KR20100073808A - Method for configurating addresses of mobile node in multiples of gateway connected manet and method for selecting a basic gateway of mobile node - Google Patents

Abstract

PURPOSE: A method for selecting a basic gateway and setting the address of mobile node which is connected with moving wireless network are provided to maintain the set session without the change of address, even though the basic gateway is changed. CONSTITUTION: A mobile node receives a RA(Router Advertisement) message from a first gateway(S201). The mobile node transmits a registration request message to a first gateway(S203). The first gateway transmits a proxy binding update message to a LMA(Local Mobility Anchor, S204). The LMA transmits a PBAck(Proxy Binding Acknowledgement) message to the first gateway(S205). The first gateway transmits a RC(Registration Confirmation) message to the mobile node(S206).

Description

{METHOD FOR CONFIGURATING ADDRESSES OF MOBILE NODE IN MULTIPLES OF GATEWAY CONNECTED MANET AND METHOD FOR SELECTING A BASIC GATEWAY OF MOBILE NODE}

The present invention relates to an address setting method and a default gateway selection method of a mobile node in a mobile wireless network to which a plurality of gateways are connected. More particularly, the mobile node may be configured by advertising the same network prefix in a mobile wireless network to which a plurality of gateways are connected. The present invention relates to an address setting method and a default gateway selection method of a mobile node in a mobile wireless network to which multiple gateways are connected, so that even if the default gateway is changed to maintain the existing session without changing the address even if the gateway is changed.

A mobile ad-hoc network (MANET, hereinafter referred to as a "mobile radio network") is a network in which mobile nodes communicate with one another without infrastructure, such as a base station or wireless access point. . At this time, among the mobile nodes constituting the mobile wireless network, a source node and a destination node perform multi-hop communication through other mobile nodes when they are out of the radio range.

Mobile wireless network is divided into Standalone type that is independently connected to the Internet without being connected to the Internet, and Connected type that is connected to the Internet through a gateway. In particular, in a connected MANET, a mobile node within a mobile wireless network exchanges traffic with another mobile node within the same mobile wireless network or with any correspondent node connected to the Internet. At this time, mobile nodes constituting the mobile wireless network in the connected MANET should be set with a global IP address suitable for the Internet topology.

Meanwhile, in the related art, an internet connection technique (hereinafter, referred to as a "single gateway connection technique") in a single gateway-based Connected MANET has been proposed. That is, when the mobile node constituting the mobile wireless network receives a response message for the request message from the gateway after broadcasting a request message for obtaining a network prefix, the network prefix and its MAC in the response message are received. Set an IPv6 address using the address. Thereafter, the mobile node adds a routing header including the address information of the gateway to the packet so that the IPv6 packet can be transmitted to any counterpart node in the Internet through the gateway, and then transmits the packet. This single gateway connection technique assumes that there is only one gateway that connects the mobile wireless network and the Internet, which reduces performance due to congestion as all traffic exchanged between the mobile wireless network and the Internet is exchanged through one gateway. There may be a limit in that communication between the mobile wireless network and the Internet is interrupted when a gateway fails.

As an alternative to overcome this limitation, the Internet connection technique (hereinafter referred to as "multi-gateway connection technique") in a multi-gateway-based Connected MANET has been proposed. In other words, the multi-gateway connection scheme improves network reliability and prevents traffic degradation due to traffic congestion caused by traffic converging between mobile wireless networks and the Internet through a single gateway, or communication loss due to gateway failure. It can improve the performance of the whole network. Accordingly, a multi-gateway connection technique in which mobile nodes of a mobile wireless network are connected to the Internet through at least two or more gateways is essential in a connected MANET environment.

In general, in a multi-gateway connection scheme, any gateway transmits a Router Advertisement (RA) message including a network prefix according to a request of a mobile node or a predetermined period, and the mobile node transmits a Router Advertisement (RA) message. Receive an RA message and set an IPv6 address using the network prefix included in the RA message and its MAC address. However, in the conventional multi-gateway connection scheme, each gateway has a different network prefix for setting an address. When the mobile node moves and receives an RA message from a gateway having a different network prefix, the mobile node sets an address and sets a default gateway. This means that you will have to go through a series of selections again.

In the conventional multi-gateway connection scheme, the mobile node selects a gateway based on a minimum length or stability based method.

