KR100759465B1 - Methods and system for available bandwidth-guaranteed high-speed parallel mobility management with multiple identical interfaces in wireless lan/man system - Google Patents

Abstract

A method and a system for managing available bandwidth-guaranteed high-speed parallel mobility with multiple identical interfaces in a wireless LAN/MAN(Local Area Network/Metro area Network) are provided to apply intelligent mobility detection, parallel packet processing, and a spider handover technique to a mobile node, thereby dynamically providing an available bandwidth as much as necessary for the QOS(Quality of Service) request of a user and preventing handover time delay or packet loss according to movement between cells. A method for managing available bandwidth-guaranteed high-speed parallel mobility comprises the following steps of: selecting the AR(Access Router) of a main AP(Access Point) connected to a mobile node as a C-DAR(Current Distribution Access Router) by using mobility detection information from a second layer according to the movement of the mobile node; and connecting plural ARs having the possibility of handover by using the COA of MIPv4(Mobile Internet Protocol version4) or MIPv6, forming plural hierarchical bi-directional tunnels for parallel packet transmission between the mobile node and the C-DAR through the connected ARs and transmitting packets, and transmitting the packets to the C-DAR and between a home agent and a target node.

Description

Method and System for Available Bandwidth-Guaranteed High-Speed Parallel Mobility Management with Multiple Identical Interfaces in Wireless LAN / MAN System}

1 is a diagram showing the degree of decrease in data rate according to radio wave strength

2 is a block diagram illustrating handover between and within an area in a WLAN / man system

Figure 3: Mobility management structure using the same multiple interface according to the present invention

Figure 4: Spider handover algorithm according to the present invention

5 is a packet transmission path of various schemes using a spider handover algorithm according to the present invention.

Figure 6: Parallel distributed algorithm in DAR for distributed packet transmission according to the present invention

7: Binding Entry and Tunneling Packet Structure of Forward Tunnel Applying Spider Handover Algorithm According to the Present Invention

8: Binding Entry and Tunneling Packet Structure of Reverse Tunnel Applying Spider Handover Algorithm According to the Present Invention

Fig. 9: Transmission and reception packet structure by indirect RO using spider handover algorithm according to the present invention

10 is a signal flow chart for inter-region mobility management of a spider handover algorithm according to the present invention.

Figure 11: Threshold for detecting the mobility of a mobile node by the propagation intensity according to the present invention

12: Intelligent mobility detection technique according to the present invention

According to the present invention, a wireless LAN / MAN system is equipped with a plurality of identical LAN or man interfaces on a mobile node, so that when the mobile node moves at a low speed or a high speed, a quality of service for various mobile multimedia applications according to a user's requirements is required. Quality of Service (QoS) relates to a high speed parallel mobility management method and system. Here, the WLAN / man system refers to a WLAN or a wireless man system.

Looking at the prior art related to the present invention, 802.11a (9-54 Mbps, 5 GHz), 802.11b (2- 11 Mbps, 2.4 GHz), 802.11g (6- 54 Mbps, 2.4 GHz), 802.11n (100 Mbps or higher) standards, 802.16 a / b / g (75 Mbps) of the IEEE 802.16 wireless man working group called WiMAX, and the 802.16e standard that supports mobility. The IEEE 802.16 wireless man standard, like IEEE 802.11 a / b / g, is a fixed type that does not support mobility to a mobile node, whereas the IEEE 802.16e Mobile WiMAX standard supports mobility and complies with a subset of 802.16e in Korea. The WiBRO standard (6-15 Mbps, 2.3 GHz) will be developed to provide commercial services in the middle of 2006. Meanwhile, IEEE 802.20 MBWA is developing a mobile wireless man standard led by Qualcomm of the United States.

Such WiFi and WiMAX technologies are expected to play an important role in B3G / 4G, the next-generation mobile communication network based on All-IP. For example, in the case of WiFi wireless LAN, the radio wave distance is limited to about 100 meters at the beginning, and is mainly used for communication in a house, a company, or a university campus. Recently, the radio wave distance has been extended to a radius of 1 km or more, It is gradually applied to outdoor environment communication. Since WiMAX can provide communication capability in a radius of 50 km, it is expected to have a big influence on the new communication structure in the future.

In general, since the strength of the radio wave decreases in inverse proportion to the distance, as the mobile node moves away from the AP (called a base station in WiMAX, hereinafter referred to as an 'AP') in the WiFi and WiMAX WLAN / man systems, bandwidth (i.e., Data rate) is also reduced. For example, the performance of a 3COM wireless adapter supporting standard IEEE 802.11a / b / g, as shown in Figure 1, the bandwidth is reduced as the distance increases. In the case of WiMAX / WiBRO, similar to FIG. 1, the data rate decreases with the strength of the radio wave. In summary, in a wireless LAN / man system based on WiFi and WiMAX / Mobile WiMAX, path loss occurs as the mobile node moves away from an access point, thereby reducing the effective data rate (or bandwidth). In order to provide the guaranteed communication quality of service required for various ubiquitous applications, the mobile node can reduce the data rate according to this distance, and handover time delay and packet loss that can occur when the mobile node moves several cells at high speed. The problem must be solved.

First, referring to the prior art for guaranteeing a communication service quality in a wireless LAN / man system, the IEEE 802.11e is developing a standard for a method of guaranteeing a quality of service (QoS) for providing a real-time multimedia service in a wireless LAN. Is for classifying traffic class in CSMA / CA based MAC layer and providing priority when accessing and waiting for channels to differentiate service quality. The method of increasing bandwidth by securing multiple packet channels during the movement of the present invention. Is different.

In particular, since IEEE 802.11e considers only the priority within one channel, bandwidth reduction is not taken into account, and thus bandwidth cannot be guaranteed while moving. Meanwhile, IEEE 802.11n has developed an ultra wideband wireless LAN technology standard that provides a bandwidth of 100 Mbps or more, but recently, due to technical problems such as radio interference with other LANs, standardization is delayed. IEEE 802.16 also does not provide compensation for data quality degradation due to propagation path loss with distance during the movement of a mobile node.

