminal accessing a femto base station to which an MME has established a connection sends an initial terminal message for activating a radio bearer to the femto base station, and the femto base station transmits an initial terminal message to the MME. A third step of transmitting the base station information to the femto base station by receiving the response from the femto base station and transmitting the PDN connection request message to the MME, and the fourth MME selecting the PDN gateway and the serving gateway for the corresponding PDN connection; Step, MME requests bearer creation for PDN connection to corresponding Serving Gateway and Serving Gateway When the PDN gateway requests this to the PDN gateway, the PDN gateway allocates resources, informs the serving gateway of the result, and the serving gateway notifies the MME of the result. In step 5, the MME notifies the terminal of accepting the PDN connection request. In step 6, the UE sends a control message to generate a radio bear, and the UE notifies the MDN of the end of the PDN connection, and updates the radio bearer information generated by the MME to the serving gateway and the PDN gateway. It consists of a seventh step.

In detail, the method for supporting local IP access of a femtocell in a wireless communication network including the femtocell of the present invention generates an initial terminal message including information of a local gateway when a service request is received from a terminal, and transmits the initial terminal message to a mobility management entity. Receiving and storing an initial context setup request message including information necessary to form a radio bearer transmitted from the mobility management entity, Receive a PDN connection request for local IP access from the terminal to transmit to the mobility management entity And when the mobility management entity sends a bearer creation request to the local gateway, the local gateway forming the radio bearer, wherein the local gateway is located in the femto cell.

In addition, in the wireless communication network including the femto cell of the present invention, the local IP access support apparatus, upon receiving a service request from the terminal, generates an initial terminal message including the information of the local gateway, and transmits to the mobility management entity, the mobility management entity A femto cell for receiving and storing an initial context setup request message including information required for radio bearer transmission transmitted from an entity, and receiving a PDN connection request for local IP access from the terminal and transmitting the request to the mobility management entity. Upon receiving a bearer creation request from a management entity, a local PDN gateway is connected to a local serving gateway and a core network that forms a radio bearer and a local PDN gateway that forms a local bearer and a radio bearer. It is characterized by including.

According to the present invention, when a terminal requests local IP access in an environment in which a femto base station gateway is installed, it is possible to use a femto base station that extends a function of a local gateway (PDN gateway alone or a PDN gateway and serving gateway) via a core network. Instead, data can be sent directly to the data network to provide an efficient data transfer environment. In addition, by using a femto base station gateway relay function, a secure function provided by the femto base station gateway may enable secure communication between the femto base station and the MME in the core network.

The terminology of the embodiment of the present invention basically conforms to the 3GPP Long Term Evolution (LTE) system standard, but is not necessarily limited thereto.

 The local IP access (LIPA) service described in the present invention refers to a service in which data of a terminal is delivered directly to a data network (or a local IP access network) without passing through a core network.

In addition, the local IP access network of the present invention refers to all networks heterogeneous from the core network, and may be, for example, a service network that provides the Internet or a home service.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that, in the drawings, the same components are denoted by the same reference symbols as possible. Further, the detailed description of well-known functions and constructions that may obscure the gist of the present invention will be omitted.

First, the structure of a wireless communication network according to an embodiment of the present invention will be described. A wireless communication network according to an embodiment of the present invention is based on a cellular system, and a wireless communication network in which macro base stations and femto base stations coexist among the cellular systems will be described.

1 is a diagram illustrating a structure of a wireless communication network including a femto base station and a femto base station gateway. The wireless communication network according to FIG. 1 includes a femto base station 103, a macro base station 108, a femto base station gateway 104, and mobility having a function of a terminal 100, a local PDN gateway 101, and a local serving gateway 102. MME 105 which is a related entity, a macro serving gateway 106 existing in the core network and a PDN gateway 107 existing in the core network may be included.

Macro eNB 108 is a base station that manages macro cells.

The macro base station 108 is connected to the terminal 100 through a radio channel and controls radio resources. For example, the macro base station 108 may generate and broadcast necessary control information in the macro cell as system information, or allocate radio resources to transmit and receive data or control information with the terminal 100. In addition, the macro base station 108 may collect the channel measurement result information of the current cell and the neighbor cells from the terminal 100 to determine the handover and command the handover. The macro base station 108 for this purpose includes a control protocol such as a radio resource protocol related to radio resource management.

