KR101053618B1 - How to reset temporary IP address - Google Patents

Abstract

According to the present invention, a multi-mode mobile terminal performs a connection and connection establishment procedure, and when a subnet of the mobile terminal is changed, receiving an IP address reset instruction including a temporary IP address from the access point, and receiving an external agent. And a method of resetting a temporary IP address comprising transmitting a message for finding, receiving an agent advertisement message from a specific external agent, and registering a temporary address with a home agent according to the agent advertisement message. Receiving an IP address reset instruction after the handover from the previous access point before the multi-mode mobile terminal handovers, performing a new connection point and connection establishment procedure, and the information received by the mobile terminal from the previous access point. Set the IP address The IP address resetting method includes a method for resetting an IP address, which can be used to quickly reset an IP temporary address when a multi-mode mobile terminal is handed over to another subnet in the same interface network or the subnet is changed due to a handover to a different interface network. It works.

Multimode Mobile Terminal, Subnet, Handover, IP Address

Description

{Method for Configuration of Temporary IP Address}

1 is a diagram illustrating an embodiment of a multi-mode mobile terminal.

2 is an embodiment structural diagram illustrating a MIH structure and a transport protocol;

3 is a diagram illustrating an embodiment of an event trigger.

4 is a diagram illustrating an embodiment of a trigger generated until a new link is established from a link to which a mobile terminal is currently connected.

Figure 5 is a structure diagram of an embodiment showing a structure for a Link Event, MIH Event model in the present invention.

6 is a structural diagram of an embodiment showing a structure for a Remote Link Event model according to the present invention;

7 is a structural diagram of an embodiment showing a structure for a Remote MIH Event model according to the present invention;

8 is a diagram showing the structure of an MIH Command and a Link Command model according to an embodiment of the present invention.

9 is a structural diagram of an embodiment showing a structure for a Remote MIH Command model in the present invention.

10 is a structural diagram of an embodiment showing the structure of a Remote Link Command model in the present invention;

11 is an exemplary explanatory diagram showing operation of mobile IPv4.

12 is a flowchart illustrating an example of a process in which a DHCP client is automatically assigned an IP address from a DHCP server.

FIG. 13 is a diagram illustrating an embodiment of operation of mobile IPv6. FIG.

14 is a diagram illustrating an embodiment of an operation procedure of DHCPv6.

15 is a flowchart illustrating a resetting procedure of a temporary address when a multi-mode mobile terminal performs handover to another interface network.

16 is a diagram illustrating an embodiment of a protocol stack and an IP address setting trigger of a multimode terminal.

FIG. 17 is a flowchart illustrating a procedure of reconfiguring an IP address using FA-CoA of mobile IPv4 as a temporary address when the mobile terminal is handed over to another interface network. FIG.

18 is a flowchart illustrating a method for resetting an address using Co-located CoA of mobile IPv4 as a temporary address when the mobile station is handed over to another interface network.

19 is a flowchart illustrating an address resetting method using a stateless address of Moible IPv6 as a temporary address when a mobile station hands over to another interface network and changes its subnet.

20 is a flowchart illustrating a method for reconfiguring an address using a stateful address of Moible IPv6 as a temporary address when a mobile station hands over to another interface network and changes its subnet.

21 is a diagram illustrating an embodiment of a protocol stack, an IP address setting trigger, and a command of a multimode terminal.

FIG. 22 is a flowchart illustrating a procedure for resetting an IP address by an upper management entity using FA-CoA of mobile IPv4 as a temporary address when the mobile terminal is handed over to another interface network. FIG.

FIG. 23 is a flowchart illustrating a method for resetting an address by an upper management entity by using a mobile IPv4 Co-located CoA as a temporary address when the mobile terminal is handed over to another interface network.

24 is a flowchart illustrating an address resetting method by an upper management entity using a mobile IPv6 stateless address as a temporary address when a mobile terminal hands over to another interface network and changes its subnet.

FIG. 25 is a flowchart illustrating a method for reconfiguring an address by an upper management entity using a mobile IPv6 stateful address as a temporary address when the mobile terminal is handed over to another interface network. FIG.

FIG. 26 is a flowchart illustrating a method of resetting an IP address after a handover by being informed from a previous access point that a subnet will be changed before the mobile terminal hands over to another interface network.

The present invention relates to a temporary IP address resetting method, and more particularly, to a method for setting a temporary IP address when the mobile terminal performs a handover between different networks.

IEEE802.21, which is undergoing international standardization of Media Independent Handover (MIH) between heterogeneous networks, provides seamless handover and service continuity between heterogeneous networks. The purpose of the present invention is to improve the user convenience of a mobile terminal device. The basic requirements include MIH functions, event services, command services, and information services (IS).

A mobile terminal is a multimode node that supports more than one interface type. The interface type may be a wire-line type such as 802.3 based Ethernet, a wireless interface based on IEEE802.XX (eg, a broadband wireless access system, a wireless LAN, a wired LAN, a cellular system interface) or 3GPP, It may be any of the interfaces defined by a cellular standardization organization such as 3GPP2.

1 is a diagram illustrating an embodiment of a multi-mode mobile terminal. As shown in FIG. 1, a mobile terminal configured in a multi mode has a physical layer (PHY) layer and a medium access control layer (MAC) layer in each mode, and is located below the IP layer. It has a Media Independent Handover (hereinafter 'MIH') layer.

MIH is defined between 802 series interface or between 802 series interface and non-802 interface (3GPP, 3GPP2), and Mobile IP and Session Initiation Protocol (SIP) for handover and seamless service. It has a higher layer mobility support protocol such as.

The MIH function can be located below the IP layer and facilitates the handover process using input values from Layer 2, such as trigger events and information about other networks. In addition, the MIH function may include user policy and configuration based inputs that may affect the handover process, and may include a layer 3 such as mobile IP or SIP. Generic interfaces are defined between the entity and the MIH function. These interfaces provide information about layer 1 (physical layer) and layer 2 (media access control layer) and mobility management. The MIH layer obtains information about lower layers and networks with the help of events and information services.

Therefore, a higher management object for monitoring and controlling the status of various links in the mobile terminal is located in the upper layer to perform a handover control function and a device manager function. At this time, the handover control function and the device manager may be independently located, respectively, the two functions may be included as a higher management object.