Next, the mobility management technology for providing a seamless connection without handover time delay and packet loss when the mobile node moves at a low speed or a high speed in the WLAN / man system, these technologies are largely divided into two-layer mobility management and It can be classified into three-layer mobility management technique. Currently, the IEEE 802.11 WLAN standard does not provide a two-layer handover feature that supports seamless connectivity. In the wireless man field, although IEEE 802.16e provides two-layer handover function, it is difficult to guarantee QoS guaranteed real-time multimedia service to mobile nodes because it does not consider the reduction of data rate according to the distance of mobile nodes. .

In connection with the three-layer mobility management technology, the IETF, the Internet standardization organization, has developed several international standards such as mobile IPv4 (MIPv4), mobile IPv6 (MIPv6), hierarchical MIPv6 (HMIPv6), and high speed handover (FMIPv6). Prior arts do not consider quality of service guarantees (bandwidth guarantees) while moving, and in particular, when the prediction of the mobility of the mobile node is wrong in a WLAN or the top, the time delay due to handover may be large.

Lastly, in relation to the research using multiple interfaces in the WLAN / man system, the IETF monami6 working group uses multi-homing technology to provide a certain level of data service quality while the mobile node moves. Efforts have been made, but the emphasis is on distributed system service reliability and load sharing methods for mobile nodes. More specifically, when a mobile node is equipped with several different interfaces (WiFi, CDMA, GSM, etc.), the mobile node's home agent has multiple home addresses, in which case the mobile node has many temporary The focus is on how to bind IP addresses effectively.

In the present invention, in case of binding one home IP address and one temporary IP address based on MIPv4 or MIPv6, parallel distributed packets between an AR (Access Router) and a mobile node located in the middle rather than end-to-end using a plurality of interfaces. It is different from the research currently underway at IETF because it is about the method and system of tunnel construction.

In conclusion, most of the prior art and researches currently being developed or promoted by the IEEE and the IETF do not guarantee the quality of service available to the mobile node, especially when the prediction about the mobility of the mobile node is wrong or moves at high speed. In this case, due to the large delay time and packet loss due to handover, there is a problem that the actual application is not activated in the real-time mobile multimedia services such as VoIP and video conferencing.

The technical problem to be achieved by the present invention is to solve the problems of the prior art, Intelligent Mobility Detection by mounting a plurality of the same LAN or man interface on the mobile node in a wireless LAN / man system (Intelligent Mobility Detection) And parallel packet processing and spider handover algorithms to dynamically provide the available bandwidth as needed according to the user's quality of service requirements while moving. The purpose is to implement an efficient high speed parallel mobility management method and system for preventing packet loss.

It is another object of the present invention to apply the same multi-interface and parallel distributed processing techniques to dynamically guarantee the bandwidth required for a mobile node.

It is another object of the present invention to apply a spider handover algorithm using the same multiple interface so that handover delay time and packet loss do not occur even when a mobile node moves at high speed.

Another object of the present invention is to intelligently detect a movement pattern of a mobile node using the same multi-interface to reduce the handover delay time to the mobile node and determine the optimal handover execution time to efficiently perform the handover. There is.

According to the present invention, a plurality of identical LAN / man interfaces are mounted on a mobile node in a wireless local area network or a wireless metropolitan area network system, and thus, when the mobile node moves between cells at low speed or high speed, various movements are performed according to user requirements. A high speed parallel mobility management method and system for guaranteeing quality of service for a multimedia application.

Hereinafter, the configuration and operation of the embodiments of the present invention with reference to the accompanying drawings, the configuration and operation of the present invention shown and described in the drawings will be described by at least one embodiment, whereby the present invention described above The technical idea and its core composition and operation are not limited.

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FIG. 2 illustrates a wireless network structure in which a mobile node (MN) moves through two areas composed of several APs. Here, the domain refers to a set of AP cells connected to an AR (Access Router) having the same network prefix.

In the present invention, when a mobile node moves between APs, a handover that does not require IP change during movement is called an intra-domain handover, and an IP change is required when handover between APs occurs. It is called Inter-Domain Handover. In a MIPv4 or MIPv6 based inter-zone handover, when a mobile node changes a cell, a change to a new care-of-address (NCoA) is generally required.

In FIG. 2, CAP refers to an AP to which a mobile node is currently connected, that is, a current access point, and NAP refers to an AP of a next cell, that is, a next AP, to which the mobile node will move. In FIG. 2, a CAR refers to an AR to which a mobile node is currently connected through a CAP, that is, a current access router, and a NAR refers to an AR to which a mobile node next accesses through a NAP, that is, a next AR. In FIG. 2, HA refers to a Home Agent (HA) in MIPv4 and MIPv6, and a target node refers to a Correspondent Node (CN).

In FIG. 2, an intra-region handover occurs between CAP1 and CAP2 and an inter-region handover occurs between CAP1 and NAP1. When a mobile node moves in one area at low speed or high speed, only Layer 2 (L2) AP handover is required for seamless connection between APs without changing IP. According to the change, the efficient layer 3 (Layer 3: L3) handover function is required. In the wireless communication environment in a building, there are many areas where radio waves overlap from multiple APs as shown in FIG. 2, and radio waves from a plurality of APs (or base stations in the case of a wireless man) in a large metropolitan city complex even when outdoors. There are many overlapping areas. In particular, as the WLAN / man system is expanded, the WLAN / man system having an overlapping area of several AP cells is expected to become common.

In the present invention, when a mobile node moves in such a radio overlap region, a plurality of identical interfaces are mounted on the mobile node to secure a required bandwidth and a high speed parallel mobility management method without handover time delay or packet loss.

3 illustrates a mobility management structure of a mobile node using the same multiple interface. In FIG. 3, the WLAN / man interface is composed of a physical layer and a data link layer. To provide guaranteed quality of service even when the mobile node moves at high speed, and to prevent time delay and packet loss due to handover, the mobile node has a number of scalable interface interfaces and two-tier mobility associated with it. It consists of management system and three-layer mobility management system.

It is composed of MIH (Media Independent Handover) interface proposed by IEEE 802.21 working group for synchronization of 2nd layer mobility management and 3rd layer mobility management. Here, the dotted line of the MIH block indicates that a proprietary interface having similar functions can be used in addition to the MIH. In FIG. 3, three-layer mobility management instructs execution of a two-layer handover using a command service, and two-layer mobility management uses an event service to indicate the urgency of two-layer handover according to a decrease in received radio wave strength. Notify layer mobility management. Information services are also used for various other information exchanges related to layer 2 and 3 mobility management.

In FIG. 3, the mobile node uses a number of interfaces to identify mobility patterns from nearby APs. The mobility pattern is determined by comprehensively collecting and determining the position of the AP, the moving speed of the mobile terminal, the radio wave strength from the neighboring APs, the related data transmission rate, and the like. This information collection is very difficult to perform with a single network interface and therefore uses multiple interfaces.

In addition, the mobile node attempts to connect with other APs in the vicinity using an interface other than the currently connected interface to compensate for the reduction in the available data bandwidth when the mobile node moves away from the previously connected AP using multiple interfaces. Receiving packets in parallel increases the total available data bandwidth. When handover is needed, an appropriate one is selected from the existing NARs / NAPs, and the handover function is performed at high speed without handover time delay or packet loss.

In addition, the mobility management function using multiple interfaces not only performs high-speed handover while providing guaranteed quality of service using multiple interfaces when the mobile node moves between different cells. In the event of a break, other interfaces not currently in use can be used to discover alternate paths and provide fast recovery of faulty data channels.

4 is a flowchart illustrating a spider handover algorithm (SPIDER) for performing high-speed handover while guaranteeing quality of service (QoS) according to the present invention. It is shown. The second layer mobility management module of FIG. 3 measures the radio wave strength from the currently connected CAP when the mobile node moves, and notifies the third layer mobility management module of the handover preparation or execution status in the second layer. Here, the intelligent mobility detection technique can detect various conditions necessary for preparation or execution for a two-layer handover by using the strength or location information of the radio waves.

If a two-layer handover request is urgent, the spider handover algorithm attempts to connect to the distributed AR (N-DAR) next connected to the currently connected distributed distribution access router (C-DAR). After changing the AR responsible for parallel distributed packet transmission, two-layer handover is executed. If several NARs are already registered in the parallel distributed cache table of the C-DAR, the optimal NAR is selected among the NARs registered in the C-DAR and set as N-DAR to change the parallel distributed AR. If no NAR is connected in the past, the NAP provided by the intelligent mobility detection method finds the corresponding NAR, creates a new temporary IP address, checks for redundancy, and registers the C-DAR.

The mobile node changes the binding cache entries of NAR and C-DAR to distribute data paths (tunnels) for parallel packet transmission between the existing C-DARs and the N-DARs. After performing the over and finally notifying the HA and CNs of the change of the parallel distributed AR, the handover is completed, and the C-DAR deletes the disconnected AR information from its parallel distributed cache table. In this case, one of three packet transmission methods, BT (Bi-Directional Tunneling), Indirect RO (Route Optimization) and Hybrid (Hybrid), are selected between the DAR and the target node. In the case of the hybrid scheme with BT, a reverse tunnel is established from the DAR to the HA and the target node, respectively. In the indirect route optimization scheme, the representative temporary IP address (Representative CoA: RCoA) of the HoA (Home IP Address) of the mobile node is established in the DAR. It forms and registers in the DAR's binding table, and the DAR replaces the source address of the packet destined for the destination node with the RCoA.

The handover operation as described above is moved by using a certain seam (DAR in the present invention) of the spider when the spider moves the spider web, is connected to the spider web at the same time using multiple feet at the same time never connected to the present invention The proposed handover algorithm also uses multiple interfaces to form multiple data channels at the same time with multiple ARs to perform handover between DARs in a connected state.

In Figure 4, the authentication process follows the authentication model of the IETF associated with AAA (Authentication, Authorization and Accounting). Other router solicitations, address redundancy check requests and responses, tunneling and home agent (HA), and target node (CN) binding update messages can also be implemented according to the security mechanisms commonly applied to MIPv6. have.

MITM Attack and DoS Attack prevention technology, Mobile Prefix Solicitation and Advertisement security technology, BU message security technology, Crypographically Generated Home Address, etc. Since various security technologies have been developed, authentication and access rights protocols, message encryption methods, etc. to be applied in the present invention are not limited to the IETF or MIPv6 model.

In the case of FIG. 4, it is important that in most cases, when the mobile node moves away from the current access point, in order to compensate for data reduction, in connection with another AP in advance and exchanging data packets in parallel, a delay caused by handover may occur. No packet loss occurs.

In particular, even when the prediction of the movement of the mobile node is incorrect due to the multipath fading or the radio shading effect in the downtown, it is connected to multiple ARs or APs using multiple interfaces. It can reduce the probability.

FIG. 5 illustrates the parallel transmission of packets transmitted from a home agent and a target node by a mobile node equipped with the same four interfaces by applying the spider handover algorithm of FIG. 4 through C-DAR, NAR1, NAR2, and NAR3. Indicates a scenario being received. In FIG. 5, the home agent intercepts packets when transmitting from CN1 (Correspondent Node1) to MN's HoA (Home Address), and sets its own address as a source address, and C-DAR (Current Distribution Access). Router forwards to the C-DAR by establishing a forward tunnel with the destination address.

The C-DAR de-capsulates the packet received from the HA, checks the destination address, and then uses the entries in the Parallel Distribution Cache Table to determine the destination address. In addition, it is distributed in forward tunnel constructed with NAR3 and transmitted simultaneously in parallel. Other packets destined for CCoA (Current CoA) are forwarded directly to the mobile node without going through the intermediate AR.

NAR1, NAR2 or NAR3 decapsulate the packets received from the C-DAR as described above, and then refer to the entry of the forward binding cache table shown in FIG. 5 and immediately move to the corresponding temporary IP address of the mobile node, namely NCoA1, NCoA2 and NCoA3. Pass each to The mobile node collects packets input to CCoA, NCoA1, NCoA2, and NCoA3, and delivers them to a higher transport layer. In this case, packets received to different temporary IP addresses of each LAN / man interface are decapsulated, and since the source address is the same as CN1, the packet is transparently transmitted to the upper transport layer regardless of the different receiving IP addresses. .

In the parallel distributed packet transmission, unlike multicast transmission using simultaneous binding, each packet is loaded in parallel to each other's output channel at high speed in parallel for multiple packets input to the AR. By spreading and transmitting at the same time, the effective bandwidth available to the mobile node is increased.

