KR20060119128A - Method of executing handover between map domains - Google Patents

Abstract

A handover performance method between MAP(Mobility Anchor Point) domains is provided to enable an MSS(Mobile Subscriber Station) to establish a link with a new MAP domain before being handed over to the new MAP domain from the currently belonging MAP domain, thus delay occurring while a link with a new MAP is established can be reduced. An MSS senses that the current MAP domain is changed. An IP(Internet Protocol) address is reset with a primitive delivered by an MIH(Media Independent Handover) entity by using lower link information. If the MSS is handed over to a new MAP domain from the currently belonging MAP domain, a link with the new MAP domain is set before the MSS is handed over to the new MAP domain.

Description

Method of executing handover between MAP domains}

1 is a diagram illustrating a protocol layer configuration of a mobile terminal configured in a multi-mode in the prior art.

2 is a view for explaining the functional entities and transmission protocol of the mobile terminal and the network including the MIH function in the prior art.

Fig. 3 shows the structure of a trigger model in the prior art.

Figure 4 is an exemplary view showing a trigger that occurs until the quality of the link to which the mobile terminal is currently connected in the prior art until a new link is established.

5 is a view for explaining the basic operation of the mobile IPv4 according to the prior art.

6 is a view for explaining the basic operation of the mobile IPv6 according to the prior art.

7 is a view for explaining the basic operation of the HMIPv6 according to the prior art.

8 and 9 are diagrams for explaining an operation procedure of FMIPv6 according to the prior art.

10 is a view for explaining the operation of the F-HMIPv6 according to the prior art.

11 illustrates an FBU message format according to the present invention.

12 is a diagram illustrating a network configuration during handover between MAPs according to the present invention.

Figure 13 is a procedure flow diagram of one preferred embodiment of the present invention.

14 is a process flow diagram of another preferred embodiment of the present invention.

The present invention relates to a method for performing handover between different MAP domains. More specifically, the present invention relates to a method for performing handover between MAP domains, which can reduce a delay in establishing a connection with a new MAP when the mobile terminal leaves the current MAP domain and handovers to a new MAP domain.

IEEE802.21, which is in the international standardization of Media Independent Handover (MIH) between heterogeneous networks, provides mobile handset by providing seamless handover and service continuity between heterogeneous networks. To improve the user convenience of the device, the basic requirements are defined MIH function (MIH function), Event Trigger (Event Trigger) and Information Service (IS).

A mobile subscriber station (MSS) is a multi-mode node that supports more than one interface type. The interface type may be a wire-line interface type such as Ethernet based on IEEE802.3, a wireless interface type based on IEEE802.XX such as IEEE802.11, IEEE802.15, IEEE802.16, or 3GPP. , May be any one of interface types defined by a cellular standardization organization such as 3GPP2. However, it is not limited thereto.

1 is a diagram illustrating a protocol layer configuration of a mobile terminal configured in a multi-mode. Referring to FIG. 1, a multi-mode mobile terminal has a physical layer (PHY) and a medium access control layer (MAC) layer for each mode, and a MIH layer is located below the IP layer.

Media Independent Handover (MIH) should be defined between IEEE802 series interfaces or between non-802 series interfaces such as IEEE802 series interfaces and interface types defined by cellular standardization organizations such as 3GPP and 3GPP2. Higher layer mobility support protocols such as Mobile IP (IP) and Session Initiation Protocol (SIP) should be supported for handover and seamless service.

Hereinafter, mobile IPv4 will be described. The network supporting mobile IP is composed of a home agent, a foreign agent, and a mobile terminal. The following functions are required for the operation of Mobile IP.

1) Agent Discovery

Agent discovery is a way 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 detect that it has moved to another network.

2) Registration

When the registration function detects that the mobile terminal has moved to another network, the registration function provides a flexible mechanism that delivers 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.

3) Routing

The routing function is a function necessary for properly routing datagrams to be transmitted and received from or to the terminal when the mobile terminal is connected to the external network.

4) Temporary Address (CoA)

Mobile IP provides two methods, FA-CoA and co-located CoA, for temporary address setting when a mobile node moves to another subnet.

FA-CoA is provided by Foreign Agent through Agent Advertisement message, and IP address of external agent is used as temporary address. Co-located CoA is a method in which a mobile node receives a temporary address through a DHCP server located in a visited network.

Hereinafter, mobile IPv6 will be described. Mobile IPv6 supports mobility more effectively than mobile IPv4 and has superior scalability. The following is a description of basic elements and functions for the operation of Mobile IPv6.

1) Mobile Node (MN): Host or router that changes its network connection

2) Corresponding node (CN): host or router communicating with mobile node

3) Home Agent (HA): Router that has the registration information of mobile node among routers in home network and sends datagram to current location of mobile node in external network

4) Temporary address (CoA): IP address connected to the mobile node when the mobile node moves to the external network

5) Binding: Match the home address of the node with the CoA registered by the mobile node in the home agent.

6) BU (Binding Update): Used by mobile node to inform HA and CNs of its CoA.

