KR100562670B1 - Hand-off method and materialized system using subnet - Google Patents

Abstract

The present invention relates to a handoff method using a subnet and a system implementing the same.

The present invention assigns a subnet unit IP address to a subnet formed in a mobile unit, and then routes packet data received through an IP network according to the assigned subnet unit IP address to a subnet formed in the mobile unit, and upon request for handoff, A BS for approving handoffs per subnet; By assigning an IP address to a terminal forming a subnet according to the assigned subnet unit IP address, routing packet data received from the BS to the corresponding terminal, and handoff to the formed subnet unit when the mobile moves. It is comprised with the MR which requests | requires.

Accordingly, the present invention provides the same network in a communication system supporting mobility to a plurality of mobile communication terminals, notebook computers, PDAs (Personal Digital Assistants) while moving while maintaining the same network domain through mobile devices such as ships, subways and trains. By assigning a subnet unit IP address to a subnet formed in the mobile unit to have a domain, and assigning an IP address to each terminal in the mobile unit accordingly, handoff is performed by the subnet unit formed in the mobile unit when the mobile unit moves. Since terminals do not perform handoffs individually, but multiple terminals simultaneously perform handoffs to prevent instantaneous overloading of the system, the system can be stably supported while supporting mobility to multiple terminals existing in the same moving object. It is effective to operate.

Description

HAND-OFF METHOD AND MATERIALIZED SYSTEM USING SUBNET}             

1 is a network diagram schematically showing the configuration of a next-generation mobile communication network using a conventional mobile IP.

Figure 2 is a network configuration showing a simplified network configuration of a communication system implementing a handoff using the present invention subnet.

FIG. 3 is a signal flow diagram illustrating a signal flow of a process of registering and forming one subnet in an initialization state in a handoff method using a subnet of the present invention; FIG.

4 is a signal of a process in which a terminal in a mobile station performs handoff when a mobile moves from a service area of a first FAS to a second FAS service area in a handoff method using a subnet of the present invention; Signal flow diagram showing flow.

*** Description of the symbols for the main parts of the drawings ***

100: IP network 200: BSR

300 to 330: FAS 400: MAR

500: mobile body 600-620: terminal

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system, and in particular, a communication system supporting mobility to a plurality of mobile communication terminals, notebook computers, and PDAs (Personal Digital Assistants) moving while maintaining the same network domain through mobile devices such as ships, subways, and trains. In the present invention, a subnet unit IP address is assigned to a subnet formed in a mobile unit to have the same network domain, and accordingly an IP address is assigned to each terminal in the mobile unit, and when the mobile unit moves, handoff is performed in the subnet unit formed in the mobile unit. By doing so, the present invention relates to a handoff method using a subnet in which a plurality of terminals simultaneously perform handoffs, rather than individual terminals performing handoffs, and a system implementing the same.

1 is a network diagram schematically showing the configuration of a next-generation mobile communication network using a conventional mobile IP. As shown in FIG. 1, an IP network 10, a home agent 11, and a plurality of terminals 12-1 to FIG. 12-3 and 14, and a foreign agent 13.

In general, Mobile IP (Mobile Internet Protocol) protocol for supporting mobility necessary when building a wireless LAN network in a next generation mobile communication network is provided to two mobile hosts or terminals 12-1 to 12-3. It is possible to move between different network domains by assigning an IP address, and the terminals 12-1 to 12-3 are mobile communication terminals, personal computers such as desktops or laptops, personal digital assistants (PDAs), and the like. It refers to a fixed or mobile communication terminal.

That is, each of the terminals 12-1 to 12-3 has a home address that is designated and does not change regardless of the current position, and indicates the current position of the mobile host while changing according to the moving position. It has a care of address.

Here, the mobile address is an address of a mobile agent 11 or 13 currently supporting a wireless connection or a temporary address temporarily assigned by the agent 11 or 13.

The home agent 11 refers to a host or a router that manages current location information of each terminal 12-1 to 12-3 and performs a tunneling function to the visited agent 13, and the visited agent 13. ) Is located in a network visited by the mobile terminal 12-1, detunneling the packet data tunneled by the home agent 11, and forwarding the packet data to the terminal 12-1. In addition, it refers to a host or router that provides a routing service for packet data transmitted by the terminal 12-1 registered therein.

On the other hand, when the first terminal 12-1 moves from the home agent 11 to the new visit agent 13, the first terminal 12-1 manages the new visited agent 13 to manage the moved area. In this case, the user's presence is registered, and accordingly, the mobile agent's mobile address newly assigned from the new visit agent 13 is reported to the home agent 11.

At this time, the first terminal 12-1 registers the mobility binding information generated by pairing the mobile address allocated based on its home address and the current location to the home agent 11, The received home agent 11 performs packet data transmission to the terminals 12-1 to 12-3 later by using the mobility binding information.

Meanwhile, the m-th terminal 14 corresponding to various hosts connected to the IP network 10, that is, a correspondent node, transmits packet data to the mobile host, that is, the first terminal 12-1. In this case, the m-th terminal 14 transmits the packet data to the home agent 11 without knowing the movement of the first terminal 12-1, and thus the home agent 11 sends the packet data to the home agent 11. The first terminal 12-1 retransmits the packet data to the mobile address based on previously registered mobility binding information.

In this case, a method of transmitting packet data to the visited agent 13 to which the first terminal 12-1 is connected is performed through tunneling of packet data, and the endpoint address of the tunnel used is the mobile address. For encapsulation, various encapsulation techniques such as 'IP in IP' are used.

However, in the conventional technology as described above, in case of supporting mobility to mobile subscribers in a next generation mobile communication network, two IP addresses are assigned to mobile subscribers, and a home agent (registered with the mobile subscriber) is registered. Home Agent) tunnels and transmits packet data transmitted to the mobile subscribers while managing the two IP addresses as mobility binding information, and thus, a plurality of mobile subscribers moving through mobile devices such as ships, subways, trains, and the like. In case of performing hand off or transmitting packet data, the home agent is not only overloaded at the moment, but also a mobile address (Care) to a plurality of mobile subscribers existing in the same service area. Of Address) has to be allocated, there is a problem that waste of IP address resources.

Accordingly, the present invention has been proposed to solve the above-mentioned problems, and a plurality of mobile communication terminals, notebook computers, PDAs (Personal Digital Assistants) moving while maintaining the same network domain through mobile devices such as ships, subways, and trains. In a communication system supporting mobility, a sub-unit IP address is assigned to a subnet formed in a mobile object to have the same network domain, and accordingly an IP address is assigned to each terminal in the mobile device, and then the mobile device moves when the mobile device moves. It is an object of the present invention to provide a method for implementing a handoff by a plurality of terminals at the same time, rather than an individual terminal performing a handoff by performing a handoff on a per-subnet basis.

The present invention for achieving the above object, the step of allocating a subnet unit IP address to the subnet formed on the moving object; Allocating an IP address to a terminal within the mobile unit according to the allocated subnet unit IP address; When the moving object moves, performing a handoff in the unit of the subnet formed on the moving object.

In addition, the present invention assigns a subnet unit IP address to the subnet formed on the mobile, and then route the packet data received through the IP network according to the assigned subnet unit IP address to the subnet formed on the mobile, when handoff request A BS for approving handoff by the formed subnet unit; By assigning an IP address to a terminal forming a subnet according to the assigned subnet unit IP address, routing packet data received from the BS to the corresponding terminal, and handoff to the formed subnet unit when the mobile moves. Characterized in that it comprises a MR.

Hereinafter, an embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a network diagram illustrating a network configuration of a communication system implementing a handoff using a subnet of the present invention. As shown in FIG. 2, after assigning a subnet unit IP address to a subnet formed on a mobile object 500, The BSR routes packet data received through the IP network 100 to the subnet formed in the mobile 500 according to the assigned subnet unit IP address, and approves handoff in the formed subnet unit upon request for handoff. A base station switch router (200); Located between the BSR (200) and the plurality of terminals (600 ~ 620) to switch the packet data, and temporarily stores the packet data to be delivered to the corresponding terminal (600 ~ 620) in its service area when the handoff occurs A plurality of FAS 300 to 330 for switching afterwards; Packets received from BSR 200 through FAS 300 to 330 by allocating IP addresses to terminals 600 to 620 forming subnets according to the assigned subnet unit IP address. In addition to routing data to the terminals 600 to 620, when the mobile unit 500 moves, the mobile terminal 500 includes a moving access router (MAR) 400 for requesting handoff in the formed subnet unit.

The present invention assumes the case of supporting mobility to a plurality of wireless LAN subscribers moving while maintaining the same network domain through a mobile 500 such as a ship, subway, train, etc. A set of a plurality of terminals 600 to 620 present in the network 500 and having the same network domain is referred to as a subnet, which may form one or more in the same mobile object 500, (MAR) 400 is responsible for IP address allocation and management of the terminal (600 ~ 620) in the unit of the subnet, the MB (MAR) 400 and the BSR (BSR) (in the unit of the formed subnet) Hand off is performed between 200).

Here, the terminals 600 to 620 refer to a communication terminal supporting mobility, such as a mobile communication terminal, a notebook computer, and a personal digital assistant (PDA) in a next generation mobile communication network based on high speed packet transmission. When applied to, the same subnet unit IP address is assigned to a plurality of mobile subscribers moving through the mobile unit 500 such as a ship, subway, train, etc. to support mobility in the allocated subnet unit.

With reference to the signal flow diagram of Figures 3 and 4 attached to the operation of the present invention.

In the present invention, the BSR 200 is configured to assign a subnet unit IP address to the subnet such that a plurality of terminals 600 to 620 present in the subnet formed in the mobile unit 500 have the same network domain. After the allocation, the packet data received through the IP network 100 is routed to the subnet formed in the mobile unit 500 according to the assigned subnet unit IP address, or the terminal 600 to the subnet formed in the mobile unit 500. The packet data transmitted by 620 is routed to the destination address through the IP network 100.

When a handoff request is received from a moving access router (MAR) 400 managing a subnet formed in the mobile object 500, the handoff is approved in the formed subnet unit.

First, a case in which an MAR 400 forms one subnet for a set of predetermined terminals 600 to 620 in an initialization state and registers the same, will be described. The UE requests allocation of the IP address per subnet to the BSR 200 through the first FAS 300.

Then, the BSR 200 searches for an IP pool managed by the BSR 200 and allocates an available subnet unit IP address to the MAR 400.

Here, the FAS 300 to 330 are located between the BSR 200 and the plurality of terminals 600 to 620 to switch packet data, and when a handoff occurs, the FAS 300 to 330 corresponding to the FAS 300 to 330. The packet data to be transmitted to the terminals 600 to 620 are temporarily stored and then switched.

In addition, the IP pool is the same network domain, i.e., '150.150.140.XXX', '150.150.141.XXX', '150.150.141.XXX', etc. A table for managing IP address resources so that the existence of available IP resources is classified by subnet, and implemented using a Dynamic Host Configuration Protocol (DHCP) server, for example, a subnet IP managed by the IP pool. In the case of IPv4, the first three digits of the IP address are the same and the last one is different, and this means an IP address for distinguishing each terminal 600 to 620.

In the above case, when the BSR 200 allocates the available subnet unit IP address '150.150.140.XXX' to the MAR 400, the BSR 200 And allocating the subnet unit IP address, and displaying on the routing table that the subnet unit IP address '150.150.140.XXX' is allocated within the service area of the first FAS 300, It is used to route the packet data to be sent to the AR 400.

That is, when packet data having a subnet unit IP address assigned to the MAR 400 as a destination address is received through the IP network 100, the BSR 200 stores the data separately. After loading the routing table stored in the means (not shown), and compares the IP address on the routing table with the destination address of the received packet data to perform the service (FAS) (300 ~ 330) to perform the service by IP address per subnet And route the received packet data to the FAS 300 to 330. In this case, the BSR 200 refers to the routing table to the subnet unit IP address' 150.150. Packet data having '.140.XXX' is routed to the first FS300.

Similarly, the BSR 200 may search for available subnet unit IP addresses and search for available subnet unit IP addresses for each other MAR 400 requiring assignment of subnet unit IP addresses, respectively. FAS 300 which provides a service to each MAR 400 having the IP address along with the subnet unit IP address on the routing table while allocating '150.150.141.XXX' and the like. 330) to be used for routing the packet data to the MAR 400 later.

Meanwhile, the MAR 400 assigned '150.150.140.XXX' as the subnet unit IP address is an IP address from the terminals 600 to 620 existing in the mobile unit 500 according to the subnet unit IP address. Receiving an address assignment request and assigning an IP address and managing the IP address, while routing the packet data received from the first FAS (300) to the terminal (600 ~ 620), the mobile unit 500 When moving, handoff is performed by subnet.

That is, when the MAR 400 moving together with the moving object 500 is requested to allocate an IP address from the terminals 600 to 620 in the moving object 500, the MAR ( 400) retrieves an available IP address according to the assigned subnet unit IP address '150.150.140.XXX' and then '150.150.140.1' to the first terminal 600 and '150.150' to the second terminal 610. ... 140.3 'is allocated to search for an available IP address up to the m-th terminal 620 in the mobile object 500.