When a mobile node transmits a packet to a target node, first, packets received from the upper transport layer are distributed in parallel to a temporary IP address of a LAN / man interface that is currently active, and transmitted simultaneously to the corresponding destination.

In the case of FIG. 5, the mobile node configures the source address as the current temporary IP address when transmitting the packet to the target node, and delivers it to C-DAR, NAR1, NAR2, and NAR3. NAR1, NAR2 and NAR3 upload C-DAR packets using reverse tunnels as opposed to forward tunnels for packet download from C-DAR. The C-DAR checks the destination address of the mobile node or packets received from NAR1, NAR2, and NAR3 through decapsulation, and then checks an entry in the reverse binding cache table to transmit the corresponding packet to the HA through the reverse tunnel.

The HA decapsulates the packet received from the C-DAR and delivers it to the target node using normal Internet routing technology. In FIG. 5, forward and reverse binding binding table entries are shown for each AR.

In FIG. 5, the transfer mode using the forward and reverse tunnels described above between the mobile node and the target node CN is referred to as a bi-direction tunneling mode. In addition to the two-way packet forwarding mode, the spider handover algorithm supports two additional packet forwarding modes: direct route optimization (DRO) and indirect route optimization (IRD).

The direct router optimization method is a method of directly transmitting a packet to a target node without using the aforementioned tunneling by using a temporary IP address as a source address in the mobile node, similar to the router optimization method of MIPv6. In this case, the packet received from the target node from different temporary IP addresses by sending HoA to the IPv6 extension head of the transmission packet by using the Home Address Destination Option defined in Internet Standard RFC 3775 MIPv6. These packets are treated as packets with the same source address HoA in the upper transport layer so that they are delivered transparently.

The target node inserts a HoA into the Type 2 router header of RFC 3775 using the temporary IP address of the mobile node and HoA binding cache information stored inside to extend the temporary IP address head and send it directly to the mobile node. Packets arriving at different temporary IP addresses of the mobile node are transparently delivered to the transport layer using the HoA stored in the Type 2 router header as the source address. FIG. 5 shows a case in which packets transmitted from CCoA and NCoA2 of a mobile node communicate with CN2 by a direct router optimization method.

Unlike the direct route optimization method, the indirect route optimization method collects packets transmitted in parallel from the mobile node in the C-DAR to the target node through the reverse tunnel to the target node, and the target node does not go through the home agent. This is a method of directly transmitting a packet to a mobile node through a network, and uses the home address destination option and the type 2 router header as in the direct router optimization method.

However, unlike direct route optimization, C-DAR transmits HoA using Home Address Destination Option by changing source address to C-RCoA (Current RCoA) when sending packet to target node. When sending a packet received from a node to a mobile node, a HoA is put in a Type 2 router header and distributed in parallel by referring to a parallel distributed cache table. Therefore, the target node receives the packet with the source address C-RCoA from the C-DAR, forwards the packet with the source HoA to the transport layer using the home address destination option, and inserts the HoA in the Type 2 router header when transmitting. Send a packet to C-RCoA with reference.

In FIG. 5, the mobile node uses an indirect router optimization method for communication with CN3. The difference between the direct router optimization method and the indirect router optimization method is almost the same except that the packet is collected in the C-DAR in the middle. In general, the direct router optimization method can expect the best performance in response time or throughput due to the end-to-end parallel distributed packet path, but the handover delay time and the overhead of the handover signal may be large. On the other hand, bi-directional tunneling can expect the best performance in terms of handover latency or signal overhead, but in some cases it may not be as good as direct route optimization in response time at target node by using single route between target node and DAR. have. In general, since wired core networks are mostly high speed, the above phenomenon does not occur.

The indirect router optimization method is an optimal method having both of the above two advantages, but time delay may occur in routing table processing by replacing the source packet address with C-RCoA in C-DAR. For intra-domain handover, hierarchical MIP (Hyper only) changes only the binding cache information related to HoA of C-DAR without the need of sending BU (Binding Update) message from mobile node to home agent or target node. Like HMIP, it reduces the overhead of signal messages and reduces the handover delay time.

Because HA / CN communicates with current Representative CoA (C-RCOA) address of mobile node stored in C-DAR, it is necessary to know about temporary IP address change of mobile node managed by C-DAR. There is no. This has the effect of reducing handover signaling overhead and handover latency like IETF HMIPv6. In FIG. 5, the NCOA may be configured in the form of a link or site-local IPv6 address.

In addition, in the indirect method, a hybrid method of generating only a reverse tunnel between the C-DAR and the target node is shown between C-DAR and CN4 in FIG. In the hybrid method, the C-DAR and the target node communicate directly with each other using a reverse tunnel without going through a home agent, and packets from the target node to the mobile node are delivered in the same manner as the direct route optimization method. Finally, in FIG. 5, CN5 shows a case where a target node communicates by a general IP routing method without using a tunnel when the target node exists in the same area as the mobile node.

6 shows a flowchart of a distributed parallel packet transfer algorithm according to the present invention. The C-DAR checks whether an incoming packet is an INBOUND packet from a home agent or target node or an OUTBOUND packet from a mobile node. If the packet is an INBOUND packet, it decapsulates the packet of the C-DAR to determine the address, and then transmits each packet in parallel to the next destination through the corresponding tunnel by referring to the parallel distributed cache table. At this time, if there is information such as a delay, a failure, or a jam on the route to the corresponding destination, the packet may be transmitted according to the priority of the temporary IP address for the destination mobile node recorded in the parallel distributed cache table.

If the packet from the mobile node is an OUTBOUND packet, it is first checked whether the Bi-Directional Tunneling (BT) method or the indirect route optimization method is used. If the BT method is mixed or mixed, the packet is decapsulated to identify the destination address, and then the packet is transmitted to the destination through the corresponding reverse tunnel by referring to the reverse binding cache table. If indirect route optimization method, source address of receiving packet is replaced with C-RCoA and transmitted to destination. In case of BT or indirect method, when the mobile node accesses various APs during the movement and transmits data in parallel, the mobile node reduces the overhead of modifying the binding and delay time that may be imposed on the home agent and the target node. It makes the handover to the liver more efficient.

