Method and apparatus for neighbor discovery in IPv6-based mobile system

A mobile station and method for neighbor discovery are provided. The mobile station comprises a mapping table storing a connection identifier (CID) prefix and a neighbor identifier, a controller generating a CID with respect to a message that will be transmitted by referring to the mapping table, and a message transmitter transmitting, by using the CID, the message to a base station connected to the mobile station.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an Internet Protocol Version 6 (IPv6)-based mobile system. More particularly, the present invention relates to an apparatus and method for neighbor discovery in an IPv6-based mobile system using an Institute of Electrical and Electronics Engineers (IEEE) 802.16 link.

2. Description of the Related Art

IPv6 is a next generation Internet protocol that has been developed by the Internet Engineering Task Force (IETF) to solve problems of IPv4 currently used on the Internet. Neighbor discovery is a very important process in the operation of the IPv6. Nodes use the neighbor discovery to determine the link-layer addresses for neighbors known to reside on attached links. A node includes a host and a router.

Conversely, since broadband wireless access provides broadband communication without a wire, a larger amount of research with respect to the broadband wireless access has been conducted. According to the research, the Institute of Electrical and Electronics Engineers (IEEE) created IEEE 802.16 as a broadband wireless access specification, thereby causing a focus of research on broadband communication using EEE 802.16. IEEE 802.16 is a standard for a wireless air interface for wireless metropolitan area network (MAN)

FIG. 1is a diagram illustrating a network in which mobile stations101,102, and103are connected to a base station104by an IEEE 802.16 link form an IPv6 link with access routers105,106, and107. InFIG. 1, the mobile stations101,102, and103are connected to the base station104by the IEEE 802.16 link. The mobile stations101,102, and103are connected to the access routers105,106, and107by the IPv6 link. Namely, the mobile stations101,102, and103and the access routers105,106, and107for an IPv6 network in which the mobile stations101,102, and103and the base station104use the IEEE 802.16 link.

As described above, in IPv6, neighbor discovery must be performed. For transmission of a message to a destination from the mobile stations101,102, and103, the base station104must know a link layer address of a next hop to which the message received from the mobile stations101,102, and103will be transmitted. This process of looking for the link layer address of the next hop to which the message will be transmitted is known as neighbor discovery.

However, there have been no standards with respect to neighbor discovery operation on the IEEE 802.16 network until recently. From a viewpoint of IPv6 neighbor discovery, the base station104is just a link-level bridge. However, unlike IEEE 802.11, in IEEE 802.16, the base station104uses a connection identifier (CID) instead of a Media Access Control (MAC) address, thereby always operating as a termination point with respect to communication. Even though a message is received from the mobile stations101,102, and103, the base station104has no way of determining where the message should be transmitted.

FIG. 2is a diagram illustrating an IEEE 802.16 MAC header used in the IEEE 802.16 link between the mobile stations101,102, and103and the base station104. As shown inFIG. 2, a field capable of storing a link layer address of a next hop is not defined in the IEEE 802.16 MAC header. In the IEEE 802.16 link, the mobile station103, for example, uses CIDs201and202for communication with the base station104.

As described above, IEEE 802.16 does not provide any solution with respect to the neighbor discovery operation. Therefore, a method in which a mobile station transmits an IEEE 802.16 header including an Ethernet header to a base station has been provided. However, according to the method, a frame including fields for the Ethernet header, which are not used, must be transmitted.

Accordingly, there is a need for a neighbor discovery function that facilitates the operation of IPv6 with respect to a link technology that does not provide the neighbor discovery operation, such as IEEE 802.16.

SUMMARY OF THE INVENTION

An aspect of exemplary embodiments of the present invention is to address at least the above problems and/or disadvantages and to provide at lest the advantages described below. Accordingly, an aspect of exemplary embodiments of the present invention is to provide a method and apparatus capable of supporting efficient neighbor discovery on an IEEE 802.16 network.

An aspect of an exemplary embodiment of the present invention also provides an efficient neighbor discovery method and apparatus that facilitates the operation of IPv6 with respect to a network technology that does not provide a neighbor discovery function.

According to an aspect of an exemplary embodiment of the present invention, a mobile station comprising a mapping table, a controller and a message transmitter is provided. The mapping table stores a connection identifier (CID) prefix and a neighbor identifier. The controller generates by:referring to the mapping table, a CID with respect to a message that will be transmitted. The message transmitter transmits, by using the CID, the message to a base station connected to the mobile station. The controller may identify a next hop CID prefix corresponding to a neighbor identifier of a next hop to which the message will be transmitted by referring to the mapping table, and may generate the CID based on the next hop CID prefix.

