KR20090056441A - Mtehod and system for reallocating address of internet protocol - Google Patents

Abstract

A method and a system for resetting an internet protocol address are provided to offer an IP service without interruption by using a new IP address by supplying the change information of the gateway to a terminal using the IP address without the mobility for the change of the gateway. A new position registration is requested according to the handover in an arbitrary terminal(502). In MME(Mobility Management Evolution) requested for the position registration, the IP address and the IP type about the terminal are requested to the prior network(503). If the MME receives the IP address through an NAS(Non-access-stratum) message by the requested information, the generation of bearer including the new IP address information is requested to the gateway(505). The bearer response information including the new IP address is transmitted to the MME according to the bearer generating request in the gateway. When the MME transmits the position registration response to the terminal, the newly allocated IP address is included.

Description

METHODS AND SYSTEM FOR REALLOCATING ADDRESS OF INTERNET PROTOCOL}

The present invention relates to a system and method for setting an address in a communication system according to the Internet Protocol (hereinafter referred to as "IP"), and more particularly, to a method for setting a new IP address for a terminal using the Internet protocol. It is about the system.

In general, IP is one protocol proposed to provide various services to a wired terminal. The terminal receives the IP address and receives the packet service. The IP address assigned to the terminal remains the same in the subnet managed by the gateway to which the IP address is assigned. However, when the terminal moves or the gateway changes due to a specific situation, the terminal is assigned a new IP from the changed gateway. In this case, the service provided through the existing IP is terminated or terminated. That is, continuity of services provided to the terminal is not guaranteed. Let's take a look at this as an example.

Suppose that a user's terminal assigned an IP address is making a voice call with the other party using a VoIP technique. In this case, the user may move out of the area managed by the gateway assigned an IP address while the user uses public transportation, a car, or walks. In this case, the terminal is assigned a new IP address at the new gateway. Then, the terminal receiving the VoIP service using the previously allocated IP address cannot receive the continuous VoIP service. That is, the voice call with the other party is disconnected. Thus, the user is faced with having to call again.

One of the solutions studied to solve the above problem is mobile IP. Mobile IP is a method of allocating a fixed IP address that does not change regardless of the mobility of the terminal and an IP address that changes according to the movement of the terminal, that is, two IP addresses. A fixed IP address that does not change regardless of the mobility of the terminal is called a home address (hereinafter referred to as “HoA”), and is an IP address that the terminal notifies to use the service. In addition, the IP address that changes according to the movement of the terminal is called a care address (hereinafter referred to as "CoA").

Referring to the mobile IP applied to the terminal receiving the VoIP service described above is as follows. Mobile IP applied terminal has HoA and CoA. Therefore, CoA is changed when the terminal moves. However, even when the terminal moves, the HoA is maintained so that the terminal receiving the VoIP service can continuously maintain the voice call service.

As described above, a specific service must support continuity of service due to its characteristics. For example, VoIP services, FTP services, streaming services, and the like. For this reason, support for continuity of services has become a big issue in the development of next generation packet networks that are actively underway, and mobile IP is often adopted.

1 is a diagram illustrating a Service Architecture Evolution (SAE) architecture, which is an evolved packet system in 3GPP.

SAE is largely E-UTRAN (Evolved UTRAN) 103, Mobility Management Entity (hereinafter referred to as "MME") 113, Serving Gateway (hereinafter referred to as "SGW") 105, Packet A data network gateway (Packet or Public Data Network (PDN) Gateway: hereinafter referred to as "PGW") 107. The E-UTRAN 103 is an evolved access network and an evolved base station ( enhanced Node B (hereinafter referred to as “eNB”) (not shown in Fig. 1.) The MME 113 includes NAS signaling (Non-access-stratum signaling), NAS signaling security, and 3GPP network. Mobility management between the Idle mode UE, the roaming, authentication, bearer management, etc. The SGW 105 performs the functions between eNBs. Mobility management, mobility management between 3GPP networks, idle mode downlink packet buffering, E-UTRAN idle mode downlink, It manages raw interception, packet routing and forwarding, etc. The PGW 107 manages policy enforcement, per-user based packet filtering, charging support, lawful interception, UE IP allocation, packet screening, etc. Performs the function of.

