KR20070041037A - A method of routing and hand over for wibro system - Google Patents

Abstract

The present invention relates to a WiBro system, and more particularly, to a method for providing handover and routing of a WiBro system for improving the efficiency of system operation and quality of service (QoS) of a handover service by configuring a WiBro system based on mobile IPv6. .

The present invention is a method for providing handover and routing of a WiBro system, which reduces a delay time when a terminal handovers to a target ACR and solves an ingress filtering problem in a WiBRO system based on mobile IPv6.

In the present invention, the ACR does not need to process the FA function in the WiBro system built on the mobile IPv6, and only the Router Advertisement function is used, thereby reducing the load of the ACR and reducing the unit cost.

WiBro, WiBro System, Mobile IPv6, MSS, RAS, ACR.

Description

A method of routing and hand over for Wibro system

1 is a configuration diagram for processing a handover between the ACR of the conventional mobile IPv4-based WiBro system,

2 is a flowchart illustrating a handover operation between an access control station (ACR) of a conventional mobile IPv4-based WiBro system.

 3 is a configuration diagram for processing handover between ACRs of a mobile IPv6 based WiBro system according to the present invention;

4 is a flowchart illustrating a handover operation between an access control station (ACR) of a mobile IPv6-based WiBro system according to the present invention;

5 is a flowchart illustrating a routing optimization in the WiBro system of the present invention.

<Description of Major Symbols in Drawing>

80: MSS (Mobile Subscriber Station)

82, 83: RAS (Radio Access Station)

84, 85: ACR (Access Control Router)

86: CN (Correspondent Node)

88: HA (Home Agent)

90: AAA (Authentication Authorization and Accounting)

The present invention relates to a WiBro system, and more particularly, to a method for providing handover and routing of a WiBro system for improving the efficiency of system operation and quality of service (QoS) of a handover service by configuring a WiBro system based on mobile IPv6. .

In general, WiBro (wireless broadband) is a service that enables high-speed wireless Internet access at any time, anywhere, even during stoppages and movements, using various mobile Internet terminals such as PDAs or smartphones, or laptops.

It is an IP-based wireless data system having up-down asymmetric transmission characteristics using a wideband wireless transmission technology of Orthogonal Frequency Division Multiple Access / Time Division Duplex (OFDMA / TDD). It is a high-speed portable Internet service of 2.3GHz frequency band. WiBro refers to a mobile Internet service that provides mobility of more than 60 km per hour and a transmission speed of 1 Mbps. The radio transmission distance of WiBro reaches up to 48 km, which means that it can be used only in service areas called hotspots. Service radius is more than 10 times wider. WiBro technology standard, developed by Korean companies, HPi (high-speed portable internet) is an international technology standard that conforms to IEEE 802.16e, the next-generation wireless broadband transmission technology standard recently approved by IEEE. There is currently no commercial service.

Internet Protocol Version 6 (IPv6) is also known as IP Next Generation (IPng). IPv6 is a set of official IETF specifications.

The most obvious improvement over IPv4 is that the length of the IP address has increased from 32 bits to 128 bits. This expansion provides a response to the concern that the Internet will explode in the near future, which will quickly shorten network addresses. IPv6 has three rules for address types: unicast, anycast (from one host to multiple hosts nearby), and multicast.

In addition, IPv6 can describe options in an extended header, which is only retrieved at the destination, which speeds up the overall network speed. IPv6 expands the header, allowing you to specify mechanisms for authenticating packets, ensuring data integrity, and ensuring confidentiality.

A handover processing in a conventional mobile IPv4-based WiBro system will be described with reference to the accompanying drawings.

1 is a configuration diagram for processing handover between ACRs of a conventional mobile IPv4-based WiBro system, and FIG. 2 is a flowchart illustrating a handover operation between ACRs of a conventional mobile IPv4-based WiBro system.

1 shows a mobile subscriber station (MSS) 20, which is a terminal using WiBro service, a radio access station (RAS) 22 and 23 for processing a role of a base station of a mobile communication system, and an ACR for processing and routing access control. (Access Control Router) (24, 25), HA (Home Agent) (26), CN (Correspondent Node) (28), AAA server (Authentication Authorization and Accounting) (30) that handles authentication and accounting, etc. 32 and an Internet Protocol version 4 (IPv4) network.