7) BACK (Binding Acknowledge): Response message to BU

8) BR (Binding Request): A message requesting a BU if the corresponding node does not receive a BU before the mobile node's timer for binding information expires.

9) CoA Acquisition: Neighbor Discovery and Address auto-configuration can be used to automatically configure their location information when a node moves.

10) Route Optimization: After the correspondent node saves the binding information, the correspondent node can communicate with the mobile node directly without going through the home agent.

11) Address auto-configuration

The automatic generation of IP addresses includes stateful address autoconfiguration that obtains an address using a server such as DHCP, and stateless autoconfiguration that generates an address by the host. When using a server, the host side requests an address from a DHCP server, and then assigns one of the addresses assigned by the server to the host side. The stateless address autoconfiguration method generates an address by combining its interface ID information with prefix information obtained from a router or well-known prefix information.

Hereinafter, FMIPv6 (Fast Handovers for Mobile IPv6) will be described. Fast Handovers for Mobile IPv6 (FMIPv6) is a protocol for reducing the overall handover delay in the L3 layer by accelerating the movement detection and acquisition of a new care of address (NCoA) based on the handover prediction information in the L2 layer. The following describes the basic elements and messages for the operation of FMIPv6.

1) PAR (Previous Access Router): Default router before handover of mobile node

2) NAR (New Access Router): Default router expected for handover of mobile node

3) PCoA (Previous Care of Address): Valid temporary address of mobile node in PAR subnet

4) NCoA (New Care of Address): Valid temporary address of mobile node in NAR subnet

5) RtsolPr (Router Solicitation for Proxy): A message sent from a mobile node to a PAR requesting information for potential handover.

6) PrRtAdv (Proxy Router Advertisement): This message is sent from PAR to mobile node and provides information about NAVER link. It also acts as a trigger for network initiated handover.

7) Fast Binding Update (FBU): A message that a mobile node requests a PAR to change its traffic destination to NAR.

8) FBACK (Fast Binding Acknowledge): Response message to FBU generated from PAR

9) HI (Handover Initiation): Message sent from PAR to NAR to inform handover of mobile node.

10) HACK (Handover Acknowledge): A message sent from NAR to PAR and response message to HI.

11) FNA (Fast Neighbor Advertisement): A message sent from the mobile node to the NAR. This message confirms the use of NCoA when the mobile node has not yet received the FBACK and informs that it has connected to a new network.

Fast Handover for Hierarchical Mobile IPv6 (F-HMIPv6) is a protocol combining the FMIPv6 and HMIPv6 methods. In this method, it is possible to efficiently utilize the hierarchical structure of HMIPv6 by allowing MAP to play the role of the previous access router (PAR) in FMIPv6. There are no newly defined messages other than those defined in HMIPv6 and FMIPv6.

Hereinafter, the handover technology between heterogeneous networks will be described. For handover between heterogeneous networks, MIH (Media Independent Handover) function, information service, primitive, etc. should be defined.

The MIH function is located below the IP layer and facilitates a handover process by using input values from Layer 2, such as a trigger event and information about another network. 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.

In the upper layer, a higher management entity for monitoring and controlling the status of various links in the mobile terminal is located 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 together as a higher management entity. FIG. 2 illustrates functional entities and transport protocols of a mobile terminal and a network including MIH functions, and a dotted line in FIG. 2 represents a primitive, an event trigger, and the like.

For fast handover, the network layer needs to use the information from the link layer so that the connection can be reestablished as soon as possible. Link layer events can help predict user movement and can help the mobile terminal and network to prepare for handover in advance.

Triggers for handover can be initiated from the physical layer (PHY), the media access control layer (MAC), and the source for these triggers can be a local stack or a remote stack. Figure 3 shows the structure for the trigger model.

Event triggers provide a change in the state of the current signal and other network states, future predicted changes, and include changes in the physical and media access control layers or changes in the properties of a particular network.

The event type may be classified into a PHY layer event, a media access control layer event, a MAC layer event, a management event, an L3 event, an application event, and the like. .

The basic trigger events are as follows:

'Link_Up' occurs when a two-layer connection is established on a particular link interface and can transmit three-layer packets in the upper layer. At this time, it is determined that all two-layer configuration constituting the link is completed. At this time, event sources are 'Local MAC' and 'Remote MAC'. Table 1 shows an example of a parameter of 'Link_Up'.

Name Type Description EventSource EVENT_LAYER_TYPE Source where the event was generated EventDestination EVENT_LAYER_TYPE Destination to which event will be delivered MacMobileTerminal MAC Address MAC address of mobile terminal MacOldAccessRouter MAC Address MAC address of the previous access router MacNewAccessRouter MAC Address MAC address of new access router NetworkIdentifer Media Specific Network identifier that can be used to detect changes in subnet

'Link_Down' occurs when a layer 2 connection is released on a particular interface and no more layer 3 packets can be sent. The event source is 'Local MAC'. Table 2 shows an example of the parameter of 'Link_Down'.