The PCRF (Policy Control and Charging Rules Function) 111 manages a policy, QoS, etc. to be applied to the terminal. The Serving GPRS Support Node (SGSN) 115 is an entity associated with a legacy packet network (GPRS), and the Home Subscriber Server (HSS) 115 manages user subscription information and location information. In addition, the above-mentioned entities may have additional functions.

The SAE having the above configuration adopts a proxy mobile IP (hereinafter referred to as “PMIP”) as one method for supporting service continuity. The PMIP has a difference in that the network supports IP mobility without changing the terminal, whereas the conventional mobile IP must provide a stack supporting the mobile IP to the terminal. That is, the terminal does not need to know the mobile IP procedure. Other differences will be omitted. In SAE, the PGW 107 allocates a PMIP to the UE. That is, the PGW 107 serves as HA. In other words, all calls must be anchored to the PGW 107 for mobility.

However, the configuration as described above generates unnecessary PMIP signaling, and also causes overhead in the network since all calls must pass through the PGW 107 performing the HA function. As a result, the network is heavily loaded to ensure the mobility of all calls, which can also affect the quality of service provided to the user. This will be described in more detail.

If a user uses a service that does not require service continuity guarantee, for example, when a terminal is provided with a non-continuous service such as reading an article by reading a news server or finding weather information, If you use an IP you don't need, you can solve the problems mentioned above. As a result, there may be a case where a terminal uses an IP address that is guaranteed mobility and a case where an IP address that is not guaranteed mobility is used. In other words, when the IP mobility is not guaranteed, when the gateway providing the service to the terminal is changed, the terminal can no longer use the IP address being used and must be discarded. Therefore, when IP mobility is guaranteed, the terminal may use the same IP address anytime and anywhere. However, if IP mobility is not guaranteed, the terminal should know how long the IP address in use is available. For example, when a terminal originally connected to a 3GPP network moves to a WiMAX network, the terminal may know that the gateway has been changed because the wireless access method has been changed, and thus, an IP address that does not guarantee IP mobility may be more. It can be seen without any effort that it is not valid. However, if the gateway is changed while the terminal is moving in the same network, there is no way for the terminal to know this.

The present invention provides a method and system for notifying the terminal of when an IP address for which IP mobility is not guaranteed should be updated.

In another aspect, the present invention provides a method and system for allocating an IP address to the terminal to ensure the mobility of the terminal.

The method according to the embodiment of the present invention is a method for providing a validity of an IP address to a terminal in a mobility management entity (MME) of a communication system using an Internet protocol (IP). As it moves to, the following two methods can be used.

In the first method, a mobility management entity provides a new IP address to a terminal during a handover procedure or a tracking area update procedure so that the terminal replaces an existing IP address with a new IP address.

In the second method, the mobility management entity revokes a bearer used to deliver an existing IP packet during a handover procedure or a tracking area update procedure, and informs the terminal that the bearer has been terminated, and the terminal IPs the new gateway. Ask for the address again.

In addition, the system according to an embodiment of the present invention, a system for providing an IP service to a terminal using the Internet Protocol (IP), the mobile (Mobile) according to the service and region to be used when IP is requested from the terminal If it checks and remembers whether IP or Simple IP is needed and the gateway is changed, the existing mobility management entity sends the mobility management entity connected to the new gateway with the terminal's IP address information along with the terminal's IP address information. Pass or not. The mobility management entity that receives this information receives a new IP address from the new gateway and delivers it to the terminal, or informs the terminal to request a new IP address by terminating the bearer for simple IP.