Then, since the IP address allocated from the MAR 400 becomes a care-of-address (COA) of the terminal 600 to 620, the IP network 100 from the corresponding node (Correspondent Node). Packet data transmitted through the BSR 200 and the first FAS 300 are bypassed in the MAR 400 to be a destination address of the first terminal 600. Is delivered.

On the other hand, when the moving object 500 moves from the 'area 1' which is the service area of the first FAS 300 to the 'area 2' which is the service area of the second FAS 310, the moving object ( Terminals 600 to 620 in 500 perform a hand off.

In this case, the terminals 600 to 620 in the mobile unit 500 do not individually perform handoffs according to mobility, but are subnet units in which the terminals 600 to 620 are formed by the MAR 400. Handoff is performed.

That is, as shown in FIG. 4, when the MAR 400 moves and enters the 'region 1' from the 'region 1', the second allocated from the system according to the increase or decrease of the strength of the pilot signal A handoff is performed with the FAS 310. First, a handoff is requested to a second FAS 310 in service in the 'area 2' that is currently entering, and accordingly, the second FAS is requested. The (FAS) 310 requests a handoff to the upper BSR 200.

Then, the BSR 200 loads the routing table and routes the packet data to the MAR 400 assigned the subnet unit IP address '150.150.140.XXX'. By updating the information about the first FAS (300) designated to serve by the subnet unit IP address to the second FAS (310), the later through the IP network 100 (MAR) Packet data having a destination address of 400 is routed through the second FAS 310.

Next, the BSR 200 transmits a handoff acknowledgment message to the second FAS 310, and between the second FAS 310 and the MS 400. As the normal radio section handoff process is performed, the radio section with the existing first FAS 300 is disconnected and the radio section is connected to the new second FAS 310 to complete the handoff.

Accordingly, packet data received by the BSR 200 through the IP network 100 after the handoff has occurred is routed on a routing table for the BSR 200 to route the packet data. Since the information has been updated, it is immediately routed to the second FAS 310 to be passed to the MS 400, and the MS 400 bypasses it to the corresponding terminals 600 to 620. To pass.

In addition, when a handoff occurs, the wireless channel may be disconnected for a while. In order to prevent the loss of packet data, the second FAS (FAS) that receives a handoff request from the MB 400 ( 310 buffers and temporarily stores the packet data destined for the MB 400 through an internal buffer (not shown) until the handoff acknowledgment message is received from the BSR 200. When the handoff approval message is received, the temporarily stored packet data is transmitted to the MB 400.

As described above, the present invention provides a communication system supporting mobility to a plurality of mobile communication terminals, notebook computers, PDAs (Personal Digital Assistants) while moving while maintaining the same network domain through mobile devices such as ships, subways, and trains. In this case, a subnet unit IP address is assigned to a subnet formed in the mobile unit to have the same network domain, and accordingly an IP address is assigned to each terminal in the mobile unit, and when the mobile unit moves, handoff is performed in the subnet unit formed in the mobile unit. In this way, each terminal does not perform handoffs individually but multiple terminals simultaneously perform handoffs, thereby preventing instantaneous overloading of the system, thereby supporting mobility to multiple terminals existing in the same mobile body. It is effective to operate the system stably.

Claims (5)

In the handoff method using a subnet, Allocating a subnet unit IP address to a subnet formed in the moving object; Allocating an IP address to a terminal in the mobile device according to the allocated subnet unit IP address; When the mobile moves, performing a handoff in units of subnets formed in the mobile. The method of claim 1, wherein the allocating the subnet unit IP address comprises: retrieving an available subnet unit IP address and allocating the subnet unit IP address to the corresponding MA in response to a request of the ME moving with the moving object. and; And updating a routing table according to the changed contents. The handoff method according to claim 1 or 2, wherein the allocated subnet unit IP address is assigned to a set of a plurality of terminals existing in the same mobile body and having the same network domain. 2. The method of claim 1, wherein performing a handoff on a per-subnet basis changes a FSA that a BS has to service with a subnet-specific IP address assigned to the MS according to a handoff request of an MS. Handoff method using a subnet, characterized in that performed by updating the routing table. In a system implementing handoff using a subnet, After assigning a subnet unit IP address to a subnet formed in the mobile unit, the packet data received through the IP network is routed to the subnet formed in the mobile unit according to the assigned subnet unit IP address, and when the handoff request is made to the formed subnet unit BS to approve the handoff; By assigning an IP address to a terminal forming a subnet according to the assigned subnet unit IP address, routing packet data received from the BS to the corresponding terminal, and handoff to the formed subnet unit when the mobile moves. System that implements handoff using a subnet, characterized in that the configuration including the MB that requires.

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