KR20010035104A - A Mobile IP Registration Mechanism with Minimum Bandwidth for UMTS/GPRS - Google Patents

Abstract

PURPOSE: A method for registering a mobile IP(Internet Protocol) having a minimum band in an asynchronous mobile communication system is provided to decide the reservation of wired/wireless resources according to a result of the mobile IP registration in an HM(Home Agent), and to use a minimum band if the mobile IP registration is failed. CONSTITUTION: An MS(Mobile Station,1) transmits a PDP(Packet Data Protocol) context activation request(301) to an SGSN(Serving GPRS(General Packet Radio System) Support Node,3). The SGSN(3) selects an appropriate GGSN/FA(Gateway GPRS Support Node/Foreign Agent,4)(302), and transmits a PDP context generation request(303) to the selected GGSN/FA(4). The GGSN/FA(4) transmits a PDP context generation response(304) to the SGSN(3). The SGSN(3) transmits a PDP context activation response(305) to the MS(1) through a UTRAN(UMTS(Universal Mobile Telecommunication System) Terrestrial Radio Access Network,2). The GGSN/FA(4) transmits an agent advertisement(306) of a mobile IP(Internet Protocol) to the MS(1). The MS(1) transmits a mobile IP registration request(307) to the GGSN/FA(4). The GGSN/FA(4) performs a mobile IP registration request(308) to an HA(Home Agent,5). The HA(5) transmits a mobile IP registration response(309) to the GGSN/FA(4). The GGSN/FA(4) transmits the mobile IP registration response(310) to the MS(1), and designated a decided home address of the MS(1) in a PDP context(311). The MS(1) transmits a PDP context correction request(321) to SGSN(3). The SGSN(3) transmits a PDP context update request to the GGSN/FA(4). The GGSN/FA(4) transmits a PDP context update response(323) to the SGSN(3). The SGSN(3) transmits a PDP context correction response(324) to the MS(1) through the UTRAN(2).

Description

Mobile IP Registration Mechanism with Minimum Bandwidth for UMTS / GPRS in Asynchronous Mobile Communication System

Field of the Invention The present invention relates to a technique of applying the Mobile IP protocol to a GPRS network, which is a packet-based network of UMTS, the third-generation mobile communication system in Europe. The new mobile IP registration scheme can be used to improve the inefficient use of the system. It may be the Mobile IP application process described in the standards document TR 23.923 (Release 99) of the 3GPP (3 ^rd Generation Partnership Project), which leads the UMTS standard as the prior art in this field. This is shown in FIGS. 1 and 2.

1 shows a conventional Mobile IP registration successful procedure. UMTS / GPRS provides the Mobile IP Protocol (RFC 2002) defined by the IETF to accommodate Mobile IP users. However, the Mobile IP protocol does not apply to UMTS / GPRS as it is, and a slightly modified form is applied to the wireless environment. The roles of the functional entities defined in FIG. 1 are as follows. The mobile station (MS) 1 is a terminal supporting GPRS and provides a Mobile IP function. The mobile terminal may connect terminal equipment, a notebook, or a PDA. A base station (UTRAN; UMTS Terrestrial Radio Access Network) includes base station and control station functions, and the base station and the mobile terminal have a radio interface. The Serving GPRS Support Node (SGSN) 3 serves as a regional IP switch. The gateway / external agent 4 provides a function of combining a gateway GPRS support node (GGSN) defined in GPRS and a foreign agent (FA) defined in Mobile IP. The gateway acts as a gateway that connects to the Internet, and the external agent acts as an agent that provides local Mobile IP services. The home agent 5 is located in the public Internet, not in the GPRS network, and is an agent that assigns an address to a mobile terminal that receives an initial Mobile IP service and manages it.

The operation principle of each procedure shown in FIG. 1 will be described. The applied scenario is a procedure in which a GPRS mobile terminal 1 supporting Mobile IP requests Mobile IP registration and supports Mobile IP registration in a GPRS network through signaling between home agents in a public Internet network.