Conventional WiBro systems have used the Mobile IPv4 technology established in the RFC 3344 standard to provide mobility.

The access control routers (ACRs) 24 and 25 perform the functions of foreign agents (FAs) to allocate and provide IP addresses to the MSS 20, and provide a care of address (CoA) indicating an address. In this case, the CN 28 transmits the received packet to the MSS 20 through tunneling through the HA 26.

The access control routers (ACR) 24 and 25 connect the MSS 20 to an Internet Protocol version 4 (IPv4) network.

The HA 26 is located on the home link in the core network. When the MSS 20 hands over to another ACR, the HA 26 receives the packet and transfers the packet to the link where the MSS is located. The AAA server 30 transmits the packet to the MSS 20. To handle the authentication and billing addition.

Transmission of packets from CN 28 to MSS 20 is via tunneling via HA 26, whereas packet forwarding from MSS 20 to CN 28 does not go through HA 26. Are sent without.

2 is a flowchart illustrating a handover operation between ACRs of a conventional mobile IPv4 based WiBro system.

Meanwhile, in the handover procedure of the conventional mobile IPv4-based WiBro system, the signal strength of the serving RAS 22 after scanning the surrounding RAS 23 in the MSS 20 has a threshold ( If it is less than the threshold and it is difficult to continue the service, it starts by sending a handover request.

Thereafter, a handover procedure is performed between the MSS 20 terminal and the serving RAS / target RAS 22, 23.

The network re-entry procedure at handover can be simplified by informing the context information of the MSS terminal acquired through the backbone from the destination RAS 23 in the serving RAS 22 in advance.

A handover procedure using mobile IPv4 will be described.

In FIG. 2, the MSS 20 serving as the terminal, the serving RAS 22 and the serving ACR 24 to which the MSS 20 is wirelessly connected, and the destination RAS 23 and the destination ACR 25 to which the MSS 20 is handed over are illustrated in FIG. ) And the HA 26 to handle the handover.

The MSS 20 determines a recommended RAS (Recommended RAS) based on the surrounding RAS scanning results, and serves a MOB-MSHO-REQ message including CILP values of the scanned RASs and SLP, which is address information. RAS) (22).

The serving RAS 22 sends a recommended RAS (Recommended RAS) in the MOB-MSHO-REQ message sent by the MSS 20 to the requested bandwidth information and the HO-pre-notification backbone message including QoS. Transmit (S32).

Recommended RASs (23) that receive the HO-pre-notification backbone message sent by the Serving RAS (22) receive the requested bandwidth (BW) information and the calculated result for QoS. ) Is transmitted to the serving RAS 22 as a HO-pre-notification-response response message (S34).

The serving RAS 22 sorts the response message received in the above-mentioned steps from the recommended RAS 23 in the above-described steps, in order of the RAS 23 satisfying the required bandwidth and QoS, and then the MOB. -Send to the MSS 20 using the BSHO-RSP message (S36).

The MSS 20 determines an appropriate target RAS (Target RAS) 23 from the message transmitted from the serving RAS 22 and transmits it to the serving RAS 22 using the MOB-HO-IND message (S38). ).

Serving RAS 22 provides information for HO Optimization to target RAS 23 to shorten handover time.

Information for handover optimization (HO Optimization) is the TLV value of SBC-REQ / PKM-xxx / REG-REQ, where the IP address allocation in the REG-REQ is mobile IPv4.

Serving RAS 22 serves a target target RAS (HO-confirm) message including the calculated required bandwidth (WW), calculated QoS information, and the like through the ACR 25. 23) (S40).

The target RAS 23 transmits a fast ranging message including the MSS MAC address to the MSS 20 (S42).

A non-competitive initial ranging procedure is performed between the MSS 20 and the target RAS 23 using the RNG-REQ / RSP message as shown in FIG. 2. The RNG-RSP message includes entry information to be optimized (S44 to S46).