The mobility management entity (MME) 105 manages an idle terminal and selects a packet data network (PDN) gateway and a serving gateway. In addition, the mobility management entity performs roaming and authentication related functions. The mobility management entity 105 then processes the bearer signal originating from the terminal 105.

The Serving Gateway 106 serves as a mobility anchor during handover between base stations or when moving between 3GPP radio networks.

The PDN gateway 107 assigns an IP address of the terminal 170, performs packet data related functions of the core network, and serves as a mobility anchor when moving between the 3GPP wireless network and the non-3GPP wireless network. To perform. In addition, the PDN gateway determines the bearer band provided to the subscriber, and is in charge of forwarding and routing functions for packet data.

The femto base station (Home eNB, HeNB) 103 is connected to a core network such as the mobility management entity 120 through a radio network controller to provide a mobile communication service to the terminal 100. Here, the femto cell is also commonly used as a closed subscriber group cell (CSG cell), and the CSG cell refers to a cell accessible only to terminals belonging to a specific group (ie, CSG) registered in advance to access the cell. Such a CSG cell may be a home cell that is typically installed in a small area such as an individual's home, or an enterprise / regional network cell that is installed in a large area for an enterprise or a specific organization. The femto base station 103 according to an embodiment of the present invention provides a mobile communication service only to a terminal registered to the mobile station, and includes identification information of a specific group that provides the service, that is, a CSG ID, in a system information block (SIB). Broadcast.

Local Serving Gateway (L-SGW) 102 is a serving gateway existing in the femto base station.

The local packet data network gateway (L-PGW) 107 is a PDN gateway existing in the femto base station.

The femto base station gateway (HeNB GW) 104 serves to connect the femto base station 103 with the MME 105, which is a mobility management entity.

The terminal 100 may connect to the core network through the macro base station 108 or the femto base station 103.

<First Embodiment>

The first embodiment includes a process and procedure equipment for performing the procedure of FIG. 7 to support local IP access in the network structure of FIGS. 1 and 2.

The femto base station 103 or femto base station gateway 104 of FIG. 1 obtains an IP address using DHCP or a static configuration, and then creates a connection for communication with the MME 105. In order to connect with the MME 105, the femto base station gateway 104 transmits a message (S1 SETUP REQUEST, S1 setup request message) 201 including its ID to the MME and receives a response 202 from the MME. The femto base station 103 also creates a connection with the femto base station gateway by sending a message containing its ID (S1 SETUP REQUEST, S1 setup request message) 203 to the femto base station gateway 104 and receiving a response 204. .

After the connection is made between the femto base station and the femto base station gateway, the femto base station gateway and the MME, if the terminal 100 transmits an initial message (Service Request) 205 through the femto base station 103, femto base station 103 ) Transmits a message (initial UE message) 206 indicating that an initial message has been received from the terminal to the femto base station gateway 104 connected to the femto base station 103 to obtain information on the corresponding terminal. In this case, the transmitted message 206 is included in the femto base station. Local gateway information including all information for transmitting and receiving control messages such as IPv4 and / or IPv6 addresses and ports of the local PDN gateway 4101 and the local serving gateway 4102. GW-info).

The femto base station gateway 104 receiving the 206 message stores the S-TMSI, which is the terminal user ID information used between the MME 105 and the base station, and the received local gateway information (Local GW-info). Forward to MME (207). In response, the MME sends a message (Initial Context Setup Request) 208 to the femto base station gateway in response to the message containing the information needed to form a radio bearer for the terminal user. Sends this message 209 to the femto base station 103. Receiving 209, the femto base station stores information related to forming a radio bearer for the terminal user, and then transmits a response (Initial Context Setup Response) 210 to the MME through the femto base station gateway. (211).

After the radio bearer establishment related information for the terminal user is transmitted to the femto base station, the terminal sends a message 212 requesting a PDN connection establishment for a local IP access (PDN Connectivity Request, PDN connection request message) to the femto base station 103 ). The transmitted request 212 is communicated to the MME 105 via femto base station 103 and femto base station gateway 104. After receiving the request 214, the MME 105 checks (215) whether the PDN connection creation request is for local IP access, and uses the local gateway information received in the message 207 if it is for local IP access. Send a message (Create Session Request) (216) directly to the local serving gateway.

