KR20060097518A - Method for handover of mobile commnunication - Google Patents

Abstract

The present invention recognizes that a mobile terminal configured in multimode (e.g., a broadband wireless access network system and a wireless LAN interface, a wired LAN, cellular system interfaces) can no longer operate with an existing mobility management protocol in a new network. By greatly reducing the delay time in the process of setting a temporary address with the mobility management protocol, a new temporary address can be set quickly without packet loss or time delay. The handover method of the mobile communication system according to the present invention comprises the steps of providing the mobile terminal with mobility management protocol information supported by the new network through a predetermined event trigger when the mobile terminal hands over to another type of network; ; With reference to the information, the process of setting a new temporary address of the mobile terminal and performing a handover procedure.

Multimode Mobile Terminal, Handover, Mobility Management Protocol

Description

Handover method of mobile communication system {method for handover of mobile commnunication}

1 is a diagram showing a protocol stack structure of a multi-mode mobile terminal.

2 illustrates an MIH structure and transmission protocol.

3 illustrates a trigger model.

4 is a diagram showing an event trigger when a handover occurs.

5 is a diagram illustrating a procedure of a multi-mode mobile terminal acquiring network related information through an information server.

6 is a diagram illustrating an operation procedure of Mobile IPv4.

7 is a diagram showing the structure of a DHCP message;

8 is an operational flowchart of a DHCP client-server model.

9 is a diagram illustrating an operation procedure of Mobile IPv6.

10 is a diagram showing an operation procedure of DHCPv6.

11 is a view showing an IP address setting procedure according to the prior art.

Fig. 12 shows the structure of the Link Event, MIH Event model in the present invention.

Fig. 13 shows the structure of the Remote Link Event model in the present invention.

Fig. 14 shows the structure of the Remote MIH Event model in the present invention.

Fig. 15 shows the structure of the MIH Command and Link Command models in the present invention.

Fig. 16 shows the structure of the Remote MIH Command model in the present invention.

Fig. 17 shows the structure of the Remote Link Command model in the present invention.

Figure 18 illustrates a protocol stack structure in accordance with the present invention.

19 is a diagram showing an IP address setting procedure according to the first embodiment of the present invention.

20 is a diagram showing an IP address setting procedure according to the second embodiment of the present invention.

21 is a diagram showing an IP address setting procedure according to the third embodiment of the present invention.

22 is a diagram showing an IP address setting procedure according to the fourth embodiment of the present invention.

23 is a diagram showing an IP address setting procedure according to the fifth embodiment of the present invention.

24 is a diagram showing a protocol stack structure including a higher management entity according to the present invention.

25 is a diagram showing an IP address setting procedure according to the sixth embodiment of the present invention.

Figure 26 illustrates an IP address setting procedure according to the seventh embodiment of the present invention.

27 is a diagram showing an IP address setting procedure according to the eighth embodiment of the present invention.

28 is a diagram showing an IP address setting procedure according to the ninth embodiment of the present invention.

29 is a diagram showing an IP address setting procedure according to a tenth embodiment of the present invention.

30 is a diagram showing an IP address setting procedure according to another embodiment of the present invention.

The present invention relates to a handover method of a mobile communication system. In particular, the present invention relates to a mobile terminal composed of multimode (eg, a broadband wireless access network system and a wireless LAN, a wired LAN, and a cellular system interface). The present invention relates to a handover method of a mobile communication system that supports over.

IEEE802.21, which is undergoing international standardization of Media Independent Handover (MIH) between heterogeneous networks, provides seamless handover and service continuity between heterogeneous networks. Its purpose is to improve user convenience of mobile terminal devices. The basic requirements include the Media Independent Handover (MIH), Event Service, Command Service, and Information Service (IS). It is defined.

A mobile terminal is a multimode node that supports one or more interface types, and the supported interfaces include a wire-line interface such as 802.3 based Ethernet, IEEE802.XX (IEEE 802.11, Wireless interfaces based on IEEE802.15 and IEEE802.16, and interfaces defined by cellular standardization bodies such as 3GPP and 3GPP2.

1 is a diagram illustrating a protocol stack structure of a multi-mode mobile terminal.

As shown in FIG. 1, the MAC structure including IEEE802.11, IEEE802.16, and 3G interfaces and the MIH are located under the IP layer, and several mobility management protocols are included in the network layer in the mobile terminal. The mobile terminal selects the mobility management protocol existing in its network layer according to the type of mobility management protocol supported by the access point to which the access point is connected to establish an IP connection.

Hereinafter, the media independent handover (MIH) function, an event service, an event service, a command service, and an information service (IS) will be described.

1. MIH function

As shown in FIG. 1, a mobile terminal configured in a multi-mode has a physical layer and a medium access control layer in each mode, and a MIH layer is located below the IP layer.

The MIH, or Media Independent Handover, located below the IP layer must be defined between the 802 series interface or between the 802 series interface and the above-mentioned non-802 interface (3GPP, 3GPP2), and trigger event. Handover processing is facilitated using input values from Layer 2, such as trigger events and information about other networks.

In addition, the MIH may include user policy and configuration-based input values that may affect the handover process, and may include a Layer 3 entity such as Mobile IP or SIP. Generic interfaces are defined between and MIH functions. These interfaces provide information about the first layer (physical layer), the second layer (media access control layer), and mobility management. MIH obtains information about lower layers and networks with the help of events and information services. In the upper layer, the upper management object 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. In this case, the handover control function and the device manager may be independently located, respectively, the two functions may be included as a higher management object.