After completing the initial ranging procedure in the above-described step, between the MSS 20 and the target RAS (Target RAS) 23 through the DSA-REQ / DSA-RSP / DSA-ACK process as shown in Figure 2 (service flow) Make a provisioned connection of (S48 ~ S52).

In the above step, the destination RAS checks the authority of the required service of the MSS 20 and checks whether the QoS requirement can be satisfied.

The MSS 20 transmits agent solicitation to the target ACR (FA) 25 and induces agent advertisement of the target ACR (FA) 25 (S54). .

The destination ACR (FA) 25 sends an Agent Advertisement to the MSS 20 in response to Agent Solicitation and the MSS determines whether its subnet location is the home subnet or external. It can determine whether it is a subnet and whether or not it moves between home and external subnets and between different external subnets.

In addition, the Agent Advertisement transmitted from the target ACR (FA) 25 provides a Care of Address (CoA), which is address allocation information that can be used even when handed over to the MSS 20 (S56). .

The MSS 20 transmits a registration request message to the target ACR (FA) 25, and the target ACR (FA) 25 transmits a registration request message to the HA 28 (S58 to S60).

CoA, which is newly allocated address information included in Agent Advertisement, is transmitted to the HA 26 to transmit a registration request message, so that the service can be continuously maintained even when the MSS 20 is handed over.

When the MSS 20 receives a registration response to the registration request message from the destination ACR (FA) 25 via the HA 26, the HA 26 has a new IP address of the MSS 20 terminal. It will be registered to use the service as (S62 ~ S64).

Tunneling is created between the MSS 20 and the destination ACR (FA) 25.

After completing the network entry procedure as described above in steps S48 to S64, the destination RAS 23 sends the serving RAS 22 the I-am-host-of which includes the MSS MAC address information and the like. The message is sent to complete the handover procedure (S66).

The serving RAS 22 releases resources allocated to the MSS 20 to complete the handover.

As described above, FIG. 2 has described the processing of handover between ACRs, such as controllers, in the MSS 20, which is a WiBro terminal in the WiBro system.

The conventional mobile IPv4-based WiBro system has some problems in supporting mobility of terminals because the IPv4 protocol itself does not consider mobility or scalability at the time of design.

First, in mobile IPv4 network, MSS existing in external network can send packet directly to CN to communicate with, but CN must be tunneled through HA to send packet to MSS, mobile terminal located in external network. The situation that occurs because the routing path is not optimized is called a triangular routing problem. The routing problem of the WiBro system, which must guarantee mobility of up to 60 km / h, is a problem that can cause serious delays in providing real-time traffic.

Secondly, for ingress filtering, for security reasons, many modern routers are configured to perform a policy called ingress filtering. Ingress filtering is a feature that blocks packets with invalid source addresses from being forwarded. If the MSS sends a packet using its home address as the source when the ACR is performing ingress filtering, the home address is not an address belonging to the network where the mobile subscriber station (MSS) is located. This causes the ACR (Access Control Router) to discard the packet.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem. In the WiBro system based on mobile IPv6, the WiBro system reduces the delay time when the MSS terminal hands over to the target ACR and solves the ingress filtering problem. An object of the present invention is to provide a handover and routing providing method.

In the WiBro system handover and routing providing method of the present invention for achieving the above object, in the MSS handovers between the ACR, after completing the initial ranging procedure between the MSS and the target RAS to be handed over, In step 1 of establishing a vision connection, the MSS sends a router solicitation message to the destination ACR, and the destination ACR sends a router advertisement message in response to the message, and the MSS is in a different subnet. Step 3 of identifying the movement has been moved to a new method and generating a CoA with the new IP address information by the specified method, MSS sends a binding update message to the HA to register the CoA, HA, In step 5 in which a binding acknowledgment message is transmitted to the MSS in response to the binding update message of the MSS, the network It completes the network entry procedure.

In addition, step 4 stores the home address and the CoA to which the MSS accesses the binding cache managed by the HA, and the packet received at the home address of the MSS in the HA to the CoA. And tunneling and transmitting the same to the MSS.

In addition, the present invention is a sixth step of performing a test to send and receive packet data from the CN when the MSS is handed over to register the CoA in the HA, and the MSS sends a binding update message to the CN to address the CoA Step 7 informing that it has moved to, and if the CN is normally processed, sending a binding acknowledgment message to the MSS in response, and the MSS and the CN transmit and receive packet data without passing through the HA. It is done.

In addition, in step 7, the binding update message is transmitted from the MSS to the CN by setting a source address to a newly allocated CoA and inserting its own home address in the home address option. And, CN, by processing the exchange of the source address and the address of the home address option.

In addition, in the sixth step of the present invention, when the test is requested from the MSS to the HA, the HA requests the CN to the CN, and the MSS starts the CoA test between the CNs. Requesting a test to the MSS through the; and performing a test of the CoA between the MSSs in the CN; and the above-described handover and routing scheme of the present invention uses a mobile IPv6 network. It handles handover and routing.

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

3 is a configuration diagram for handling handover between ACRs of a mobile IPv6 based WiBro system of the present invention, and FIG. 4 is a flowchart illustrating handover operation between ACRs of a mobile IPv6 based WiBro system of the present invention. 5 illustrates a routing optimization flowchart in the WiBro system of the present invention.

In the future, the IT environment is expected to be a networking environment in which most devices, including information terminals and information appliances, are connected to the network and all-IP based wired and wireless are integrated.

As such, the transition from IPv4 to IPv6 is considered to be essential, and mobile IPv6 is a technology field that is gaining more attention in recent years as the introduction of IPv6 is being accelerated as a technology for providing mobility.

In contrast to the conventional mobile IPv4, ACR plays the role of a foreign agent (FA), mobile IPv6 handles the role of the FA itself in the MSS WiBro terminal, thus eliminating the need for the FA function.

In addition, because it solves the routing problem that existed in mobile IPv4, MSS WiBro terminal can move to other area at 60km / h, but it is very suitable for WiBro system.

FIG. 3 is a block diagram illustrating a handover between ACRs of a mobile IPv6-based WiBro system according to the present invention. The mobile subscriber station (MSS) 80, which is a terminal using WiBro services, processes the role of a wireless base station. RAS (Radio Access Station) 82, 83, Access Control Router (ACR) 84, 85, HA (Home Agent) 88, Correspondent Node (CN) connecting MSS 80 to mobile IPv6 network 86, an AAA server (Authentication Authorization and Accounting) 900 that handles authentication, and the like, and other servers 92 are shown.

In the mobile IPv6-based WiBro system, since the CoA information is generated by the MSS 80 terminal in the handover process and handles the handover, the FA function in the ACR 84 is not necessary.

When the MSS 80 hands over the home link and connects to another link, the MSS automatically obtains a care of address (CoA), which is a temporary address for the visited link, and places the CoA on its home link. Register with HA 88.

After registering the Colocated Address (CoA) of the MSS 80 with the HA 88, if a packet having the home address of the MSS 80 as the destination is delivered, the HA 88 receives the packet on behalf of the MSS 80. Receive

The HA 88 tunnels the received packet to the destination address by tunneling CoA to the destination address, and the MSS 80 removes the tunneling header from the packet transmitted from the HA 88 to obtain the original packet. Serve

On the contrary, when the MSS 80 transmits a packet to the CN (Correspondent Node) 86, the first packet transmission is delivered to the CN 86 through reverse tunneling of the HA 88.

In this case, the CN registers a CoA indicating new IP address information of the MSS 80 through a method called Return Routability (RR), and after CoA, which is new IP address information of the MSS 80, is registered in the CN 86, two CNs are registered. The nodes can directly communicate with each other without passing through the HA 88.

The ACR 86 plays a role of a router of IPv6, and provides information that an MSS 80 terminal can set by itself using a router advertisement embedded with prefix information. It can be seen that the handover is performed and connected to the RAS of the other ACR 85. This significantly reduces the load on the ACR compared to previous mobile IPv4.

4 is a flowchart illustrating a process of registering a newly allocated CoA of an MSS to an HA in a handover operation flow chart between ACRs of a mobile IPv6 based WiBro system according to the present invention.

In FIG. 4, the MSS 80, which is a terminal, a serving RAS 82 and a serving ACR 84 to which the MSS 20 is wirelessly connected, and an objective RAS 83 and a target ACR 85 to which the MSS 80 is to be handed over. ) And the HA 88 to handle the handover.