Name Type Description EventSource EVENT_LAYER_TYPE Source where the event was generated EventDestination EVENT_LAYER_TYPE Destination to which event will be delivered MacMobileTerminal MAC Address MAC address of mobile terminal MacOldAccessRouter MAC Address MAC address of the previous access router ReasonCode Reason for unlinking

'Link_Going_Down' occurs when a layer 2 connection is expected to be 'linked down' within a specific time, and may be a signal for initiating a handover procedure. Event sources are 'Local MAC' and 'Remote MAC'. Table 3 shows an example of a parameter of 'Link_Going_Down'.

Name Type Description EventSource EVENT_LAYER_TYPE Source where the event was generated EventDestination EVENT_LAYER_TYPE Destination to which event will be delivered MacMobileTerminal MAC Address MAC address of mobile terminal MacOldAccessRouter MAC Address MAC address of the previous access router MacNewAccessRouter MAC Address MAC address of 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. UniqueEventIdentifer Used when event rollback occurs

'Link_Going_Up' occurs when a layer 2 connection is expected to be 'Link_Up' within a certain time and is used when the network takes a long time to initialize. Event sources are 'Local MAC' and 'Remote MAC'. Table 4 shows an example of a parameter of 'Link_Going_Up'.

Name Type Description EventSource EVENT_LAYER_TYPE Source where the event was generated EventDestination EVENT_LAYER_TYPE Destination to which event will be delivered MacMobileTerminal MAC Address MAC address of mobile terminal MacNewAccessRouter MAC Address MAC address of new access router Timeinterval Time in msecs Estimated time to be Link_UP ConfidenceLevel % The level at which a link is expected to be Link_Up at a specific time UniqueEventIdentifer Used when event rollback occurs

'Link_Event_Rollback' is used in combination with 'Link_Going_Up' and 'Link_Going_Down'. Trigger that occurs when 'Link_Going_Up' or 'Link_Going_Down' is transmitted but it is predicted that 'Link_UP' or 'Link_Down' will no longer occur within a certain time. Event sources are 'Local MAC' and 'Remote MAC'. Table 5 shows an example of parameters of 'Link_Event_Rollback'.

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

'Link_Available' indicates that a new specific link is available and indicates that the new base station or access point may provide better link quality than the base station or access point (AP) to which the mobile station is currently connected. Indicates. Event sources are 'Local MAC' and 'Remote MAC'. Table 6 shows an example of a parameter of 'Link_Available'.

Name Type Description EventSource EVENT_LAYER_TYPE Source where the event was generated EventDestination EVENT_LAYER_TYPE Destination to which event will be delivered MacMobileTerminal MAC Address MAC address of mobile terminal MacNewAccessRouter MAC Address MAC address of the previous access router MacOldAccessRouter MAC Address MAC address of new access router

'Link_Parameters_Change' is an event that occurs when the change of a link parameter value exceeds a certain limit level. This may include link layer parameters such as link speed, quality of service (QoS), encryption values, and the like. Event sources are 'Local MAC' and 'Remote MAC'. Table 7 shows an example of parameters of 'Link_Parameters_Change'.

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

4 is an exemplary diagram illustrating a trigger generated until a quality of a link to which a mobile terminal is currently connected is degraded and a new link is established.

The Information Service provides detailed information about the network needed for network discovery and selection, and must be accessible from any network. Information services include link access parameters, security mechanisms, neighbor maps, locations, service providers and other access information, and link costs. information elements such as link).

Hereinafter, primitives required for this inter-network handover technology will be described.

1) IP_Information.request

This primitive is a MIH signaling message between access points (broadband wireless access point base station, WLAN AP, or cellular system base station, or access router), where the previous access point of the mobile station is the access router address of the new access point to the new access point. It is transmitted to request information (eg, information included in Router Advertisement) or FA (Foreign Agent) address information (eg, information included in Agent Advertisement). If the previous access point has information that can reach the access router or foreign agent that is connected to the new access point to which the mobile station is to move, the previous access point can send it directly to the access router or foreign agent. Can be. The previous access point may inform the new access point via this message that a particular terminal will hand over to the new access point. In addition, the MIH of the access point or external agent that received this primitive can trigger it in the upper layer. This primitive may be requested at the new access point by the mobile terminal. Table 8 shows an example of the data format of the IP_Informatio.request primitive.

Name Type Description EventSource EVENT_LAYER_TYPE Source where the event was generated EventDestination EVENT_LAYER_TYPE Destination to which event will be delivered MacMobileTerminal MAC Address MAC address of mobile terminal MacAccessRouter MAC Address MAC address of access router New PoA MAC Address MAC Address MAC address of new connection point Home Address IP Address Home Address of Mobile Terminal CoA IP Address Temporary IP Address Currently Used by Mobile Terminal Old FA Address IP Address This parameter is included when MIPv4. Previous FA's IP Address Old Access Router Address IP Address This parameter is included when MIPv6. IP address of the previous Access Router

2) IP_Information.confirm

This primitive is a MIH signal message between access points (broadband wireless access network base station, WLAN AP, or cellular system base station) and is transmitted to respond to the result of a new IP_Information.request of the mobile station. This primitive contains the address information of the access router requested by IP_Information.request (for example, information included in Router Advertisement) or FA (Foreign Agent) address information (for example, information included in Agent Advertisement). Are included and transmitted.