FIG. 2 is a diagram illustrating an MIH structure and a transmission protocol, and illustrates functional entities and transmission protocols of a terminal and a network including the MIH function. In FIG. 2, a dotted line means a primitive, an event trigger, or the like.

2. Event Trigger

For fast handover, the network layer needs to use the information from the link layer to reestablish the connection as soon as possible. The link layer event may help predict the user's movement, and may help the mobile terminal and the 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 of these triggers can be a local stack or a remote stack. 3 shows a structure for a trigger model.

Event triggers provide a state change for the current signal and other network states, and foreseeable changes in the future, and include changes in the physical layer and the media access control layer or changes in the properties of a particular network. When the events are divided into types, the PHY layer event, the MAC layer event, the management event, the L3 event, and the application event ).

Basic trigger events include Link_Up, Link_Down, Link_Going_Down, Link_Going_Up, Link_Event_Rollback, Link_Available, Link_Parameters_ Change, IP_Renewal_Indication, IP_Renewal_Request, and the like.

Table 1 shows the parameters of Link_Up.

Link up occurs when a layer 2 connection is established on a particular link interface and the upper layer is able to transmit layer 3 packets. At this time, it is determined that all two-layer configuration constituting the link is completed. The event source of Link Up is Local MAC and Remote MAC.

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 IP_Renewal_Indicator Indicates whether or not the IP temporary address needs to be changed 0: No change required 1: Change required

Table 2 shows the parameters of Link_Down.

Link Down occurs when a Layer 2 connection is broken on a particular interface and Layer 3 packets can no longer be sent. The source of the event of Link_Down is Local MAC.

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

Table 3 shows the parameters of Link_Going_Down.

Link Going Down occurs when a layer 2 connection is expected to be Link_Down within a certain time and may be a signal to initiate a handover procedure. The event source of Link_Going_Down is Local MAC and Remote MAC.

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

Table 4 shows the parameters of Link_Going_Up.

Link_Going_Up occurs when a two-layer connection is expected to be Link_Up within a certain time and is used when the network takes a long time to initialize. The event sources of Link_Going_Up are Local MAC and Remote MAC.

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

Table 5 shows the parameters of Link_Event_Rollback.

Link_Event_Rollback is used in combination with Link_Going_Up and Link_Going_Down. This trigger 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. The event sources of Link_Event_Rollback are Local MAC and Remote MAC.

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

Table 6 shows the parameters of Link_Available.

Link_Available indicates that a new specific link is available, indicating 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. The event source of Link_Available is Local MAC and Remote MAC.

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 IP_Renewal_Indicator Indicates whether or not the IP temporary address needs to be changed 0: No change required 1: Change required

Table 7 shows the parameters of Link_Parameters_Change.

Link_Parameters_Change occurs when a change in a link parameter's value exceeds a certain threshold. And link layer parameters such as link speed, quality of service (QoS), encryption value, and the like. The event sources for Link_Parameters_Change are Local MAC and Remote MAC.

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

Table 8 shows parameters of IP_Renewal_Indication.

The new access point (e.g., base station or AP) of the mobile station receives the Link_UP trigger, and then the IP address to which the IP packet is delivered to the mobile station. IP_Renewal_Indication is triggered to inform the mobile station of the change of the address (CoA) and the newly autoconfigured address in case of Mobile IPv6. The event source of IP_Renewal_Indication is Remote MAC, MIH.

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 MacMobileTerminal MAC Address MAC address of mobile terminal Network ID IP Address The network address that the mobile was connected to on the previous link

Table 9 shows the parameters of IP_Renewal_Request.

When the mobile station's MIH receives the IP_Renewal_Indication trigger indicating the address reset, it sends an IP_Renewal_Request to the network layer to request the IP temporary address to be reset. Event source of IP_Renewal_Request is Remote MAC, MIH.

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 was connected to on the previous link

4 illustrates an event trigger when a handover occurs, and shows a trigger generated until a new link is established due to a deterioration of a link to which a mobile station is connected.

3. Command Service

The command service plays a role in which an upper layer commands a lower layer. It contains commands from the upper layer to the MIH or from the MIH to the lower layer. These commands primarily convey the decisions of the upper layers to the lower layers and adjust the behavior of lower layer entities.

4. Information Service

The information service provides detailed information about the network necessary 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 cost of information elements such as link).

5 is a diagram illustrating a procedure of a multimode mobile terminal acquiring network related information through an information server.

As shown in FIG. 5, the multi-mode mobile terminal acquires various information related to a network through an information server, performs handover evaluation and link selection, and handovers. Proceed with the procedure.

That is, the mobile terminal acquires various information related to the network from the information server through the current access point by using an information request / response message and a query / response list of available networks message, and performs handover evaluation and link selection. . If a new link is selected, the mobile station obtains information about the new network through a new access point and a MIH Resource Query / Response message.

In the above, the MIH function, the event service, the command service, and the information service have been described, and the protocols for supporting the mobility of the terminal (Mobile IPv4, DHCPv4, Mobile IPv6, DHCPv6, etc.) will be described.

A. Mobile IPv4

6 is a diagram illustrating an operation procedure of Mobile IP v4.

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 function to support it. However, if the path optimization is not used, the change of the correspondent node communicating with the mobile station is not necessary. In this case, the mobile host represents an IP host that supports mobility, and the home agent is a router that maintains location information about the mobile host and performs tunneling for the visiting agent or mobile host, and the visiting agent supports mobility in the visiting network. Each router.