The MSS 80 determines that a handover is necessary because the wireless signal with the currently connected serving RAS 82 is weakened, and the surrounding RAS is scanned, and an appropriate recommended RAS (Recommended RAS) is determined and scanned according to the result. A MOB-MSHO-REQ message including an ID, a preamble index, a CINR average value, and address information of one RAS is transmitted to a serving RAS 82 (S300).

Serving RAS (82) is required bandwidth information (Required BandWidth) and QoS information, MSS MAC address information, SFID information to the recommended RAS (Recommended RAS) in the MOB-MSHO-REQ message transmitted from the MSS (80) Transmits an embedded HO-pre-notification message (S302).

Recommended RASs that receive the HO-pre-notification backbone message sent by the serving RAS 82 receive the requested bandwidth (BW) information and the estimated result for QoS. A pre-notification-response response message is transmitted to the serving RAS 82 (S304).

The serving RAS 82 sorts the recommended RASs satisfying the bandwidth and QoS requirements in HO-pre-notification-response response messages received from the recommended RASs. By using the MOB-BSHO-RSP message is transmitted to the MSS (80) (S306).

The MSS 80 selects an appropriate target RAS 83 from a message received from the serving RAS 82, and serves a serving RAS using a MOB-HO-IND message including ID information. RAS) (82) (S308).

The Serving RAS 82 provides the target RAS 83 with the relevant information of the MSS 80 for HO Optimization to shorten the handover time. In the HO optimization information, the TLV value of SBC-REQ / PKM-xxx / REG-REQ and the IP address allocation value in the REG-REQ are mobile IPv6.

In addition, the serving RAS 82 serves a target target RAS through the ACR 84 with a handover confirm message including a calculated required bandwidth (WW), calculated QoS information, and the like. To (83) (S310).

The target RAS 83 transmits a fast ranging message including the MSS MAC address to the MSS 80 (S312).

A non-competitive initial ranging procedure is performed between the MSS 80 and the target RAS 83 using the RNG-REQ / RNG-RSP message as shown in FIG. 4. The RNG-RSP message includes entry information to be optimized (S314 to S316).

After the initial ranging procedure is completed in the above-described steps, the MSS 80 and the target RAS 83 may use a DSA-REQ / DSA-RSP / DSA-ACK message to establish a service flow. Make a provisioned connection (S318 ~ S322).

In the above step, the destination RAS checks the authority of the required service of the MSS 80 and checks whether the QoS requirement can be satisfied.

The MSS 80 transmits a Router Solicitation message to the destination ACR 85, and the destination ACR 85 transmits a Router Advertisement as a response message (S324).

The destination ACR 85 sends a Router Advertisement to the MSS 80 in response to Router Solicitation and the MSS 80 receives the prefix information from the Router Advertisement message. It can determine whether its own subnet is the home subnet or the external subnet, and whether the home subnet and the external subnet can move between different external subnets.

If it is detected that the mobile station has moved to another subnet, the MSS 80 generates a new IP address in order to use the service continuously in the corresponding subnet (S326).

The MSS 80, which has formed the CoA, sends a binding update message to the HA 88, and the home address (the first time the MSS 80 connects to the binding cache managed by the HA 88) Home Address) and the CoA, and the packet data received by the MSS 80 afterwards allows the HA 88 to tunnel and transmit packets entering the Home Address of the MSS 80 to the CoA ( S328).

The MSS 80 registers with the HA 88 a CoA with new IP address information that can continue service in the handed over WiBro system.

If the storage registration of the new CoA of the MSS is normally processed, the HA 88 transmits a binding acknowledgment message to the MSS 80 as a response message (S330).

After completing the optimized network entry procedure of the present invention, the destination RAS 83 transmits an I-am-host-of message including MSS MAC address information to the serving RAS 82. The serving RAS 82 releases resources allocated to the MSS 80 (S332).

FIG. 5 is a routing optimization flowchart in the WiBro system of the present invention. In FIG. 4, after the newly allocated CoA of the MSS 80 is registered with the HA 88, the MSS and the CN 86 are route optimized. It is a flowchart of direct communication without passing through (Home Agent) 88.