According to the present invention, it is possible to provide an IP service without interruption by informing the terminal using the IP address to which the mobility is not provided due to the gateway change so that the terminal uses the new IP address.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

The present invention provides a method for informing a terminal using an IP address without mobility that the gateway providing the IP service is not changed and the service is not provided to the IP address.

First, if the gateway is changed while the terminal is performing a handover or location registration procedure, if the IP address currently being used by the terminal is a simple IP that cannot be used at the new gateway, the network changes the gateway to the IP address to be used at the new gateway. Inform the terminal in advance during the procedure. It is apparent to those skilled in the art that the method of allocating a new IP address to the terminal during the above-described gateway change procedure can be applied not only to the case of Simple IP but also to other cases requiring the same operation.

Second, when the gateway is changed while the terminal is performing a handover or location registration procedure, when the IP address currently being used by the terminal is a simple IP that cannot be used in the new gateway, and the terminal needs to request an IP address directly, For example, if the IP stack is not in the terminal device, such as when an LTE terminal is connected to a PC and used, the gateway or MME releases the bearer for packet forwarding corresponding to the IP address in use instead of assigning a new IP address. The terminal notified that the bearer has been released requests a new IP address.

As another example of the second method, an IP reset request can be made directly to the terminal without canceling the bearer. That is, the MME may request the bearer creation to the new gateway in the same manner as the existing mobility guarantee procedure, and may inform the terminal to request the IP address for the bearer again.

2 is a system configuration diagram when the gateway changes as the terminal moves. It should be noted that other entities are omitted since the drawings highlight only the main entities related to the present invention. The ENodeBs 201 and 211 are evolved base stations that provide wireless network access, and the MMEs 203 and 213 are entities that manage mobility of the terminal 200. The MMEs 203 and 213 generate signals necessary for the gateway and the eNodeB to provide mobility to the terminal 200. According to the present invention, the MMEs 203 and 213 should be added with a function of managing validity of Simple IP and informing the terminal appropriately. The PDN GWs 205 and 215 and the Serving GWs 207 and 217, which are classified according to the SAE structure, represent a gateway providing an IP packet service.

Although the configuration diagram shown in FIG. 2 takes an SAE system as an example, it is obvious that the present invention can be equally applied to other mobile communication systems including a Radio Access network and a Core Network network. In addition, other configurations in addition to the method illustrated in FIG. 2 described above may be sufficiently applied by those skilled in the art using the present invention.

3 is a signaling flowchart when a gateway is changed while a UE performs a location registration procedure while a UE moves from an idle state according to an embodiment of the present invention.

In the signaling flow diagram of FIG. 3, the parameters included in each message indicate only those related to the present invention, and there may be additional changes in each message. In addition, in FIG. 3, a method of allocating a new IP address to be delivered by the MME and a method of releasing a bearer or sending an IP reset request implicitly are illustrated in one diagram. Referring to FIG. Let's look at the process.

In step 301, the UE 320 moves to a new MME or Serving GW area and starts a location registration request as it leaves a location registered in a current network. In step 302, the UE 320 sends a location registration request (Tracking Area Update: TAU) to the new MME 322 through the eNB 321. Then, in step 303, the new MME 322 makes a context request to the previous MME 323. Accordingly, the previous MME 323 notifies the new MME 322 with the context information in step 304, whether the IP address used by the terminal and the corresponding IP is a simple IP. Upon receiving this information, the new MME 322 sends a context response signal in step 305 to respond to the context response from the previous MME 323.