The network supporting mobile IP is composed of a home agent, a home agent, and a mobile subscriber station (MSS). The following functions are required for the operation of mobile IP. First, the agent discovery function is a method of determining whether a mobile terminal is currently connected to its home network or located in a foreign network. By this method, the mobile terminal can recognize that it has moved to another network.

When the registration function recognizes that the mobile station has moved to another network, the registration function provides a mechanism to deliver the current location information to the home agent so that the service provided on the home network can be provided on the new network as it is. Meanwhile, the routing function is a function necessary for properly routing datagrams transmitted from or to the mobile terminal when the mobile terminal is connected to an external network.

Mobile IP provides two methods for setting a care of address (CoA) when the mobile node moves to another subnet. First, FA-CoA is provided by Foreign Agent through Agent Advertisement message, and IP address of external agent is used as temporary address. In addition, co-located CoA is a method in which a mobile node is assigned a temporary address through a Dynamic Host Configuration Protocol (DHCP) server located in a visited network.

DHCP is a protocol that provides network administrators with the ability to centrally manage and assign IP addresses over networks within an organization. When computer users connect to the Internet in an organization, each computer must be assigned an IP address. In DHCP, network administrators centrally manage and assign IP addresses, and allow the computer to automatically send new IP addresses when connected to other locations on the network.

DHCP uses the concept of "lease", which allows a given IP address to be valid for that computer for only a certain amount of time. The lease time may vary depending on how long the user will need to access the Internet at a particular location. DHCP can dynamically reconfigure the network by shortening the lease time of IP addresses, even if there are more computers than there are available.

When the system starts up, clients request the IP address for their system from a DHCP server. When borrowing an IP address from a DHCP server, the TCP / IP configuration is initialized and the client can communicate with other hosts using the TCP / IP protocol. The DHCP server responds to the DHCP client's IP address lease request, and maintains a scope, which is a range of assignable IP addresses, for this purpose (eg, 203.224.29.10 to 203.224.29.100).

Table 1 shows an example of the DHCP message format.

 Table 2 shows the types and uses of DHCP messages.

Message Use DHCPDISCOVER Client broadcast to locate available servers. DHCPOFFER Server to client in response to DHCPDISCOVER with offer of configuration parameters. DHCPREQUEST Client message to servers either (a) requesting offered parameters from one server and implicitly declining offers from all others, (b) confirming correctness of previously allocated address after, eg, system reboot, or (c) extending the lease on a particular network address . DHCPACK Server to client with configuration parameters, including committed network address. DHCPNAK Server to client indicating client's notion of network address is incorrect (e.g., client has moved to new subnet) or client's lease as expired DHCPDECLINE Client to server indicating network address is already in use. DHCPRELEASE Client to server relinquishing network address and canceling remaining lease. DHCPINFORM Client to server, asking only for local configuration parameters; client already has externally configured network address.

The following describes the basic elements and functions for the operation of Mobile IPv6. First, the mobile node MN is a host or router that changes its network connection, and the corresponding node CN is a host or router communicating with the mobile node. On the other hand, the home agent (HA) is a router that holds the registration information of the mobile node of the routers in the home network, and transmits the datagram to the current position of the mobile node in the external network.

The temporary address (CoA) refers to an IP address connected to the mobile node when the mobile node moves to an external network, and the binding indicates that the mobile node matches the home address of the node with the CoA registered with the home agent. Say. BU (Binding Update) is used by the mobile node to inform its HA and CNs of its CoA, BACK (Binding Acknowledge) is a response message to the BU, and BR (Binding Request) indicates that the corresponding node is responsible for binding information of the mobile node. If the BU is not received before the timer expires, this is a message for requesting the BU.

The mobile node can automatically configure its location information when the node moves by acquiring CoA using the neighbor discovery function and the address auto-configuration function. After the correspondent node saves the binding information, the correspondent node can communicate directly with the mobile node without going through the home agent. That is, route optimization is performed.

The address auto-configuration method includes a stateful address autoconfiguration method for obtaining an address using a server such as DHCP and a stateless address autoconfiguration method for generating an address by the host. The stateful address automatic setting method of obtaining an address using a server is a method of requesting an address from a host side such as DHCP and assigning one of the addresses allocated from the server to the host side. The stateless address autoconfiguration method is a method of generating an address by combining its interface ID information with prefix information obtained from a router or well-known prefix information.

DHCPv6 is a DHCP protocol for IPV6 that supports stateful address autoconfiguration. DHCP is a mechanism that reduces maintenance costs by centralizing the management of network resources and information such as IP addresses, routing information, etc. on a few DHCP servers.

DHCPv6 uses two types of multicast addresses: First, All_DHCP_Relay_Agents_and_Servers is a link local multicast address used by a client to communicate with an agent on a link when the link-local address of the agent is not known. At this time, all servers and agents are members of the multicast group.

On the other hand, All_DHCP_Servers is a site-local multicast address used by a client or relay to communicate with servers when the client or relay sends a message to all servers or does not know the unicast address of the servers. In order for the client to use this address, it must have a sufficient range of addresses for the server to reach. At this point, all servers in the site are members of this multicast group.

The messages used in the basic operation of DHCPv6 are as follows. First, the SOLICIT message is used by the client to know the location of the server. It is multitasked using the All_DHCP_Servers address.

The ADVERTISE message is a response to the SOLICIT message, which the DHCP server responds to. The REQUEST message is used by the client to obtain configuration parameters including the IP address for the selected server. It is multitasked using the All_DHCP_Relay_Agents address. The REPLY message is a response message to the REQEST, RENEW, and RELEASE messages. The RENEW message is for the client to obtain the lifetime of the client address and configuration parameters originally assigned. The RELEASE message is a message used by the client to return one or more IP addresses to the server.

2 is a structural diagram of an embodiment showing a MIH structure and a transport protocol. Referring to FIG. 2, heterogeneous networks and handover techniques will be described. The MIH function is located under the IP and facilitates the handover process by using input values from Layer 2, such as a trigger event or other network information. In addition, the MIH function may include user policy and configuration-based input values that may affect the handover process, and layer 3 entities such as mobile IP or SIP. Generic interfaces are defined between and MIH functions. These interfaces provide information about layer 1 (physical layer) and layer 2 (MAC layer) and mobility management. MIH obtains information about lower layers and networks with the help of events and information services.

