KR100703809B1 - Mobile communication method of mobile node with multiple interfaces - Google Patents

Abstract

A mobile communication method of a mobile node having multiple interfaces is provided. In the mobile communication method of a mobile node having multiple interfaces, when a predetermined interface among the multiple interfaces of the mobile node returns to the home network, the mobile node examines whether there is a CoA of another interface registered with the home agent and the home agent. If a CoA of another registered interface exists, sending a registration request message to the home agent; and if the CoA selected to send the intercepted packet to the mobile node is a CoA that exists in the home network, the home agent sends the packet. Transmitting to the mobile node via the link layer address.

Mobile IP (MIP), HA, FN, Home Agent

Description

Method for mobile communication of mobile node with multi-interface}

1 illustrates a conventional mobile communication method of a mobile node having multiple interfaces.

2 illustrates a binding table of a home agent when some of the conventional multiple interfaces return to the home network.

3 is a flowchart illustrating an operation of a mobile node when a predetermined interface among multiple interfaces returns to a home network according to an embodiment of the present invention.

4 illustrates a binding table of a home agent according to an embodiment of the present invention.

5 is a flowchart illustrating an operation of a home agent according to an embodiment of the present invention.

6 illustrates a link layer address option format according to an embodiment of the present invention.

<Explanation of symbols on main parts of the drawings>

102: home address field

104: CoA field

106: Lifetime field

108: Binding ID field

The present invention relates to a mobile communication method of a mobile node having multiple interfaces. More particularly, the present invention relates to a mobile communication method of a mobile node having multiple interfaces so that all the interfaces can be used even when some of the multiple interfaces return to the home network. It is about.

Recently, a mobile node having multiple interfaces to support various networks has been developed in a situation where a user needs to use multiple networks simultaneously, and a service providing method through multiple interfaces has been proposed.

In particular, Mobile IP, a technology that maintains the sustainability of mobile communication while using the IP address in use when the user moves to another network, satisfies the requirements such as overcoming the limitations of the place, scalability and compatibility. .

Mobile IP has two address systems: Home Address (HoA) and Care of Address (COA). The home address is an address that does not change to satisfy that the session once established must maintain the same IP address for that set time, and the COA moves to a temporary address obtained by automatic addressing when the mobile node moves to an external network. It has prefix information of the network where the node is currently located. In addition, a home agent (HA) has a registration information of a mobile node among routers in a home network, and thus can transmit a packet to a current location of a mobile node in an external network.

1 illustrates a conventional mobile communication method of a mobile node having multiple interfaces.

As shown in FIG. 1 (a), when a mobile node having multiple interfaces is connected to an external network in a communication channel of a wireless network interface, each interface is assigned a different CoA (ie, CoA1, CoA2, CoA3). .

In addition, a single home address may be used to bind a plurality of CoAs, which may be useful when some of the multiple interfaces return to the home network.

In this case, when using mobile IP in a mobile node using multiple interfaces, additional information and functions are required, unlike when using one interface. That is, when registering CoAs assigned by multiple interfaces to one home agent, an identifier for distinguishing each interface may be formatted. To this end, the home agent can distinguish a plurality of allocated CoAs mapped to one home address (HoA) through a binding ID, which is illustrated in FIG. 1B below.

As shown in FIG. 1B, the binding table of the home agent includes a home address field 102, a CoA field 104, a lifetime field 106, and a binding ID field 108.

If it is determined that the mobile node's interface is in a foreign network, the home agent registers the CoA assigned to each interface in the CoA field 104. At this time, the binding ID for identifying each interface is registered together in the binding ID field 108. Accordingly, the home agent may identify each interface through the home address registered in the home address field 102 and the binding ID registered in the binding ID field 108.

For example, if three CoAs (ie, CoA1, CoA2, CoA3) are allocated to one home address of a: b: c: d, they may be registered with a home agent by distinguishing them by binding IDs.