Thereafter, in step 306, the new MME 322 sends a Create Bearer Request to the gateway 324 which is newly operated as a serving gateway. In this case, when the terminal receives an IP address from the network through a NAS message, the terminal requests a simple IP address as an IP type in order to receive a new IP address from the new gateway 324. In this case, since the address area of the new gateway 324 may be the same as before, the IP address received from the previous MME 323 may be transferred together, so that the gateway 324 may allocate the same IP address as before. When the bearer creation request is received from the new MME 322, that is, when there is a simple IP address request, the new serving gateway 324 allocates a new IP address for the terminal 320 in step 307 and includes the response in the MME 322. Send to. Steps 306 and 307 may be repeated when the terminal uses several IP addresses at the same time. In addition, Mobile IP, which is guaranteed mobility, is not shown in the signaling of FIG. 3 because it is irrelevant to the present invention. On the other hand, the terminal 320 is not assigned an IP address through a NAS message, the MME 322 does not perform steps 306 and 307 in the case of a simple IP address received directly requested.

After performing the above process, in step 308, the MME 322 registers the location of the terminal 320 in the HSS 326. When the MME 322 sends a tracking area update accept to the terminal 320 in step 309, the location registration response message may include newly allocated IP address information. Alternatively, it may include bearer status information indicating that a bearer using Simple IP has been deleted or an indicator indicating new allocation of an IP address. Alternatively, you can include both. In step 310, the terminal 320 transmits a TAU response according to the message reception.

Meanwhile, the new serving gateway 324 requests the bearer deletion to the previous serving gateway 325 in step 311, and the previous serving gateway 325 deletes the bearer formed with the terminal 320 when the bearer deletion request is requested in step 312. The bearer delete response is sent to the new serving gateway 324. Steps 309 and 310, and steps 311 and 312 are processes that can be performed sequentially or simultaneously. Since this is determined by the design of the system, it is not limited here.

If the bearer using Simple IP is deleted or if a new MME 322 is instructed to renew the IP address request, the terminal 320 requests a new IP address in step 313. The present invention does not deal with the specific IP address request method.

4 is a signaling flowchart when a gateway is changed while a UE performs a handover procedure while moving in an ACTIVE state.

In the signaling flow diagram of FIG. 4, the parameters included in each message indicate only those related to the present invention, and there may be additional changes. In addition, in FIG. 4, it should be noted that a method of allocating a new IP address and transmitting the MME and releasing a bearer is illustrated in one diagram.

If the UE 430 or the eNB 431 determines to perform handover in step 401, the eNB 431 sends a handover request message (Relocation Required) to the MME 433 in step 402. Then, in step 403, the MME 433 transmits a handover request message to the target MME 434 (Forward Relocation Request). At this time, whether the IP address being used by the terminal 430 is a simple IP and the IP address being used are transmitted together. In step 404, the target MME 434 receiving the request sends a bearer creation request to the target gateway 436. The bearer creation request includes a simple IP request for requesting a new address assignment and an old IP address of the terminal. In step 405, when there is a simple IP request, the target gateway 436 allocates a new address and includes the address in a bearer create response message. In some cases, the address area of the new gateway 436 may be the same as the old gateway 435, so that the gateway 436 may assign the same IP address as the previous one.

In the second method, if the terminal first accesses the network, if a simple IP address is not allocated from the network through a NAS message, steps 404, 405, 413 and 414 are not performed. Therefore, in this case, when configuring the target eNB 432 in step 406, radio resources for bearers using simple IP are not allocated.

In step 407, the target MME 434 transmits the newly allocated IP address information to the terminal 430 in steps 408 and 409. At this time, the bearer status is delivered in the RAN container.

Steps 410 to 415 follow the normal handover procedure. However, steps 413 and 414 are not performed for some bearers not generated in steps 404 and 405.

According to the second scheme, the UE requests a new IP address in step 416 where the bearer is not generated in steps 404 and 405. The detailed procedure for requesting an IP address is not covered in the present invention.

In the second method, the MME requests the bearer creation to the new gateway in steps 406 to 407, and informs the UE that only the IP address request is newly made in step 409.

FIG. 5 is a flowchart of setting an IP address of a terminal when the terminal receives a location registration request response or after performing a handover procedure.