Therefore, the MIH function should be located to monitor and control the status of other links in the mobile terminal in the upper layer. In FIG. 2, dotted lines indicate primitives, event triggers, and the like.

3 is a diagram illustrating an embodiment of an event trigger. For fast handover, the network layer should be able to reestablish the connection as quickly as possible. At this time, it is necessary to use the information from the link layer. The link layer event helps to predict the user's movement and may help the mobile terminal and the network prepare for the handover in advance.

Referring to FIG. 3, a trigger for handover may be started from a physical layer (PHY), a media access control layer (MAC layer), and a source for such a trigger may be a local stack or a remote stack. Stack). Event triggers provide a predicted change in the state of the current signal and other networks and future changes, including changes on the physical and MAC layers or changes in the properties of a particular network.

The event type includes a physical layer event (PHY layer event), a media access control layer event (MAC layer layer event), a management event (Management event), a three layer event (L3 event) and an application event (Application event).

 4 is a diagram illustrating an embodiment of a trigger generated until a new link is established from a link to which a mobile terminal is currently connected. Referring to Figure 4, the basic trigger event will be described.

Link Up occurs when a second layer connection is established on a particular link interface and the third layer packets can be transmitted from a higher layer. At this time, it is determined that all second layer configurations constituting the link are completed. Event sources are the Local MAC layer and the Remote MAC layer.

Table 3 shows an example of link up parameters.

Name Type Description EventSource EVENT_LAYER_TYPE Source where the event was generated EventDescription EVENT_LAYER_TYPE Destination to which event will be delivered MAC layer MAC layer Address MAC layer address of mobile terminal MAC Layer Old Access Router MAC layer Address MAC layer address of the previous access router MAC Layer NewAccessRouter MAC layer Address MAC layer address of the new access router NetworkIdentifier Media Specific Network identifier that can be used to detect changes in subnet

Link down occurs when the second layer connection is released on a particular interface and no longer can transmit the third layer packet. The event source is the local MAC layer. Table 4 shows an example of link down parameters.

Name Type Description EventSource EVENT_LAYER_TYPE Source where the event was generated EventDescription EVENT_LAYER_TYPE Destination to which event will be delivered MAC layer MAC layer Address MAC layer address of mobile terminal MAC Layer Old Access Router MAC layer Address The MAC hierarchy of the previous access router ReasonCode Reason for unlinking

Link going down occurs when a layer 2 connection is expected to be linked down (Link_Down) within a specific time, and may be a signal for initiating a handover procedure. The event source is the Local MAC Layer and the Remote MAC Layer. Table 5 shows an example of the link go down parameter.

Name Type Description EventSource EVENT_LAYER_TYPE Source where the event was generated EventDestination EVENT_LAYER_TYPE Destination to which event will be delivered MAC layer MAC layer Address MAC layer address of mobile terminal MAC Layer Old Access Router MAC layer Address MAC layer address of the previous access router MAC Layer NewAccessRouter MAC layer Address MAC layer address of the new access router Timeinterval Time in msecs The time when the link is expected to be Link_Down ConfidenceLevel % The level at which a link is expected to be Link_Down at a specific time. UniqueEventIdentifier Used when event rollback occurs

Link Going Down (Link_Going_Up) occurs when the second layer connection is expected to be Linked Up (Link_Up) within a certain time and is used when the network takes a long time to initialize. The event source is the Local MAC Layer and the Remote MAC Layer. Table 6 shows an example of the link go down parameter.

Name Type Description EventSource EVENT_LAYER_TYPE Source where the event was generated EventDestination EVENT_LAYER_TYPE Destination to which event will be delivered MAC layer MAC layer Address MAC layer address of mobile terminal MAC Layer NewAccessRouter MAC layer Address MAC layer address of the new access router Timeinterval Time in msecs The time when the link is expected to be Link_Down ConfidenceLevel % The level at which a link is expected to be Link_Down at a specific time. UniqueEventIdentifier Used when event rollback occurs

Link event rollback (Link_Event_Rollback) is used in combination with Link Going Up and Link Going Down. The trigger occurs when Link_Going_Up or Link_Going_Down is transmitted, but it is predicted that no more Link_UP or Link_Down will occur within a certain time. Event sources are the Local MAC layer and the Remote MAC layer. Table 7 shows an example of link event rollback parameters.

Name Type Description EventSource EVENT_LAYER_TYPE Source where the event was generated EventDestination EVENT_LAYER_TYPE Destination to which event will be delivered MAC layer MAC layer Address MAC layer address of mobile terminal MAC Layer NewAccessRouter MAC layer Address MAC layer address of the new access router UniqueEventIdentifier Used when event rollback occurs

Link available means that a new specific link is available, and that the new base station or access point may provide better link quality than the base station or access point to which the mobile station is currently connected. Event sources are the Local MAC layer and the Remote MAC layer. Table 8 shows an example of link available parameters.

Name Type Description EventSource EVENT_LAYER_TYPE Source where the event was generated EventDestination EVENT_LAYER_TYPE Destination to which event will be delivered MAC layer MAC layer Address MAC layer address of mobile terminal MAC Layer NewAccessRouter MAC layer Address MAC layer address of the previous access router MAC Layer Old Access Router MAC layer Address MAC layer address of the new access router

Link parameter change Link_Parameters_Change occurs when a change in a link parameter value exceeds a threshold level. This may include link layer parameters such as link speed, quality of service (QoS), encryption values, and the like. Event sources are the Local MAC layer and the Remote MAC layer. Table 9 shows an example of link parameter change parameters.

Name Type Description EventSource EVENT_LAYER_TYPE Source where the event was generated EventDestination EVENT_LAYER_TYPE Destination to which event will be delivered MAC layer MAC layer Address MAC layer address of mobile terminal MAC Layer NewAccessRouter MAC layer Address MAC layer address of the new access router oldValueOfLinkParameter Previous value of link parameter newValueOfLinkParameter
New value for the link parameter

The information service provides detailed information about the network needed for network discovery and selection and should be accessible from any network. Information services include link access parameters, security mechanisms, neighbor maps, location, provider and other access information, and cost of information element).