FIG. 5 is a procedure called Round Routability, which forms a mutual security relationship by authenticating binding update and binding acknowledgment messages between the MSS 80 and the CN 86 in this step. Protect against invaders.

The MSS 80 terminal transmits a home test init message to the HA 88 for testing of the newly allocated CoA, and the HA 88 transmits to the CN 86 providing packet data.

In addition, the MSS 80 terminal transmits a CoA Test init message to the CN 86, and the CN 86 transmits a home test result message to the MSS 80 terminal via the HA 88. Then, the CN 86 transmits a CoA test result message (S350 to S356).

The MSS 80 updates the binding cache by sending a binding update message to the CN 86.

The CN 86 determines that the MSS 80 has been handed over to a new IP address, registers it, and sends a binding acknowledgment message to the MSS as a response message (S358 to S360).

Thereafter, the packet between the MSS 80 and the CN 86 may transmit packet data directly without being relayed by the HA 88.

When the MSS 80 transmits a packet to the CN 86, the source address is used as a newly allocated CoA, and its home address is inserted into the home address option and transmitted. Maintains a higher layer connection that distinguishes connections by address and port pairs, such as TCP connections, by swapping the addresses of the original source address and the home address option on the CN 86 side. Not only that, but a network that implements ingress filtering can pass through without difficulty.

FIG. 5 shows that the MSS that has been assigned a new CoA initially passes through the HA 88 when receiving data from the CN 86. However, after the MS 86 has grasped and registered new CoA information of the MSS 80, the HA has received the HA. Packet data can be communicated directly without passing through (88).

So far, the configuration and operation of the present invention have been described in detail. The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the technical idea of the present invention.

As described above, the present invention can reduce the delay time when the MSS terminal handovers to the target ACR in the WiBro system built on the mobile IPv6, and also solves the ingress filtering problem. The expected WiBro system has a modest effect.

In addition, the present invention has the effect of reducing the load and the unit cost of the ACR, because the ACR, unlike the mobile IPv4 to process the router advertisement (Router Advertisement) which is a mobile IPv6 function.

Claims (6)

In the mobile internet system In MSS handover between ACR, A first step of completing an initial ranging procedure between the MSS and the RAS for handover and establishing a provisioning connection of a service flow; The MSS sends a router solicitation message to the destination ACR, and the destination ACR sends a router advertisement message in response to the message; The MSS determines that the mobile station has been moved to another subnet and generates a CoA with new IP address information by a specified method; The MSS registers the CoA by sending a binding update message to the HA; Handover and routing of the WiBro system comprising the step of completing a network entry procedure by transmitting a binding acknowledgment message to the MSS in response to the binding update message of the MSS in the HA. How to Provide. The method of claim 1, The fourth step is Storing a home address and the CoA connected to the MSS in a binding cache managed by the HA; And handing the packet received at the home address of the MSS to the HA by tunneling the packet to the CoA in the HA to the MSS. Performing a test to transmit and receive packet data from the CN when the MSS is handed over to register the CoA with the HA; Transmitting, by the MSS, a binding update message to the CN to inform the MSS that the CoA has moved to the address; Handover and routing of the WiBro system, wherein if the CN is normally processed, the binding acknowledgment message is transmitted to the MSS in response to the MSS, and the MSS and the CN transmit and receive packet data without passing through the HA. How to Provide. The method of claim 3, wherein In step 7, when the binding update message is transmitted from the MSS to the CN, the source address is set to the newly assigned CoA, and the home address option is inserted into the home address. ; And the CN exchanges the source address with the address of the home address option and processes the handover and routing of the WiBro system. The method according to claim 3 or 4, Performing the test in step 6, requesting a test from the MSS to HA and requesting from the HA to the CN; Initiating CoA testing between the CNs in the MSS; Conversely requesting a test from the CN to the MSS via the HA; And performing testing of the CoA between the MSSs in the CN. The method according to claim 1 or 4, The handover and routing method is a handover and routing providing method of the WiBro system, characterized in that for handling the handover and routing using a mobile IPv6 network.

Images