First, the bearer setup procedure 100 is performed. The mobile terminal designates an access point name (APN) as MIPV4FA (external agent that supports Mobile IP Version4) to receive Mobile IP service, and specifies bearer information (Bandwidth) of the traffic channel requested by the user. . Then, they are included in the Protocol Data Type (PDP) Context Activation Request 101 message and transmitted to the packet exchanger through the base station. Receiving this, the packet switch selects an appropriate gateway / external agent (102), and includes user request band information received from the mobile terminal in the PDP context creation request (103) message to transmit to the selected gateway / external agent. The gateway / external agent determines whether to accept the requested PDP context, and if so, allocates itself the bandwidth requested by the user. The bandwidth allocation result is included in the PDP context creation response 104 message and transmitted to the packet switch. Upon receiving this, the packet exchange assigns itself a band requested by the user. At this time, the wired bearer setup is completed. After that, when the packet exchange delivers the PDP context activation response 105 to the mobile terminal through the base station, the wired / wireless bearer of the lower layer is configured. When this procedure is completed, the bearer of the traffic channel between the mobile terminal and the gateway / external agent is completed.

If one traffic channel is established, the Mobile IP registration procedure between the mobile terminal and the gateway / external agent is performed through the established traffic channel. The gateway / external agent sends an Agent Advertisement 106 to the mobile terminal, and the mobile terminal makes a Mobile IP registration request 107 to the gateway / external agent in response. Upon receipt of this, the gateway / external agent makes a Mobile IP registration request 108 to the home agent located on the public Internet. The home agent registers the mobile terminal and the external agent information and includes the registration result in the Mobile IP registration response 109 to transmit it to the gateway / external agent. The gateway / external agent receiving the message includes the registration result in the mobile IP registration response 110 and transmits the registration result to the mobile terminal. After this step, the Mobile IP registration procedure is completed, and the home address of the mobile terminal is determined. The gateway / external agent inserts a home address into the PDP context of the corresponding mobile terminal (111).

2 shows a conventional Mobile IP registration failure procedure. Initially, the existing Mobile IP registration procedure 200 shown in FIG. 1 is performed in the same manner. That is, the procedures from (101) to (109) of FIG. 1 are performed in the same manner. Consider a case where Mobile IP registration fails in a home agent located on a public Internet network. Mobile IP registration at this stage is not done in the UMTS / GPRS network, but through the public internet network. Therefore, registration failure can occur frequently because it is made through a plurality of nodes (router, backbone, etc.) located in the public Internet network. If Mobile IP registration fails, the home agent sends the gateway / external agent including the cause of the failure in the Mobile IP registration response (109 of FIG. 1) message. The gateway / external agent receiving the message includes the cause of Mobile IP registration failure in the Mobile IP registration response (110 of FIG. 2) message and transmits the message to the mobile terminal to notify that Mobile IP registration has failed.

In case of Mobile IP registration failure, the previously established bearer is released from the GPRS network. For this purpose, a bearer release procedure, that is, procedures 201 to 205 of FIG. 2 are performed. The procedure is briefly described as follows. If Mobile IP registration fails, the gateway / external agent requests 201 the packet exchange to delete the PDP context of the mobile terminal. Upon receiving this, the packet exchange again transmits a PDP context deactivation request 202 to the mobile terminal. In response, the mobile terminal sends a PDP context deactivation acknowledgment 203 to the packet exchange, which in turn sends a PDP context deletion response 204 to the gateway / external agent. In this process, all wired / wireless bearers set in advance between the mobile terminal and the gateway / external agent (including the base station) are released.

The conventional Mobile IP registration procedure in the GPRS network does not properly consider the case of registration failure. To describe this, look at the Mobile IP registration procedure as follows. First, when Mobile IP registration is requested from the mobile terminal, the GPRS network reserves wired and wireless resources of its own system. After that, Mobile IP registration request is made to home agent located in public internet network. As a problem of this procedure, if Mobile IP registration fails in the home agent, the GPRS network performs the procedure of releasing the previously set radio resource. Therefore, even when Mobile IP registration fails, it leads to unnecessary preemption of wired and wireless resources, especially expensive wireless resources.