FIG. 5 illustrates a structure of a link event and a MIH event model according to the present invention. The MIH event is an event transmitted from the MIH to a higher management entity or higher layer. Triggers correspond to this. The link event is an event delivered from the lower layer (MAC or PHY) to the MIH and primitives used in each interface MAC layer or PHY layer are used.

6 illustrates a structure of a remote link event model according to the present invention, in which a link event generated at a lower layer (MAC or PHY) in a local stack is delivered to a MIH, which is transmitted to the MIH of the remote stack. Is sent.

7 illustrates a structure of a Remote MIH Event model according to the present invention, in which a MIH in a local stack generates a remote MIH event and transmits it to a counterpart MIH in a remote stack. The MIH of the remote stack delivers the received event to a higher management entity or higher layer in the remote stack. The same is true when an event is generated from a MIH in the remote stack to a local stack MIH, and the local stack MIH delivers the event to an upper layer of the local stack.

FIG. 8 illustrates the structure of a MIH command and a link command model according to the present invention. The MIH command is generated from a higher management entity or higher layer and is transmitted to the MIH, indicating an action to the MIH. The link command is generated from the MIH and transmitted to the lower layer, which instructs the lower layer to perform some action.

9 illustrates a structure of a remote MIH command model according to the present invention, in which a remote MIH command is generated from an upper management entity or higher layer in a local stack and transmitted to the MIH, and the MIH remotely stacks the received MIH command. Delivers to relative MIH in The same applies to a case where a command is generated from the upper layer in the remote stack to the MIH of the remote stack, and the remote stack MIH transfers the command to the MIH of the local stack.

FIG. 10 illustrates a structure of a remote link command model according to the present invention, in which a MIH in a local stack generates a remote link command and delivers it to a counterpart MIH in a remote stack. The MIH in the remote stack delivers the received remote link command to lower layers in the remote stack. The same is also true when a command is generated from a MIH in a remote stack to a local stack MIH, and the local stack MIH delivers a command to the local stack sublayer.

11 is a diagram illustrating an embodiment of operation of mobile IPv4. Referring to FIG. 11, mobile IPv4 basically aims to support mobility with transparency to a higher layer, and needs to add a mobile host, a home agent, and a foreign agent function to support it. Shall be.

However, when the path optimization is not used, the change of the correspondent node communicating with the mobile terminal is not necessary. In this case, the mobile host represents an IP host with mobility support, and the home agent is a router that maintains location information about the mobile host and performs tunneling to the visiting agent or the mobile host. Meanwhile, the visit agent refers to a router supporting mobility in the visited network.

When a mobile host moves from its home network to a foreign network, the mobile host recognizes that the mobile host has moved by receiving an advertisement message broadcast from the visiting network, and then sends a message to the home agent in the home network. It registers a temporary address (CoA) indicating its current location (S111).

In this case, CoA is an IP address of the visited agent (FA-CoA) or a co-located CoA address temporarily assigned by the mobile host through DHCP in the visited network. Packets sent from the outside to the mobile host are transmitted to the home network, and the packets are intercepted by the home agent that is aware of the movement of the mobile terminal (S112).

The home agent encapsulates the packet delivered to the mobile host as a destination (when FA-CoA is used) as the destination (SFA) and delivers the packet to the visiting agent (S113). The encapsulated and forwarded packet is de-capsulated at the visited agent, recovered to the first forwarded packet, and finally delivered to the mobile host (S114). The packet transmitted from the mobile host to the counterpart host may be directly transmitted through the visiting agent, or may be forwarded using a reverse tunnel when there is a problem of ingress filtering (S115).

The main functions required for mobile IP are as follows. First, the agent discovery function is a method of determining whether a mobile terminal is currently connected to its home network or a visited network. By this method, the mobile terminal can recognize that it has moved to another network.

Mobile IP extends the existing Internet Control Message Protocol (ICMP) Router Discovery [IETF RFC 1256] for agent discovery. The Agent Advertisement message periodically broadcasted by an agent (home agent, visiting agent) is transmitted by including a Mobility Agent Advertisement Extension in an ICMP Router Advertisement message. The Agent Solicitation message transmitted by the MS to find an agent uses the same method as the existing ICMP Router Solicitation message.

The registration function is a function of delivering the current location information to the home agent when the mobile terminal detects that the mobile terminal has moved to another network so that the service provided on the home network can be provided as it is on the new network.

Mobile IP defines two different registration procedures. If a mobile terminal uses FA-CoA, it must register with a visiting agent. If a mobile terminal uses co-located CoA, the mobile terminal registers directly with a home agent.

The routing function defines a function necessary for properly routing datagrams to be transmitted and received from or to the mobile terminal when the mobile terminal is connected to an external network. Datagrams include unicast as well as multicast and broadcast packets.

 The operation of DHCP is as follows. For DHCP to work properly, your network must have at least one DHCP server and at least one DHCP client. You also need a range of TCP / IP addresses and a gateway address and subnet mask. The DHCP client gets its TCP / IP address information from the server during startup. This address is not permanent, and the DHCP server provides the client with an address lease that can expire regularly and must be renewed.

Client DHCP states include: INIT, SELECTING, REQUESTING, BOUND, RENEWING, and REBINDING. The address lease is obtained and maintained through a handshake step.

 12 is a flowchart illustrating an example of a process in which a DHCP client is automatically assigned an IP address from a DHCP server. As shown in FIG. 12, the client broadcasts a DHCPDISCOVER packet to neighboring servers (S121), and each server responds with a DHCPOFFER packet to the client that sent the DHCPDISCOVER packet.

The client receives a DHCPOFFER packet from one or more servers (S122), selects one server to request configuration parameters, and broadcasts a DHCPREQUEST packet (S123). When each server receives the DHCPREQUEST packet and recognizes that it has not been selected, it recognizes that the DHCPOFFER packet has been rejected.

The server selected from the DHCPREQUEST packet transmits a DHCPACK packet including address configuration information of the requested client to the client (S124). The client configures the address after receiving the DHCPACK packet. On the other hand, if the client receives a DHCPNAK packet, it restarts the above process. When the client returns the loaned address, the client may transmit a DHCPRELEASE packet to the server (S125).