Name Type Description EventSource EVENT_LAYER_TYPE Source where the event was generated EventDestination EVENT_LAYER_TYPE Destination to which event will be delivered MacMobileTerminal MAC Address MAC address of mobile terminal Mobility Management Protocol Support Type Bitmap Indicates the Mobility Management Protocol Support type supported by the router. 0: MIPv4 with FA (FA-CoA) 1: MIPv4 without FA (Co-located CoA) 2: MIPv6 3: MIPv6 with DHCPv6 4: FMIPv6 5: HMIPv6 6: SIP 7: Reserved  IP Address Change Notification This field indicates whether the current address should be changed when the mobile station's IP address (including Care of Address) moves to a new access point. 0: IP Address Change 1: IP Address No Change FA-CoA or Router Address If the Mobility Management Protocol Support type is 0, FA-Address is included. If type is 2, Router Address is included. It is also included only when the IP Address Change Notification is 0. Mobility Agent Advertisement Extension This parameter is included only when the Mobility Management Protocol Support type is 0 and is the same information as that included in Agent Advertisement provided by FA. It is also included only when the IP Address Change Notification is 0. (E.g. CoA information, Registration life time, encapulsation information) Router information This parameter is included only when the Mobility Management Protocol Support type is 2 and is the same information as that included in the Router Advertisement provided by the IPv6 router. It is also included only when the IP Address Change Notification is 0. (E.g. Router Address, Stateful Auto Address Setting Method, Router Lifetime, etc.) Home Address  IP Address Home Address of Mobile Terminal

Hereinafter, a detailed operation procedure of mobile IPv4 will be described. Mobile IPv4 aims to support transparent mobility to the upper layer by default, and requires the addition of a mobile host, a home agent, and a foreign agent to support it. However, when the path optimization is not used, the change of the correspondent node communicating with the mobile terminal is not necessary. Where a mobile host represents an IP host that is supported for mobility, and a home agent is a router that maintains location information about the mobile host and tunnels to or as a visiting agent, and a visiting agent is a router that supports mobility in the visiting network. Means each. The basic operation in mobile IPv4 can be described as shown in FIG. 5 below.

Description of each step operation in Figure 5 is as follows.

(1) 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 broadcasted from the visiting network, and the home in the home network Register a temporary address (CoA) with the agent indicating its current location

(2) At this time, the CoA is the IP address of the visited agent (FA-CoA) or the co-located CoA temporarily assigned by the mobile host through DHCP in the visited network. Packets sent from the outside to the mobile host are sent to the home network, which is intercepted by the home agent that is aware of the mobile terminal's movement.

(3) The home agent encapsulates the packet delivered to the mobile host with the FA address as the destination (when FA-CoA is used) and then forwards the packet to the visiting agent.

(4) The encapsulated and forwarded packet is de-capsulated at the visiting agent, recovered to the original forwarding packet, and finally delivered to the mobile host.

(5) A 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.

Key features required for mobile IP include:

(1) Agent Discovery

Agent discovery is a method of determining whether a mobile terminal is currently connected to its home network or located in a visiting network. By this method, the mobile terminal can detect that it has moved to another network.

Mobile IP extends 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 the Mobility Agent Advertisement Extension in the ICMP Router Advertisement message. The 'Agent Solicitation' message sent by the mobile station to find an agent uses the same method as the existing 'ICMP Router Solicitation' message.

(2) Registration

When the registration function detects that the mobile terminal has moved to another network, the registration function provides a flexible mechanism that delivers 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. Mobile IP defines two different registration procedures. If a mobile terminal uses a FA-CoA, it must be registered through a visiting agent. When using a co-located CoA, the mobile terminal registers directly with a home agent.

(3) Routing

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

6 is a diagram illustrating an operation procedure of mobile IPv6. The operation procedure of the mobile IPv6 may be described sequentially in FIG.

0. MN moves from Subnet A to Subnet B.

1. MN detects movement using prefix information of RA message and neighbor unreachable detection (NUD) mechanism.

2. Obtain CoA by itself through 'Address auto-configuration' method.

3. Send BU message notifying HA of acquired CoA.

4. HA binds MN's home address and CoA and sends BAck in response to BU.

5. The CN that communicates with the MN for the first time did not detect the MN's movement, so set the destination address as the MN's home address and send the packet.

6. The HA managing the MN intercepts the packet and tunnels it to the current MN's location.

7. The MN that receives the tunneled packet determines that the CN that sent the packet does not have the binding information and sends a BU message to the CN to notify its CoA.

8. The CN stores the binding information and then communicates directly with the MN using that information.

7 is a configuration diagram for explaining the basic operation of the HMIPv6. When the mobile station enters the area managed by the MAP, the AR1 receives a periodically broadcast router advertisement message including the MAP option. The mobile terminal receiving the router advertisement message including the MAP option generates LCoA, a CoA on AR1, and RCoA, a CoA on MAP, in a 'stateless auto-configuration' form. Each procedure in FIG. 7 is described as follows.