The local serving gateway 102 receiving the 216 message generates a bearer that directly connects the requested bearer, that is, the local serving gateway 120 and the local PDN gateway 101 together with the local PDN gateway 101 and generates the bearer. Inform the MME of the result 217 (Create Session Response).

After confirming bearer creation to the serving gateway and the PDN gateway through the 217 message, the MME femto receives a message for generating a radio bearer (Bearer Setup Request) 218 and a message for accepting a PDN connection creation request (PDN Connectivity Accept) 218. A radio bearer is generated 220 by transmission 219 to base station 103.

When a message accepting a PDN connection creation request (PDN Connectivity Accept) is transmitted to the terminal, the terminal transmits a message 222 indicating that the creation of the PDN connection for local IP access is completed through the femto base station 103 to the MME 105. do. Receiving this, the MME 105 checks whether it is necessary to update radio bearer related information to the serving gateway or PDN gateway, and if necessary, the femto base station 103 sends a message (Modify Bearer Request) 224 including update bearer information. Sending to the local serving gateway 102 in the receiving and receiving a response (Modify Bearer Response) 225 to terminate the process for forming a local PDN connection. In the above process, the local gateway information (Local GW-info) delivered in 203 can be delivered in 203 or 210 messages.

The embodiment of FIG. 1 may also be applied to a case where a femto base station includes only a local PDN gateway and a serving gateway uses a macro serving gateway as shown in FIG. 2. The difference in executing the process of FIG. 7 in the network structure of FIG. 2 is that messages delivered from the MME to the local serving gateway and the local PDN gateway are delivered from the MME to the macro serving gateway and then to the macro PDN gateway.

Second Embodiment

The second embodiment includes a process and procedure equipment for performing the procedures of FIGS. 8 and 9, and FIGS. 10 and 11 to support local IP access in the network structure of FIGS. 3 and 4.

As described in the first embodiment, the femto base station 4103 or the femto base station gateway 4104 of FIG. 3 obtains an IP address using DHCP or static configuration, and then creates a connection for communication with the MME 4105. . To connect with the MME, the femto base station gateway sends a message 401 including its ID to the MME and receives a response 402 from the MME. The femto base station 4103 also creates a connection with the femto base station gateway by sending a message 403 including its ID to the femto base station gateway 4104 and receiving a response 404.

 After the connection between the femto base station 4103 and the femto base station gateway 4104 and the femto base station gateway and the MME 4105 is created, the terminal 4100 transmits an initial message (Service Request) 405 through the corresponding femto base station 4103. The femto base station 4103 transmits a femto base station gateway 4104 connected to the femto base station with a message (initial terminal message, Initial UE message) 406 indicating that it has received an initial message received by the terminal in order to obtain information about the terminal. To send). In this case, the transmitted message 406 is included in the femto base station. Local gateway information including all information for transmitting and receiving control messages such as IPv4 and / or IPv6 addresses and ports of the local PDN gateway 4101 and the local serving gateway 4102. GW-info).

The femto base station gateway 4104 receiving the 406 message stores the S-TMSI, which is the terminal user ID information used between the MME and the base station, and the received local gateway information (Local GW-info) information. A serving gateway proxy 4110 is generated 407 to receive and process information sent to the gateway. In addition, after changing from the received local gateway information (Local GW-info) to serving gateway proxy that generated the serving gateway information, it transmits to the MME (408). In response, the MME, in response, sends a message (Initial Context Setup Request) 409 to the femto base station gateway, including the information needed to form a radio bearer for the terminal user. Sends this message 409 to the femto base station 4103. After receiving the 410, the femto base station stores the radio bearer-related information for the terminal user and transmits a response (Initial Context Setup Response) 411 to the MME through the femto base station gateway ( 412).