The lifetime field 106 is invalidated unless the node shifted to the registration maintenance time matches the CoA registered with the home agent and the node's home address in the lifetime. That is, when the lifetime ends, the connection with the existing mobile node is terminated by deleting the registration information and deleting the routing information and the tunnel.

After registration, the home agent intercepts the packet transmitted to the home address, selects one CoA among CoA1, CoA2, and CoA3, and transmits the packet to the mobile node through tunneling.

2 illustrates a binding table of a home agent when some of the conventional multiple interfaces return to the home network.

In FIG. 1 (a), for example, when a mobile node moves and an interface whose assigned CoA is CoA3 moves to the home network, the mobile node informs the home agent that no further tunneling is required. This is mainly done through deregistration. In case of using multiple interfaces, one of two methods may be selected. Hereinafter, the method will be described in detail with reference to FIGS. 2A and 2B.

At this time, depending on whether the interface returned to the home network is the primary interface, the method of processing the non-registration of the interface returned to the home network is different.

As shown in FIG. 2 (a), when the interface returned to the home network is the primary interface, the first method processes CoA of all binding IDs of the corresponding home address.

That is, for example, when an interface having an assigned CoA of CoA3 returns to the home network, a method of transmitting a deregistration request message except for a binding sub option may be used during the deregistration process. Can be. The binding sub option includes a binding ID proposed as an identifier for registering a plurality of CoAs in one home agent, and the home agent can distinguish a plurality of CoAs mapped to one home address through the binding sub option.

When performing the non-registration by transmitting the non-registration request message except the binding suboption, the home agent removes all CoAs corresponding to the home address, and the home agent proxy ARP (proxy address resolution protocol) for intercepting packets. ) Or proxy neighbor discovery function no longer performed.

As shown in FIG. 2 (b), when the interface returned to the home network is not the primary interface, only the CoA of the binding ID of the corresponding interface is deregistered.

That is, for example, when the interface in which the assigned CoA is CoA3 returns to the home network, a method of binding and transmitting a binding sub-option to a non-registration request message may be used during the non-registration process.

When the non-registration is performed by binding the binding suboption to the non-registration request message, the home agent deletes only CoA, that is, CoA3 of the corresponding binding ID, from the binding table. Therefore, when the home agent intercepts a packet received at the home address and tries to tunnel to the mobile node, the home agent selects one of the registered CoA1 and CoA2, so the interface in the real home network (the interface assigned to CoA3) is selected. Cannot communicate with the home address.

As described above, when the primary interface is selected from among the multiple interfaces and the primary interface returns to the home network, the first method (FIG. 2 (a)) is performed. When an interface other than the primary interface returns to the home network, The second method (Fig. 2 (b)) is used.

Please refer to 'RFC3344' and 'draft-wakikawa-mobileip-multiplecoa-04' for related documents.

However, according to the conventional method described above, when some of the multiple interfaces return to the home network, the non-registration method is always used so that other interfaces except for the interface or the interface returned to the home network cannot be used and thus do not fully utilize the interface. There is a problem of inefficiency.

Therefore, there is a need to increase efficiency by making all interfaces available even when some of the multiple interfaces return to the home network.

It is an object of the present invention to provide a mobile communication method of a mobile node having multiple interfaces.

The objects of the present invention are not limited to the above-mentioned objects, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, in the mobile communication method of a mobile node having multiple interfaces according to an embodiment of the present invention, when a predetermined interface among the multiple interfaces of the mobile node returns to the home network, the mobile node is registered with the home agent. Investigating whether a CoA of another interface exists, sending a registration request message to the home agent if there is a CoA of another interface registered to the home agent, and selecting to send a packet intercepted by the home agent to the mobile node. If the CoA is a CoA present in the home network, the home agent includes sending a packet to the mobile node via a link layer address.

Specific details of other embodiments are included in the detailed description and the drawings.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a flowchart illustrating an operation of a mobile node when a predetermined interface among multiple interfaces returns to a home network according to an embodiment of the present invention.

When a predetermined interface among the multiple interfaces of the mobile node returns to the home network in the communication channel of the wireless network interface, the mobile node checks whether CoA of another active interface registered in the home agent exists (S301, S311). ).