7 shows the binding entry and tunneling packet structure of the forward tunnel to which spider handover is applied. In addition to the source and home addresses, the entries of the parallel cache entry include QoS-related information, priority of packet transmission, and survival time. Other information may include a flag or a sequence number. All packets destined for the destination address HoA in the parallel distributed binding cache entry are tunneled to the next address or sent directly. In addition, packets arriving from the destination node to different temporary IP addresses of the mobile node are delivered as packets of destination address HoA to the upper transport layer by MIPv6 Type-2 Router Header Option, regardless of other temporary IP addresses. It is transmitted transparently.

In FIG. 7, the next address CCoA is a temporary IP address directly connected to the C-DAR and serves as a central axis of the layer 3 handover as the main CoA during handover. That is, if the propagation strength of the AP to which the CCoA is connected cannot maintain the connection, handover to another NAR having an AP having strong propagation strength, and change the AR of the CCoA and the corresponding AP to complete the handover.

8 shows a binding entry and tunneling packet structure of a reverse tunnel to which spider handover is applied. In FIG. 8, the OUTBOUND packets destined for the target node from the C-DAR may pass through the ingress filtering of the firewall since the source address is the IP address of the C-DAR. 9 shows a packet structure in which a home address option header of MIPv6 is attached to a destination option header of IPv6. Packets with different source temporary IP addresses sent from different interfaces of the mobile node are transparently delivered to the upper transport layer regardless of the packet source address using MIPv6 home address destination selection when they arrive at the destination node. Also, in the case of direct routing in the area, packets arriving at different temporary IP addresses are transferred to HoA, the same router destination address, by using Type-2 Routing Header.

Figure 10 also shows the transmission and reception packet structure by the indirect route optimization method applied spider handover. FIG. 10 is a signaling sequence diagram for inter-region mobility management using a bidirectional tunneling scheme of spider handover algorithm. In FIG. 10, the mobile node is connected to the C-DAR through NAR1 to communicate with the HA / CN. When the mobile node encounters NAR2, it attempts to connect to NAR2 to satisfy the QoS requirements. First, it exchanges messages such as NAR2, RS / RA, DAD request / response, acknowledgment request / response, etc., and then asks C-DAR for binding for parallel distributed packet transmission. When the C-DAR receives the request, the packet is distributed through NAR1 and NAR2 and delivered to the mobile node in parallel. At this time, if an event that the handover is urgent from the second layer is delivered, the mobile node requests the C-DAR to change the parallel distributed AR, and the C-DAR selects the NAR2, the handover optimum NAR, among the currently connected NARs. Send DAR change request message. At this time, C-DAR transmits all forward and backward binding information which it currently has to NAR2 when requesting DAR change.

NAR2 modifies its forward and reverse binding tables by referring to the binding information received from C-DAR after receiving the DAR change request. And since the packet from NAR1 to HA is not transferred to N-DAR, N-DAR modifies NAR1's reverse binding cache table so that it can send a packet to HA in the future.

The mobile node sends a DAR change acknowledgment message to the C-DAR when it receives an acknowledgment of the reverse binding cache table modification from the NAR. From then on, all packets flowing into the N-DAR by the binding information of the forward binding table are distributed and transmitted in parallel to the mobile node, and are also transmitted to the HA by the backward binding cache table. C-DAR deletes all other binding cache information related to HoA, leaving the binding information for the forward tunnel to N_DAR. The forward tunnel from C-DAR to N-DAR prevents packet loss due to handover.

Finally, the N-DAR sends a binding modification message to the HA, requesting that the HA send a message to the mobile node's HoA forward, establishing a forward tunnel with the HA. The case of applying the Luther optimization method is similar to that described above.

The mobile node exhibits various mobility that is generally difficult to predict during the movement. For example, in the case of highways and trains, the speed of movement is usually predictable, but in large cities, various mobility patterns are displayed depending on the traffic volume on the road or the driving habits of the driver.

The present invention proposes a mobility detector method based on radio wave strength to detect such mobility patterns. FIG. 11 shows changes in radio wave strength and threshold values associated with movement of a mobile node. In FIG. 11, Ts denotes a point of attachment (PoA) switch threshold value, Tp denotes a handover prepared sentence threshold value, and Ta denotes an AP association threshold value.

Layer 2 handover is executed when the radio wave strength from the corresponding NAP is greater than Ts in the connection point switch condition of the intelligent mobility detector method. Therefore, the error caused by radio wave shading effect, multi-pass fading and non-LOS is wrong. Reduces mobility prediction probability, sends binding modification messages to HA / CN after layer 2 handover, ensures available bandwidth, and deactivates the interface being handed over, reducing power consumption, It is configured to reduce the ping-pong effect by determining whether the connected AP is the same AP and adjusting the Ts value.

The mobile node's interfaces are all in a human state, with the exception of one active interface normally to reduce power consumption. If the radio wave strength from the current access AP is less than Tp due to the movement of the mobile node, the mobile node wakes up the human interface to prepare for handover to enter the handover ready state. The activated interface receives radio waves from APs and, when the received radio wave intensity is greater than Ta, associates with the AP and participates in parallel packet transmission. If the 2nd layer handover execution command is issued from the 3rd layer mobility management function, the radio wave strength from the NAP is analyzed and if it is larger than Ts, the 2nd layer handover is executed. As such, three threshold values of Ta, Tp, and Ts are used as a reference for intelligent mobility detection described later. The threshold values are not fixed but depend on the movement pattern of the mobile node.

Figure 12 illustrates an Intelligent Mobility Detection algorithm. In FIG. 12, if the propagation intensity from the CAP, which is the modern-accessed AP, is less than Tp, the mobile node notifies the C-DAR of an urgent need for a two-layer handover, and waits for a three-layer handover execution command from the three-layer handover. In this case, the notification and command for synchronization between the second and third layers may follow the IEEE MIH standard illustrated in FIG. 2.

If the handover is approved from Layer 3, it checks whether the radio wave strength from NAP is insufficient and if it is greater than Ts, executes Layer 2 Handover, and the interface associated with the existing CAP remains inactive to reduce power consumption. Let's do it. Even if the radio wave strength from the CAP is not less than Tp, if the total bandwidth available from the currently connected interfaces is not satisfied to satisfy the quality requirements of the mobile node's real-time multimedia service, the other interface in the human state is activated. As described above, the association is established to form a new packet transmission path.

In order to reduce the signal overhead and delay caused by the ping-pong movement at the boundary point between cells, the mobile node solves the problem by configuring the handover execution threshold value Ts depending on the movement pattern. That is, in the intelligent mobility detection scheme of FIG. 12, the previous AP refers to an AP that the mobile node has accessed just before it is connected to the current AP. In the intelligent mobility detection algorithm, when the mobile node has a movement pattern that moves back and forth between several adjacent cells, the previous AP and the next AP are the same, and in this case, the Ts value is rapidly increased to make the handover difficult. In conclusion, the intelligent mobility detector method enables high-speed handover while significantly reducing signal overhead, packet loss, and time delay due to handover in consideration of the movement pattern of the mobile node.

In summary of the mobility management method of the mobile node in the above-described wireless LAN or the top, a) the mobile node is equipped with multiple interfaces to the mobile node in order to guarantee the available bandwidth and to prevent packet loss and time delay due to handover. Selecting the AR of the primary AP connected to the mobile node as the current distributed AR (C-DAR) by using the mobility detection information from the second layer according to the movement of the node, and b) the total available bandwidth does not satisfy the quality of service requirements. If not, a connection is made using MIPv4 or MIPv6 temporary IP addresses to a plurality of ARs that may be handed over, and a plurality of parallel packet transmission tunnels are formed between the mobile node and the C-DAR through the connected ARs. Transmitting, and transmitting packets of various methods between the C-DAR and HA / CN to reduce handover time delay, and c) the movement of the mobile node. In case of urgent two-layer handover using the mobility detection information from the second layer, the next distributed AR (N-DAR) is selected by applying a spider handover algorithm and the existing parallel packet transmission tunnel between the mobile node and the C-DAR. D) between the mobile node and the N-DAR to form a new parallel packet transmission tunnel, and d) using the intelligent mobility detection technique and the spider handover algorithm, if the access point change condition is satisfied, the second layer handover is executed immediately. Completion of the over, and the binding modification message according to the change is sent to the home agent and the corresponding nodes according to the change of the primary temporary IP address.

In the step of transmitting a packet by forming a plurality of parallel packet transmission tunnels between the mobile node and the C-DAR through the connected ARs, the mobile node weakens the radio wave strength from the AP currently connected while moving, thereby making the bandwidth available. If it does not meet the requirements, the intelligent mobility detector method is applied to select the corresponding AR whose radio wave strength value from the nearby AP that is accessible during the move is greater than the AP-associated threshold (Ta), and applies the spider handover algorithm to apply the temporary IP. After forming the address and checking redundancy and authentication, the AR is registered in the C-DAR to form one or more packet transmission tunnels between the mobile node and the C-DAR, and the multiple ARs are satisfied until the available bandwidth quality of service requirements are satisfied. By using a plurality of parallel packet transmission tunnels are formed to distribute the packets in parallel to transmit.

In the step of transmitting various types of packets to reduce the handover time delay between the C-DAR and the HA / CN, the packets are transmitted by the bidirectional tunnel method between the C-DAR and the HA, and between the C-DAR and the target node. Select one of the two-way tunnel (BT) method, indirect router optimization method, and mixed method, and the indirect router optimization method is configured so that it does not need to send a binding modification message to HA or target node for intra-region movement. It is configured to reduce delay time and signal overhead, and it is possible to use direct router optimization method between mobile node and target node.

In the step of forming a new parallel packet transmission tunnel between the mobile node and the next distributed AR, the intelligent mobility detection technique is a two-layer hand when the radio wave strength from the primary AP is smaller than the handover preparation threshold value Tp according to the movement of the mobile node. Notify the urgent need of the 3rd layer handover, and use the spider handover algorithm to estimate the mobility pattern of the mobile node by examining the location information or the radio wave strength among the connected ARs, and then calculate the optimal AR for the next distributed AR (N-DAR After changing the parallel distributed binding cache table of C-DAR and the reverse binding cache table of other NARs, the existing two-way parallel packet transmission tunnel between the mobile node and C-DAR is removed, and the mobile node and N-DAR between A new bidirectional packet transmission tunnel is formed to distribute packets in parallel.

In the step of transmitting the binding modification message, when the propagation strength from the corresponding NAP is greater than Ts under the connection point switch condition of the intelligent mobility detector method, two-layer handover is configured to perform radio shading, multipath fading, and random loss. Reduces the probability of false mobility prediction due to (non-LOS), sends binding modification messages to HA / CN after a two-layer handover, ensures available bandwidth, and deactivates the handovered interface to reduce power consumption In addition, it is determined whether the previously connected AP and the next connected AP are the same AP to reduce the ping-pong effect by adjusting the Ts value.

In summary, the mobility management system of a mobile node in the above-described wireless LAN or top is a) mobility from the second layer according to the movement of the mobile node in order to ensure the available bandwidth and to prevent packet loss and time delay due to handover. Multiple interfaces mounted on the mobile node to select the AR of the primary AP connected to the mobile node as the C-DAR using the detection information, and b) the sum of the total available bandwidths using the intelligent mobility detector method satisfy the quality of service requirements. In case of failing to do so, MIPv4 or MIPv6 ephemeral IP addresses are connected to a plurality of ARs that may be handed over, and a plurality of parallel packet transmission tunnels between the mobile node and the C-DAR through a plurality of connected ARs. Means for transmitting various packets between the C-DAR and the HA / CN, and c) from the second layer according to the movement of the mobile node. In case of urgent two-layer handover using gender detection information, a spider handover algorithm is applied to select a N-DAR to be moved based on the multiple parallel packet transmission tunnels between the mobile node and the C-DAR. Means for forming a new parallel packet transmission tunnel between the network and d) using the intelligent mobility detector method and spider handover algorithm, if the access point change condition is satisfied, the second layer handover is executed immediately to complete the handover, and the primary temporary IP address. It consists of means of sending binding modification message that occurs according to the change to home agent and corresponding nodes.

In the means for transmitting the packet between the C-DAR and the HA / CN, the intelligent mobility detector method is applied when the available bandwidth does not satisfy the quality of service requirements due to the weakening of the radio wave strength of the AP currently connected while the mobile node is moving. Select the AR whose radio wave strength value from the nearby AP accessible from the mobile is greater than the AP-associated threshold value (Ta), apply the spider handover algorithm to form a temporary IP address, verify redundancy and authentication, and then apply the AR. By registering with the C-DAR to form one or more packet transmission tunnels between the mobile node and the C-DAR, multiple parallel packet transmission tunnels are formed by using multiple ARs until packets satisfying the quality of service requirements, available bandwidth, It consists of means to transmit in parallel.