After the information related to the establishment of a radio bearer for a terminal user is transmitted to the femto base station, the terminal sends a request message (PDN Connectivity Request, PDN connection request message) 413 to form a PDN connection for local IP access. Send to 103. The sent request 413 is forwarded to the MME 4105 through femto base station 4103 and femto base station gateway 4104. After receiving the request 415, the MME 4105 checks (416) whether the PDN connection request is for local IP access, and then sends a bearer creation request message using the local gateway information received in message 408 if the request is for local IP access. (Create Session Request) (417) The request message 417 transmitted includes IMSI, which is a terminal user ID used between the serving gateway and the MME, and S-TMSI, which is a terminal user ID used between the base station and the MME, and a 408 message as the PDN gateway information. Contains local PDN gateway information received through.

The information on the local serving gateway 4102, which is the destination of the 417 message, also uses the information obtained in the 408 message. Since the information is a serving gateway proxy 4110 generated by the femto base station gateway, the 417 message is transmitted to the femto base station gateway 4110. Is sent. The femto base station gateway 4104 receiving the 417 message stores the terminal information IMSI and S-TMSI 418 in the message, and the S-TMSI and local gateway information already received and stored through the message 406 (Local GW-info After searching for a local serving gateway to receive a bearer creation request using the information, a bearer creation request message (Create Session Request) 419 is transmitted. Prior to transmitting the bearer creation request message, the femto base station gateway 4104 generates an MME proxy 4109 such that a control message sent from the local serving gateway 4102 to the MME 4104 is passed through it. And access information such as the address and port information of the MME proxy 4109 together with the bearer create session request 419 as the former sender F-TEID for control plane, and then the local serving gateway in the femto base station ( 4102).

The local serving gateway receiving the bearer creation message requests the bearer creation to the local PDN gateway 4101 to create a bearer between the local serving gateway 4102 and the local PDN gateway 4101 (420), and then outputs the result of the femto. Create session response 421 to the MME proxy 4109 in the base station gateway.

The femto gateway receiving the 421 message modifies the sender F-TEID to the serving gateway proxy and delivers the message to the MME (422).

 Upon receiving the 422 message, the MME sends a message to the femto base station through a femto gateway along with a message (Bearer Setup Request) requesting the creation of a radio bearer and a message (PDN Connectivity Accept) indicating that the PDN connection creation request requested by the terminal is allowed. Forward to base station (423,424). The femto base station receiving the 424 message creates a radio bearer (425) and forwards the result to the MME via the femto base station gateway (426, 427).

After all of these processes, the UE transmits a message (PDN Connectivity Complete) 428 indicating that the PDN connection generation for the local IP access is completed to the MME 4105 through the femto base station 4103 and the femto base station gateway 4104 ( 429,430).

On the other hand, when the MME 4105 needs to update the generated radio bearer related information, the bearer update request (Modify Bearer Request) 431 via the serving gateway proxy 4110 local serving gateway in the femto base station 4103 (432). The local serving gateway 4102 updates 443 bearer related information with the local PDN gateway 4101 in the femto base station, and then transmits an update response to the MME 4105 through the MME proxy 4109 (435). ), The process for establishing a local PDN connection is terminated. In the above process, the local gateway information (Local GW-info) can be delivered through the message delivered in 403 and the message delivered in 410. In addition, if there is no need to update the corresponding information to the serving gateway and the PDN gate after generating the radio bearer, steps 431 to 435 of FIG. 9 are not executed.

3 may be applied to a network structure in which a femto base station includes only a local PDN gateway and a serving gateway uses a macro serving gateway as shown in FIG. 4. When applied to the structure shown in Figure 4 it is performed as in the procedure of Figures 10 and 11.