(1) After configuring LCoA and RCoA, mobile station sends local binding message to MAP.

(2) The MAP binds LCoA and RCoA and returns a binding confirmation message to the mobile node, indicating whether the binding is successful or not.

(3) (4) If local binding is successful, the mobile station performs binding update specified in mobile IPv6 for HA and CN.

(5) If the mobile station moves to another AR in the MAP area, since it has the same RCoA for HA / CN, no binding update is required, and only local binding update for updating the LCoA is necessary. If it moves into a new MAP area, binding update should be performed for HA and CN.

8 and 9 are diagrams for describing an operation procedure of FMIPv6. FIG. 8 is an operation procedure of a 'Proactivie' state, and FIG. 9 shows an operation procedure of a 'Reactive' state. There are 'Proactive' states for sending and receiving FBU / FBACK messages on the link of the PAR and 'Reactive' states for sending and receiving FBU / FBACK messages from the link of the NAR . The 'Proactive' state checks the authenticity of the generated NCoA before disconnecting from the PAR. In the 'Reactive' state, the NCoA is checked after the mobile node arrives at the new subnet.

Referring to Fig. 8, the operation procedure of the 'Proactive' state will be described.

1) The mobile node discovers APs capable of handover based on the L2 layer information (for example, scanning in a WLAN system) and sends a RtSolPr to the PAR to obtain subnet information corresponding to the found AP identifiers. Send a message.

2) The PAR receiving the RtSolPr message sends a PrRtAdv message to the mobile node with a tuple of [AP-ID, AR-Info] type corresponding to each subnet information corresponding to the transmitted APs. This message can sometimes be sent 'solicit' after the mobile node has detected a router.

3) Mobility creates a new temporary address (NCoA) based on the AR-Info in the PrRtAdv message.

4) The mobile node sends a FB message to the PAR to bind PCoA and NCoA so that packets arriving at the PAR can be tunneled to the NAR.

5) The PAR sends a notification message that the mobile node is going to handover to the NAR, that is, HI. The NAR receives the HI message and performs duplicate checking of the NCoA generated by the mobile node. If the NCoA is not suitable for duplicate checking, the NAR sets a new temporary address for the mobile node.

6) The NAR sends a HACK to the PAR in response to the HI. In this case, the newly generated NCoA may be included in 6).

7) After receiving the HACK, the PAR sends a FBACK to the mobile node and the NAR, indicating that the PAR starts tunneling the mobile node's packet to the real NCoA address. At this time, the connection between the mobile node and the PAR is lost.

8) Packets arriving at the PAR are forwarded to the NAR.

9) As soon as the mobile node establishes a new link with the NAR, it sends a FNA message to the NAR indicating that the node is connected to the NAR's network.

10) Packets are sent via NAR.

Referring to Fig. 9, the operation procedure of the 'Reactive' state will be described.

1) The mobile node discovers APs capable of handover based on the L2 layer information (for example, scanning in a WLAN system), and obtains subnet information corresponding to the AP identifiers (RtSolPr) found to the PAR. Send a message.

2) The PAR receiving the RtSolPr message sends a PrRtAdv message to the mobile node with a tuple of [AP-ID, AR-Info] type corresponding to each subnet information corresponding to the transmitted APs. This message can sometimes be sent 'solicit' after the mobile node has detected a router.

3) The mobile node creates a new temporary address (NCoA) based on the AR-Info in the PrRtAdv message and disconnects from the PAR.

4) As soon as the mobile node connects to the NAR, it initiates a procedure to encapsulate the FBU message in the message to the FNA so that packets arriving at the PAR are immediately forwarded to the NAR and let the NAR verify that the NCoA is valid. .

5) NAR sends a FB message to PAR to bind PCoA and NCoA. If NCoA is not valid in the FBU received by the NAR, the NAR discards the FBU packet and sends a Router Advertisement containing an alternate address.

6) PAR sends FBACK to NAR in response to FBU. At this time, tunneling setup is completed between the actual PAR and NAR.

7) Packets arriving at the PAR are forwarded to the NAR.

8) Packets are sent via NAR.

10 is a flowchart illustrating an operation procedure of F-HMIPv6. The operation of F-HMIPv6 will be described with reference to FIG.

1) The mobile terminal having the link layer information to move to the NAR first sends a proxy router request message (RtSolPr) requesting the NAR's IP information to the MAP using the link layer ID of the NAR included in the link layer information.

2) The MAP receiving the RtSolPr uses the information on its own NAR to configure the NLCoA to be used by the mobile terminal in the NAR, and sends the proxy router advertisement message (PrRtAdv) to the mobile terminal with the NAR's IP address.

3) A fast binding update (FBU) is requested to the MAP by using a mobile terminal which previously obtained an NLCoA to be used in a new access router NAR through PrRtAdv.

4) The MAP receiving the FBU sends a handover initiation message (HI) to the NAR requesting a handover to the NAR to confirm availability for the NLCoA. This HI message includes a message requesting the establishment of a bidirectional tunnel between the MAP and the NAR to prevent routing failure during the binding update in the NAR.