First, in the minimum length-based gateway selection method, the gateway having the smallest hop number from the mobile node is selected as the default gateway. In this gateway selection method, when the mobile node finds a gateway that has the smallest hop count to the gateway, it sets the gateway as the default gateway and uses its network prefix included in the RA message advertised from the changed default gateway. Reset it. However, the minimum length-based gateway selection method has a limitation that the established session is terminated and the session must be newly established because the socket address composed of the IP address and port number of the source node and the destination node is changed when the address is reset. have.

For this, the stability-based gateway selection method maintains the current address and communicates with the counterpart node on the Internet through the current default gateway whenever possible for a session connected to the counterpart node on the Internet. In this gateway selection method, an IP-in-IP encapsulation method and a routing header method that allow a mobile node to exchange traffic with a counterpart node on the Internet through the current default gateway have been proposed, and intermediate nodes between the mobile node and the gateway are proposed. A prefix continuity scheme has been proposed to have the same network prefix. In particular, a conventional analysis result of the performance of the prefix continuity scheme has been proposed in a situation in which the gateway moves.

The stability-based gateway selection method has a limitation in selecting an optimized route by selecting a gateway of the minimum distance as the default gateway and then maintaining the default gateway even when the mobile node moves. In particular, in the stability-based gateway selection scheme, when the mobile node moves and the mobile wireless network is separated, the route to the default gateway may be lost and communication may be interrupted. Accordingly, the network included in the RA message advertised from the new gateway may be lost. You may need to reset the address using the prefix.

Therefore, in the conventional multi-gateway connection scheme, even if a mobile node in a mobile wireless network moves, a technique for automatically setting an address and maintaining the set address and selecting an optimized default gateway needs to be proposed.

Therefore, the prior art as described above has a different network prefix for each gateway in a mobile wireless network to which a plurality of gateways are connected, and there is a problem in that address setting and default gateway selection need to be performed again as the mobile node in the mobile wireless network moves. In order to solve this problem, it is an object of the present invention.

Therefore, in the present invention, the gateway advertises the same network prefix in a mobile wireless network to which multiple gateways are connected, so that even if the mobile node moves and the default gateway is changed, the existing session can be maintained without changing the address. The purpose of the present invention is to provide a mobile node address setting method and a default gateway selection method in a mobile wireless network to which a gateway is connected.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention which are not mentioned can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

According to an aspect of the present invention, there is provided a method of addressing a mobile node in a mobile wireless network to which a plurality of gateways are connected, the method comprising: receiving a network prefix identically allocated to the plurality of gateways; And setting an address using the received network prefix and identification information of the mobile node.

The present invention also provides a method for selecting a default gateway of a mobile node in a mobile wireless network to which a plurality of gateways are connected, wherein the mobile node whose address is set using a network prefix assigned to the plurality of gateways receives an advertisement message from another gateway. Confirming the address of the other gateway; And modifying the default gateway address to the address of the other gateway by comparing the distance value identified through the advertisement message with the distance value of the preset default gateway.

In addition, the present invention provides a mobile node having a processor for receiving a network prefix that is equally assigned to a plurality of gateways; And a computer readable recording medium having recorded thereon a program for realizing a function of setting an address using the received network prefix and identification information of the mobile node.

In addition, the present invention, if the mobile node having an address set by using the network prefix assigned to the plurality of gateways to the mobile node having a processor receives an advertisement message from the other gateway, confirming the confirmation of the address of the other gateway function; And comparing a distance value checked through the advertisement message with a distance value of a preset default gateway, and a computer-readable recording medium having recorded thereon a program for realizing a correction function for modifying the default gateway address to the address of the other gateway. to provide.

In the present invention as described above, the gateways advertise the same network prefix in a mobile wireless network to which multiple gateways are connected, so that even if the mobile node moves and the default gateway is changed, the existing session can be maintained without changing the address. It is effective.

In addition, the present invention has the effect of selecting the optimal path because the mobile node uses the gateway in the shortest distance without changing the address.

In addition, the present invention has the effect that the mobile node can continue to use the existing address even when the mobile wireless network is separated or merged.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, It can be easily carried out. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a configuration diagram of an embodiment of a mobile wireless network to which a plurality of gateways to which the present invention is applied are connected.