The difference between the procedure of FIG. 8 and FIG. 9 and the procedure of FIG. 10 and FIG. 11, which is the process of FIG. 4, is assigned by the serving gateway proxy in 407 of FIG. 8. Unlike this, the PDN gateway proxy 5112 is assigned at 507 of 10, and thus, unlike the 408 message of FIG. 8, only the access information of the PDN gateway proxy is transmitted to the 508 message of FIG. In addition, unlike the 417 message of FIG. 8 that is delivered to the serving gateway proxy, the 517 message of FIG. 10 is delivered to the macro serving gateway 5106 and then delivered to the PDN gateway proxy 5112, and then the 518 message that is delivered thereafter is also delivered. Like the 517 message, it includes both IMSI and S-TMSI, and unlike step 418 of Fig. 8, step 519 of Fig. 11 assigns a Serving Gateway proxy 5111 and accesses the Serving Gateway proxy generated to the message sent to 520. When the information is included and the answer is passed from the femto base station through the femto base station gateway to the macro serving gateway, the sender F-TEID of the 522 message is changed to the PDN gateway proxy (5112) and the sender F-TEID of the 523 message is the macro serving. Changed and forwarded to the gateway. In addition, after generating the radio bearer, the sender F-TEID is changed to the serving gateway proxy in step 534 to transmit the radio bearer information to the local PDN gateway. In addition to the above description, processes 509 to 516 of FIG. 10 and 409 to 416 of FIG. 8 are the same, processes 524 to 531 of FIG. 11 and processes 423 to 430 of FIG. In the above process, the local GW-info can be delivered through the message delivered at 503 and the message delivered at 512. In addition, if there is no need to update the corresponding information to the serving gateway and the PDN gate after generating the radio bearer, steps 532 to 536 in FIG. 11 are not executed.

Third Embodiment

The third embodiment includes a process and procedure equipment for performing the procedures of FIGS. 12 and 13 to support local IP access in the network structure of FIGS. 5 and 6.

The femto base station 6103 of FIG. 12 obtains an IP address using DHCP or static configuration, and then creates a connection for communication with the MME 6105. Connection creation for communication with the MME 6105 is achieved by the femto base station 6103 sending an S1 Setup request message 601 to the MME and receiving a response message 602 thereto.

After the communication connection between the femto base station and the MME is created, when the terminal 6100 transmits an initial message (Service Request) (603), the femto base station 6103 receiving the initial message is the local PDN gateway 6101 in the femto base station. And local gateway information (Local GW-info) including both IPv4 and / or IPv6 addresses and ports of the serving gateway 6102 are transmitted to the MME as one message 604 together with the initial message received from the terminal. .

After receiving the message 604, the MME stores terminal related information including Local User Information (S-TMSI) and Local Gateway Information (Local GW-info), which are used to distinguish the terminal between the base station and the MME. The radio bearer necessary information between the terminal and the base station is transmitted in a message (Initial Context Setup Request). The femto base station receiving this message 605 forwards the response message 606 to the MME 6105.

After the terminal user information is delivered to the base station, the terminal sends a request message 607 to form a PDN connection for local IP access to the femto base station 6103. The PDN connection request message is delivered to the MME 6105 via the femto base station 6103.

The MME checks whether the received PDN connection creation request is a PDN connection request for local IP access, and if it is for local IP access, the terminal user originally used in a bearer creation request message (Create Session Request) 609 sent to the serving gateway. Along with IMSI, which is an ID, S-TMSI, which is a terminal user ID used between a base station and an MME, is put together and transmitted (609). In addition, the MME refers to local gateway information that has received and stored 602 messages in order to send the bearer creation request message 609 directly to the local serving gateway. The local serving gateway 6102 receiving the bearer creation message 609 from the MME 6105 is a bearer requested together with the local PDN gateway 6101, that is, a bearer that directly connects the local serving gateway 120 and the local PDN gateway 101. The MME confirms the bearer creation of the serving gateway and the PDN gateway through the response message 611 after transmitting the result to the MME in a bearer creation response 611 message (Create Session Response). A request message for a generator (Bearer Setup Request) and a message for allowing a PDN connection creation request (PDN Connectivity Accept) are forwarded together (612) to the femto base station 6103.

The femto base station which receives this generates a radio bearer (613) and informs the result of the result to the MME in a response message (Bearer Setup Response) 614, and the terminal receiving the PDN connection creation request permission message also generates a radio bearer ( After 613, a PDN connectivity complete message 615 indicating that the PDN connection generation is completed is transferred 616 to the MME through the femto base station 616.

Finally, the MME 6105 transmits a message (Modify Bearer Request) 617 and receives a response (Modify Bearer Response) 618 in order to update radio bearer related information to the serving gateway to form a local PDN connection. End the process. In the above process, the local gateway information (Local GW-info) transmitted in 604 may be transmitted through 601 message for establishing a connection between the femto base station gateway and MME, and message 606 for transmitting terminal user related information in the base station. have. In addition, in the message transmitted through 609, only the S-TMSI may be used without transmitting the IMSI.