13 is a diagram illustrating an embodiment of operation of mobile IPv6. As shown in FIG. 13, when the mobile node MN moves from subnet A to subnet B, the MN recognizes the movement by using prefix information of the RA message and a neighbor unreachable detection (NUD) mechanism. It obtains CoA by itself through address auto-configuration method and transmits BU message informing HA of acquired CoA. The HA binds the MN's home address and CoA and sends a BACK in response to the BU.

Since the CN communicating with the MN for the first time did not detect the MN's movement, it transmits the packet by setting the destination address as the home address of the MN, and the HA managing the MN intercepts the packet and tunnels to the current MN's location. . Meanwhile, the MN receiving the tunneled packet determines that the CN which transmitted the packet does not have binding information, and sends a BU message to the CN to inform its CoA. The CN stores the binding information and then communicates directly with the MN using that information.

14 is a diagram illustrating an embodiment of an operation procedure of DHCPv6. As shown in Figure 14, the client sends a SOLICIT message to the All_DHCP_Server address to know the location of the server. On the other hand, possible DHCPv6 servers respond with an ADVERTISE message, including the prefix. The client selects a DHCPv6 server and sends a REQUEST message requesting additional configuration parameters. The DHCPv6 server sends a REPLY message in response to a REQUEST.

By sending a RENEW message, the client can update existing configuration parameters, update the lifetime of the assigned address, and start the timer T1 (time to contact the server that obtained the existing address to extend the lifetime of the current address). do. The DHCPv6 server sends a REPLY message in response to RENEW. When the client no longer uses the assigned address, it releases the address by sending a RELEASE message.

FIG. 15 is a flowchart illustrating a resetting procedure of a temporary address when a multi-mode mobile terminal performs handover to another interface network. The multi-mode mobile terminal can use mobile IPv4 or mobile IPv6 for mobility management. In Mobile IPv4, FA-CoA or Co-located CoA is used as a temporary address, and in Mobile IPv6, a stateful address or a stateless address is used as a temporary address.

When the multi-mode mobile terminal performs handover to another interface network with reference to FIG. 15, the resetting procedure of the temporary address will be described as follows. First, the mobile terminal is currently connected with the link of the interface network. When a good signal quality link is found in the MAC layer of the new interface, it triggers a link available to the MIH.

The new MAC layer performs a new connection point and connection establishment procedure. After the connection establishment procedure is completed, after performing the authentication procedure, the MIH of the mobile station and the MH of the new access point are notified that the link is established. After the new link is established, the mobile station listens to the periodic Agent Advertisement message of the external agent and learns that the subnet has changed. The mobile terminal registers the temporary address (FA-CoA) with the home agent (HA).

When a multimode mobile terminal handovers to a different subnet in the currently connected interface network, or when a subnet address is changed due to a handover to another interface network, the mobile station must execute an IP temporary address reconfiguration procedure. In the prior art, since only three layer (Network Layer) information is used for the IP temporary address reconfiguration procedure, there is a problem in that the time delay until the address is reconfigured is long.

It is an object of the present invention to provide a method for quickly resetting an IP address without a time delay when a multi-mode mobile terminal is handed over to another subnet in the same interface network or a subnet is changed due to a handover to a different interface network.

According to an aspect of the present invention, there is provided a mobile terminal performing a connection establishment procedure with an access point, receiving a temporary address reset instruction from the access point when a subnet of the mobile terminal is changed, and receiving an external agent. And sending a message to find, receiving an agent advertisement message from a specific external agent, and registering a temporary address with a home agent according to the agent advertisement message.

The method may further include receiving an IP address reset instruction after a handover from a previous access point before performing a handover, performing a connection establishment procedure with a new access point, and information received by the mobile terminal from the previous access point. Including the step of setting the IP address.

In the present invention, the existing trigger model is extended to an event service and a command service. Event service is divided into MIH event and link event, and command service is divided into MIH command and link command.

The above-mentioned objects, features and advantages will become more apparent from the following detailed description in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the detailed description of the invention, reference may be made to the IEEE802.21 document. The proposed event service and command service related to the IP address reconfiguration procedure are as follows. After the new access point (e.g., base station or AP) of the mobile station receives the Link_UP trigger, it is the IP address to which the IP packet is delivered to the mobile station. In order to notify the mobile station of the change of the address (CoA) and the newly autoconfigured address in case of mobile IPv6, the IP_Renewal_Indication link event is triggered. The event source is the Remote MAC Layer and the MIH.

In addition, the previous access point (e.g., base station or AP) of the mobile terminal acquires IP address related information of the mobile terminal by mutual communication with a new access point to which the mobile terminal moves, and then an IP address for delivering an IP packet to the mobile terminal. (This address is a newly allocated IP address in case of DHCP, a new temporary address (CoA) in case of Mobile IPv4, and a newly autoconfigured address in case of Mobile IPv6). In addition, IP_Renewal_Indication triggers a Link Event and transmits it to the mobile terminal.

Table 10 shows an example of the IP_Renewal_Indication parameter.

Name Type Description EventSource EVENT_LAYER_TYPE Source where the event was generated EventDestination EVENT_LAYER_TYPE Destination to which event will be delivered IP Renewal Indicator Indicates whether the IP temporary address needs to be changed
0: no change required
1: change required MAC layer MAC layer Address MAC layer address of mobile terminal Network ID IP Address The network address that the mobile terminal was connected to on the previous link

When the mobile terminal's MIH receives an IP_Renewal_Indication trigger indicating an address reset, it sends an IP_Renewal_Request MIH event to the parent management object including the mobility management object to reset the IP temporary address. do. When the MIH transparently delivers IP_Renewal_Indication to the parent management entity, it has the same message format as IP_Renewal_Request. The event source is the Local MAC Layer and the MIH. Table 11 shows an example of parameters of the IP renewal request.

Name Type Description EventSource EVENT_LAYER_TYPE Source where the event was generated EventDestination EVENT_LAYER_TYPE Destination to which event will be delivered Network ID IP Address The network address that the mobile device connected to on the previous link

Upon receiving the IP_Renewal_Request event from the MIH, the upper management entity sends an IP_Linksetup_Complete command to the MIH after completing the IP temporary address resetting procedure. The event source is the remote MAC layer. Table 12 shows an example of parameters of the IP link setup complete (IP_Linksetup_Complete).