As shown in FIG. 1, a mobile wireless network (ie, a connected gateway based on multiple gateways) connected to a plurality of gateways according to the present invention is connected to the Internet through an IPv6-based PMIPv6 (Proxy Mobile IPv6) network. That is, a mobile node in a mobile wireless network exchanges IPv6-based traffic with another node connected to the Internet through at least two gateways operating as a Mobility Access Gateway (MAG) of a PMIPv6 network, or in a mobile wireless network. Exchange IPv6-based traffic with other mobile nodes. Here, the PMIPv6 network is designed for mobility in a domain in which IP mobility is managed using the PMIPv6 protocol (that is, the PMIPv6 domain), which is a Local Mobility Anchor (LMA) and an access point acting as a home agent. Includes a Mobility Access Gateway (MAG). The protocol of the PMIPv6 network is defined in "Proxy Mobile IPv6, Internet draft, work in progress, May 2008" by S.Gundavelli, K.Leung, V.Devarapalli, K.Chowdhury and B.Patil. Those skilled in the art can easily understand and will be omitted.

In particular, all gateways of the present invention advertise RA messages containing the same network prefix, which means that one network prefix is assigned to the mobile wireless network. At this time, if the gateway sets the value of 'distance field of the RA message' (hereinafter referred to as 'distance value') to '0' and advertises, the distance value is generated whenever the RA message passes through the mobile node forming the mobile wireless network. Increment by 1 (the number on the arrow in FIG. 1 is the distance value).

In the mobile wireless network connected to the plurality of gateways according to the present invention, a mobile node (N1 to N7) (111 to 117), a first to third gateways 121 to 123 operating as a MAG, and an LMA for forming a PMIPv6 tunnel with the MAG 130, the other node 140 connected to the Internet. Here, the mobile nodes for which the first gateway 121 is set as the default gateway are N1 111, N2 112, and N7 117, and in particular, N2 112 is a next-hop neighbor node of N1 111. . In addition, the mobile node in which the second gateway 121 is set as the default gateway is N3 113, and the neighbor nodes in which the third gateway 123 is set as the default gateway are N4 114, N5 115, and N6 116. to be.

2A is a flowchart illustrating a method for determining a gateway of a mobile node in a mobile wireless network to which multiple gateways having the same network prefix are connected according to the present invention.

For convenience of description, it is assumed that the default gateway is set from the first gateway 121 to the second gateway 122 as the mobile node N1 111 of FIG. 1 moves.

First, the mobile node 111 receives the advertised RA message from the first gateway 121 when accessing the mobile wireless network (S201). At this time, the mobile node 111 uses the 'network prefix derived from the address of the first gateway 121 and the network prefix length included in the RA message' and the 'MAC address of its own 111' to automatically generate a stateless address. According to the configuration (IPv6 Stateless Address Autoconfiguration) to set the IPv6 address to its own mobile wireless network interface (S202).

Thereafter, the mobile node 111 sets the default gateway address as the address of the first gateway 121 and sets the distance value to the first gateway 121 by adding 1 to the distance value included in the RA message. Then, it is added to the route table entry of itself 111. In addition, the mobile node 111 sets the address of the neighbor node that broadcasts the RA message (that is, the source IP address of the IP packet header included in the RA message) as a next-hop address for the default gateway, and then establishes itself (111). To the route table entry.

Subsequently, the mobile node 111 adds the first gateway 121 related route table ent, which is the default gateway, and then modifies the distance value to the first gateway 121 to include in the RA message and broadcasts again. At this time, the mobile node 111 transmits a registration request (RR) message to the first gateway 121 (S203).

Meanwhile, the first gateway 121 receives the RR message transmitted from the mobile node 111 and performs a proxy binding update (PBU) including address information of the mobile node 111. ) Transmits the message to the LMA 130 (S204). In this case, the LMA 130 stores binding information for the mobile node 111 and the first gateway 121, and transmits a proxy binding notification (PBAck) to the first gateway 121 (hereinafter, referred to as “PBAck”). ) Message is transmitted (S205). Thus, the PMIPv6 tunnel for the mobile node 111 is established between the first gateway 121 and the LMA 130.

Thereafter, the first gateway 121 receives the PBAck message from the LMA 130 and transmits a Registration Confirmation (RC) message to the mobile node 111 (S206).

Thereafter, the mobile node 111 may communicate with any counterpart node 140 connected to the Internet (S207). That is, the first gateway 121 transmits the IPv6-based packet transmitted from the mobile node 111 to the LMA 130 through the PMIPv6 tunnel, where the LMA 130 connects the received IPv6-based packet to the Internet. It transmits to the correspondent node 140.

However, even if the IPv6 address is set, the mobile node 111 may receive at least one or more RA messages advertised from the gateway (S208). This is because RA messages are advertised periodically from each gateway.

The mobile node 111 operates as follows by comparing 'next-hop information' and 'default gateway address' included in the received RA message with values set in the route table entry. Reference is made to FIG. 2B, which shows a detailed description of step S208 to aid in the understanding of the description. 2B is an explanatory diagram illustrating a method of operating a mobile node according to a received RA message.

First, when the mobile node 111 receives the RA message broadcasted from the neighbor node set as the next-hop for the default gateway in the route table entry (S208①), the default gateway address of the route table entry is the default gateway of the RA message. If it is the same as the address (S208②), the default gateway distance value of the route table entry is modified to a value obtained by adding 1 to the distance value of the RA message (S208③).

Next, when the mobile node 111 receives the RA message broadcasted from the neighbor node set as the next-hop for the default gateway in the route table entry (S208①), the default gateway address of the route table entry is the default of the RA message. If it is not the same as the gateway address (S208②), the default gateway address of the route table entry is changed to the default gateway address of the RA message, and the default gateway distance value of the route table entry is changed to the distance value of the RA message plus 1. (S208④). At this time, the mobile node 111 transmits the RR message to the newly set default gateway (S209), and adds 1 to the distance value of the RA message in order to relay the received RA message and broadcasts it again.

Next, when the mobile node 111 receives a broadcasted RA message from a neighbor node not set as a next-hop for the default gateway (S208①), the mobile node 111 adds 1 to the distance value of the RA message and a route table entry. Comparing the default gateway distance value of (S208⑤). At this time, the mobile node 111 discards the RA message when the value obtained by adding 1 to the distance value of the RA message is larger than the default gateway distance value to the route table entry (S208⑤).

On the other hand, the mobile node 111, when the distance value of the RA message plus 1 is smaller than the default gateway distance value of the route table entry (S208⑤), the default gateway address of the route table entry is the value of the RA message. If it is the same as the default gateway address (S208 ⑦), the default gateway distance value of the route table entry is changed to the distance value of the RA message plus 1, and the next-hop for the default gateway of the route table entry is transmitted. Modify to neighbor node (S208⑧).

Also, when the mobile node 111 adds 1 to the distance value of the RA message is smaller than the default gateway distance value of the route table entry (S208⑤), the default node address of the route table entry is the same as the default gateway address of the RA message. If not (S208⑦), the default gateway distance value of the route table entry is changed to the distance value of the RA message plus 1, and the next-hop for the default gateway in the route table entry is sent to the neighbor node that transmitted the RA message. Modify the default gateway address of the route table entry to the default gateway address of the RA message (S208⑨). At this time, the mobile node 111 transmits the RR message to the newly set default gateway (S209), and adds 1 to the distance value of the RA message in order to relay the received RA message and broadcasts it again.

In FIG. 2A, when the mobile node 111 receives an RA message from the second gateway 122 instead of the first gateway 121, as in S208 ④ and S208⑨ corresponding to the case where the default gateway addresses are not the same in FIG. 2B. Consider.

Even if the default gateway address is changed as described above, the mobile node 111 can continue to use the network prefix for the mobile wireless network without changing the IPv6 address set in its own wireless interface. That is, even if the default gateway address is changed, the mobile node 111 may continue to maintain the established session.

In addition, even if the default gateway address is changed, the mobile node 111 is configured to have the same IPv6 address. Therefore, the mobile node 111 transmits a packet transmitted from the counterpart node 140 connected to the Internet before address registration is completed in the PMIPv6 domain. It can be received through the old gateway, preventing packet loss due to changes in the default gateway address.

In addition, the mobile node 111 uses the RA message transmitted in the next-hop when the RA message is not received for a predetermined time in the next-hop for the default gateway, or when the next-hop is no longer the neighbor node. Delete the default gateway related entry from the route table entry set up.