The operation procedure of Mobile IPv4 shown in FIG. 6 will be described sequentially.

When the mobile host moves from its home network to the foreign network (S10), the mobile host recognizes that the mobile host has moved by receiving an advertisement message broadcast from the visiting network and sends it to the home agent. Register a temporary address (CoA) indicating its current location (S20). At this time, CoA is the IP address (FA-CoA) of the visiting agent or the temporary address (Co) assigned by the mobile host through DHCP, etc. in the visiting network. -located CoA).

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. (S30) And the home agent intercepting the packet sets the destination address of the packet delivered to the mobile host as the address of the visited agent (FA) (if FA-CoA is used), after encapsula-tion send. (S40)

Thereafter, the encapsulated and transmitted packet is delivered to the visiting agent, which de-capsulates the delivered packet to restore the original packet, and finally delivers the packet to the mobile host. (S50)

Packets delivered by the mobile host to the counterpart host may be delivered directly through the visiting agent, or may be delivered using a reverse tunnel when there is a problem of ingress filtering.

The main functions required for Mobile IP include agent discovery, registration, routing, and so on.

Agent Discovery

Agent discovery is a method of determining whether a mobile terminal is currently connected to its home network or located in a visited network. In this way, the mobile terminal can detect 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. Agent Advertisement messages periodically broadcasted by an agent (home agent, visiting agent) are 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.

* Registration

The registration function provides a flexible mechanism to deliver 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 new network can receive the service provided by the home network. .

Mobile IP provides two different registration procedures (FA-CoA, Co-located CoA) to set up a temporary address when the mobile terminal moves to a different subnet.

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. In addition, when using FA-CoA, a temporary address (CoA) is provided by a Foreign Agent through an Agent Advertisement message, and the IP address of the external agent is used as the temporary address. In the case of using a co-located CoA, a mobile station is assigned a temporary address through a DHCP server located in a foreign network.

Routing

The Routing function defines a function necessary for properly routing datagrams for transmission (or reception) to and from a mobile terminal when the mobile terminal is connected to an external network. Datagrams include unicast as well as multicast and broadcast packets.

B. Dynamic Host Configuration Protocol (DHCPv4)

DHCP is a protocol that allows network administrators to centrally manage and assign IP addresses on networks within an organization. When computer users in an organization access the Internet, an IP address must be assigned to each computer. DHCP allows network administrators to centrally manage and assign IP addresses, and to automatically send new IP addresses when computers connect to other locations on the network.

DHCP uses the concept of "lease" to ensure that a given IP address is valid for that computer for only a certain amount of time. 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 the number of available IP addresses.

For DHCP to work properly, there must be at least one DHCP server and one DHCP client on the network. In addition to the range of TCP / IP addresses (for example, 203.224.29.10 to 203.224.29.100), there must be a gateway address and subnet mask.

The DHCP client gets its TCP / IP address information from a DHCP server during startup. This address is not permanent, and the DHCP server provides clients with an address lease that can expire regularly and must be renewed.

The DHCP client obtains and maintains the address lease through several handshake phases called states. Client DHCP statuses include INIT, SELECTING, REQUESTING, BOUND, RENEWING, and REBINDING.

7 shows the format of a DHCP message. 8 is a flowchart illustrating a DHCP client-server model in which a DHCP client is automatically assigned an IP address from a DHCP server.

Table 10 shows the types and uses of DHCP messages shown in FIG.

Message Use DHCPDISCOVER Message broadcast by the client to locate available servers DHCPOFFER A message sent by the server to the client in response to DHCPDISCOVER, which contains a number of parameters. DHCPREQUEST (a) to request parameters provided from one server, or to unconditionally reject all server suggestions, (b) to verify the accuracy of previously assigned addresses for reasons such as system reboots, and (C) A message sent by a client to a server for the purposes of (a), (b) and (c) to extend the lease. DHCPACK The message sent by the server to the client with the parameters, including the associated network address. DHCPNAK Message sent by the server to the client to inform the client that the network address is incorrect or to notify the client that its lease has expired. DHCPDECLINE A message sent by the client to the server to indicate that a network address is already in use. DHCPRELEASE Message sent by the client to the server to cancel the remaining lease and transfer the network address. DHCPINFORM A message sent by the client to the server to request only some configuration parameters. The client already has an externally configured network address.

Referring to FIG. 8 and Table 10, a procedure for a DHCP client is automatically assigned an IP address from a DHCP server as follows.

First, the client broadcasts a DHCPDISCOVER message (S110). Each server receiving the DHCPDISCOVER message responds with a DHCPOFFER message (S120).

The client that broadcasts the DHCPDISCOVER message then receives a DHCPOFFER message from one or more servers, and selects one of them to request configuration parameters.

Thereafter, the client broadcasts DHCPREQUEST (S130). At this time, the servers not selected in the DHCPREQUEST message are accepted as rejected by the client. The server selected in the DHCPREQUEST message responds by putting the address configuration information of the requested client on the DHCPACK (S140).

When receiving a DHCPACK message from the selected server, the client configures the address (S150). However, if the DHCPNAK message is received, the above process is restarted.

The client may send a DHCPRELEASE to the server to return the leased address (S160).

C. Mobile IPv6

9 is a diagram illustrating an operation procedure of Mobile IP v6.

Mobile IPv6 supports mobility more effectively than mobile IPv4 and has superior scalability. Referring to Figure 9, the basic elements for the operation of Mobile IPv6 and the function of each element will be described.

In Fig. 9, 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. In addition, the home agent (HA) is a router that sends the datagram to the current position of the mobile node in the external network because of the registration information of the mobile node among the routers in the home network, the temporary address (CoA) is the mobile node When moving to the network, this means the IP address connected to the mobile node.

Binding means that the CoA registered with the home agent matches the home address of the node, and the BU (Binding Update) indicates that the mobile node provides the home agent (HA) and the corresponding nodes (CNs). This message is used to announce its own CoA.

BACK (Binding Acknowledge) is a response message to the BU, Binding Request (BR) is a message for requesting the BU when the corresponding node does not receive the BU before the timer of the binding information of the mobile node expires.

Acquiring CoA means that the mobile node configures its own location information automatically when using the Neighbor Discovery function and the Address auto-configuration function. ) Refers to a procedure that allows the correspondent node to communicate directly with the mobile node without passing through the home agent after storing the binding information. The address auto-configuration 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.

In the stateful address auto-configuration method, when a host requests an address from a DHCP server, one of the addresses allocated by the server is allocated to the host. The stateless address autoconfiguration method generates an address by combining its interface ID information with prefix information or well-known prefix information obtained from a router.

Referring to the operation procedure of Mobile IPv6 shown in Figure 9 in order as follows.

When the location of the mobile node (MN) is moved from subnet A to B (S200), the mobile node (MN) detects its movement using the prefix information of the RA message and the neighbor unreachable detection (NUD) mechanism. S210)

The mobile node MN acquires a temporary address CoA according to the address auto-configuration method (S220). Then, the mobile node MN transmits a BU message to inform the home agent of the obtained temporary address (CoA). )

Upon receiving the BU message, the HA binds the home address and temporary address CoA of the mobile node MN, and transmits a BAck in response to the BU message (S240).

Since the corresponding node CN communicating with the mobile node MN for the first time does not detect the movement of the mobile node MN, the destination node is set as the home address of the mobile node MN and transmits a packet. S250)

Then, the home agent HA managing the mobile node MN intercepts the packet of the corresponding node and tunnels to the current location of the mobile node MN. (S260)

Receiving the tunneled packet, the mobile node MN determines that the corresponding node CN having transmitted the packet does not have binding information, and sends a BU message to the corresponding node CN to send its own temporary address CoA. (S270)

After receiving the temporary address CoA of the mobile node MN, the corresponding node CN stores the binding information and directly communicates with the mobile node MN using the information (S280).

B. Dynamic Host Configuration Protocol (DHCPv6)

10 is a diagram illustrating an operation procedure of DHCP v6.

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

DHCPv6 uses two types of multicast addresses: All_DHCP_Relay_Agents_ and_Servers and All_DHCP_Servers.

* All_DHCP_Relay_Agents_and_Servers

If the link-local address of the agent is not known, it is a link-local multicast address that clients use to communicate with agents on the link, and all servers and agents are members of this multicast group.

* All_DHCP_Servers

Site-local multicast address used by a client or relay to communicate with servers when the client or relay does not send a message to all servers or 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. All servers in the site are members of this multicast group.

SOLICIT, ADVERTISE, REQUEST, REPLY, RENEW, and RELEASE are the messages used in the basic operation of DHCPv6.

The SOLICIT is a message used by the client to know the location of the server, and is multitasked using the All_DHCP_Server address. The ADVERTISE is a response message to the SOLICIT message, which a possible DHCP server responds to.

The REQUEST is a message used by the client to obtain a configuration parameter including an IP address from a selected server, and is multitasked using the All_DHCP_Relay_Agents address.

And the REPLY is a response message for the REQEST, RENEW, and RELEASE messages, wherein the RENEW is a message for acquiring the lifetime of the client address and configuration parameters to which the client was originally assigned, and the RELEASE is one or more IP addresses for the client to the server. This message is used to return them.

Referring to the operation of the DHCP v6 shown in Figure 10 in sequence as follows.

First, the client sends a SOLICIT message to the All_DHCP_Server address in order to know the location of the server.

Thereafter, the client selects one of the DHCPv6 servers and requests additional configuration parameters by sending a REQUEST message to the selected server (S330). The selected DHCPv6 server then responds to the REQUEST with a REPLY message. (S340)

The client receiving the REPLY can update the existing configuration parameters, update the lifetime of the assigned address by sending a RENEW message to the DHCPv6 server, and T1 (the server that has acquired the existing address to extend the life of the current address). Time to contact) Starts the timer (S350).

The DHCPv6 server sends a REPLY message in response to the RENEW. In operation S370, the client releases the address by sending a RELEASE message when the allocated address is no longer used.

FIG. 11 is a diagram illustrating an IP address setting procedure according to the prior art, and illustrates a procedure in which a mobility management protocol of a new network is different from a mobility management protocol of a previous network when a multi-mode mobile terminal is handed over.

In FIG. 11, the old network supports the mobility management protocol of Mobile IPv4, the new network supports the mobility management protocol of Mobile IPv6, and the multimode mobile terminal supports the mobility management protocol of Mobile IPv4 and Mobile IPv6 in the stack. Assume that it is mounted.

When the handover occurs, the mobile station receives the IP_Renewal_Indication trigger and then performs the temporary address resetting procedure. That is, the mobile terminal that used Mobile IPv4 as the mobility management protocol in the previous network broadcasts an Agent Solicitation message to obtain a new temporary address. However, since the current handed over network (new network) supports mobility to IPv6 based Mobile IPv6, the Agent Solicitation message is discarded.