Name Type Description CommandSource COMMAND_LAYER_TYPE Source where the command was generated CommandDescription COMMAND_LAYER_TYPE Destination to which command will be delivered Old Network ID IP Address The network address that the mobile device connected to on the previous link New network id IP Address Network address set by mobile station on new link

The relationship between the proposed event service and the command service related to the stack of the multimode terminal in relation to the IP address reconfiguration procedure is as follows. 16 is a diagram illustrating an embodiment of a protocol stack and an IP address setting trigger of a multimode terminal.

If a new handover network cannot use the previously used IP address, IP renewal indication (IP_Renewal_Indication) is transmitted to MIH. There are two cases depending on the network. First, when the handing over network can use the previous network to indicate whether it can use the address used in the previous network. Second, the handing over network uses the previous network. In some cases, it is not possible to inform whether a message can be used as a MAC layer message.

In the first case, the trigger is generated in the MAC layer because the reset message is transmitted to the second layer. However, in the second case, the second layer does not know whether to reset the address according to the handover. The MIH (AP or base station to be connected) in the network transmits it to the MIH in the terminal, and in this case, the second layer transparently transmits the message to the MIH.

The embodiment of the first case may be Bit # 3 of the HO Process Optimization TLV of IEEE802.16 and may be realized in other networks by using a similar indicator in handover. IP_LinkSetup_Complete is a trigger that notifies the MIH when a new IP layer address is set, and allows the MIH to take necessary actions afterwards. For example, in the case of Make before break handover, the release of MAC / PHY, which maintains the connection (link) with the previous network, is completely established (link) with the current network, and the IP transport protocol completes the IP address setting. This should be done at one point, so it can be a point where IP_LinkSetup_Complete notifies you.

The operation description using the method proposed by the present invention uses a case of using FA-CoA or Co-located CoA of Mobile IPv4 as a temporary address, and using a stateful address or a stateless address of Mobile IPv6 as a temporary address. This can be explained as follows.

An example of using a mobile IPv4 FA-CoA as a temporary address when a mobile terminal is handed over to another interface network is as follows.

FIG. 17 is a flowchart illustrating a procedure of reconfiguring an IP address by using a mobile IPv4 FA-CoA as a temporary address when the mobile terminal is handed over to another interface network.

Referring to FIG. 17, the mobile terminal is currently connected with a link of an interface network. When a good signal quality link is found in the MAC layer of the new interface, it triggers Link Available to the MIH. The new MAC layer performs a new connection point and connection establishment procedure. When the connection establishment procedure is completed, after performing the authentication procedure, the MIH of the mobile station and the MH of the new access point are notified that the link is established.

The MIH of the new access point sends an IP_Renewal_Indication to the mobile terminal's MIH indicating the temporary address reset when the mobile station's subnet is changed. If IP_Renewal_Indication indicates temporary address resetting, the mobile station's MIH requests the network layer to reset the temporary address by triggering IP_Renewal_Request.

When the mobile station's network layer receives an IP_Renewal_Request trigger, it sends a Agent Solicitation message to an external agent to obtain a new temporary address. The external agent responds with an Agent Advertisement message to the mobile station. After receiving the Agent Advertisement message, the network layer of the mobile station registers a temporary address with the home agent (HA). When the temporary address reconfiguration procedure is completed, the mobile station's network layer triggers an IP_Linksetup_Complete message to the MIH.

An example of using a mobile IPv4 Co-located CoA as a temporary address when a mobile terminal is handed over to another interface network is as follows.

FIG. 18 is a flowchart illustrating a method for resetting an address by using a mobile IPv4 Co-located CoA as a temporary address when the mobile terminal is handed over to another interface network.

Referring to FIG. 18, when a mobile station resets an IP temporary address using a co-located CoA, when the mobile station receives an IP_Renewal_Indication indicating a temporary address reset from the MIH of the new access point, the mobile station's MIH triggers an IP_Renewal_Request to the network layer. do. The network layer of the mobile station receives the IP_Renewal_Request and then sends a DHCP Discovery message to be assigned a temporary address. After receiving the temporary address by the DHCP address assignment procedure, the mobile terminal registers it with the home agent.

After completing the registration procedure of the home agent, the network layer of the mobile station sends an IP_Linksetup_Complete trigger to the MIH.

When a mobile terminal hands over to another interface network, a method of using a mobile IPv6 stateless address as a temporary address will be described.

19 is a flowchart illustrating a method for resetting an address using a stateless address of Moible IPv6 as a temporary address when a mobile station hands over to another interface network and changes its subnet.

The MIH of the new access point sends an IP_Renewal_Indication to the mobile terminal's MIH indicating the temporary address resetting when the subnet of the mobile station changes. The MIH of the mobile terminal requests the network layer to reset the temporary address by triggering IP_Renewal_Request. When the network layer of the mobile terminal receives the IP_Renewal_Request trigger, it sends a Router Solicitation message to the access router to form a new temporary address.

The router responds to the mobile station with its own prefix and various other address configuration information. The mobile terminal sets its own temporary address by combining its interface ID and the prefix information received from the router. At this time, the mobile station must go through a process of checking whether the temporary address configured by the mobile station collides with the neighbor solicitation message and the neighbor advertisement message. If the mobile station does not receive the Neighbor Advertisement message for a certain period of time, it determines that the uniqueness of this address is verified and uses this address.

The mobile terminal registers its temporary address with the home agent through a Binding Update message. The home agent responds with a Binding Acknowledgment message. After completing the registration procedure of the home agent, the mobile terminal transmits an IP_Linksetup_Complete trigger to the MIH.

In the case where the mobile terminal hands over to another interface network, an example of using the mobile IPv6 stateful address as a temporary address will be described.

20 is a flowchart illustrating a method for reconfiguring an address using a stateful address of Moible IPv6 as a temporary address when a mobile station hands over to another interface network and changes its subnet.

The MIH of the new access point sends an IP_Renewal_Indication to the mobile station's MIH indicating the temporary address resetting when the subnet of the mobile station changes. The MIH of the mobile terminal requests the network layer to reset the temporary address by triggering IP_Renewal_Request. When the network layer of the mobile station receives the IP_Renewal_Request trigger, it sends a SOLICIT message to the DHCPv6 server as a multicast address to form a new temporary address.

