KR101430245B1 - Method for detecting mobile movement to another IP network and data processing method during the mobile movement - Google Patents

Abstract

The present invention relates to a network-based mobility detection method and a corresponding data processing method, and more particularly, to a network-based mobility detection method and a corresponding data processing method, If there is no response message, the mobile terminal informs a first MAG (Mobile Access Gateway) of the subnet A of the movement notification message notifying the movement to another subnet, and starts data buffering upon receiving the movement notification message in the first MAG, If the buffered data request message is received from the second MAG located in the subnet B of the second IP during data buffering, the buffered data is provided to the second MAG or a move notification cancel message of the mobile terminal is received from the first AP during data buffering Stop the data buffering and delete the buffered data. Therefore, the present invention can detect the fact that the mobile terminal has moved to another IP network in real time, and prevent data loss by buffering data corresponding to the detection of the mobility of the real time mobile terminal.

Data buffering, handover, mobility, subnet, real-time

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a network-based mobility detection method,

The present invention relates to handover to different IP (Internet Protocol) networks. In particular, the present invention relates to a method for detecting that a mobile terminal moves to a Mobile Access Gateway (MAG) in another IP network in an IEEE 802.11 access network (hereinafter referred to as "PMIPv6 network") to which the PMIPv6 protocol is applied, To a method for processing data to be provided.

The currently standardized Mobile Internet Protocol version 6 (MIPv6) protocol has a HoA (Home Address) which is a unique address of a mobile terminal (hereinafter referred to as "MN (Mobile Node)") through a binary address system, And supports the mobility of the MN by binding a care-of address (CoA) generated by the MN to the HA (Home Agent). In particular, if the correspondent node (CN) accommodates the MIPv6 protocol, it can send the CN to the CN so as to support an optimized routing path for the data packet.

However, since the MIPv6 protocol is related to the MN's location registration and the route re-establishment for the data packet of the currently communicating session, the MIPv6 protocol has a level of satisfying real-time communication such as Voice of IP (VoIP) and Video On-Demand There are many problems to support mobility. In this case, since the MIPv6 uses a binary addressing scheme (ie, HoA and CoA), there is waste of IP resources, and the MN is actively involved in mobility management, so that the mobility management signaling message with the HA or CN existing in the network There is a problem that the processing load on the MN is increased because it needs to be exchanged.

Recently, standardization organizations such as WiMAX, 3GPP, and 3GPP2 have pointed to network-based mobility processing technology as a candidate technology for IP mobility processing. In response to this trend, the IETF Working Group for Network-based Localized Mobility Management (NETM) has standardized the PMIPv6 (Proxy MIPv6) protocol. Currently, the first method proposed by S. Gundavelli et al. And the second method proposed by A. Singh et al. Branch mechanisms have been proposed.

When the PMIPv6 protocol is used, the MN does not need to change or update the information for mobility management in addition to the IPv6 stack.

For example, referring to FIG. 1, a mobility management method according to the first method proposed by S. Gundavelli et al. Will be described. 1 is a data flow diagram illustrating a mobility management method according to the PMIPv6 protocol according to a conventional example.

When the MN is turned on or enters the PMIPv6 network and accesses the MAG_old (S101), the MAG_old receives the address of the LMA (Local Mobility Anchor) to which the MN wants to connect from a policy server (not shown) in the access network ID information of the MN, and a network prefix to be additionally allocated to the MN.

Then, MAG_old generates a PBU (Proxy Binding Update) message using the information received from the policy server and transmits it to the LMA (S102). This PBU message includes the MN's ID, the network prefix assigned to the MN, and the IP address of the MN. The LMA receiving the PBU message transmits an ACK message to the MAG_old and checks whether there is information corresponding to the MN ID in its binding cache entry. If not, the MN adds information about the MN (S103). Then, the LMA establishes a tunnel between the LMA and the MAG 1 using the address information of the MAG1 (S104).

Meanwhile, the MAG_old transmits an RA (Router Advertisement) message to the MN using the information received from the policy server, in addition to the operation of transmitting the PBU message (S105). The MN sets its own IP address using this information, and receives the packet data received from the CN through the LMA and the MAG_old (S106 to S108).

In step S109, the MAG_new obtains information on the MN, and transmits a PBU message to the LMA (steps S110 and S111) in the same manner as described above. .

The LMA receiving the PBU message detects that the MN has moved to the new network using the ID information of the MN and the address information of the MAG2, and changes the tunnel for the MN from the existing LMA-MAG1 to the LMA-MAG2 (S112).

Then, MAG_new advertises the same network prefix information to the MN (S113). When the MN receives the same network prefix information, the MN considers that the MN itself is continuously connected to the same network as before.

When the data transmission path between the NN and the LMA is thus established, the transmission path of the packet data provided to the MN is changed from MAG_old to MAG_new (S114 to S116).

However, the management of the mobility of the MN according to the conventional PMIPv6 protocol requires packet data to be transmitted after the MN is connected to a new network, that is, after the handover is completed. Generally, Problems arise.

Such a conventional problem is caused by the fact that the MN can not detect the mobility in real time and detects when the MN requests the MN to find a new network to be handed over.

According to an aspect of the present invention, there is provided a network-based mobility detection method for detecting movement of an MN moved to a new network in real time.

According to another aspect of the present invention, there is provided a data processing method for network-based mobility detection, which provides securely providing handover-completed packet data in response to mobility of an MN detected in real time .

According to an aspect of the present invention, there is provided a method for detecting a network-based mobility in a network to which a Proxy Mobile Internet Protocol version 6 (PMIPv6) protocol is applied. The network-based mobility notification method includes: a first step in which a first AP (Access Point) located in a subnet A of a first IP transmits first packet data to a mobile terminal serving in its own station and waits for a response; And a second step of notifying a first MAG (Mobile Access Gateway) of the subnet A of a mobile notification message informing that the mobile terminal moves to another subnet if there is no response message from the mobile terminal during the setup response wait time.

The method may further include: a third step of determining whether a response message is received by attempting retransmission of the first packet data after transmitting the mobile notification message; and if the response message is received, And a fourth step of transmitting a move notification cancel message indicating that the mobile terminal does not move to another subnet.

The method may further include a fifth step of receiving second packet data to be transmitted next to the first packet data from the first MAG after transmitting the mobile notification cancel message and providing the second packet data to the mobile terminal .

According to another aspect of the present invention, there is provided a data processing method for detecting network-based mobility in a network to which a PMIPv6 protocol is applied. The data processing method corresponding to the network-based mobility detection includes a first step in which a first MAG located in a subnet A of a first IP transmits first packet data to a first AP of its own station; A second step of starting data buffering upon receiving a move notification message informing movement of the mobile terminal from the first AP to another subnet; A third step of providing the buffered data to the second MAG upon receiving a buffering data request message from a second MAG located in a subnet B of the second IP during the data buffering; And a fourth step of discontinuing the data buffering and deleting the buffered data when the mobile station notifies the mobile terminal of the move notification cancel message from the first AP during the data buffering.

The method may further include a fifth step of discontinuing the data buffering and deleting the buffered data when the set buffer time elapses during the data buffering.

The second step sequentially buffers subsequent packet data starting from the first packet data.

Here, the second MAG is a MAG located in the subnet B of the second IP handed over from the subnet A by the mobile terminal.

According to an embodiment of the present invention, the present invention can detect in real time the fact that an MN has moved to a network of another IP and prevent data loss by buffering data corresponding to the detection of mobility of the real-time MN.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise. Also, the terms " part, "" module," and " module ", etc. in the specification mean a unit for processing at least one function or operation and may be implemented by hardware or software or a combination of hardware and software have.

In this specification, a mobile node (MN) includes a terminal, a mobile terminal (MT), a subscriber station (SS), a portable subscriber station (PSS) An access terminal (AT), and the like, and may include all or some of functions of a mobile terminal, a subscriber station, a mobile subscriber station, a user equipment, and the like.

In this specification, an access point (AP) may refer to a radio access station (RAS), a node B, a base transceiver station (BTS), a mobile multihop relay (MMR) And may include all or some of the functions of the access point, the radio access station, the node B, the base transceiver station, and the MMR-BS.

Hereinafter, a network-based mobility detection method and a corresponding data processing method according to an embodiment of the present invention will be described with reference to FIGS. 2 to 6 attached hereto.

First, a network environment according to an embodiment of the present invention will be described with reference to FIG. 2 is a simplified block diagram of a PMIPv6 network to which the present invention is applied.

2, the PMIPv6 network includes a MN (1), a MAG_old (4), a MAG_new (5), a LMA 6 and a CN 7, 10 and the AP2 3 is located in the subnet B 20 formed by the MAG_new 5. Of course, the subnet A 10 and the subnet 20 may be additionally located in addition to the AP 1 2 or the AP 2 3.

The MN 1 is a node that moves between various subnets, such as a mobile phone, a PDA (Personal Digital Assistant), and a notebook computer. The AP1 2 and the AP2 3 connect the MN 1 to the subnet to which the MN 1 belongs so that the MN 1 can access the wired network such as the Internet.

The MAG_old 4 and the MAG_new 5 perform mobility support signaling on behalf of the MN 1 and generally serve as a MAG by adding a mobility support signaling function to an access router that is a basic router of the terminal .

The LMA 6 creates a tunnel between the LMA and the MAG and transmits the packet received from the CN (Correspondent Node) 7 to the corresponding MAG through the tunnel between the LMA 6 and the MAG (4 or 5).

CN 7 is a host (e.g., mobile phone, PDA, notebook computer, etc.) or router that is in communication with MN 1. [

Hereinafter, with reference to FIG. 3, a method of detecting a mobility performed by an AP in a subnet to which an MN is connected will be described. 3 is a flowchart illustrating a method of detecting mobility in an AP in a current subnet according to an embodiment of the present invention. In the description with reference to FIG. 3, it is assumed that the MN 1 is connected to the subnet A 10 and is using a data service.