The present invention intends to devise a new Mobile IP registration procedure that can supplement the above problems. The proposed mobile IP registration procedure attempts to determine the reservation of wired and wireless resources according to the mobile IP registration result in the home agent and, if possible, uses the minimum bandwidth in case of mobile IP registration failure.

1 is a conventional mobile IP registration success procedure

2 is a conventional mobile IP registration failure procedure

3 is a proposed Mobile IP registration success procedure

4 is a proposed mobile IP registration failure procedure

5 is a channel used in the existing Mobile IP registration procedure

6 shows channel usage in the proposed Mobile IP registration procedure

7 is a state machine of the proposed mobile terminal

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As a core idea of the present invention, the bearer setting process was completed as one (100 in FIG. 1), but was separated into two (300 and 320 in FIG. 3). In the first bearer setup procedure (300 of FIG. 3), only the minimum band is allocated. Thereafter, only when the mobile IP registration from the home agent succeeds, the bearer of the minimum band initially set is modified to extend to the bearer having the band requested by the user. If the result of Mobile IP registration fails, the bearer of the existing minimum band is released. Therefore, when Mobile IP registration fails, the effect of preempting only the minimum band can be obtained.

In order to accomplish this, the existing Mobile IP registration procedure must be changed. In the present invention, in order to minimize the change of other functions by modifying the existing bearer setup procedure, the existing Mobile IP registration procedure is left as it is, and a new procedure is added to achieve the object.

The mobile IP registration procedure proposed in FIG. 3 is shown. Compared with the existing procedure of FIG. 1, three things are different. First, although one bearer setup procedure (100 of FIG. 1) is defined in the prior art, the present invention is divided into a bearer setup procedure (300 of FIG. 3) and a bearer modification procedure (320 of FIG. 3). The bearer setup procedure is the same as before, and the bearer modification procedure is newly defined. Second, although a band has been allocated based on a user request band in a bearer setup procedure, in the present invention, a bearer having a minimum band is set in an initial bearer setup procedure, and a bearer of a predetermined minimum band is modified in a bearer modification procedure. Finally, one bearer is set up. That is, the bearer modification procedure is used to expand the band for the bearer of the minimum band by the band requested by the user, rather than creating a new bearer.

The bearer modification procedure uses the signaling message defined in the existing 3GPP standard document (TS 23.060). The function of the signaling message and the information elements in the message are also used.

The mobile IP registration success procedure proposed based on FIG. 3 will be described. The mobile terminal temporarily stores the bearer information of the traffic channel requested by the user, that is, the band for the traffic channel. This information is for later use in bearer modification procedures. Subsequently, in order to receive Mobile IP service, an APN (APN) is designated as MIPV4FA (an external agent supporting Mobile IP Version 4), and a bearer specifies only a minimum band. Then, they are included in the PDP context activation request 301 message and transmitted to the packet switch. Upon receiving this, the packet exchange selects a suitable gateway / external agent (302), and sends a PDP Context Creation Request (303) message to the selected gateway / external agent. The gateway / external agent determines whether to accept the requested PDP context and, if so, allocates the minimum band itself. In addition, the bandwidth allocation result is included in the PDP context creation response 304 message and transmitted to the packet switch. Upon receipt of this, the packet exchange assigns itself a minimum band. At this time, the wired bearer setup having the minimum bandwidth between the two entities is completed. Thereafter, the packet exchange transmits the PDP context activation response 305 to the mobile terminal through the base station to establish a wired / wireless bearer of a lower layer. When this procedure is completed, the bearer of the traffic channel having the minimum bandwidth between the mobile terminal and the gateway / external agent is completed.