In response to SOLICIT, an available DHCPv6 server sends an ADVERTISE message. The mobile station receiving the ADVERTISE message selects one server and sends a REQUEST message to obtain additional configuration parameters. In response, the DHCPv6 server sends a REPLY message, and the mobile station registers with the home agent through the Binding Update message using the CoA included in the message as a temporary address.

The home agent sends a Binding Acknowledgement message in response. The mobile station sends an IP_Linksetup_Complete trigger to the MIH when the temporary address configuration procedure is completed. The embodiments described above describe procedures for resetting a temporary address using mobile IPv4 and mobile IPv6 when a multi-mode mobile terminal hands over to another interface network and changes its subnet. However, even when a multi-mode mobile terminal hands over to another subnet in the currently connected interface network, it is applicable to reconfiguring a temporary address using triggers (IP_Renewal_Indication, IP_Renewal_Request, IP_Linksetup_Complete) proposed in the present invention.

21 is a diagram illustrating an operation of a protocol stack, an IP address setting event service, and a command service of a multimode terminal. If a newly handed over network fails to use the previously used IP address, IP renewal indication (IP_Renewal_Indication) is transmitted from the MAC layer to the MIH. After receiving the IP_Renewal_Indication, the MIH sends the MIH event IP_Renewal_Request to the parent management object to request the IP address setting. After receiving the IP_Renewal_Request, the parent management object sends the MIH command IP_LinkSetup_Complete to the MIH after completing the IP configuration through the IP layer to inform the MIH that the IP address configuration is complete.

FIG. 22 is a flowchart illustrating a procedure for resetting an IP address by an upper management entity using a mobile IPv4 FA-CoA as a temporary address when the mobile terminal hands over to another interface network.

Referring to FIG. 22, the mobile terminal is currently connected with a link of an interface network. When a good signal quality link is found in the MAC layer of the new interface, it triggers Link Available to the MIH. The new MAC layer performs a new connection point and connection establishment procedure. When the connection establishment procedure is completed, after performing the authentication procedure, the MIH of the mobile station and the MIH of the new access point are notified that the link is established.

The MIH of the new access point sends a link event, IP_Renewal_Indication, to the mobile station's MIH, indicating the temporary address reset when the subnet of the mobile station changes. The MIH of the mobile station that receives IP_Renewal_Indication sends the MIH event IP_Renewal_Request to the higher management object, and the higher management object requests to reset the temporary address through the IP layer.

Upon receiving the IPHRenewal_Request MIH event, the parent management entity of the mobile station sends a Agent Solicitation message to an external agent to obtain a new temporary address. The external agent responds with an Agent Advertisement message to the mobile station. After receiving the Agent Advertisement message, the network layer of the mobile station registers a temporary address with the home agent (HA). When the temporary address reconfiguration procedure is completed, the host management entity of the mobile station sends an IP_Linksetup_Complete MIH command to the MIH.

FIG. 23 is a flowchart illustrating a method for resetting an address by an upper management entity using a mobile IPv4 Co-located CoA as a temporary address when the mobile terminal is handed over to another interface network.

Referring to FIG. 23, when a mobile station resets an IP temporary address using a Co-located CoA, when the mobile station receives a link event, IP_Renewal_Indication indicating a temporary address reset, from the MIH of the new access point, the MIH of the mobile station is sent to the upper management entity. Send IP_Renewal_Request, a MIH event. After receiving the IP_Renewal_Request, the parent object sends a DHCP Discovery message to get a temporary address. After receiving the temporary address by the DHCP address assignment procedure, the mobile terminal registers it with the home agent.

After completing the registration procedure of the home agent through the IP layer, the upper management entity of the mobile terminal transmits the MIH command IP_Linksetup_Complete to the MIH.

24 is a flowchart illustrating a method for resetting an address by an upper management entity using a mobile IPv6 stateless address as a temporary address when a mobile terminal hands over to another interface network and changes its subnet.

When the subnet of the mobile station is changed, the MIH of the new access point sends a link event, IP_Renewal_Indication, indicating the temporary address reconfiguration to the mobile station's MIH. The MIH of the mobile terminal sends a MIH event, IP_Renewal_Request, to the higher management entity to request resetting the temporary address through the IP layer. When the parent management object receives an IP_Renewal_Request, it sends a Router Solicitation message to the access router to form a new temporary address.

The router responds to the mobile station with its own prefix and various other address configuration information. The mobile terminal sets its own temporary address by combining its interface ID and the prefix information received from the router. At this time, the mobile station must go through a process of checking whether the temporary address configured by the mobile station collides with the neighbor solicitation message and the neighbor advertisement message. If the mobile station does not receive the Neighbor Advertisement message for a certain period of time, it determines that the uniqueness of this address is verified and uses this address.

The mobile terminal registers its temporary address with the home agent through a Binding Update message. The home agent responds with a Binding Acknowledgment message. After completing the registration procedure of the home agent, the host management object sends the MIH command IP_Linksetup_Complete to the MIH.

FIG. 25 is a flowchart illustrating a method for reconfiguring an address by an upper management entity using a stateful address of Moible IPv6 as a temporary address when a mobile terminal hands over to another interface network and changes its subnet.

The MIH of the new access point sends an IP_Renewal_Indication Link event to the mobile terminal MIH indicating the temporary address reset when the subnet of the mobile terminal changes. The MIH of the mobile terminal sends an IP_Renewal_Request, which is a MIH event, to the parent management object to request that the temporary address be reset. Upon receiving the IP_Renewal_Request, the parent object sends a SOLICIT message to the DHCPv6 server as a multicast address to form a new temporary address.

In response to SOLICIT, an available DHCPv6 server sends an ADVERTISE message. The mobile station receiving the ADVERTISE message selects one server and sends a REQUEST message to obtain additional configuration parameters. In response, the DHCPv6 server sends a REPLY message, and the mobile station registers with the home agent through the Binding Update message using the CoA included in the message as a temporary address.

The home agent sends a Binding Acknowledgement message in response. Upon completion of the temporary address setup procedure, the parent management object sends the MIH command IP_Linksetup_Complete to the MIH.

FIG. 26 is a flowchart illustrating a method of resetting an IP address after handover after being informed from a previous access point that a subnet will be changed before the mobile station hands over to another interface network.

At the previous access point, the mobile station notifies the upper management entity through Link Going Down when a handover is necessary due to the deterioration of the link quality. It also informs the MIH of the access point that is currently connected through the remote link go down. If the previous access point knows whether the previous access point should change the IP address for communication after the mobile terminal moves, it informs the MIH of the mobile terminal through IP_Renewal_Indication. The mobile terminal may transparently deliver this message to the higher management entity or inform the user through IP_Renewal_Request. After the mobile terminal establishes the link through the link establishment procedure with the new access point, the mobile station performs the IP address establishment procedure quickly by referring to the IP address setting information obtained from the previous access point.

The embodiments described above describe procedures for resetting a temporary address using mobile IPv4 and mobile IPv6 when a multi-mode mobile terminal hands over to another interface network and changes its subnet. However, even when a multi-mode mobile terminal hands over to another subnet in the currently connected interface network, it is applicable to reconfiguring a temporary address using triggers (IP_Renewal_Indication, IP_Renewal_Request, IP_Linksetup_Complete) proposed in the present invention.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

According to the present invention, when a mobile terminal configured in a multi-mode handovers to another subnet in the same interface network or a subnet is changed by handover to another interface network, the IP temporary address can be quickly reset without time delay.

Claims (23)

In the method of setting a network address of a mobile terminal in a mobile communication system, Performing a handover of the mobile terminal with at least one of a homogeneous network and a heterogeneous network through a media independent handover function (MIHF) module of the mobile terminal; And Prior to setting a network address for at least one of a homogeneous and heterogeneous network, an indicator is sent from the MIHF module of the mobile terminal to a higher layer of the mobile terminal, wherein the indicator changes the network address of the mobile terminal for data communication. Indicating whether it needs to be, The MIHF module is configured to converge information from at least one network interface module associated with one of the homogeneous and heterogeneous networks in a unified form, and to transmit the unified information to the upper layer of the mobile terminal. Way. The method of claim 1, And setting a network address for at least one of the homogeneous network and the heterogeneous network, wherein the network address is an Internet Protocol (IP) address. The method of claim 1, And sending the indicator from the MIHF module of the mobile terminal to a higher layer of the mobile terminal occurs when the subnet of the mobile terminal is changed. The method of claim 1, The performing of the handover may include performing a handover from a medium access control (MAC) layer of the current network to at least one MAC layer of a homogeneous or heterogeneous network. The method of claim 1, Receiving, by the MIHF module of the mobile terminal, an indicator from a lower layer of the mobile terminal, the indicator indicating whether the network address of the mobile terminal needs to be changed for data communication; And sending the indicator to the upper layer of the mobile terminal informs the upper layer of the indicator received from the lower layer. The method of claim 1, And sending an indicator from a lower layer of the mobile terminal to the MIHF module of the mobile terminal, wherein the indicator indicates whether the network address of the mobile terminal needs to be changed for data communication. To set the network address. The method of claim 1, Receiving an indication message sent from a remote MIHF module at the MIHF module of the mobile terminal, wherein the indication message indicates whether the network address of the mobile terminal needs to be changed for data communication; , Sending the indicator to a higher layer of the mobile terminal is performed as a result of receiving the indication message sent from the remote MIHF module. The method of claim 1, The upper layer includes at least one of a mobility management protocol and a higher management entity. The method of claim 2, And informing the MIHF module of the mobile terminal from the upper layer that a network address for at least one of a homogeneous network and a heterogeneous network has been set. The method of claim 5, And sending an indicator from a lower layer of the mobile terminal to the MIHF module of the mobile terminal, wherein the indicator indicates whether the network address of the mobile terminal needs to be changed for data communication. To set the network address. The method of claim 1, And sending the indicator from the MIHF module of the mobile terminal to a higher layer of the mobile terminal occurs before performing the handover. The method of claim 1, And establishing a connection with at least one of a homogeneous network and a heterogeneous network. The method of claim 12, wherein the establishing of the connection comprises: And establishing a connection between the MAC layer of the mobile terminal and at least one MAC layer of a homogeneous or heterogeneous network. In a mobile terminal capable of setting a network address in a mobile communication system, Media Independent Handover Function (MIHF) configured to converge information from at least one network interface module associated with one of the homogeneous and heterogeneous networks in a unified form, and to convey the information converged in the unified form to a higher layer of the mobile terminal. Contains modules, The MIHF module performs a handover of the mobile terminal to at least one of a homogeneous network and a heterogeneous network, The MIHF module sends an indicator to the upper layer of the mobile terminal before setting a network address for at least one of a homogeneous and heterogeneous network, the indicator needing to change the network address of the mobile terminal for data communication. Mobile terminal indicating whether there is. The method of claim 14, The upper layer sets a network address for at least one of the homogeneous network and heterogeneous network, wherein the network address is an IP (Internet Protocol) address. The method of claim 14, And the MIHF module sends an indicator to a higher layer of the mobile terminal when the subnet of the mobile terminal is changed. The method of claim 14, The MIHF module is a mobile terminal, characterized in that for performing a handover from the MAC (Medium Access Control) layer of the current network to at least one MAC layer of homogeneous and heterogeneous networks. The method of claim 14, The MIHF module receives an indicator from a lower layer of the mobile terminal, the indicator indicates whether the network address of the mobile terminal needs to be changed for data communication, and the MIHF module receives the received information from the lower layer. And an indicator for notifying the upper layer of the indicator to the upper layer of the mobile terminal. The method of claim 14, And the MIHF module receives an indicator from a lower layer of the mobile terminal, and the indicator indicates whether the network address of the mobile terminal needs to be changed for data communication. The method of claim 14, The MIHF module receives an indication message sent from a remote MIHF module, the indication message indicates whether the network address of the mobile terminal needs to be changed for data communication, And the MIHF module sends an indicator to a higher layer as a result of receiving the indication message sent from the remote MIHF module. The method of claim 14, The upper layer includes at least one of a mobility management protocol and a higher management entity. The method of claim 14, And from the upper layer to the MIHF module of the mobile terminal notifying that a network address for at least one of a homogeneous network and a heterogeneous network has been set. The method of claim 19, A lower layer of the mobile terminal sends an indicator to the MIHF module of the mobile terminal, the indicator indicating whether the network address of the mobile terminal needs to be changed for data communication.

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