According to another aspect of an exemplary embodiment of the present invention, a base station comprising a mapping table, a controller and a message transmitter is provided. The base station stores a CID prefix and neighbor identifier. The controller identifies a next hop to which a message will be transmitted, from a CID of the message received from a mobile station by referring to the mapping table. The message transmitter transmits the message to the next hop. The controller may identify a next CID prefix from N upper bits of the CID and may identify a neighbor identifier of a next hop to which the message will be transmitted, from the next hop CID prefix by referring to the mapping table.

According to still another aspect of an exemplary embodiment of the present invention, a mobile station comprising a controller and a message transmitter is provided. The controller identifies a link layer address of a next hop to which a message will be transmitted by using a predetermined neighbor discovery method. The message transmitter transmits a frame comprising the message and the link layer address of the next hop to a base station, wherein the next hop is on the same link as the base station connected to the mobile station and the frame does not include an Ethernet header. The link layer address of the next hop may be included in a predetermined field of an IEEE 802.16 frame.

According to yet another aspect of an exemplary embodiment of the present invention, a base station comprising a message receiver and a message transmitter is provided. The message receiver receives a frame from a mobile station, the frame comprising a message and a link layer address of a next hop, which is on the same link as the base station. The message transmitter transmits the message to the next hop by using the link layer address of the next hop wherein the frame does not include an Ethernet header. The link layer address of the next hop may be included in a predetermined field of an IEEE 802.16 frame.

According to a further aspect of an exemplary embodiment of the present invention, abase station comprising-a message receiver, a destination cache, a controller and a message transmitter is provided. The message receiver receives a message in the form of IEEE 802.16 from a mobile station. The destination cache stores a destination IP address and an IP address of a next hop corresponding to the destination IP address. The controller determines the IP address of the next hop corresponding to the destination IP address by referring to the destination cache when the destination IP address of the message is stored in the destination cache. The message transmitter transmits the message received from the mobile station to the next hop by using the IP address of the next hop.

According to another aspect of an exemplary embodiment of the present invention, a base station comprising a storage unit, a message receiver, a controller and a message transmitter is provided. The storage unit stores a default router list, an on-link prefix list, a destination cache and a neighbor cache that are defined in Request For Comment (RFC) 2461. The message receiver receives a message from a mobile station. The controller determines a link layer address of a next hop to which the received message will be transmitted, by using a neighbor discovery method of RFC 2461, referring to the default router list, the on-link prefix list, the destination cache, and the neighbor cache. The message transmitter transmits the message to the next hop, referring to the link layer address of the next hop.

According to another aspect of an exemplary embodiment of the present invention, a neighbor discovery method is provided. A mapping table is maintained which stores a CID prefix and a neighbor identifier. A CID is generated with respect to a message that will be transmitted by referring to the mapping table. The message is transmitted to a base station connected to the mobile station by using the CID.

According to another aspect of an exemplary embodiment of the present invention, a neighbor discovery method is provided. A mapping table that stores a CID prefix and a neighbor identifier is maintained. A next hop to which a message received from a mobile station will be transmitted is identified, from a CID of the message by referring to the mapping table. The message is transmitted to the next hop.

According to another aspect of an exemplary embodiment of the present invention, a neighbor discovery method is provided. A link layer address of a next hop to which a message will be transmitted is identified by using a predetermined neighbor discovery method. A frame including the message and the link layer address of the next hop is transmitted to a base station connected to a mobile station, wherein the next hop is on the same link as the base station and the frame does not include an Ethernet header.

According to another aspect of an exemplary embodiment of the present invention, a neighbor discovery method is provided in which a frame is received. The frame includes a link layer address of a next hop and a message from a mobile station. The message is transmitted to the next hop by using the link layer address of the next hop, wherein the next hop is on the same link as a base station and the frame does not include an Ethernet header.

According to another aspect of an exemplary embodiment of the present invention, a neighbor discovery method is provided in which a message in the form of IEEE 802.16 is received from a mobile station. A destination cache is maintained and a destination IP address and an IP address of a next hop is stored corresponding to the destination IP address. The IP address of the next hop corresponding to a destination IP address of the message is determined when the destination IP address is stored in the destination cache. The message received from the mobile station is transmitted to the next hop by using the IP address of the next hop.