In the means for transmitting the packet between the C-DAR and HA / CN, in the transmission between the mobile network and the HA / CN, the packet is transmitted to the C-DAR and HA by a bidirectional tunnel method, and the bi-directional communication between the C-DAR and the target node Select one of tunnel method, indirect router optimization method, and mixed method, and the indirect router optimization method is configured not to send binding modification message to HA or target node for intra-region movement. It is configured to reduce the overhead, and is configured to use the direct routing optimization method between the mobile node and the target node.

In the means for forming a new parallel packet transmission tunnel between the mobile node and the N-DAR, the intelligent mobility detection technique is a two-layer handover when the radio wave strength from the primary AP is less than the handover preparation statement Tp according to the movement of the mobile node. Notify the urgent of the 3rd layer handover, predict the mobility pattern of the mobile node by investigating the location information or the radio wave strength among the connected AR based on the spider handover algorithm, select the optimal AR as N-DAR, and then select C Change the contents of the parallel distributed binding cache table of the DAR and the reverse binding cache table of other NARs to remove the bidirectional parallel packet transmission tunnel between the mobile node and the C-DAR, and to create a new bidirectional packet transmission tunnel between the mobile node and the N-DAR. Means for distributing packets in parallel and transmitting them.

In the means for transmitting the binding modification message, two-layer handover is executed when the propagation strength from the corresponding NAP is larger than Ts under the connection point switch condition based on the intelligent mobility detector method, so that radio wave shading effect, multi-pass fading, and random loss are performed. Reduces the probability of false mobility prediction due to (non-LOS), sends binding modification messages to HA / CN after a two-layer handover, ensures available bandwidth, and deactivates the handovered interface to reduce power consumption In addition, it is a means to reduce the actual ping-pong effect by adjusting the Ts value by determining whether the previously connected AP and the next connected AP are the same AP.

The wireless LAN / man system is not used when the connection is lost due to radio interference using the scalable multiple interface interface that prevents handover delay or packet loss by using intelligent mobility detection and spider handover algorithm. The fault path recovery means is provided by finding and connecting to alternative paths using a plurality of interfaces.

The present invention can build a mobile agent system performing a C-DAR function in a wireless LAN or a man built in a system supporting a MIPv4 or MIPv6 router or operate in an intelligent agent server system.

According to the present invention, a wireless LAN / man system is equipped with a plurality of identical LAN or man interfaces to a mobile node to apply intelligent mobility detection, parallel packet processing, and spider handover techniques, so as to make available as needed according to the user's quality of service requirements. While providing bandwidth dynamically, there is an effect of preventing handover time delay and packet loss due to movement between cells.

Another effect of the present invention is to apply the same multi-interface and parallel distributed processing techniques to dynamically guarantee the required bandwidth for the mobile node.

Another effect of the present invention is to apply a spider handover algorithm using the same multi-interface so that handover delay time and packet loss do not occur even when the mobile node moves at high speed.

Another effect of the present invention is to intelligently detect a movement pattern of a mobile node using the same multi-interface to reduce the handover delay time to the mobile node and perform the handover at the optimal time.

Claims (12)