If there is no CoA of another active interface registered in the home agent, the deregistration request message is set by setting livetime to zero as in the case of a single interface. Transfer to the home agent (S321).

On the other hand, if there is a CoA of another active interface registered in the home agent, a registration request message is transmitted to the home agent (S331).

At this point, the home agent's CoA field 104 can be informed of the home address 402 or a specific IP address (for example 0.0.0.0) to indicate that the interface is present in the home network. Update the registration request message including the corresponding binding ID in the binding suboption. Therefore, in case of the registration request message received from the interface of the home network, the home agent does not tunnel to the corresponding CoA. 4 shows an update of the CoA field.

4 illustrates a binding table of a home agent according to an embodiment of the present invention.

When a mobile node moves in a communication channel of a wireless network interface, and when one of the mobile node's multiple interfaces returns to the home network, the mobile node registers with the home agent to investigate whether there is another active interface in use and If there is an active interface, the home agent's CoA field 104 informs the home agent's CoA field 104 of the home address 402 or a specific IP address to inform the home agent that the interface currently exists in the home network. (For example, 0.0.0.0).

5 is a flowchart illustrating an operation of a home agent according to an embodiment of the present invention.

The home agent intercepts the packet transmitted to the home address through proxy ARP or proxy neighbor discovery (S501).

In order to transmit the intercepted packet to the mobile node, one of the CoAs mapped to the corresponding home address is selected (S511).

If the CoA selected to transmit the intercepted packet to the mobile node is a CoA present in the home network, the home agent transmits the packet to the mobile node through a link layer address instead of tunneling the packet. (S521, S531).

On the other hand, if the CoA selected to transmit the intercepted packet to the mobile node is a CoA not present in the home network, the packet is tunneled and transmitted to the mobile node (S541).

The link layer address of the interface existing in the home network may be known through a registration request message, and the mobile node may transmit a link layer address option format including information of the link layer address in a registration request message. Hereinafter, the link layer address option format is illustrated in FIG. 6.

6 illustrates a link layer address option format according to an embodiment of the present invention.

In general, it can be applied to both MIPv4 / v6 (Mobile Internet Protocol version 4 / version6). Hereinafter, the link layer address option format will be described using the short extension format of MIPv4 as an example.

The link layer address option format includes a type field 602, a length field 604, a sub-type field 606, and a data field 608.

Since the type field 602 can be determined later, it can be left as To Be Determined (TBD), and the length field 604 is the link layer address length plus the length of the data field 608 + 1. It can be defined as. The link layer address length can vary from network to network, such as 802.11 In the case of a network (Ethernet), it is defined as 6 bytes (48 bits).

The sub-type field 606 indicates a network type, that is, a link layer address type, so that the network type and the length of the link layer address may be known. For example, in the case of Ethernet, the subtype 606 may be defined as 1, and when another link layer address type is added, it may be defined as 2, 3, or the like.

Data field 608 defines the link layer address.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

According to the mobile communication method of a mobile node having multiple interfaces as described above, all the interfaces can be used even when some of the multiple interfaces return to the home network, thereby increasing the efficiency of interface utilization.

Claims (3)

If the mobile node returns to a home network from among the multiple interfaces of the mobile node, the mobile node checks whether a CoA of another interface registered with the home agent exists; Transmitting a registration request message to the home agent when a CoA of the other interface registered to the home agent exists; And And when the CoA selected for transmitting the packet intercepted by the home agent to the mobile node is a CoA present in the home network, the home agent transmitting the packet to the mobile node through a link layer address. Mobile communication method of a mobile node having an interface. The method of claim 1, The registration request message includes a binding ID of the interface returned to the home network and moves a mobile node having multiple interfaces that updates the CoA field of the home agent to a home address or a specific IP address indicating that it is in a home network. Communication method. The method of claim 2, And the mobile node binds the link layer address option format including information of the link layer address to the registration request message and transmits the link layer address option format to the home agent.

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