According to another aspect of an exemplary embodiment of the present invention, a neighbor discovery method is provided in which a default router list, an on-link prefix list, a destination cache, and a neighbor cache that are defined in RFC 2461 are maintained. A message from a mobile station is received. A link layer address of a next hop to which the received message will be transmitted by referring to the default router list, the on-link prefix list, the destination cache, and the neighbor cache, is determined by using a neighbor discovery method of RFC 2461. The message is transmitted to the next hop by referring to the link layer address of the next hop.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 3is a block diagram illustrating a mobile station310and a base station320according to a first exemplary embodiment of the present invention.

The mobile station310is connected to the base station320by an IEEE 802.16 link. According to the exemplary embodiment of the present invention, the mobile station310and the base station320include mapping tables311and321, respectively. The mapping tables311and321include CID prefixes and neighbor identifiers, respectively. The mobile station310transmits an IEEE 802.16 frame including a mutually agreed upon CID prefix with respect to a next hop that is a neighbor to which a message will be transmitted, to the base station320. The base station320may recognize the next hop to which the received message will be transmitted.

The mobile station310includes the mapping table311, a controller312, a message transmitter313, and a message receiver314.

The mapping table311stores a CID prefix315and a neighbor identifier316. The CID prefix315is N upper bits of a CID. In the exemplary embodiment of the present invention, bits forming the CID, namely, the CID prefix315, are used for identifying the next hop. According to an exemplary embodiment of the present invention, different CID prefixes are assigned to each router on the same link as the base station320. Also, the same CID prefix is assigned to all the nodes excluding any router on the same link as the base station320. The neighbor identifier316is an identifier with respect to the node on the same link as the base station320connected to the mobile station310. As the neighbor identifier316, a link layer address of the node or an IP address of the node may be used.

For example, a case in which a CID prefix is four bits will be described. A CID prefix “0001” is an indicator with respect to the access router105connected to the base station104, and a CID prefix “0010” is an indicator with respect to the access router106, and a CID prefix “0011” is an indicator with respect to the access router107. The mapping table311stores the CID prefix “0001” and a neighbor identifier with respect to the access router105. The neighbor identifier may be a link layer address or an IP address of the access router105. Similarly, the CID prefix “0010” and a neighbor identifier of the access router106are stored in the mapping table311. The CID prefix “0011” and a neighbor identifier of the access router107are stored in the mapping table311.

The controller312of the mobile station310generates a CID by referring to the mapping table311, with respect to a message that will be transmitted. The controller312identifies a next hop CID prefix corresponding to a neighbor identifier of a next hop that will receive the message. For example, when the next hop that will receive the message is the access router105, the CID prefix “0001” with respect to the access router105is identified by referring to the mapping table311. The controller312generates a CID based on the next hop CID prefix. In detail, the controller312assigns a CID postfix with respect to the next hop. For example, since a CID is 16 bits according to IEEE 802.16, when N bits are used as a CID prefix, 16-N bits are used as a CID postfix. In the above example, since four bits are used as the CID prefix, the CID postfix is 12 bits. Since only one CID can be between a mobile station and a base station, a CID postfix is assigned to satisfy this condition. For example, when “000011110000” is assigned to the CID postfix, the controller312generates a CID by concatenating the next hop CID prefix and the CID postfix. When the CID prefix is “0001” and the CID prefix is “000011110000,” the generated CID becomes “0001000011110000”.

The message transmitter313transmits the message to the base station320connected to the mobile station310by using the generated CID because communication between the mobile station310and the base station320is performed by using the CID. The message receiver314receives the message from the base station.

The base station320includes the mapping table321, a controller322, and a message transmitter323, and a message receiver324.

The mapping table321stores a CID prefix325and a neighbor identifier326. Since the CID prefix325and the neighbor identifier326are identical with the CID prefix315and the neighbor identifier316of the mapping table311of the mobile station320, a detailed description will be omitted. The message receiver324receives an IEEE 802.16 frame including a CID and a message.

The message receiver324receives a message from the mobile station310, and the message transmitter323transmits the message to a next hop.

The controller322identifies the next hop to which the message will be transmitted, from a CID of the message received from the mobile station310by referring to the mapping table321. The controller322identifies a next hop CID prefix in detail from N upper bits of the CID and identifies a neighbor identifier of the next hop to which the message will be transmitted, from the next hop CID prefix by referring to the mapping table321. For example, when four upper bits are used as the next hop CID prefix, the controller322may identify the next hop from the four upper bits of the CID. When the CID prefix is “0001,” the controller322may recognize that the received message has to be transmitted to the access router105. A link layer address of a node on the same link as the base station320may be used as the neighbor identifier325of the mapping table321. In the above example, when the CID prefix is “0001,” the message received by the base station320has to be transmitted to the access router105. In this case, the message is transmitted to the access router105that is the next hop, by using a link layer address of the access router105corresponding to the CID prefix “0001” in the mapping table321. When the neighbor identifier325of the mapping table321is not the link layer address of the node, the controller322identifies the link layer address of the next hop by using Address Resolution Protocol (ARP).

FIG. 4is a diagram illustrating a CID field of an IEEE 802.16 frame when a mobile station is connected to a base station by an IEEE 802.16, according to the first exemplary embodiment of the present invention. In an exemplary embodiment of the present invention, a CID is divided into a CID prefix and a CID postfix. The CID prefix is N upper bits of the CID and is used for identifying a next hop. According to an exemplary embodiment of the present invention, different CID prefixes are assigned to each router on the same link as the base station. A CID prefix411of a CID410is an indicator of a first router, and another CID prefix421of another CID420is an indicator of a second router. According to an exemplary implementation, different values are assigned since the CID prefix411and the other CID prefix421identify different routers. Also, the same CID is assigned to nodes excluding the routers on the same link as the base station. For example, a CID prefix431of a CID430is a non-router indicator and “1100” is assigned to the CID prefix431. In this case, when there are four nodes excluding the routers on the same link as the base station, the CID prefix “1100” is assigned to all the nodes. The CID postfixes412,422, and432are values assigned by the mobile station to make the CID a unique value.

When a next hop CID prefix of the message received by the message receiver324is the CID prefix with respect to the nodes excluding the routers, for example, the non-router indicator, the controller322identifies a link layer address of a next hop to which the message will be transmitted, by using ARP. When the next hop is not a router, the next hop becomes one of the terminal nodes connected to the base station320. In this case, the next hop is a destination that will receive the message.

FIG. 5is a flowchart illustrating a neighbor discovery method according to the first exemplary embodiment of the present invention.

In step501, the mobile station310maintains the mapping table311by storing a CID prefix and a neighbor identifier.

In step502through step504, the mobile station310generates a CID with respect to a message that will be transmitted, by referring to the mapping table311. In detail, in step502, the controller312of the mobile station310identifies a next hop CID prefix corresponding to a neighbor identifier of a next hop to which the message will be transmitted, by referring to the mapping table311. In step503, the controller312assigns a CID postfix with respect to the next hop. In step504, the controller312generates the CID by concatenating the next hop CID prefix and the CID postfix.

In step505, the mobile station310transmits the message to the base station320connected to the mobile station310, by using the CID. In this case, the message will be transmitted by an IEEE 802.16 link.

In step506, the base station320maintains the mapping table321storing a CID prefix and a neighbor identifier.

In step507, the base station320identifies a next hop to which a message will be transmitted, from a CID of the message received from the mobile station310, by referring to the mapping table321. In detail, the base station320identifies a next hop CID prefix from N upper bits of the CID and identifies a neighbor identifier of the next hop to which the message will be transmitted, from the next hop CID prefix by referring to the mapping table321. In step508, when the next hop CID prefix is a CID prefix with respect to nodes excluding routers, the base station320identifies a link layer address of the next hop to which the message will be transmitted, by using ARP.

In step509, the base station320transmits the message to the next hop by using the identified link layer address of the next hop. When the next hop CID prefix is a CID prefix with respect to a router and the neighbor identifier corresponding to the CID prefix of the mapping table321is a link layer address of the router, the base station320transmits the message to the next hop by using the link layer address of the router.

FIG. 6is a block diagram illustrating a mobile station and a base station according to a second exemplary embodiment of the present invention.

In the second exemplary embodiment of the present invention, the mobile station identifies a link layer address of a next hop and transmits an IEEE 802.16 frame, including the link layer address, to the base station. The base station transmits a message to the next hop by using the received link layer address of the next hop.

A mobile station610includes a controller611, a message receiver612, and a message transmitter613. The message receiver612receives a message from a base station620, and the message transmitter transmits a message to the base station620.

The controller611identifies a link layer address of a next hop to which a message will be transmitted, by using a predetermined neighbor discovery method. The next hop is a node on the same link as the base station620that is connected to the mobile station610. Using the neighbor discovery method, the mobile station610may request information of all nodes on the same link as the base station620. This may include a link layer address, of the base station620connected to the mobile station610. Based on the received information, the mobile station610identifies the link layer address of the next hop to which the message will be transmitted.

The message transmitter613transmits a frame including the message and the link layer address of the next hop, to the base station620. An example of the frame is illustrated inFIG. 7. Referring toFIG. 7, the message transmitter613transmits the message, including the link layer address of the next hop in a predetermined field of IEEE 802.16 frame. As shown inFIG. 7, according to the exemplary embodiment of the present invention, a field702storing the link layer address of the next hop is included in addition to an IEEE 802.16 header701. In this case, when the message, including an IPv6 header703, is transmitted, IPv6 may be supported and neighbor discovery may be supported. Particularly, as shown inFIG. 7, in the exemplary embodiment of the present invention, the frame transmitted from the mobile station610to the base station620does not include an Ethernet header. In an exemplary embodiment of the present invention, the neighbor discovery may be supported while minimizing data size of data added to the frame transmitted from the mobile station610since an entire Ethernet header is not included and only a link layer address of a next hop is included in a frame.

The base station620includes a controller621, a message receiver622, and a message transmitter623.

The message receiver622receives a frame including a link layer address of a next hop and a message from the mobile station610. The next hop is on the same link as the base station620. According to an exemplary embodiment of the present invention, the link layer address of the next hop is included in a predetermined field of an IEEE 802.16 frame.

The controller621identifies the link layer address of the next hop from the frame received from the mobile station610. The message transmitter623transmits the message to the next hop by using the link layer address of the next hop.

FIG. 8is a flowchart illustrating a neighbor discovery method according to the second exemplary embodiment of the present invention.

In step801, the mobile station610identifies a link layer address of a next hop to which a message will be transmitted, by using a predetermined neighbor discovery method. The next hop is on the same link as the base station620connected to the mobile station610.

In step802, the mobile station610generates a frame including the message and the link layer address of the next hop. In this case, the link layer address of the next hop is included in a predetermined field of an IEEE 802.16 frame.

In step803, the mobile station610transmits the frame including the message and the link layer address of the next hop, to the base station620.

In step804, the base station620receives the frame including the link layer address of the next hop and the message from the mobile station610. The next hop is on the same link as the base station620.

In step805, the base station620verifies the link layer address of the next hop from the received frame.

In step806, the base station620transmits the message to the next hop by using the link layer address of the next hop.

FIG. 9is a block diagram illustrating a base station900according to a third exemplary embodiment of the present invention.

In the exemplary embodiment of the present invention, neighbor discovery according to RFC 2461 is performed by the base station900, instead of mobile stations connected to the base station900. The base station900maintains a default router list940, an on-link prefix list950, a destination cache960and a neighbor cache970that are defined in RFC 2461. The base station900determines a link layer address of a next hop to which a received message will be transmitted, by using a neighbor discovery method. The base station900also determines a link layer address by referring to the default router list940, the on-link prefix list950, the destination cache960and the neighbor cache970. After directly determining the link layer address of the next hop, the base station900transmits the message to the next hop by referring to the link layer address of the next hop. In this case, mobile stations do not support the neighbor discovery method of RFC 2461 and just have to communicate with the base station900by IEEE 802.16.

The base station900, according to the exemplary embodiment of the present invention, includes a message receiver910, a message transmitter920, a controller930and a storage unit. The storage unit includes the default router list940, the on-link prefix list950, the destination cache960, and the neighbor cache970that are defined in RFC2461. According to RFC 2461, the default list940, the on-link prefix list950, the destination cache960, and the neighbor cache970are stored in each of nodes. However, in an exemplary embodiment of the present invention, the default list940, the on-link prefix list950, the destination cache960, and the neighbor cache970are stored only in the base station900.

The message receiver910receives a message in the form of IEEE 802.16 from a mobile station. The message transmitter920transmits the message received from the mobile station to a next hop by using an IP address of the next hop.

The default router list940stores information with respect to default routers. In detail, the default router list940stores a list941of the default routers and a lifetime field942indicating a valid time period of the default router list information. The on-link prefix list950stores an IP address prefix of a node on the same link as the base station900. In detail, the on-link prefix list950stores a prefix list field951of network addresses of nodes on the same link as the base station900and a lifetime field952are included.

The destination cache960stores a destination IP address961and an IP address of a next hop962corresponding to the destination IP address. In detail, a destination IP address961and an IP address of a next hop962storing an IP address of a next hop to which a message having a corresponding destination IP address will be transmitted are included. Also, a PMUT field963used in a transport protocol and a round trip timer field964maintained by the transport protocol.

The neighbor cache970stores an IP address of a node on the same link as the base station900and a link layer address of the node. In detail, the neighbor cache970includes a next hop address field971storing the IP address of the node on the same link and an L2 address field972storing the link layer address of the node (next hop). Also, the neighbor cache970includes a flag field973identifying whether a next hop is a host or a router, a pointer974to any queued packets waiting for address resolution to complete, a reachability state field975, a number of unanswered probes976, and a neighbor unreachability detection (NUD) time field977.

FIG. 10is a flowchart illustrating a neighbor discovery method according to the third exemplary embodiment of the present invention.

In step1001, a mobile station transmits a message to the base station900. When the mobile station communicates with the base station900by an IEEE 802.16 link, the message is in the form of IEEE 802.16. In step1002, the message receiver910of the base station900receives the message in the form of IEEE 802.16 from the mobile station. The base station maintains the default list940, the on-link prefix list950, the destination cache960, and the neighbor cache970that are defined in RFC 2461.

In step1003, the controller930verifies whether a destination IP address of the message is stored in the destination cache960. In step1004, a determination is made as to whether the destination IP address of the message is stored in the destination cache960. In step1005, when it is determined in step1004that the destination IP address of the message is stored in the destination cache960, the controller930determines an IP address of a next hop corresponding to the destination IP address by referring to the destination cache960.

In step1006, when it is determined in step1004that the destination IP address of the message is not stored in the destination cache960, the controller930verifies whether the destination IP address of the message matches an IP address prefix stored in the on-link prefix list950. In step1007, whether the destination IP address of the message matches the IP address prefix stored in the on-link prefix list950is determined. In step1009, when it is determined in step1007that the destination IP address matches the IP address prefix stored in the on-link prefix list950, the destination IP address is determined to be the IP address of the next hop.

In step1008, when it is determined in step1007that the destination IP address does not match the IP address prefix stored in the on-link prefix list950, whether a default router exists in the default router list940is verified. When the default router exists, the controller930determines an IP address to be the IP address of the next hop in step1010.

Using the IP address of the next hop, determined in step1009and step1010, the controller930updates the destination IP address field961and the next hop IP address field962in the destination cache960in step1011.

In step1012, the controller930verifies whether a link layer address of the next hop corresponding to the IP address of the next hop, determined in step1009and step1010, is stored in the neighbor cache970.

In step1013, whether the link layer address of the next hop corresponding to the IP address of the next hop is stored in the neighbor cache970is determined.

When it is determined in step1013that the link layer address of the next hop corresponding to the IP address of the next hop is stored in the neighbor cache970, the controller930determines the link layer address of the next hop corresponding to the IP address of the next hop by referring to the neighbor cache970in step1014.

When it is determined in step1013that the link layer address of the next hop corresponding to the IP address of the next hop is not stored in the neighbor cache970, the controller930determines the link layer address of the next hop corresponding to the IP address of the next hop by using ARP in step1015.

The message transmitter920transmits the message to the next hop by using the determined link layer address of the next hop.

According to an exemplary embodiment of the present invention, since address resolution is not performed in a mobile station, consumption of bandwidth may be reduced and power consumption of the mobile station may be reduced.

According to a method and apparatus of an exemplary embodiment of the present invention, efficient neighbor discovery on an IEEE 802.16 network is supported. Also, according to an aspect of an exemplary embodiment of the present invention, an efficient neighbor discovery method and an apparatus using the same is provided. This facilitates the operation of IPv6 with respect to a network technology that does not provide a neighbor discovery function.

Also, in an exemplary embodiment of the present invention, since a change occurs with respect to a mobile station and a base station, all routers according to an IPv6 specification may be connected and used.

The case of using the IEEE 802.16 link has been described above. However, exemplary embodiments of the present invention may be applied to the other network technologies that do not provide a neighbor discovery function.