In the mobility management method of a mobile node in a wireless LAN or a man, In order to guarantee the available bandwidth and to prevent packet loss and time delay due to handover, the mobile node is equipped with multiple interfaces and the mobility detection information from the second layer according to the movement of the mobile node is used to determine the Selecting AR as a C-DAR, If the sum of the total available bandwidths does not meet the quality of service requirements, the MIPv4 or MIPv6 ephemeral IP addresses are connected to the multiple ARs that are likely to be handed over, and the mobile node and the C- are connected through the multiple ARs connected. Transmitting a packet by forming a plurality of hierarchical bidirectional tunnels for parallel packet transmission between DARs, and transmitting a packet between a C-DAR, a home agent, and a target node; N-DAR is selected by applying a spider handover algorithm in case of urgent two-layer handover using the mobility detection information from the second layer according to the movement of the mobile node, and the existing parallel packet transmission between the mobile node and the C-DAR. Transferring the tunnel to the N-DAR to form a new parallel packet transmission tunnel between the mobile node and the N-DAR; When the access point change condition is satisfied using the intelligent mobility detection technique and the spider handover algorithm, the second layer handover is executed to complete the handover, and the primary temporary IP address is changed to the home agent and target nodes according to the primary temporary IP address change. An available bandwidth-guaranteed high speed parallel mobility management method comprising transmitting a binding modification message according to the present invention. The method according to claim 1, If the sum of the total available bandwidths does not satisfy the quality of service requirements, the MIPv4 or MIPv6 temporary IP addresses are connected to the multiple ARs that may be handed over, and the mobile node and the C- are connected through the multiple ARs connected. In the step of transmitting a packet by forming a plurality of hierarchical bidirectional tunnel for parallel packet transmission between the DAR, When the mobile node has weakened the radio wave strength from the currently connected AP during the movement, and the available bandwidth does not satisfy the quality of service requirements, the value of the radio wave strength measured from the nearby AP accessible by moving is applied by applying the intelligent mobility detector method. After selecting the AR of AP larger than the value (Ta), applying the spider handover algorithm to form a temporary IP address, checking redundancy and authentication, and registering the AR in the C-DAR, Forming more than one parallel packet transmission tunnel, the step of continuing to select a plurality of AR, and forming a plurality of parallel packet transmission tunnel until the available bandwidth meets the quality of service requirements to distribute the packets in parallel Available bandwidth guarantee high-speed parallel mobility management method consisting of. The method according to claim 1, In the step of transmitting a packet between the C-DAR and a home agent and a target node, The packet is transmitted to the C-DAR and the home agent by the bidirectional tunnel method, and between the C-DAR and the target node, one of the two-way tunnel method, the indirect router optimization method, and the mixed method is used. The indirect routing optimization method is configured to reduce the handover delay time or the signal overhead by configuring the home agent or the target node not to send a binding modification message for the movement in the area, and to directly route between the mobile node and the target node. Fast bandwidth guaranteed high mobility mobility management method configured to use optimization method. The method according to claim 1, In the step of forming a new parallel packet transmission tunnel between the mobile node and N-DAR, The intelligent mobility detection technique notifies the 3rd layer handover that the 2nd layer handover is urgent when the radio wave intensity measured from the main AP is smaller than the handover prepared sentence threshold (Tp) according to the movement of the mobile node, and the spider handover algorithm is applied. After predicting the mobility pattern of the mobile node by investigating the location information or the radio wave strength among multiple connected ARs, the optimal AR is selected as N-DAR, and then the C-DAR parallel distributed binding cache table and the reverse binding cache of other NARs. By changing the contents of the table, it is possible to remove the bidirectional parallel packet transmission tunnel between the existing mobile node and the C-DAR, form a new bidirectional packet transmission tunnel between the mobile node and the N-DAR, and distribute and transmit the packets in parallel. Bandwidth Guaranteed High Speed Parallel Mobility Management. The method according to claim 1, In the step of transmitting the binding modification message, Layer 2 handover is executed when the radio wave intensity measured from the corresponding NAP is larger than the handover execution threshold (Ts) under the access point switch condition of the intelligent mobility detector method. Reduce the probability of false mobility prediction due to LOS), send binding modification messages to home agents and target nodes after a two-layer handover, ensure available bandwidth, and deactivate the interface being handed over to reduce power consumption. An available bandwidth-guaranteed fast parallel mobility management method comprising the steps of reducing the ping-pong effect by determining whether a previously connected AP and a next connected AP are the same AP and adjusting a handover execution threshold value (Ts). In the mobility management system of a mobile node in a wireless LAN or a man, In order to select the AR of the primary AP connected to the mobile node as the C-DAR using mobility detection information from the second layer according to the movement of the mobile node to prevent the packet loss and time delay caused by the handover while ensuring the available bandwidth. A number of interfaces mounted on the mobile node, Using intelligent mobility detector method, MIPv4 or MIPv6 ephemeral IP addresses are connected to multiple ARs that may be handed over if the total available bandwidth does not meet the quality of service requirements. Means for forming a plurality of hierarchical bidirectional tunnels for parallel packet transmission between the mobile node and the C-DAR and transmitting packets between the C-DAR, the home agent, and the target node; N-DAR is selected in case of urgent two-layer handover using mobility detection information from Layer 2 according to the movement of mobile node, and the existing parallel packet transmission tunnel between mobile node and C-DAR is transferred to N-DAR. Means for forming a new parallel packet transmission tunnel between the mobile node and the N-DAR; When the connection point change condition is satisfied using the intelligent mobility detector method and the spider handover algorithm, the second layer handover is executed immediately to complete the handover, and the binding modification message generated by the primary temporary IP address change is the home agent and the target node. Bandwidth guaranteed high-speed parallel mobility management system consisting of means for transmitting to them. The method according to claim 6, Means for transmitting a packet between the C-DAR and a home agent and a target node, When the mobile node has weakened the radio wave strength from the currently connected AP during the movement, and the available bandwidth does not satisfy the quality of service requirements, the value of the radio wave strength measured from the nearby AP accessible by moving is applied by applying the intelligent mobility detector method. After selecting the AR of AP larger than the value (Ta), applying the spider handover algorithm to form a temporary IP address, checking redundancy and authentication, and registering the AR in the C-DAR, Means for forming at least two parallel packet transmission tunnels, wherein said means continues to select a plurality of ARs and forms a plurality of parallel packet transmission tunnels until the available bandwidth satisfies the quality of service requirements and distributes the packets in parallel. Available bandwidth guarantee high-speed parallel mobility management system. The method according to claim 6 or 7, Means for transmitting a packet between the C-DAR and a home agent and a target node,  The packet is transmitted to the C-DAR and the home agent by the bidirectional tunnel method, and between the C-DAR and the target node, one of the two-way tunnel method, the indirect router optimization method, and the mixed method is used. The indirect routing optimization method is configured to reduce the handover delay time or the signal overhead by configuring the home agent or the target node not to send a binding modification message for the movement in the area, and to directly route between the mobile node and the target node. An available bandwidth-guaranteed high-speed parallel mobility management system configured to transmit data using an optimized method. The method according to claim 6 or 7, Means for forming a new parallel packet transmission tunnel between the mobile node and N-DAR; The intelligent mobility detection technique notifies the 3rd layer handover that it is urgent to do the 2nd layer handover when the radio wave intensity measured from the main AP is smaller than the handover prepared sentence threshold (Tp) according to the movement of the mobile node, and based on the spider handover algorithm. Predict mobility patterns of mobile nodes by investigating location information or radio wave strength among existing connected ARs, select optimal AR as N-DAR, and then parallel-distributed binding cache table of C-DAR and reverse binding cache table of other NARs. Available bandwidth consisting of means to remove the bidirectional parallel packet transmission tunnel between the existing mobile node and C-DAR by forming a new method, and to form a new bidirectional packet transmission tunnel between the mobile node and N-DAR to distribute packets in parallel. Guaranteed high speed parallel mobility management system. The method according to claim 6 or 7, Means for sending the binding modification message, Layer 2 handover is executed when the radio wave strength measured from the corresponding NAP is larger than the handover execution threshold (Ts) under the junction switch condition based on the intelligent mobility detector method. Reduce the likelihood of false mobility prediction due to LOS), send binding modification messages to home agent and target node after two-layer handover, ensure available bandwidth, reduce power consumption by deactivating handovered interface, An available bandwidth-guaranteed high speed parallel mobility management system comprising means for reducing a ping-pong effect by determining whether a previously connected AP and a next connected AP are the same AP and changing and adjusting the handover execution threshold value (Ts). The method according to claim 6 or 7, The wireless LAN / man system is not used when the connection is lost due to radio interference using the scalable multiple interface interface that prevents handover delay or packet loss by using intelligent mobility detection and spider handover algorithm. An available bandwidth-guaranteed high speed parallel mobility management system having a means of recovering a fault channel by finding and connecting to alternate paths using multiple interfaces. The method according to claim 6 or 7, In the wireless LAN or DAR, available bandwidth-guaranteed high speed parallel mobility management system that may be built in a proxy router system supporting MIPv4 or MIPv6 or may be built and operated in a separate external mobile agent server system.

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