The gateway / external agent then sends an agent broadcast 306 of the Mobile IP protocol to the mobile terminal. Agent broadcast 306 is conventionally transmitted on a traffic channel, but in the present invention, since the traffic channel is completed, the agent broadcast 306 is transmitted to a mobile terminal through a signal channel. In the same manner, the mobile terminal transmits the Mobile IP registration request 307 to the gateway / external agent through a signal channel. Upon receipt of this, the gateway / external agent makes a Mobile IP registration request 308 to the home agent located on the public Internet. The home agent registers the mobile terminal and the external agent information and includes the registration result in the Mobile IP registration response 309 to transmit to the gateway / external agent. The gateway / external agent receiving the message includes the registration result in the mobile IP registration response 310 and transmits the registration result to the mobile terminal.

After this step, Mobile IP registration is completed between the mobile terminal and the home agent of the public Internet. In the UMTS / GPRS network, the bearer of the traffic channel having the minimum bandwidth is completed. The home address of the mobile terminal is determined. The gateway / external agent assigns the determined home terminal's home address to the PDP context (311).

Since the mobile IP registration is successful, the mobile terminal includes the user's request band information stored in the PDP context modification request 321 message and transmits it to the packet exchange via the base station. Upon receiving this, the packet exchange sends a PDP Context Update Request 322 message to the gateway / external agent. The gateway / external agent expands the bearer of the initially set minimum band by the band requested by the user, and transmits the result to the PDP context update response 323 to the packet exchanger. The packet exchanger also modifies the bearer itself and includes the result in the PDP context modification response 324 message and transmits it to the mobile terminal through the base station. The mobile terminal and the base station modify the radio bearer using a lower layer protocol. After this step, the initially set minimum traffic bearer is modified to a bearer having a band requested by the user. Thereafter, IP traffic communication between the mobile terminal and the host existing in the public Internet network is performed through the established traffic channel.

The proposed mobile IP registration failure procedure will be described with reference to FIG. 4. Consider the case where registration fails when the gateway / external agent receives the Mobile IP registration response 309 from the home agent of the public Internet network. The causes of registration failure are as follows.

ㆍ Unknown reason

ㆍ Registration is prohibited for administrative purposes

ㆍ lack of resources

ㆍ Authentication failure of terminal equipment

External agent's authentication failed

Registration ID Mismatch

Insufficient contents of registration request message

Too many mobility bindings at the same time

Unknown home agent address

In this case, the GPRS network releases the bearer of the existing minimum band. For this purpose, a bearer release procedure, that is, procedures 401 to 405 of FIG. 4 are performed. The procedure is briefly described as follows. If Mobile IP registration fails, the gateway / external agent requests 401 to delete the PDP context of the mobile terminal. Upon receiving this, the packet exchange again transmits a PDP context deactivation request 402 to the mobile terminal. In response, the mobile terminal sends the PDP context deactivation acknowledgment 403 to the packet exchanger, which in turn sends a PDP context deletion response 404 to the gateway / external agent. When this step is completed, the predetermined minimum band wired / wireless bearer between the mobile terminal and the gateway / external agent (including the base station) is released.

5 shows channel usage in the existing Mobile IP registration procedure. PDP Context messages related to bearer establishment use signaling channels. Mobile IP related messages and Mobile IP traffic use traffic channels. However, in the proposed Mobile IP registration procedure as shown in FIG. 6, channel usage is different. PDP Context messages related to bearer setup and Mobile IP related messages use the same signaling channel. And only Mobile IP traffic uses the traffic channel. The reason for the change in channel usage is that the bearer of the traffic channel is modified even after all Mobile IP signaling procedures are performed, and thus it cannot be used until the traffic channel is completed.

7 illustrates a state machine of a mobile terminal. In order for the present invention to be completed, the mobile terminal must maintain such a state machine. When the mobile terminal receives the mobile IP service request from the mobile terminal in the initial idle state 501, the mobile terminal transitions to the mobile IP progress state 502 while transmitting a PDP context activation request 301 message to the packet exchanger. In this state, if the PDP Context Activation Response 301 / Agent Broadcast 306 / Mobile IP Registration Request 307 message is transmitted and received, the state does not transition. Thereafter, when the Mobile IP registration response 301 is received from the gateway / external agent, the state transitions to the PDP context modification request state 503. After the bearer is established and receives the PDP context modification response 324, the bearer transitions to the dormant state 501.