After receiving the TAU response or the Handover command in step 501, the UE performs the processing procedure for the TAU response or the Handover command in step 502 and then performs the procedure added after step 503. The terminal checks whether the bearer using the preset IP address is connected through the response message received in step 503. This can be confirmed using the connection information of the bearer included in the response message received in step 503. If the bearer that used Simple IP is deleted in the terminal location registration process, the terminal recognizes that the gateway has been changed and makes an IP request to the new gateway in step 505.

On the other hand, if the process proceeds to step 504, the UE checks whether the received message includes the bearer information and the new IP address for the bearer. If a new IP address different from the preset IP address is included, the terminal proceeds to step 506 and the terminal resets the interface using the changed IP address to the newly received IP address. On the other hand, if the IP address is the same, it is checked in step 507 whether there is an IP reset request in the received message, and if it is necessary to request the IP again, in step 508, the gateway requests a new IP.

6 is a flowchart illustrating an operation for setting a bearer by an MME receiving a location registration request or a new target MME receiving a handover request.

Referring to FIG. 6, when the gateway is changed, the MME receiving the TAU request message or the handover request message (Forward Relocation Request) in step 601 is determined whether the IP address previously set and used by the terminal is simple IP in step 602. Check if the gateway changes. If it is determined that the IP address is Simple IP and the gateway is changed, it is determined in step 603 whether to assign a new IP address to the terminal. When the terminal is using the IP address allocated by the network during the access process instead of directly requesting the IP address when the terminal is first connected to the network, when a bearer request message (Create Bearer Request) is sent to the new gateway in step 604, Add a parameter to request an IP address. The IP address received from the new gateway is transmitted in the response message sent to the terminal in step 606.

On the other hand, if the terminal checks in step 603 that the terminal directly uses the allocated IP address after the network connection, in step 605, the bearer is released without generating a bearer for the IP address in the new gateway. In operation 606, a bearer connection failure is indicated on the bearer status included in the response message sent to the terminal and transmitted. Alternatively, after the bearer is generated according to a general TAU / handover procedure, the UE may be notified of reproducing an IP request for the bearer in step 606.

It is obvious that the IP address information or bearer status information is not dependent on the location on the message including the specific message format or information.

1 is a diagram illustrating a Service Architecture Evolution (SAE) architecture, which is an evolved packet system in 3GPP;

2 is a system configuration diagram when a gateway changes as a terminal moves;

3 is a signaling flowchart of a case where a gateway is changed while a terminal performs a location registration procedure while a terminal moves from an idle state according to an embodiment of the present invention;

4 is a signaling flowchart when a gateway is changed while a UE performs a handover procedure while moving in an ACTIVE state;

5 is a flowchart of setting an IP address of a terminal when the terminal receives a location registration request response or after performing a handover procedure.

6 is a flowchart illustrating an operation for establishing a bearer by an MME receiving a location registration request or a new target MME receiving a handover request;

Claims (2)

In the IP address allocation method, Requesting a new location registration according to a handover by an arbitrary terminal; Requesting information including the IP address and IP type of the terminal from the MME, which has been requested to register the location, to the previous network; Requesting a bearer creation including new IP address information to a gateway when the MME receives an IP address of the terminal through an NAS message through the requested information; Transmitting, at the gateway, a bearer response signal including a new IP address to the MME according to the bearer creation request; When the MME sends a location registration response to the terminal, including the newly allocated IP address and transmitting. In the IP address allocation method, Requesting a new location registration according to a handover by an arbitrary terminal; Requesting information including an IP address and an IP type of the terminal from the MME, which has been requested to register a location, to the previous network; Requesting creation of a bearer to a gateway when the MME is assigned an IP address of the terminal through a NAS message through the requested information; Transmitting, by the gateway, a bearer response signal including bearer status information of which a bearer previously generated is deleted according to the bearer creation request to the MME; And transmitting bearer state information when the MME sends a location registration response to the terminal.

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