The mobile station, which has not received the agent advertisement message until the life cycle of the agent solicitation message is completed, retries the transmission of the agent solicitation several times and then operates as Mobile IPv4 in the new network. If it is impossible to do so, the temporary address setting procedure is performed with a Mobile IPv6 message.

As described above, a problem of the prior art is that when the multi-mode mobile terminal hands over to a new interface network, when the mobility management protocol used in the previous network is different from the mobility management protocol supported in the new network, the mobile terminal Recognizing that this new network can no longer work with the existing mobility management protocol, it takes a very long time to set a temporary address with the new mobility management protocol. That is, it is determined that the mobile terminal cannot operate with the mobility management protocol of the previous network in the new network, and the delay time until setting the temporary address with the new mobility management protocol becomes long.

This causes a problem of packet loss and delay of service time to the mobile station which transmits / receives real-time traffic and hands over.

The present invention is to solve the problems described above, the object is,

When a handover occurs, the present invention provides a handover method of a mobile communication system that provides information on a mobility management protocol supported by a new network to an mobile terminal through an event service and an information service.

In order to achieve the above object, the mobile communication system according to the present invention

An information server for providing mobility management protocol information supported by a new network through a predetermined event service; With reference to the information, the mobile terminal is configured to set a new temporary address and perform a handover procedure.

In the present invention, the existing event 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.

FIG. 12 illustrates a structure of a local event and a MIH event model according to the present invention, in which a MIH event is an event delivered from a MIH to a higher management entity or a higher layer. do. The link event is an event delivered from the lower layer (MAC or physical layer) to the MIH and primitives used in each interface MAC layer or physical layer are used.

FIG. 13 shows the structure of the Remote Link Event model in the present invention. When an event is generated from the lower layer in the local stack to the MIH in the same local stack, the MIH is connected to the remote stack. Deliver to MIH.

FIG. 14 shows a structure for 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 partner MIH passes this to its parent management entity or higher layer in its stack.

Fig. 15 shows the structure of the MIH command and link command model in the present invention. The MIH command is generated from a higher management entity or higher layer and is transmitted to the MIH, instructing the MIH of an action. The link command is generated from the MIH and transmitted to the lower layer, which instructs the lower layer to perform some action.

16 illustrates a structure of a remote MIH command model in 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, which is then transmitted to the corresponding MIH in the remote stack. To pass.

Fig. 17 shows the structure of the Remote Link Command model in the present invention, in which the MIH in the local stack generates a Remote Link Command and delivers it to the counterpart MIH in the remote stack. The relative MIH forwards this to the lower layer in the remote stack.

Preferably, the event service is a Link_Available event service.

Preferably, the event service is a Link_Up event service.

Preferably, the event service is characterized in that the IP_Renewal_Indication link event.

Preferably, the event service is characterized in that it includes a separate parameter indicating information about the type of mobility management protocol.

In order to achieve the above object, the mobile communication system according to the present invention

An information server for providing mobility management protocol information supported by the new network through a predetermined message of the information service; With reference to the information, the mobile terminal is configured to set a new temporary address and perform a handover procedure.

Preferably, the predetermined message of the information service is a signal message between the MIH layer of the mobile terminal and the MIH layer of the current access point.

Preferably, the predetermined message of the information service is characterized in that it includes a separate parameter indicating information on the type of mobility management protocol.

In order to achieve the above object, the handover method of the mobile communication system according to the present invention

When the mobile terminal hands over to a different type of network, providing the mobile terminal with mobility management protocol information supported by the new network through a predetermined event service; With reference to the information, the process of setting a new temporary address of the mobile terminal and performing a handover procedure.

In order to achieve the above object, the handover method of the mobile communication system according to the present invention

When the mobile terminal hands over to another type of network, providing the mobile terminal with mobility management protocol information supported by the new network through a predetermined message of an information service; With reference to the information, the process of setting a new temporary address of the mobile terminal and performing a handover procedure.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

Two methods can be considered in order to provide mobility management protocol information supported in a new network to a mobile station through an event service and an information service. That is, there are a method of providing mobility management protocol information supported by a new network to a mobile terminal through an event service, and a method of providing corresponding information to a mobile terminal through an information service.

Embodiments 1, 2, 3, 6, 7, and 8 of the present invention to be described below relate to a method for providing mobility management protocol information to a mobile terminal through an event service.

18 is a diagram illustrating a protocol stack structure according to the present invention, in which an IEEE802.16 network (new network) supports a mobility management protocol MIPv6 in an IEEE 802.11 network (previous network) supporting a mobility management protocol Mobile IPv4. In case of handover, the protocol stack structure shows a method of delivering information on mobility management protocol supported by the new network (IEEE802.16 network) using the event service proposed by the present invention.

When a handover occurs, the MAC layer of the mobile station includes the mobility management protocol type information supported by the new network in the MIH event such as Link_Availble or Link_Up and sends it to the MIH, and the MIH sends the Link_Up to the mobility management protocol (MIPv6). .

The method of providing mobility management protocol information to the mobile terminal through the event service adds a new parameter to Link_Up or Link_Available or IP_Renewal_ Indication to provide the mobile terminal with information about the mobility management protocol supported in the new network. The mobile terminal knows the mobility management protocol supported by the new network through the newly added parameter. Once the parameter contains information about the mobility management protocols currently in use, it may also add information about new mobility management protocols in the future.