In order to complete the present invention, the following contents should be reflected. First, the existing Mobile IP registration procedure (FIGS. 1 and 2) should be changed to the proposed Mobile IP registration procedure (FIGS. 3 and 4). Second, the channel used for each message must be changed (see FIGS. 5 and 6). The third state machine must be operated at the mobile terminal (see FIG. 7).

By introducing the Mobile IP registration scheme proposed in the present invention, the following effects can be obtained. In case of Home IP's Mobile IP registration failure, only the minimum bandwidth is used, thus enabling efficient use of wired and wireless resources, especially high cost wireless resources. This will be described in detail as follows. In order to support a mobile IP service, a GPRS network requires radio resources between a mobile station and a base station, wired resources between a base station and a control station, wired resources between a control station and a packet switch, and wired resources between a packet switch and a gateway / external agent. . Since these resources are reserved through the Connection Oriented protocol, in order to provide Mobile IP service, a procedure for establishing wired / wireless resources must be performed first. The disadvantage is that the bearer is initially selected as much as the bandwidth required by the user, and if the mobile IP registration fails later, the bearer is released. In particular, when the user initially requests a wide band but fails to register Mobile IP, it unnecessarily preempts the wide band and results in the release. In the present invention, if the mobile IP registration fails initially while preempting only a minimum band, only this band needs to be released, thereby enabling efficient use of wired and wireless resources, particularly high-cost wireless resources.

Claims (4)

In order to improve the inefficient use of wired and wireless resources in applying Mobile IP protocol to UMTS / GPRS system, in order to improve the inefficient use of wired and wireless resources, reserve the minimum amount of wired and wireless resources in the bearer setup process, receive the mobile IP registration result from the home agent, and reflect the result With the technique to set up: Technique for reflecting Mobile IP registration received from home agent in bearer setup process of UMTS / GPRS system: The method according to claim 1, In order to reflect the result of Mobile IP registration from the home agent, a method that separates the existing bearer setup procedure into a bearer setup procedure and a bearer modification procedure, and: The mobile IP registration procedure between the separated bearer setup procedure and the bearer modification procedure reflects the mobile IP registration result of the home agent and: In order to reflect the result of Mobile IP registration from the home agent, the Mobile IP message was transmitted through the traffic channel. Techniques for placing a state machine in the mobile terminal to complete the bearer modification procedure: The method according to claim 2, A method of completing a traffic bearer by linking a bearer setup procedure with a bearer modification procedure after receiving a mobile IP registration result: In the bearer setup procedure, a scheme of allocating only the minimum bandwidth necessary for establishing a traffic bearer to occupy the minimum amount of wired and wireless resources is as follows: In the bearer modification procedure, a method of completing a traffic bearer by extending the traffic bearer of a predetermined minimum band to the band requested by the user is as follows: If Mobile IP registration from the home agent is successful, it expands and sets the wired and wireless resources of its own system, and if it fails, releases the bearer of the preset minimum band. A technique for placing a state machine in a mobile terminal and receiving a successful mobile IP registration causes the mobile terminal to start a bearer modification procedure: A technique in which a mobile terminal does not proceed with a bearer modification procedure when receiving a Mobile IP registration failure by placing a state machine in the mobile terminal: The method according to claim 3, When the mobile IP service request is received from the mobile terminal in the initial idle state, the PDP context activation request message is transferred to the packet switch while transferring the PDP context activation request message to the packet switch, and the PDP context activation response / agent in the mobile IP progress state. When the mobile IP registration request message is received, it is transitioned back to its own state.When the mobile IP registration response is received from the home agent, it is transferred to the mobile terminal, and then it is transitioned to the PDP context modification request state. A technique for operating a state machine of a mobile terminal transitioning to an idle state: