KR20110050192A - Ipv6-based user-defined network system and mobility management method thereof - Google Patents

Abstract

PURPOSE: A user-defined network system based on IPv6 and mobility management method thereof are provided to support handover in order to minimize handover delay time in case a mobile node is moved to an access point area. CONSTITUTION: A user-defined network mobility management server(208) stores an AR(Access Router) list. The user-defined network mobility management server searches for AR by using identification information of NAP(New Access Point) candidate. Identification information of NAP candidate receives a prefix request signal from a mobile terminal. After the server searches for the prefix of the AR, the server transmits prefix information to a mobile node.

Description

IPv6-based user-defined network system and mobility management method

The present invention relates to an IPv6-based custom network system and a mobility management method. The custom network is a network composed of an access point (AP) or an access router (AR) registered by a user regardless of a network management entity, and L2 handover and L3 handover between access points included in the custom network. Is supported.

The present invention enables handover between APs managed by different network management entities through a user-specified network mobility management server storing AP, AR, and mobility management server information managed by two or more network management entities constituting the custom network. The present invention relates to a custom network system and a mobility management method.

Mobility management is a function to prevent a communication session from being disconnected even when a mobile node moves between different networks in a mobile communication network. The purpose of mobility management is to continuously manage where the subscriber station is located in the mobile communication network so that various wireless Internet service functions can be delivered to the terminal.

Many solutions have been proposed to ensure the mobility of mobile nodes. Examples include Mobile IPv4, Mobile IPv6, Hierarchical Mobile IPv6, and Proxy Mobile IPv6 as presented by the IETF. Fast handover Mobile IP version 6 (FMIPv6) is an improved protocol in Mobile IPv6. This is specified in Request For Comments (RFC) 4068. FMIPv6 proposes a method for reducing packet loss as well as handover latency in Mobile IPv6.

FMIPv6 proposed a method of assigning a care-of address to the next AR to which the mobile node moves, so that the mobile node can immediately access the mobile node when it moves to the next AR. However, FMIPv6 cannot apply the FMIPv6 protocol because the mobile node does not know the information of the next AR when the mobile node accesses the Access Router (AR) belonging to different ISP. In more detail, in order to generate NCoA address addresses, network prefix information of a NAR (New Access Router) is required, but if the NAR is operated by a network management entity different from a PAR (Previous Access Router), the NAR network There is a problem that the prefix information is unknown.

In addition, because the mobile node anticipates the AR to move, NCoA (New Care-of Address) is allocated in advance by automatic address generation, which causes packet loss and handover delay when the mobile node moves to an unexpected NAR. do.

On the other hand, if a mobile node moves between zones managed by different Internet Service Providers (ISPs), if mobility management is not provided, the previously disconnected communication from the previous ISP is completely disconnected and the information is received from another ISP to reset the Internet. You will have to get access services. This will bring disconnection of application services that need to provide real time services such as VoIP. Therefore, there is a need to provide seamless communication service by supporting mobility management that does not incur packet loss even between different ISPs.

The technical problem to be achieved by the present invention is to solve the problems of the prior art as described above, when the mobile node is moved to the area of the access router or access point different network management subject, to support the handover to ensure mobility An IPv6-based custom network system and mobility management method are provided.

Another technical problem to be solved by the present invention is to provide a real-time service by supporting a fast handover to minimize handover delay time when a mobile node moves to a different access router or access point area. It is to provide an IPv6-based custom network system and mobility management method for seamlessly supporting application services such as Voice over IP (VoIP) requiring time service.

Another technical problem to be achieved by the present invention is an IPv6-based protocol that enables fast handover in a custom network with minimal modification to APs and ARs developed based on the Fast handover for Mobile IP version 6 (FMIPv6) standard. It is to provide a custom network system and mobility management method.

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

According to an aspect of the present invention, an IPv6-based custom network system according to an aspect of the present invention provides a NAP when a signal strength received from a PAR (Previous Access Router) through a current access point (CAP) is less than or equal to a handover preparation threshold. (New Access Point) NAR (New Access Router) which transmits a prefix request signal containing identification information of a candidate to a user-specified network mobility management server and manages the NAP candidate stored in a prefix request response signal received in response thereto. ) Stateless auto configuration of NCoA (New Care-of Address) using the prefix information of the candidate, and when the signal strength is less than the threshold for handover, NAP is selected from the NAR candidates by selecting NAP from the NAP. After selecting, the signal for requesting a binding update to the NCoA registered in the NAR is used. A mobile node that transmits to a user-specified network mobility management server and performs L2 handover to the NAP; And an AR list including prefix information of an access router (AR) constituting a user specified network and an AP list managed by each AR included in the AR list, and stored in the prefix request signal received from the mobile terminal. Inquiring an AR that manages the AP in the AP list using the identified NAP candidate identification information, inquiring the prefix of the AR in the AR list, and storing the inquired prefix information in the prefix request response signal. And a user-specified network mobility management server transmitting to the mobile node.

According to another aspect of the present invention, there is provided a mobility management method in an IPv6-based custom network system including an AR list and prefix list of an AR (Access Router) constituting a custom network. Storing a list of APs managed by each AR included in the AR; Using the identification information of the NAP candidate New Access Point (NAP) stored in the received prefix request signal, inquiring an AR that manages the AP in the AP list, and inquiring the prefix of the AR in the AR list, Acquiring the queried prefix information into the prefix request response signal and transmitting the received prefix information to the mobile node; And an NAR associated with the NCoA stored in the received address duplication check request signal when an address duplication check request signal containing an NCoA (New Care-of Address) automatically generated using the transmitted prefix information is received. And transmitting an address duplication check request signal to a candidate, receiving an address duplication check result from the NAR candidate, and transmitting the duplicate address check request signal to the duplication check request signal transmitting terminal as a response to the duplicate check request signal.

According to another aspect of the present invention, there is provided a mobility management method in an IPv6-based user-defined network system, in which signal strength received from a PAR (Previous Access Router) through a CAP is handovered. Transmitting a prefix request signal containing identification information of a NAP candidate to a user-specified network mobility management server, when the reference value is less than the preparation reference value; Automatically randomly generate a New Care-of Address (NCoA) using prefix information of a NAR candidate that handles the NAP candidate stored in the prefix request response signal received in response to the prefix request signal. auto configuration); And selecting a NAR from the NAR candidates by selecting a NAP among the NAPs when the signal strength is less than a handover performance reference value, and then sending a signal to the user-specified network mobility management server to request a binding update to the NCoA registered in the NAR. Transmitting and performing L2 handover to the NAP.

According to the present invention as described above, even if the mobile ISP moves to the area of the different access router or access point, the management ISP supports handover to ensure mobility, so that the mobile node initially connected to the home network maintains the connection. Therefore, even when entering a communication area of an access router or an access point managed by an ISP different from the home network, the connection can be maintained.

In addition, VoIP (Voice over IP), which requires the support of a real time service by supporting a fast handover that enables the management ISP to minimize handover delay in handover between different access routers or access points, There is an effect that can seamlessly support application services such as.

First, some terms used in the present specification will be defined.

A mobile node is a mobile terminal supporting IPv6.

A Current Access Point (CAP) is an AP to which the mobile node is connected.

A PAR (Previous Access Router) is an AR that governs the CAP.

A NAP (Next Access Point) is an AP to which the mobile node is connected after L2 handover, and a NAP candidate is one or more APs adjacent to the mobile node that can receive a signal at the time of L2 handover by the mobile node. . The NAP is one AP selected from the NAP candidates.

The NAR (Next Access Router) is an AR that governs the NAP. The NAR candidate is one or more ARs that govern the NAP candidate. The NAR is one AR selected from the NAR candidates.

New Care-of Address (NCoA) is a temporary address that can be used in the subnet of the NAR candidate. The mobile node can generate the NCoA directly from its MAC address and the network prefix value of the NAR by a stateless auto configuration method.

The L2 address refers to the address of the data link layer of the Open System Interconnection (OSI) model. The L2 address may be a media access control (MAC) address.

L2 handover means handover at the data link layer end.

The L3 address refers to the address of the network layer of the OSI (Open System Interconnection) model. The L3 address may be an IP address. The IP address is preferably an IPv6 address.

L3 handover means handover at the network layer end.

AR identification information (AR-Info) is information including the L2 address, L3 address and prefix information of the AR.

AP identification information (AP-ID) is information including the L2 address of the AP.

Hereinafter, when an AP having a routing function is used, the AP and the AR may be interpreted to mean the same device. Similarly, CAP and PAR, NAP and NAR, NAP candidate and NAR candidate may also be interpreted to mean the same device.

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

Hereinafter, the present invention will be described with reference to a block diagram or a flowchart for explaining a IPv6-based user-defined network system and a mobility management method according to embodiments of the present invention. At this point, it will be understood that each block of the flowchart illustrations and combinations of flowchart illustrations may be performed by computer program instructions. Since these computer program instructions may be mounted on a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, those instructions executed through the processor of the computer or other programmable data processing equipment may be described in flow chart block (s). It creates a means to perform the functions. These computer program instructions may be stored in a computer usable or computer readable memory that can be directed to a computer or other programmable data processing equipment to implement functionality in a particular manner, so that the computer program or computer readable instructions can be stored therein. It is also possible for the instructions stored in the memory to produce an article of manufacture containing instruction means for performing the functions described in the flowchart block (s). Computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operating steps are performed on the computer or other programmable data processing equipment to create a computer-implemented process to generate a computer or other programmable data. Instructions for performing the processing equipment may also provide steps for performing the functions described in the flowchart block (s).

In addition, each block may represent a portion of a module, segment, or code that includes one or more executable instructions for executing a specified logical function (s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of order. For example, the two blocks shown in succession may in fact be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending on the corresponding function.

First, the concept of a user defined network defined in the present invention will be described with reference to FIG. 1. 1 is a conceptual diagram of a user-specified network.

The user-defined network may be defined as a logical network of the user's point of view including wireless LAN networks that can be accessed by subscribing to a WLAN service of an ISP or configuring a private WLAN by itself. Hereinafter, a network constituting the user specified network will be referred to as a designated unit network. However, it should be noted that the designated unit network is limited to being based on IPv6.

The designated unit network may include an ISP to which the user subscribes. The ISP may be interpreted as a business entity providing an internet access service, and the like as a business entity providing a wireless LAN access service in the present invention. The ISP may include a public ISP that provides a service to a student, a school staff, etc. in a general ISP that provides a paid service, a school, or the like. In addition, the ISP provides a wireless LAN access service within a certain area, and it may be assumed that there is a shaded area where the access service is not provided in at least some areas where other ISPs provide the wireless LAN access service.

In addition, the designated unit network may be directly configured by the user, or may include a private WLAN that is allowed to access the user. The private wireless LAN is assumed to configure a wireless LAN by installing an access point. The private wireless LAN provides a network address translation (NAT) function and a dynamic host configuration protocol (DHCP) function to operate as a mobility management server. It is preferable to include an apparatus to make. For example, it may be assumed that the access point is a private WLAN configured as an access router or a wireless router providing the NAT function.

In FIG. 1, it is assumed that a user who uses the mobile node 100 is a user who can access the private WLAN 120, the ISP WLAN 122, and the public WLAN 124. The user may configure a user designated network 126 to which a private WLAN 120, an ISP WLAN 122, and a public WLAN 124 are designated as a designated unit network. On the other hand, the user may configure a user-defined network including only the private WLAN 12, ISP WLAN 122 as a designated unit network. That is, a user-specified network may be understood as a network configured by adding a WLAN network that a user wants as a subject.

However, since the user-defined network according to the present invention has a purpose of supporting seamless mobility of the mobile node, one or more WLAN networks constituting the user-defined network may have respective service providing areas. It is desirable to at least partially overlap.

As shown in FIG. 1, the mobile node 100 of the user who configures the custom network 126 is the AP 1 102, AP 2 104, AP 3 106, AP 4 108, and AP 5. Assuming that the inside of the cell of step (110) sequentially passes, according to the user-defined network mobility guarantee method of the present invention, when moving from the cell of AP 1 (102) to the cell of AP2 (104) and of the AP 3 (106) When moving from a cell to a cell of the AP 4 108, despite the different subjects that operate each AP, it is possible to seamlessly transmit data by supporting L2 handover and L3 handover.

Hereinafter, the configuration and operation of an IPv6-based custom network system according to an embodiment of the present invention will be described with reference to FIG. 2.

In FIG. 2, it is assumed that the owner of the mobile node 200 sets up the designated user network 256 as the private unit WLAN 250, the ISP A 252, and the ISP B 254 as the designated unit network. In addition, it is assumed that the mobility management server role of the private WLAN 250 is performed by the AP 1 202 having a NAT function. That is, AP 1 202 may be referred to as an access router or a wireless router.

As shown in FIG. 2, the user-defined network system according to the present embodiment is operated by a mobile node 200, a user-defined network mobility management server (UDN MM server) 208, and an ISP. Includes mobility management server (210, 212).

Hereinafter, a handover operation when a mobile node located in a cell of AP 1 202 included in private WLAN 250 moves into a cell of AP 3 206 operated by ISP B 254. The explanation is centered. That is, the user designated network may be composed of two or more designated unit networks, and the PAR 208 and the NAR 207 may belong to different designated unit networks. In addition, the designated unit network is an AP of another designated unit network constituting the user-defined network to operate at least one AP in an adjacent location so that even if the mobile node is handed over to provide a real-time service without interruption It is preferably a network. That is, the area of each designated unit network must have overlapping regions to enable handover between each designated unit network.

The mobile node 200 is a terminal having a communication module, and may be, for example, a laptop or a smartphone. The communication module may support at least one of wireless LAN, 2G (Generation) mobile communication, 3G (Generation) mobile communication, 3.5G (Generation) mobile communication, and 4G (Generation) mobile communication. The 2G mobile communication may be Global System for Mobile communications (GSM), Interim Standard 95 (IS-95). In addition, the 3G mobile communication may be Wideband Code Division Multiple Access (W-CDMA) or CDMA2000. In addition, the 3.5G mobile communication may be HSDPA (High Speed Downlink Packet Access), HSUPA (High Speed Uplink Packet Access). In addition, the 4G mobile communication may be WiMAX, Long Term Evolution (LTE) according to IEEE 802.16. However, the mobile node 200 is limited to supporting IPv6.

If the wireless signal strength received from the currently connected AP 1 202 is less than or equal to the handover preparation threshold (S250), the mobile node 200 detects an adjacent AP and generates NAP candidate identification information including identification information of the detected AP. do. The identification information of the AP may be at least one of a MAC address and a Basic Service Set Identifier (BSSID). The detection may be to broadcast an AP probe message to collect identification information of the AP responding to it. The NAP candidate identification information in FIG. 2 is assumed to be composed of identification information of AP 2 204 and AP 3 206.

The detection is not performed only when the wireless signal strength is less than or equal to the handover preparation threshold (S250), but may be performed periodically. That is, the mobile node 200 periodically manages a list of neighboring APs by broadcasting an AP probe message, or receives a beacon message broadcast from a neighboring AP to receive a beacon message of the neighboring AP that is currently broadcasting a beacon message. You can manage the list. When the mobile node manages the neighbor AP list by periodically detecting the neighbor AP, when the received radio signal strength is less than or equal to the handover preparation threshold (S250), the neighbor AP list at that time may be the NAP candidate list. have.

Next, the mobile node 200 transmits a prefix request signal containing the NAP candidate identification information to the user-defined user-defined network mobility management server 208 through the AP 1 202 (S252). The mobile node 200 preferably stores connection information of the user-specified network mobility management server 208. The access information of the user-specified network mobility management server 208 may include an Internet Protocol (IP) address.

The prefix request signal is received by the user-specified network mobility management server 208 via AP 1 202 and the Internet. The custom network mobility management server 208 stores information about the custom network 256 to support handover operation of the subscriber mobile node 200 constituting the custom network. The handover includes especially handover between different designated unit networks.

The user-specified network mobility management server 208 stores an AR list including prefix information of an access router (AR) constituting the user-specified network and an AP list managed by each AR included in the AR list.

6 is an example of the AR list. As illustrated in FIG. 6, the AR list may further include mobility management server access information of an L2 address, an L3 address, and an affiliated designation unit network of each AR constituting a user designated network. In FIG. 6, the MAC address is shown as the L2 address, and the IPv6 address is shown as the L3 address. In addition, the mobility management server access information of the designated unit network to which the AR belongs includes an IP address of the mobility management server.

7 is an example of the AP list. As illustrated in FIG. 7, the AP list corresponds to identification information of each AR and identification information (AP-ID) of one or more APs managed by the AR. As shown in FIG. 7, the AP identification information (AP-ID) may include at least one of an AP MAC address and a BSSID.

When the prefix request signal is received from the mobile terminal, the user-specified network mobility management server 208 inquires identification information of the NAP candidate included in the prefix request signal from the AP list as shown in FIG. After grasping the AR that governs, the prefix information of the corresponding AR may be determined from the AR list as illustrated in FIG. 6.

The designated network mobility management server 208 may store specific unit network information for each user. The specific unit network information may include identification information of an operating AR, identification information of an AP, and access information of a mobility management server. For example, if subscriber X configures a custom network using ISP A, ISP B, and ISP C as the designated unit network, the designated unit network information includes all AP identification information, AR identification information, and mobility operated by ISP A. Includes access information of management server, all AP identification information operated by ISP B, AR identification information and access information of mobility management server, all AP identification information operated by ISP C, AR identification information and access information of mobility management server. can do.

In the case of the custom network 256 shown in FIG. 2, the custom unit network is the private WLAN 250, the ISP A 252, and the ISP B 254, so the custom network mobility management server 208 is the ISP A ( 252) and all AP identification information, AR identification information, and access information of the mobility management server operated by each of the ISP B 254 and all AP identification information included in the private WLAN 250, AR identification information, and private WLAN ( Connection information of a device functioning as a mobility management server (250).

The device functioning as a mobility management server of the private WLAN 250 may be an access router having a NAT function and a DHCP function. If AP 1 202 has a NAT function and a DHCP function, AP 1 202 may operate as a mobility management server. In this case, the access information of the mobility management server of the private WLAN 250 may be an IP address of the AP 1 202.

The custom network mobility management server 208 may include access information of a server that can inquire the identification information of the AP without directly storing the identification information and the AR identification information of the AP operated by each designated unit network. have. In this case, it is possible to prevent waste of storage space and to query the latest AP identification information.

The user-specified network mobility management server 208 inquires an AR that manages the AP in the AP list by using identification information of the NAP candidate stored in the prefix request signal received from the mobile terminal, and in the AR list, After querying the prefix of the AR, the requested prefix information is stored in the prefix request response signal and transmitted to the mobile node (S254).

The prefix request signal S252 may be configured as an RtSolPr message based on the Fast handovers for Mobile IP version 6 (FMIPv6) standard, and the prefix request response signal S254 may be stored in a PrRtAdv message based on the FMIPv6 standard.

The mobile node 200 arbitrarily automatically generates a New Care-of Address (NCoA) using prefix information of a NAR candidate that manages the NAP candidate stored in the prefix request response signal. (S256).

The mobile node 200 automatically generates the NCoA at random, and then sends an address duplication check request signal containing the NCoA to the user-defined network mobility management server 208 (S258), and the user-specified network mobility management server 208. ) Transmits the address duplication check request signal to the NAR candidate associated with the NCoA stored in the received address duplication check request signal (S260), and receives an address duplication check result from the NAR candidate (S262). In operation S264, the mobile node 200 automatically generates an NCoA again after randomly generating the NCoA if the address duplication check result does not indicate a validity of the NCoA. The request signal may be retransmitted to the user-specified network mobility management server.

For example, the address duplication check request signal for NCoA1 generated for AP 2 204 will be delivered to the NAR candidate associated with NCoA1. The NAR candidate is preferably interpreted to mean an AR that governs the AP 2 204.

The address duplication check request signal may be an FBU message based on the FMIPv6 standard, but a binding update whether designation flag consisting of one bit of the Reserved field of the FBU message may not be activated. That is, the binding update whether designation flag is not described in FMIPv6, but may be understood to use one bit of the Reserved field.

Upon receiving the FBU message, the user-defined network mobility management server 208 generates an HI message containing the NCoA based on the FMIPv6 standard, and assigns the HI message to the designated unit to which the NAR candidate associated with the NCoA belongs. The NAR candidate associated with the NCoA may be transmitted through a mobility management server of a network.

In addition, the address duplication check result is stored in a HAck message based on FMIPv6, and is transmitted to the user-defined network mobility management server, and when the HAck message is received, the user-defined network mobility management server receives a FBAck message based on FMIPv6. May be generated and transmitted to the mobile node, but the binding update whether designation flag consisting of one bit of the Reserved field of the FBAck message may not be activated.

When the mobile node 200 moves to the jurisdiction of ISP B (S266), assuming that the strength of the signal received from the AP 1 202 falls below the threshold for performing the handover, the mobile node 200 the NAP. One of AP 2 204 and AP 3 206 included in the candidate list is selected as the NAP.

The handover preparation reference value and the handover execution reference value will be described with reference to FIG. 3. 3 is a graph illustrating the strength of a signal received from a NAP and a received signal strength indication (RSSI) as the mobile node moves away from the CAP. The T1 value indicated on the RSSI axis of FIG. 3 may be interpreted as indicating the handover preparation reference value and the T2 value indicating the handover performance reference value. That is, when the strength of the signal received from the CAP is less than T1, the handover is prepared. If the strength of the signal received from the CAP is less than T2, the handover is performed. Therefore, when the RSSI value falls below one reference value, the time required for handover can be saved rather than performing the handover. Hereinafter, the T1 value means the handover preparation reference value, and the T2 value means the handover performance reference value.

The criterion for selecting the NAP may be, for example, the number of mobile nodes connected to the AP and the strength of a received signal. That is, the AP with the smallest number of mobile nodes currently connected or the AP with the strongest signal strength may be selected. Assuming that the mobile node 200 selects AP 3 206, which is stronger than the signal received from AP 2 204 and AP 3 206, as the NAP, the mobile node 200 accesses AP 3 206. In step S268, a signal for requesting a binding update to the NCoA registered in the NAR 207 having jurisdiction is requested to the user-specified network mobility management server 208.

The signal for requesting a binding update (S268) is an FBU message based on FMIPv6 in which a binding update designation flag consisting of one bit of the Reserved field is activated, and the custom network mobility management server 208 receives the FBU message, The FARck message based on FMIPv6 is transmitted to the NAR 207 through the mobility management server 212 of the NAR 207 designated assignment unit network 254, and the mobile node 200 receives one of the reserved fields through the PAR 203. An FBAck message with a flag indicating whether to update the binding consisting of a bit may be transmitted.

In addition, the PAR 203 receives the FBAck from the custom network mobility management server 208 with the binding update designation flag activated, and the NAR 207 receives the FBAck message from the NAR 207 designated unit network 254. When receiving from the user-specified network mobility management server 208 through the mobility management server of 212, a tunnel is formed between the PAR 203 and the NAR 207 (S270), the PAR 203 is a corresponding node ( When receiving a packet destined for the mobile node 200 from a Correspondence Node (CN), the packet is provided to the NAR 207 through the tunnel, and the NAR 207 from the PAR 203 through the tunnel. Buffer the received packet.

After receiving the FBAck message with the binding update designation flag activated, the mobile node 200 may perform L2 handover to the NAP 206 (S272).

Next, when the mobile node 200 transmits a connection completion signal S274 to the NAP 206, the NAR 207 transmits the buffered packets to the mobile node 200.

Hereinafter, the operation of the user-specified network system according to the present embodiment will be described with reference to FIG. 4. 4 is a first signal flow diagram of a user-specified network system according to the present embodiment.

The mobile node searches for the neighboring AR or AP and generates NAP candidate identification information including identification information of the neighboring AR or AP (S400). When the signal strength from the CAP is smaller than T1 (S402), the prefix request signal containing the NAP candidate identification information is transmitted to the user-specified network mobility management server (S404). Hereinafter, the custom network mobility management server will be referred to as a UDN MM server. The UDN MM server queries the AR list and the AP list for prefix information of NAR candidates that manage each NAP candidate according to the stored NAP candidate identification information (S406). The prefix information of the NAR candidates is stored in a prefix response signal and transmitted to the mobile node (S408).

The mobile node randomly generates an NCoA for each NAR candidate using the prefix of the NAR candidate and its MAC address value (S410).

The mobile node transmits a signal for requesting the address duplication check of the generated NCoA to the NAR through the UDN MM server (S412) (S414). The address duplication check and the NCoA assignment result (S416) by the NAR are provided to the mobile node through the UDN MM server (S418) (S420).

When the signal strength from the CAP becomes smaller than T2 (S422), the mobile node selects one AR of the NAR candidates as the NAR (S424), and transmits a binding update signal to NCoA for the NAR to the UDN MM server. (S426). The UDN MM server receives the binding update signal and transmits a tunnel generation signal to the PAR and the NAR (S428 and S430). After the tunnel is created, a packet transmitted from a Correspondence Node (CN) to the mobile node is provided by the PAR to the NAR through the tunnel, and the NAR buffers the packet (S432).

The UDN MM server transmits a response signal to the mobile node in response to the binding update signal transmitted by the mobile node (S434). When the mobile node receives the response signal for the binding update signal, the mobile node disconnects from the PAR and accesses the NAR using the NCoA for the NAR generated in step S410 (S436). When the mobile node transmits a connection completion signal to the NAR (S438), the NAR transmits a buffered packet (S432) to the mobile node (S440).

Hereinafter, an operation compatible with the FMIPv6 standard of the user-specified network system according to the present embodiment will be described with reference to FIG. 5. 5 is a second signal flow diagram of a user-specified network system according to the present embodiment.

The mobile node searches for the adjacent AR or AP and generates NAP candidate identification information including identification information of the surrounding AR or AP (S500). When the signal strength from the CAP is smaller than T1 (S502), the RtSolPr signal, which is a prefix request signal containing the NAP candidate identification information, is transmitted to the user-specified network mobility management server (S504). The RtSolPr signal may include NAP candidate identification information. The NAP candidate identification information may be L2 address values of each NAP candidate. The UDN MM server inquires the prefix information of NAR candidates that manage each NAP candidate according to the stored NAP candidate identification information from the AR list and the AP list (S506). The prefix information of the NAR candidates is stored in a PrRtAdv signal, which is a prefix response signal, and transmitted to the mobile node (S508). The PrRtAdv signal may store AR identification information of the NAR candidates.

The mobile node randomly generates an NCoA for each NAR candidate using the prefix of the NAR candidate and its MAC address value (S510).

The mobile node transmits an FBU signal, which is a signal for requesting the address duplication check of the generated NCoA, to the NAR through the UDN MM server (S412) (S414). The FBU signal is limited to that the binding update designation flag is not activated. Hereinafter, the binding update designation flag will be referred to as a T flag.

The UDN MM server queries the mobility management server of the ISP that manages the NAR candidate in the AR list and the AP list (S514), generates a HI signal, and then, through the mobility management server of the NAR jurisdiction ISP (S516). The HI signal is transmitted to the NAR (S518). The HAck signal resulting from the address duplication check and the NCoA allocation by the NAR (S520) is provided to the UDM MM server through the MM server of the NAR jurisdiction (S522) (S522).

The UDN MM server receives the HAck signal and updates the cache table as shown in FIG. 6 (S524). That is, a CoA value registered for a specific mobile terminal in each NAR candidate and a holding time for maintaining the CoA value in the NAR candidate are stored. That is, the custom network mobility management server further stores a cache table including the mobile node identification information and the NAR candidate for which the mobile node requests an address duplication check for each of the mobile nodes accessing the custom network. The NAR candidate information may include AR identification information, CoA registered for the mobile node during the address duplication check, and a valid time of the CoA.

The user-specified network mobility management server may delete the information of the NAR candidate when the valid time of the CoA included in the information of the NAR candidate included in the cache table expires. This is because, when the valid time expires, the CoA is no longer valid in the corresponding NAR.

When the CoA for the mobile node is already registered in the corresponding NAR by the address duplication check request of the mobile node, the cache table is used to directly use the registered CoA without generating CoA again. That is, when the prefix request signal is received, the user-specified network mobility management server uses the NAP candidate identification information stored in the prefix request signal to query identification information of a NAR candidate that manages a NAP candidate, and the NAR candidate When the identification information of is included in the NAR candidate information included in the cache table, the CoA included in the NAR candidate information is provided in response to the prefix request signal, and the mobile node requests the prefix request. When the CoA information is received in response to the signal, if the NAP candidate receiving the CoA information is selected as the NAP in response to the prefix request signal without performing the automatic generation operation and the address duplication check, The binding update request may be performed using the received CoA.

After updating the cache table (S524), the UDN MM server transmits an FBAck signal to the mobile node (S526). The FBAck signal is limited to that the T flag specified in the Reserved field is not activated.

When the signal strength from the CAP is smaller than T2 (S528), the mobile node selects one AR among the NAR candidates as the NAR, and transmits an FBU signal, which is a binding update signal to NCoA for the NAR, to the UDN MM server. (S530). The FBU signal which is the binding update signal is limited to that the T flag is activated. The FBU signal, which is the binding update signal, may store an NCoA for the NAR.

The UDN MM server receives the binding update signal and transmits a FBAck signal, which is a tunnel generation signal, to the PAR and the NAR (S532, S534, and S536). The FBAck signal may include NAR identification information.

The FBAck signal transmitted to the PAR is limited to that the T flag is activated. That is, if the T flag is activated for the FBAck signal received from the UDN MM server, the PAR transfers the FBAck signal to the mobile node after creating a tunnel with the NAR (S540). If the T flag is not activated, the PAR moves as it is. It may forward to the node (S526).

After the tunnel is created, a packet transmitted from a corresponding node (Correspondence Node) to the mobile node is provided by the PAR to the NAR through the tunnel, and the NAR buffers the packet (S538).

The UDN MM server transmits an FBAck signal, which is a response signal to the binding update signal S530 transmitted by the mobile node, to the mobile node (S540). When the mobile node receives the response signal to the binding update signal, it disconnects from the PAR and accesses the NAR using the NCoA for the NAR generated in step S510 (S542). That is, the mobile node may perform L2 handover to the NAP after receiving the FBAck message with the binding update designation flag activated.

When the mobile node transmits a FNA signal that is a connection completion signal to the NAR (S544), the NAR transmits a buffered packet (S538) to the mobile node (S546).

Hereinafter, a mobility management method in an IPv6-based user specified network system according to another embodiment of the present invention will be described. It should be noted that the technical concept applied to the Ipv6-based custom network system according to another embodiment may be equally applied to the mobility management method in the Ipv6-based custom network system according to the present embodiment.

First, a mobility management method of the UDN MM server will be described.

An AR list including prefix information of an access router (AR) constituting a user-specified network and an access point (AP) list managed by each AR included in the AR list are stored.

Next, using the identification information of the NAP (New Access Point) candidate stored in the received prefix request signal to query the AR jurisdiction in the AP list, and inquire the prefix of the AR in the AR list Thereafter, the queried prefix information is stored in the prefix request response signal and transmitted to the mobile node.

Next, when an address duplication check request signal containing an automatically generated NCoA (New Care-of Address) received using the transmitted prefix information is received, the NCoA associated with the NCoA received in the received address duplication check request signal is received. The address duplication check request signal is transmitted to the NAR candidate, and an address duplication check result is received from the NAR candidate and transmitted to the duplicate check request signal transmitting terminal as a response to the duplicate check request signal.

Next, the mobility management method of the mobile node will be described.

When the signal strength received from the previous access router (PAR) through the current access point (CAP) is less than or equal to the handover preparation threshold, the prefix request signal containing the identification information of the NAP candidate is stored. Send to

Automatically randomly generate a New Care-of Address (NCoA) using prefix information of a NAR candidate that handles the NAP candidate stored in the prefix request response signal received in response to the prefix request signal. auto configuration).

After automatically generating the NCoA, the NCoA may transmit an address duplication check request signal stored in the user-specified network mobility management server.

The address duplication check request signal may be an FBU message based on the FMIPv6 standard, but a binding update whether designation flag consisting of one bit of the Reserved field of the FBU message may not be activated.

If the result of the address duplication check does not indicate the validity of the NCoA, the NCoA may be automatically generated again, and the address duplication check request signal may be retransmitted to the user-defined network mobility management server.

When the signal strength is less than the threshold for handover, NAP is selected from the NAR candidates by selecting the NAP from the NAP, and then a signal for requesting a binding update to the NCoA registered in the NAR is transmitted to the user-specified network mobility management server. And L2 handover to NAP.

The signal for requesting the binding update may be an FBU message based on FMIPv6 in which a binding update whether designation flag composed of one bit of the Reserved field is activated.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

1 is a conceptual diagram of a user-specified network according to the present invention.

2 is a configuration diagram of a user-specified network system according to an embodiment of the present invention.

3 is a diagram illustrating the concept of a handover preparation reference value and a handover execution reference value according to an embodiment of the present invention.

4 is a first signal flow diagram of a user-specified network system according to an embodiment of the present invention.

5 is a second signal flow diagram of a user-defined network system according to an embodiment of the present invention.

6 is an example data configuration of an AR list of a user-specified network mobility management server according to an embodiment of the present invention.

7 is an example of data configuration of an AP list of a user-specified network mobility management server according to an embodiment of the present invention.

8 is an example of data configuration of a cache table of a user-specified network mobility management server according to an embodiment of the present invention.

Claims (20)

When the signal strength received from the previous access router (PAR) through the current access point (CAP) is less than or equal to the handover preparation threshold, the prefix request signal containing the identification information of the NAP candidate is stored. Randomly generates a New Care-of Address (NCoA) by using prefix information of a NAR candidate that transmits to the NAP candidate stored in the prefix request response signal received in response thereto. the NAP is selected from the NAR candidates by selecting NAPs from the NAPs when the signal strength is less than a threshold for performing handover, and then a signal for requesting a binding update to the NCoA registered in the NAR is designated by the user-defined network. A mobile node transmitting to the mobility management server and performing L2 handover to the NAP; And An AR list including prefix information of an AR (Access Router) constituting a user-specified network and an AP list managed by each AR included in the AR list, and stored in the prefix request signal received from the mobile terminal. Inquiring an AR that manages the AP in the AP list using the identification information of the NAP candidate, inquiring the prefix of the AR in the AR list, and storing the inquired prefix information in the prefix request response signal. An IPv6-based custom network system that includes a custom network mobility management server that sends to mobile nodes. The method of claim 1, The custom network is composed of two or more designated unit networks, The PAR and the NAR belong to the different designation unit network different from each other IPv6 based custom network system. The method of claim 2, The AR list, An IPv6-based custom network system further comprising the mobility management server access information of the L2 address, the L3 address, and the membership unit network of each AR constituting the custom network. The method of claim 2, The designated unit network, IPv6-based user specification, which is a network that operates one or more APs in adjacent locations so that even if the mobile node is handed over to an AP of another designated unit network constituting the custom network, a real time service can be provided without interruption. Network system. The method of claim 1, The prefix request signal, Consists of RtSolPr messages based on the Fast handovers for Mobile IP version 6 (FMIPv6) standard. The prefix request response signal is, An IPv6-based custom network system housed in a PrRtAdv message based on the FMIPv6 standard. The method of claim 1, The mobile node, After autonomously generating the NCoA, the NCoA transmits an address duplication check request signal stored in the user-specified network mobility management server. The custom network mobility management server, Deliver the address duplication check request signal to the NAR candidate associated with the NCoA received in the received address duplication check request signal, receive an address duplication check result from the NAR candidate, and provide the same to the mobile node; The mobile node, If the result of the address duplication check does not indicate the validity of the NCoA, an IPv6-based protocol that automatically generates an NCoA again and retransmits the address duplication check request signal to the user-defined network mobility management server. Custom network system. The method of claim 6, The address duplication check request signal, Is an FBU message based on the FMIPv6 standard, The IPv6 based user-defined network system in which a binding update designation flag composed of one bit of the Reserved field of the FBU message is not activated. The method of claim 7, wherein The custom network mobility management server, When the FBU message is received, the NCoA based on the FMIPv6 standard is generated, and a HI message is stored, and the HI message is transmitted to the NCoA through the mobility management server of the designated unit network to which the NAR candidate associated with the NCoA belongs. An IPv6-based custom network system transmitting to the related NAR candidates. The method of claim 8, The address duplication check result is stored in a HAck message based on FMIPv6 and transmitted to the user-specified network mobility management server. When the HAck message is received, the custom network mobility management server generates an FBAck message based on FMIPv6 and transmits it to the mobile node. IPv6-based custom network system that does not activate the binding update flag consisting of one bit of the Reserved field of the FBAck message. The method of claim 1, Signal for requesting the binding update, FMBUv6 based FBU message with binding update flag consisting of one bit of Reserved field enabled. The custom network mobility management server, Receives the FBU message, transmits a FBAck message based on FMIPv6 to the NAR through the mobility management server of the NAR affiliated designated network, the mobile node whether to update the binding consisting of one bit of the Reserved field through the PAR IPv6-based custom network system that sends FBAck messages with the specified flag enabled. The method of claim 10, The PAR receives the FBAck in which the binding update designation designation flag is activated from the custom network mobility management server, and the NAR receives the FBAck message through the mobility management server of the NAR affiliated designated unit network through the custom network mobility management server. When received from, a tunnel is formed between the PAR and the NAR, when the PAR receives a packet destined for the mobile node, provides the packet to the NAR through the tunnel, the NAR is IPv6-based custom network system for buffering the packet received through the tunnel from the PAR. The method of claim 11, The mobile node, An IPv6-based custom network system that performs L2 handover to the NAP after receiving the FBAck message with the flag indicating whether to update the binding. The method of claim 6, The custom network mobility management server, For each of the mobile nodes connected to the user-specified network further stores a cache table including the mobile node identification information and the information of the NAR candidate that the mobile node requested the address duplication check, The NAR candidate information includes AR identification information, CoA registered for the mobile node during the address duplication check, and a valid time of the CoA. The method of claim 13, The custom network mobility management server, IPv6-based user-defined network system to delete the information of the NAR candidate when the valid time of the CoA included in the information of the NAR candidate included in the cache table expires. 15. The method of claim 14, The custom network mobility management server, When the prefix request signal is received, the NAR candidate identification information for NAP candidate is inquired using the NAP candidate identification information stored in the prefix request signal, and the identification information of the NAR candidate is included in the cache table. When included in the information of the NAR candidate, providing the CoA included in the information of the NAR candidate in response to the prefix request signal, The mobile node, When the CoA information is received in response to the prefix request signal, the NAP candidate receiving the CoA information in response to the prefix request signal is selected as the NAP without performing the automatic generation operation and the address duplication check. And, if the binding update request is performed using the received CoA. Storing an AR list including prefix information of an access router (AR) constituting a user designated network and an access point (AP) list managed by each AR included in the AR list; Using the identification information of the NAP candidate New Access Point (NAP) stored in the received prefix request signal, inquiring an AR that manages the AP in the AP list, and inquiring the prefix of the AR in the AR list, Acquiring the queried prefix information into the prefix request response signal and transmitting the received prefix information to the mobile node; And The NAR candidate associated with the NCoA stored in the received address duplication check request signal is received when an address duplication check request signal containing an automatically generated New Care-of Address (NCoA) is received using the transmitted prefix information. Transmitting the duplicate address check request signal to the receiver, and receiving the duplicate address check result from the NAR candidate and transmitting the duplicate check request signal to the terminal as a response to the duplicate check request signal. Mobility management method in network system. When the signal strength received from the previous access router (PAR) through the current access point (CAP) is less than or equal to the handover preparation threshold, the prefix request signal containing the identification information of the NAP candidate is stored. Transmitting to; Random automatic generation of a New Care-of Address (NCoA) using prefix information of a NAR candidate that handles the NAP candidate stored in the prefix request response signal received in response to the prefix request signal stateless auto configuration); And When the signal strength is less than the threshold for handover, NAP is selected from the NAR candidates by selecting the NAP from the NAP, and then a signal for requesting a binding update to the NCoA registered in the NAR is transmitted to the user-specified network mobility management server. And performing L2 handover to NAP. The method of claim 17, Automatically generating the NCoA randomly, Randomly generating the NCoA and transmitting the address duplication check request signal containing the NCoA to the user-specified network mobility management server; And If the result of the duplicate address check does not indicate the validity of the NCoA, randomly generating the NCoA again, and then retransmitting the duplicate address check request signal to the user-defined network mobility management server. A method for managing mobility in an IPv6-based custom network system that includes. The method of claim 18, The address duplication check request signal, A mobility management method in an IPv6-based custom network system, which is an FBU message based on the FMIPv6 standard, and a binding update designation flag composed of one bit of the Reserved field of the FBU message is not activated. The method of claim 18, Signal for requesting the binding update, A method of mobility management in an IPv6-based custom network system, which is an FBU message based on FMIPv6 with a binding update flag consisting of one bit of the Reserved field enabled.

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