5) NAR receiving HI message confirms that NLCoA can be used, establishes bidirectional tunnel between MAP to prevent routing failure, and transfers this information to MAP through handover acknowledgment message (HACK). When a bidirectional tunnel is created between the MAP and the NAR, packets destined for the mobile station are delivered to the NAR through the bidirectional tunnel.

6) After receiving the HACK, the PAR sends a FBACK to the mobile node and the NAR, indicating that the PAR starts tunneling the mobile node's packet to the address of the actual NCoA.

7) As soon as the mobile node establishes a new link with the NAR, it sends a FNA message to the NAR indicating that the node is connected to the NAR's network.

8) The mobile node registers its own location by sending Local BU to MAP.

9) The MAP sends a Local BACK to the mobile node in response.

10) Packets are sent via NAR.

In the prior art, when using FHMIPv6 mixed with HMIPv6 and FMIPv6, only mobile mobility within a single MAP domain (Micro mobility management) is defined. Therefore, if the mobile terminal performs a handover to the new MAP domain beyond the current MAP domain (Macro mobility management), there is a delay in establishing a connection with the new MAP. Clear procedures need to be established.

The present invention has been made to solve the problems of the prior art as described above, and an object of the present invention is to set up a connection with a new MAP when the mobile terminal is handed over to a new MAP domain beyond the current MAP domain. The present invention provides a method for performing handover between MAP domains of a mobile terminal which can reduce delay.

A method for performing handover between MAP domains according to the present invention may include a multi-mode (eg, broadband wireless access system (IEEE802.16) interface, a wired LAN (IEEE802.3) interface, a wireless LAN (IE) configured of two or more interfaces including wired and wireless. When a mobile terminal consisting of an IEEE802.11 interface or a cellular (3GPP / 3GPP2) interface is out of the current Mobility Anchor Point (MAP) domain, the MIH detects a change in the MAP domain through signal exchange between the MIHs and uses the sublink information to The forwarding primitive is to quickly reset an IP address and deliver IP packets without loss.

In one aspect of the present invention, a method for performing handover between MAP domains according to the present invention includes a method for performing handover of a mobile terminal configured in a multi-mode including two or more interfaces including wired and wireless communication. Detecting that a current Mobility Anchor Point (MAP) domain has been changed; And resetting an IP address to a primitive delivered by a media independent handover (MIH) entity using the lower link information.

In another aspect of the present invention, a method for performing handover between MAP domains according to the present invention includes a method for performing handover of a mobile terminal configured in a multi-mode including two or more interfaces including wired and wireless. When handing out of the current MAP domain to a new MAP domain, a connection with the new MAP domain is established before handover.

A primitive including a field proposed or added in the present invention is as follows.

1.Info_Available.notification

This primitive detects that there is no corresponding new access point in the mapping table owned by the old MAP after receiving the new PoA information from the terminal, and indicates that there is no information corresponding to the MIH function of the MAP or the mobile terminal. Used for informative role. In the hierarchical structure, since the MAP has information of access routers and access points existing in the MAP domain, it is possible to determine whether the MAC address of the access router corresponding to the access point is present. After receiving this primitive, the mobile terminal can know that the MAP for the new access point that attempts to handover is changed. This primitive may be delivered by the upper layer to the MIH function for this purpose within a protocol stack, or may be delivered remotely to the mobile terminal's MIH function. Table 10 shows an example of the data format of the Info_Available.notification primitive.

Name Type Description EventSource Event_Layer_Type Source where the event was generated EventDestination Event_Layer_Type Destination to which event will be delivered MacMobileTerminal MAC Address MAC address of mobile terminal MacNewPoA MAC Address MAC address of the new access point MacNewAccessRouter MAC Address MAC address of the new access router Information Available Enumeration Identifier to detect the change of MAP (eg 0: No information Available)

2. IP_Information.confirm

This primitive is a MIH signal message between access points (broadband wireless access network base station, WLAN AP, or cellular system base station) or access points and a mobile station, and is transmitted to respond to the result of a new IP_Information.request of the mobile station. This primitive includes the address information of the access router requested by IP_Information.request (for example, information included in Router Advertisement) and is transmitted. This primitive adds MAP option information received from the upper MAP. The present invention proposes a method in which an access point delivers MAP option information to other access points and mobile terminals, even if the mobile terminal can receive MAP option information even though the MAP option information is transmitted through another message. Table 11 shows an example of the data format of the IP_Information.confirm primitive.

Name Type Description EventSource EVENT_LAYER_TYPE Source where the event was generated EventDestination EVENT_LAYER_TYPE Destination to which event will be delivered MacMobileTerminal MAC Address MAC address of mobile terminal Mobility Management Protocol Support Type       Bitmap Indicates the Mobility Management Protocol Support type supported by the router. 0: MIPv4 with FA (FA-CoA) 1: MIPv4 without FA (Co-located CoA) 2: MIPv6 3: MIPv6 with DHCPv6 4: FMIPv6 5: HMIPv6 6: SIP 7: Reserved IP Address Change Notification This field indicates whether the current address should be changed when the mobile station's IP address (including Care of Address) moves to a new access point. 0: IP Address Change 1: IP Address No Change FA-CoA or Router Address If the Mobility Management Protocol Support type is 0, FA-Address is included. If type is 2, Router Address is included. It is also included only when the IP Address Change Notification is 0. Mobility Agent Advertisement Extension This parameter is included only when the Mobility Management Protocol Support type is 0 and is the same information as that included in Agent Advertisement provided by FA. It is also included only when the IP Address Change Notification is 0. (E.g. CoA information, Registration life time, encapulsation information) Router information This parameter is included only when the Mobility Management Protocol Support type is 2 and is the same information as that included in the Router Advertisement provided by the IPv6 router. It is also included only when the IP Address Change Notification is 0. (E.g. Router Address, Stateful Auto Address Setting Method, Router Lifetime, etc.) Home Address  IP Address Home Address of Mobile Terminal MAP Option Information MAP Option information received from upper MAP (eg, distance information between mobile terminal and MAP, priority information, MAP address, etc.)

11 shows an example of a format of an FBU message. As an aspect of the present invention, Old MAP address information may be added as information included in the 'Mobility options' field in the FBU message.

12 is a diagram illustrating a network structure during inter MAP handover according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of a method for performing handover between MAP domains according to the present invention will be described with reference to the accompanying drawings.

FIG. 13 is a flow chart of a preferred embodiment of the present invention, in which a mobile station requests address information of an access router to a new access point through an old access point using inter MIH signaling.

(1) When the signal quality of the previous link is degraded, the mobile station transmits Link Going Down to the upper layer through the MIH, and through the MIH of the previous PoA (Point of Attachment), PAR (Past Access Router), and Old MAP. Remote Link Going Down is transmitted to the upper layer of the Old MAP. At this time, the link go down includes an address (eg, MAC address) of a new PoA to be handed over.

(2) The Old MAP can determine the presence or absence of a new PoA in its MAP domain by looking at the address of the new PoA received. If a new access point does not exist in its MAP domain, it can be moved to the new MAP domain through Info_Available.notification. It informs the mobile terminal that it is a handover. Info_Available.notification is delivered to the MIH from the upper layer and additionally, it can be delivered to the MIH of the mobile terminal along the reverse path of the path through which the link go-down is delivered. The MIH of the terminal delivers the Info_Available.notification to a higher layer that requires the Info_Available.notification information. The higher layer that needs information is initially found by the registration procedure.

(3) The MIH of the mobile station transmits IP_information.request to the MIH of the new PoA through the MIH of the previous access point and requests new access router address information. The MIH of the new PoA sends IP_information.request to the MIH of its access router, and the new access router obtains address information through the upper layer. The procedure after the new access router acquires the address information may be divided into two cases, Method 1 and Method 2 below.

(4) The new access router sends IP_information.confirm, which is a MIH message including its address information, triggered by IP_information.request to the mobile station through the previous access point (in the case of Method 1). In addition to the address information, MAP option information received from the upper MAP is included.

(4) The new access router triggers by IP_information.request and sends a Router Advertisement message containing the address information and the MAP option information to the mobile terminal (Method 2). The Router Advertisement message is an extension of the existing Router Advertisement message, which is sent in the manner defined by the IETF.

(5) The mobile station creates a new LCoA using the new RCoA and the new access router information using the MAP option information.

(6) The mobile station sends a FBU message including the old MAP address information to the new MAP to request tunnel establishment between the new MAP and the new access router.

(7) The new MAP requests binding between the new MAP and the Old MAP by sending a BU (Binding Update) message to the Old MAP.

(8) The Old MAP sends a BACK (Binding Acknowledge) to the new MAP in response.

(9) If the binding succeeds, tunneling is formed between the Old MAP and the new MAP.

(10) At this point, if the Link Down link of the previous access point is released to the Old MAP, the Old MAP forwards the packet through the tunnel formed with the new MAP. The Old MAP can start packet forwarding any time it receives the Link Down of the previous access point.

(11) After tunneling is established between the old and new MAPs, the new MAP sends a Handover Initiation (HI) message to the new access router and receives a HACK (Handover Acknowledge) message in response to the tunnel between the new MAP and the new access router. To form.

(12) The new MAP sends a FBACK message to the mobile station and then forwards the packet from the new MAP to the new access router.

(13) An L2 layer link is established between the new access point and the mobile terminal.

(14) Link Up indicating that the establishment of the new link is completed is delivered to the upper layer through the new link of the mobile terminal.

(15) When the upper layer of the mobile station is informed of a new link up, it sends a FNA (Fast Neighbor Advertisement) message to the new access router so that the new access router forwards the buffered packet to the new LCoA of the mobile station. .

(16) After receiving the FNA, the new access router requests registration with the MAP by sending a local BU message to the new MAP.

(17) The new MAP may inform the registration access success by sending a local BACK to the new access router in response to the local BU.

(18) After the mobile terminal is registered in the new MAP, the mobile station registers the location by sending a global BU to CNs communicating with the home agent HA.

(19) After all registration procedures are completed, the packet is forwarded to the mobile station through a new MAP.

14 is a flowchart illustrating another preferred embodiment of the present invention, in which the Old MAP requests an address of the access router to a new access point using inter MIH signaling.

(1) When the signal quality of the previous link is deteriorated, the mobile station transmits a link going down to the upper layer through the MIH, and remote link going down to the upper layer of the old MAP through the MIH of the previous PoA, PAR, and Old MAP. Send it. At this time, the link going down includes an address (eg, MAC address) of a new PoA to be handed over.

(2) The Old MAP can determine the existence of its own MAP domain by looking at the address of the new PoA delivered. If the new access point does not exist in its MAP domain, the Old MAP is transferred from the upper layer to the new MAP domain through Info_Available.notification. It informs the mobile terminal that it is a handover. Info_Available.notification is delivered from the upper layer to the MIH. Additionally, Info_Available.notification can be delivered to the MIH of the mobile terminal along the reverse path of the path through which the link go-down is delivered. The MIH of the terminal delivers Info_Available.notification to the higher layer that needs Info_Available.notification. Higher levels of information are initially found by the registration process.

(3) After receiving the Info_Available.notification, the Old MAP's MIH sends IP_information.request to the new PoA's MIH to obtain the new MAP's information. The MIH delivers this to the upper layer. The procedure after the new access router acquires the address information may be divided into two cases, Method 1 and Method 2 below.

(4) The new access router sends IP_information.confirm, which is a MIH message including its address information, triggered by IP_information.request to the mobile station through the previous access point (in the case of Method 1). This primitive preferably includes MAP option information received from the upper MAP in addition to the address information.

(4) The new access router triggers by IP_information.request and sends a Router Advertisement message containing the address information and the MAP option information to the mobile terminal (Method 2). The Router Advertisement message is an extension of the existing Router Advertisement message, which is sent in the manner defined by the IETF.

At this time, the new access router may transmit an advertisement message in unicast to the mobile station by referring to the temporary address (CoA) field of the mobile station included in IP_information.request.

(5) The mobile station creates a new LCoA using the new RCoA and the new access router information using the MAP option information. At this time, it discovers that the new RCoA is different from the previous RCoA and recognizes that the mobile terminal will hand over to the new MAP domain.

(6) The mobile station sends a FBU message including old MAP address information to the new MAP to request tunneling between the new MAP and the new access router.

(7) The new MAP requests a binding between the new MAP and the Old MAP by sending a BU message to the Old MAP.

(8) The Old MAP sends a BACK to the new MAP in response.

(9) If the binding succeeds, tunneling is formed between the Old MAP and the new MAP.

(10) At this point, if the Link Down link of the previous access point is released to the Old MAP, the Old MAP forwards the packet through the tunnel formed with the new MAP. The Old MAP can start packet forwarding any time it receives the Link Down of the previous access point.

(11) After tunneling is formed between the old MAP and the new MAP, the new MAP informs the new MAP of the handover of the mobile station by sending a HI message to the new access router and receiving a HACK message in response.

(12) The new MAP sends a FBACK message to the mobile station in response to the FBU and then forwards the packet from the new MAP to the new access router.

(13) An L2 layer link is established between the new access point and the mobile terminal.

(14) Link Up indicating that the establishment of the new link is completed is delivered to the upper layer through the new link of the mobile terminal.

(15) When the mobile station is notified of the link up, it sends a FNA message to the new access router so that the new access router forwards the buffered packet to the new LCoA of the mobile station.

(16) After receiving the FNA, the new access router requests registration with the MAP by sending a Local BU message to the new MAP.

(17) The new MAP signals the registration procedure success by sending a local BACK to the new access router in response to the local BU.

(18) After the mobile terminal registers with the new MAP, the mobile station registers the location by sending a global BU to the corresponding nodes CNs communicating with the home agent HA.

(19) After all registration procedures are completed, the packet is forwarded to the mobile station through a new MAP.

It is apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit and essential features of the present invention. Accordingly, the above detailed description should not be construed as limiting in all aspects and should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

According to the method of performing handover between MAP domains according to the present invention, when a mobile terminal performs a handover to a new MAP domain beyond a current MAP domain, a connection with a new MAP is established by establishing a connection with a new MAP domain before handover. There is an effect that can reduce the delay in the process.

Claims (2)

A method for performing handover of a multi-mode mobile terminal including two or more interfaces including wired and wireless, Detecting that the mobile station has changed a current Mobility Anchor Point (MAP) domain; And A method of performing MAP inter-domain handover, comprising resetting an IP address to a primitive delivered by a Media Independent Handover (MIH) entity using sublink information. A method for performing handover of a multi-mode mobile terminal including two or more interfaces including wired and wireless, A method of performing handover between MAP domains, wherein the mobile terminal establishes a connection with a new MAP domain before handing over when the mobile terminal leaves the current MAP domain and handovers to a new MAP domain.

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