As described above, even if the default gateway is changed from the first gateway 121 to the second gateway 122, the mobile node 111 is configured to set a separate IPv6 address since the network prefix for the mobile wireless network is the same. Do not use it and use the existing IPv6 address. At this time, the mobile node 111 receives the RA message advertised by the second gateway 122, modifies the second gateway 122 address included in the RA message to the default gateway address of the route table entry, and then the second gateway. The RR message is transmitted to 122 (S208, S209).

The second gateway 122 receives the RR message transmitted from the mobile node 111 and transmits a PBU message including the address information of the mobile node 111 to the LMA 130 (S210). At this time, the LMA 130 stores binding information for the mobile node 111 and the second gateway 122 and transmits a PBAck message to the second gateway 122 (S211). Here, the PMIPv6 tunnel for the mobile node 111 is established between the second gateway 122 and the LMA 130.

Thereafter, the second gateway 122 receives the PBAck message from the LMA 130 and transmits the RC message to the mobile node 111 (S212).

As such, even if the default gateway is changed, the mobile node 111 may communicate with any counterpart node 140 connected to the Internet (S213). That is, the second gateway 122 transmits the IPv6-based packet transmitted from the mobile node 111 to the LMA 130 through the PMIPv6 tunnel, where the LMA 130 connects the received IPv6-based packet to the Internet. It transmits to the correspondent node 140.

On the other hand, the method of the present invention as described above can be written in a computer program. And the code and code segments constituting the program can be easily inferred by a computer programmer in the art. In addition, the written program is stored in a computer-readable recording medium (information storage medium), and read and executed by a computer to implement the method of the present invention. The recording medium may include any type of computer readable recording medium.

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

1 is a configuration diagram of an embodiment of a mobile wireless network to which a plurality of gateways to which the present invention is applied;

2A is a flowchart illustrating a method for determining a gateway of a mobile node in a mobile wireless network to which multiple gateways having the same network prefix according to the present invention are connected;

2B is an explanatory diagram illustrating a method of operating a mobile node according to a received RA message.

* Explanation of symbols for the main parts of the drawings

111 to 117 mobile nodes

121 to 123: gateway (MAG)

130: LMA

140: relative node

Claims (10)

In the mobile node address setting method in a mobile wireless network to which multiple gateways are connected, Receiving a network prefix that is equally assigned to the plurality of gateways; And Setting an address using the received network prefix and identification information of the mobile node Mobile node address setting method comprising a. The method of claim 1, The gateway is, A method of addressing a mobile node connected to the Internet through an IPv6-based PMIPv6 (PMIPv6) network. The method of claim 2, The gateway is, Method of addressing a mobile node operating as a Mobility Access Gateway (MAG) in the PMIPv6 network to advertise the same network prefix. In a method of selecting a default gateway of a mobile node in a mobile wireless network to which multiple gateways are connected, Confirming an address of the other gateway when the mobile node which has set an address using the same network prefix assigned to the plurality of gateways receives an advertisement message from the other gateway; And Modifying the default gateway address to the address of the other gateway by comparing the distance value confirmed by the advertisement message with the distance value of the preset default gateway. Default gateway selection method of a mobile node comprising a. The method of claim 4, wherein The gateway is, A method of selecting a default gateway of a mobile node connected to the Internet through an IPv6-based PMIPv6 (PMIPv6) network. The method of claim 5, The gateway is, The method of selecting a default gateway of a mobile node operating as a mobility access gateway (MAG) in the PMIPv6 network to advertise the same network prefix. The method according to any one of claims 4 to 6, The mobile node, The default gateway selection method of a mobile node, characterized in that the advertisement message is received from a neighbor node that is not set to the next-hop. The method of claim 7, wherein The modifying step, If the default gateway distance value is less than the distance value of the advertisement message plus 1, the default gateway selection method of the mobile node to modify the default gateway address to the address of the other gateway. In a mobile node with a processor, Receiving a network prefix that is equally assigned to the plurality of gateways; And A function of setting an address using the received network prefix and identification information of the mobile node A computer-readable recording medium having recorded thereon a program for realizing this. In a mobile node with a processor, A confirmation function for confirming an address of the other gateway when a mobile node which has set an address using a network prefix assigned to a plurality of gateways receives an advertisement message from another gateway; And A correction function for comparing the distance value checked through the advertisement message with the distance value of the preset default gateway and modifying the default gateway address to the address of the other gateway. A computer-readable recording medium having recorded thereon a program for realizing this.

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