The newly added parameter, that is, the mobility management protocol support type bitmap indicates types of mobility management protocols that can be supported in the new network, and a bit set to 1 indicates that the mobility management protocol can be provided in the network. Indicates.

FIG. 19 is a diagram illustrating an IP address setting procedure according to a first embodiment of the present invention, and illustrates a procedure in which a mobile terminal receives mobility management protocol information for a new network through Link_Available.

19 illustrates a Mobility Management Protocol proposed by the present invention when a mobile terminal equipped with Mobile IPv4 and Mobile IPv6 as a mobility management protocol connects to a network supporting Mobile IPv4 and hands over to a new network supporting Mobile IPv6. According to an embodiment of the present invention, a type of a mobility management protocol supported by a new network is provided to a mobile terminal before the mobile terminal performs a new link and connection establishment by including the support type bitmap in the Link_Available.

The new MAC (Media Access Control) layer of the multi-mode mobile terminal acquires mobility management protocol information (Mobile IPv6 in this embodiment) for the new access point through scanning and other messages, and then includes this information in the Link_Available event. Send to MIH layer. At this time, the MIH temporarily maintains the mobility management protocol information for the access point, and when receiving the Link_Up event indicating that the link and connection establishment is completed, the MIH refers to the retained information and then the mobile management protocol (Mobile IPv6). Send Link_Up MIH event to. Thereafter, the network layer of the mobile station executes an IPv6 temporary address setting procedure to obtain a new temporary address and registers the new temporary address with the home agent.

Table 11 is an example of a Link_Available parameter including a Mobility Management Protocol Support Type bitmap.

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 IP_Renewal_Indicator Indicates whether or not the IP temporary address needs to be changed 0: No change required 1: Change required Mobility Management Protocol Support Type bitmap 0: Mobile IPv4 with FA (FA-CoA) 1: Mobile IPv4 without FA (Co-located CoA) 2: Mobile IPv6 3: Mobile IPv6 with DHCPv6 4: SIP

20 is a diagram illustrating an IP address setting procedure according to a second embodiment of the present invention, and illustrates a procedure in which a mobile terminal receives mobility management protocol information for a new network through Link_Up.

FIG. 20 illustrates a Mobility Management Protocol proposed by the present invention when a mobile terminal equipped with Mobile IPv4 and Mobile IPv6 as a mobility management protocol is connected to a network supporting Mobile IPv4 and handovers to a new network supporting Mobile IPv6. According to an embodiment of the present invention, a type of mobility management protocol supported by a new network is provided to a mobile terminal before the network layer handover procedure is executed by including the support type bitmap in the Link_Up.

The new MAC layer of the multi-mode mobile station performs a new link and connection establishment procedure through a link establishment request / response message to obtain information on the mobility management protocol (MIPv6) supported by the new access point.

After the new link and connection establishment is completed, the Link_Up MIH event including the mobility management protocol information is transmitted to the MIH, and the MIH is referred to the Mobility Management Protocol Support Type bitmap of the trigger Link_Up to the corresponding mobility management protocol (MIPv6). Deliver the corresponding event service.

Table 12 is an example of a Link_Up parameter including a Mobility Management Protocol Support Type bitmap.

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 IP_Renewal_Indicator Indicates whether or not the IP temporary address needs to be changed 0: No change required 1: Change required Mobility Management Protocol Support Type Bitmap 0: Mobile IPv4 with FA (FA-CoA) 1: Mobile IPv4 without FA (Co-located CoA) 2: Mobile IPv6 3: Mobile IPv6 with DHCPv6 4: SIP

FIG. 21 is a diagram illustrating an IP address setting procedure according to a third embodiment of the present invention, and illustrates a procedure in which a mobile station receives mobility management protocol information for a new network through IP_Renewal_Indication. FIG. 21 illustrates a Mobility Management Protocol proposed by the present invention when a mobile terminal equipped with Mobile IPv4 and Mobile IPv6 as a mobility management protocol connects to a network supporting Mobile IPv4 and hands over to a new network supporting Mobile IPv6. According to an embodiment of the present invention, a type of mobility management protocol supported in a new network is provided to a mobile terminal before the network layer handover procedure is executed by including the support type bitmap in IP_Renewal_Indication.

After receiving the Remote Link_Up MIH event from the mobile terminal, the new access point of the mobile station transmits an IP_Renewal_Indication Link event including mobility management protocol information provided from its own network to the mobile terminal's MIH. The MIH of the mobile station refers to the Mobility Management Protocol Support Type bitmap of the IP_Renewal_Indication Link event and transmits an IP_Renewal_Request to the mobility management protocol (MIPv6).

In this embodiment, the IP_Renewal_ Indication trigger is generated after the link setup between the mobile station and the new access point is completed. Once the information has been obtained, the previous access point can provide this information even before the mobile terminal establishes a link with the new access point.

Table 13 shows an example of an IP_Renewal_Indication parameter that includes a mobility management protocol support type bitmap.

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 MacMobileTerminal MAC Address MAC address of mobile terminal Network ID IP Address The network address that the mobile was connected to on the previous link Mobility Management Protocol Support Type bitmap 0: Mobile IPv4 with FA (FA-CoA) 1: Mobile IPv4 without FA (Co-located CoA) 2: Mobile IPv6 3: Mobile IPv6 with DHCPv6 4: SIP

Hereinafter, the fourth and fifth embodiments of the present invention will be described with reference to a method for providing mobility management protocol information to a mobile terminal through an information service.

FIG. 22 is a diagram illustrating an IP address setting procedure according to a fourth embodiment of the present invention, and illustrates a procedure in which a mobile terminal receives mobility management protocol information for a new network through an information service.

As shown in FIG. 22, the method according to the fourth embodiment of the present invention includes the Mobility Management Protocol Support Type bitmap in a Query (Response) List of Available Networks message which is a signaling message between the MIH of the mobile terminal and the MIH of the current access point. By including parameters similar to, it provides the mobile station with the mobility management protocol information supported by the network.

FIG. 23 is a diagram illustrating an IP address setting procedure according to a fifth embodiment of the present invention, and illustrates a procedure in which a mobile terminal receives mobility management protocol information for a new network through an information service.

As shown in FIG. 23, the method according to the fifth embodiment of the present invention provides the Mobility Management Protocol Support in a Query More (Response) Info on 802.y Networks message which is a signaling message between the MIH of the mobile terminal and the MIH of the current access point. By including parameters similar to the Type bitmap, it provides the mobile station with the mobility management protocol information supported by the network.

24 illustrates a protocol stack structure including a higher management entity according to the present invention, in which a multimode mobile terminal supports the mobility management protocol MIPv6 in an IEEE 802.11 network (previous network) supporting the mobility management protocol Mobile IPv4. When handing over to a network (new network), a protocol stack structure shows a method of delivering information on mobility management protocol supported by the new network (IEEE802.16 network) using the event service proposed by the present invention.

When a handover occurs, the MAC layer of the mobile terminal sends an event such as Link_Availble or Link_Up to the upper management object by including the mobility management protocol type information supported by the new network, and the upper management object sends the link_Up to the mobility management protocol (MIPv6) Send it.

The method of providing mobility management protocol information to the mobile terminal through the event service adds a new parameter to Link_Up or Link_Available or IP_Renewal_Indication to provide the mobile terminal with information about the mobility management protocol supported in the new network. The mobile terminal knows the mobility management protocol supported by the new network through the newly added parameter. Once the parameter contains information about the mobility management protocols currently in use, it may also add information about new mobility management protocols in the future.

The newly added parameter, that is, the mobility management protocol support type bitmap indicates types of mobility management protocols that can be supported in the new network, and a bit set to 1 indicates that the mobility management protocol can be provided in the network. Indicates.

FIG. 25 is a diagram illustrating an IP address setting procedure according to a sixth embodiment, wherein a mobile terminal equipped with Mobile IPv4 and Mobile IPv6 as a mobility management protocol is connected to a network supporting Mobile IPv4 and supports a new mobile IPv6. When handing over to a network, the Mobility Management Protocol Support Type bitmap proposed in the present invention is included in the Link_Available MIH event to move the type of mobility management protocol supported by the new network before the mobile station executes the new link and connection setup. An embodiment showing a case of providing to a terminal. In this example, the upper management entity includes a higher layer (L3 or higher), a device manager and a handover control function.

A new MAC (Media Access Control) layer of a multimode mobile terminal acquires mobility management protocol information (Mobile IPv6 in this embodiment) for a new access point through scanning and other messages, and then includes this information in a Link_Available MIH event. It delivers to upper management object through MIH. At this time, the higher management object transmits mobility management protocol information on the access point to the upper layer so that the mobility management protocol (Mobile IPv6) is Link_Up. Thereafter, the network layer of the mobile station executes an IPv6 temporary address setting procedure to obtain a new temporary address and registers the new temporary address with the home agent.

FIG. 26 is a diagram illustrating a procedure for setting an IP address through a higher management entity according to a seventh embodiment of the present invention, and illustrates a procedure in which a mobile terminal receives mobility management protocol information for a new network through Link_Up.

FIG. 26 illustrates a Mobility Management Protocol proposed by the present invention when a mobile terminal equipped with Mobile IPv4 and Mobile IPv6 as a mobility management protocol connects to a network supporting Mobile IPv4 and hands over to a new network supporting Mobile IPv6. According to an embodiment of the present invention, a type of mobility management protocol supported by a new network is provided to a mobile terminal before the network layer handover procedure is executed by including the support type bitmap in the Link_Up. In this example, the upper management entity includes a higher layer (L3 or higher), a device manager and a handover control function.

The new MAC layer of the multi-mode mobile station performs a new link and connection establishment procedure through a link establishment request / response message to obtain information on the mobility management protocol (MIPv6) supported by the new access point.

Thereafter, when a new link and connection establishment are completed, the Link_Up MIH event including mobility management protocol information is transmitted to the parent management object, and the parent management object refers to the mobility management protocol (MIPv6) by referring to the Mobility Management Protocol Support Type bitmap of Link_Up event. To the event service.

FIG. 27 is a diagram illustrating a procedure for setting an IP address through a higher management entity according to an eighth embodiment of the present invention, and illustrates a procedure in which a mobile terminal receives mobility management protocol information for a new network through IP_Renewal_Indication, which is a link event.

FIG. 27 illustrates a Mobility Management Protocol proposed by the present invention when a mobile terminal equipped with Mobile IPv4 and Mobile IPv6 as a mobility management protocol connects to a network supporting Mobile IPv4 and hands over to a new network supporting Mobile IPv6. According to an embodiment of the present invention, a type of mobility management protocol supported in a new network is provided to a mobile terminal before the network layer handover procedure is executed by including the support type bitmap in the IP_Renewal_Indication link event. In this example, the upper management entity includes a higher layer (L3 or higher), a device manager and a handover control function.

The new access point of the mobile station receives the Remote Link_Up MIH event from the mobile station, and then sends an IP_Renewal_Indication Link event including mobility management protocol information provided from its own network to the higher management entity. The higher management object sends the IP_Renewal_Request to the mobility management protocol (MIPv6) by referring to the Mobility Management Protocol Support Type bitmap of the IP_Renewal_Indication Link event. In this embodiment, the IP_Renewal_ Indication trigger is generated after the link setup between the mobile station and the new access point is completed. However, this trigger is actually performed by the MIH signaling message for the previous access point to the new access point. Once the information has been obtained, the previous access point can provide this information even before the mobile terminal establishes a link with the new access point.

FIG. 28 is a diagram illustrating a procedure for setting an IP address through a higher management entity according to a ninth embodiment of the present invention, and illustrates a procedure in which a mobile terminal receives mobility management protocol information for a new network through an information service.

As shown in FIG. 28, a parameter similar to the Mobility Management Protocol Support Type bitmap is included in the Query (Response) List of Available Networks message, which is a signaling message between the MIH of the mobile terminal and the MIH of the current access point, and transmitted to the upper management entity. By providing the upper management entity with mobility management protocol information supported by the network.

FIG. 29 is a diagram illustrating a procedure for setting an IP address through a higher management entity according to a tenth embodiment of the present invention, and illustrates a procedure in which a mobile terminal receives mobility management protocol information for a new network through an information service.

As shown in FIG. 29, the upper management is performed by including a parameter similar to the Mobility Management Protocol Support Type bitmap in the Query More (Response) Info on 802.y Networks message, which is a signaling message between the MIH of the mobile terminal and the MIH of the current access point. By transmitting to the entity, the upper management entity provides the mobility management protocol information supported by the network.

FIG. 30 is another embodiment of the present invention, similarly to the example of FIG. 27, provided with an IP_Renewal_Indication trigger including Mobility Management Protocol Type information, but an IP_Renewal_Indication trigger occurs after the mobile terminal transmits a remote Link_Going_Down trigger to a previous access point. This is the case. After the previous access point receives the remote Link_Going_Down trigger from the mobile station, the IP-related information about the new access point can be obtained by the MIH signaling message, and then included in the IP_Renewal_Indication trigger and provided to the mobile station.

Although the present invention has been described with reference to mobile IPv4 and Mobile IPv6 as an example of a mobility management protocol, this is merely an example, and those skilled in the art may have various modifications and equivalent embodiments therefrom. I understand that it is possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

As described above, the present invention provides information on mobility management protocols supported by a new network through an event service or an information service when a multi-mode mobile terminal having multiple mobility management protocols is handed over to a new interface network. Provided to mobile terminal in advance.

Accordingly, the present invention recognizes that a mobile terminal can no longer operate with an existing mobility management protocol in a new network, and greatly reduces the delay time incurred in setting a temporary address with a new mobility management protocol. A new temporary address can be set up quickly without packet loss or time delay.

Claims (16)

An information server for providing mobility management protocol information supported by the new network through a predetermined event trigger; A mobile communication system comprising a mobile terminal for setting a new temporary address and performing a handover procedure with reference to the information. The method of claim 1, wherein the event trigger is Mobile communication system, characterized in that the Link_Available trigger. The method of claim 1, wherein the event trigger is A mobile communication system, characterized in that the Link_Up trigger. The method of claim 1, wherein the event trigger is Mobile communication system, characterized in that the IP_Renewal_Indication trigger. The method of claim 1, wherein the event trigger is And a separate parameter representing information on the type of mobility management protocol. An information server for providing mobility management protocol information supported by the new network through a predetermined message of the information service; A mobile communication system comprising a mobile terminal for setting a new temporary address and performing a handover procedure with reference to the information. The method of claim 6, wherein the predetermined message of the information service is A mobile communication system, characterized in that the signaling message between the MIH layer of the mobile terminal and the MIH layer of the current access point. The method of claim 6, wherein the predetermined message of the information service is And a separate parameter representing information on the type of mobility management protocol. In a mobile communication system for handing over a mobile terminal to another type of network, Providing mobility management protocol information supported by a new network to the mobile terminal through a predetermined event trigger; The method for handover of a mobile communication system, comprising: setting a new temporary address of the mobile terminal and performing a handover procedure with reference to the information. The method of claim 9, wherein the event trigger is Handover method of a mobile communication system, characterized in that the Link_Available trigger. The method of claim 9, wherein the event trigger is Handover method of a mobile communication system, characterized in that the Link_Up trigger. The method of claim 9, wherein the event trigger is Handover method of a mobile communication system, characterized in that the IP_Renewal_Indication trigger. The method of claim 9, wherein the event trigger is Handover method of a mobile communication system, characterized in that it comprises a separate parameter indicating information about the type of mobility management protocol. In a mobile communication system for handing over a mobile terminal to another type of network, Providing mobility management protocol information supported by a new network to the mobile terminal through a predetermined message of an information service; A handover method of a mobile communication system, comprising: setting a new temporary address of the mobile station and performing a handover procedure with reference to the information. The method of claim 14, wherein the predetermined message of the information service is A handover method of a mobile communication system, characterized in that the signaling message between the MIH layer of the mobile terminal and the MIH layer of the current access point. The method of claim 14, wherein the predetermined message of the information service is Handover method of a mobile communication system, characterized in that it comprises a separate parameter indicating information about the type of mobility management protocol.

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