The solution 3 described above may be used when only the local PDN gate exists in the femto base station and the local serving gateway uses the macro serving gateway as shown in FIG. In the network structure of FIG. 6, as shown in FIG. 13, a bearer creation request message 709 transmitted by the MME to the macro serving gateway is not transmitted to the local serving gateway, but is transmitted to the macro serving gateway, and the femto base station gateway is transmitted from the macro serving gateway. The bearer creation request message 710 is forwarded to the local PDN gateway existing at. Both 709 and 710 messages carry an additional S-TMSI. In addition, the bearer creation result is also transmitted to the macro serving gateway through the response message 711 transmitted from the local PDN gateway, and then transferred back to the MME (712). Processes 701 to 709 of FIG. 13 are the same as processes 601 to 609 of FIG. 12, and processes 713 to 719 of FIG. 13 are the same as processes 612 to 618 of FIG. 12. In the message transmitted through 710 in the process of FIG. 13, IMSI may not be transmitted and only S-TMSI may be used.

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 diagram illustrating a structure of a wireless communication network in which a femto base station and a femto base station gateway coexist with an extended macro base station, a serving gateway, and a PDN gateway function.

2 is a diagram illustrating a structure of a wireless communication network in which a femto base station and a femto base station gateway coexist with an extended macro base station and a PDN gateway function.

3 is a diagram illustrating a structure of a wireless communication network in which a femto base station and a femto base station gateway coexist with an extended macro base station, a serving gateway, a PDN gateway function, an MME proxy, and a serving gateway proxy function;

4 is a diagram illustrating a structure of a wireless communication network in which a femto base station and a femto base station gateway coexist with an extended macro base station, a PDN gateway function, a PDN gateway proxy, and a serving gateway proxy function;

5 is a diagram illustrating a structure of a wireless communication network in which a femto base station expanded to have a macro base station, a serving gateway, and a PDN gateway function coexist.

6 is a diagram illustrating a structure of a wireless communication network in which a femto base station extended to have a macro base station and a PDN gateway function coexist.

FIG. 7 illustrates a procedure for creating a PDN connection for local IP access under the network structure of FIG.

8 and 9 illustrate a procedure for creating a PDN connection for local IP access under the network structure of FIG.

10 and 11 illustrate a procedure for creating a PDN connection for local IP access under the network structure of FIG.

FIG. 12 illustrates a procedure for creating a PDN connection for local IP access under the network structure of FIG. 5. FIG.

FIG. 13 illustrates a procedure for creating a PDN connection for local IP access under the network structure of FIG.

Claims (6)

A method for supporting local IP access of a femto cell in a wireless communication network including a femto cell, Upon receiving a service request from a terminal, generating an initial terminal message including information of a local gateway and transmitting it to a mobility management entity; Receiving and storing an initial context setup request message that includes information required to form a radio bearer transmitted from the mobility management entity; Receiving a PDN connection request for local IP access from the terminal and transmitting the PDN connection request to the mobility management entity; When the mobility management entity sends a bearer creation request to the local gateway, the local gateway forming the radio bearer, wherein the local gateway is located in the femto cell. How to support access. The method of claim 1, wherein generating the initial terminal message comprises: And generating the initial terminal message that includes information of a local serving gateway and a local gateway for a local PDN gateway. The method of claim 2, wherein the local gateway information, And a local IP access IP address of the local serving gateway and the local PDN gateway. The method of claim 3, wherein the bearer creation request step, And the mobility management entity sends the bearer creation request to the local serving gateway. The method of claim 4, wherein the forming of the radio bearer by the local gateway comprises: And a bearer is formed between the local serving gateway and the local PDN gateway. An apparatus for supporting local IP access in a wireless communication network including a femto cell, When receiving a service request from the terminal, an initial terminal message including information of a local gateway is generated and transmitted to a mobility management entity, and an initial context setting request message including information necessary for forming a radio bearer transmitted from the mobility management entity is received. A femto cell which receives the PDN connection request for local IP access from the terminal and transmits the received PDN connection request to the mobility management entity; A local serving gateway that forms a radio bearer with a local PDN gateway upon receiving a bearer creation request from the mobility management entity; And And a local PDN gateway connected to a heterogeneous data network with a core network and forming a radio bearer with the local serving gateway.

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