The AP1 2 transmits the packet data transmitted from the CN 7 to the MN 1 in step S310 and then waits for an ACK message informing the MN 1 of packet data reception in step S320.

When the AP1 2 does not receive the ACK message from the MN 1 within the set time at step S330, the AP1 2 informs the MAG_old 4 that the data transmission to the MN 1 has not been performed at step S340. At this time, the present invention uses a NoAck message as a message indicating that data transmitted from the MAG to the MN can not be delivered. The NoAck message is a newly added message to the PMIPv6 protocol used in the IEEE 802.11 network for the present invention.

Generally, a situation in which the MN can not receive the packet data transmitted from the first MAG includes a first situation in which a link failure occurs, that is, data transmission fails because the communication environment between the AP and the MN is temporarily poor, There is a second situation outside the subnet served by the first MAG.

if. In the first situation, since the MN is located in the subnet of the first MAG, the first case can be overcome by retransmitting the packet data. However, the second situation can not overcome the second situation even if the packet data is retransmitted because the MN is not located in the subnet of the first MAG.

Therefore, the AP1 2 attempts to retransmit the packet data to the MN 1 to determine whether the MN 1 is in the first situation or the second situation (S350).

At this time, when the ACK message is not received from the MN 1, the retransmission of the packet data at least performs at least one retransmission and repeats the retransmission as many times as the maximum number of retransmissions. It stops the retransmission. Here, even if the MN 1 does not receive the ACK message during the retransmission of the packet data, the NoAck message is not transmitted. That is, the NoAck message is transmitted to the MAG_old (4) only once for the same packet data.

On the other hand, if it is determined in step S330 that the AP1 (2) receives the ACK message from the MN (1) within the set time, it determines whether the received ACK message is the ACK message received in the retransmission step (S360). In this case, if the ACK message is an ACK message corresponding to the initial packet data transmission, the AP1 2 transmits the next packet data to the MN 1 (S310). If the ACK message is received in the retransmission process, An Init_Buffer message is transmitted (S370).

Here, the Init_Buffer message includes a message for canceling the operation of the MAG_old (4) according to the previous NoAck message when an ACK message is received as a result of retransmission for determining the mobility of the MN (1) corresponding to the packet data that did not receive the ACK message to be. The Init_Buffer message is newly added to the PMIPv6 protocol used in the IEEE 802.11 network for the present invention.

As a result, when the AP 1 2 of the subnet providing the data service to the MN 1 detects the non-response state of the packet data of the MN 1, it is determined that the non-response state is on the line or the MN 1 moves to another subnet And detects the mobility of the MN 1.

Next, with reference to FIG. 4, the operation of the MAG_old for processing packet data to be provided to the MN according to the output of the AP that has detected the mobility of the MN will be described. 4 is a flowchart illustrating a data processing method corresponding to mobility detection in a MAG of a current subnet according to an embodiment of the present invention.

Upon receiving the NoAck message from the AP1 2 in step S410, the MAG_old 4 starts data buffering for storing data to be provided to the AP1 2 in its own buffer in step S420. At this time, it is preferable that the data stored in the buffer is packet data subsequent to the packet data in which the MN 1 has not responded.

The MAG_old (4), which performs data buffering, monitors the occurrence of data buffering interruption and continuously buffers the data until the data buffering interruption occurs.

The data buffering interruption status is the first case of receiving the Init_Buffer message from the AP1 (2), the second case of receiving the Flush message from the MAG_new (5), and the third case of buffering setting time, that is, the buffer time is completed.

The MAG_new 5 is a new MAG handed over from the MAG_old 4 by the MN 1 and the Flush message is a message for requesting buffered data from the MAG_new 5 to the MAG_old 4, This is a newly added message to the PMIPv6 protocol.

Accordingly, the MAG_old 4 determines whether the Init_Buffer message is received during data buffering (S430), determines whether a Flush message is received (S450), and determines whether butter time is completed through the self buffer timer (S460) .

If the Init_Buffer message is received or the buffer time is determined to be completed, the MAG_old (4) clears the buffer. That is, the packet data stored in the buffer is deleted (S440). Upon receiving the Flush message, the MAG_old 4 transmits the packet data stored in the buffer to the MAG_new 5 and empties the buffer (S460).

Since the MAG_old (4) indicates that the Init_Buffer message is received, the MAG_old (4) empties the buffer and simultaneously transmits the next packet data to the AP1 (2). When the buffer time is completed, the handover of the MN (1) is uncertain And the next packet data is transmitted again to AP1 (2) at the same time as the buffer is emptied.

Hereinafter, the overall operation of the network for the mobility detection method and the data processing method corresponding thereto according to the embodiment of the present invention will be described with reference to FIG. 5 is a general data flow diagram of a network-based mobility detection method and a corresponding data processing method according to an embodiment of the present invention. 5 shows an example in which the MN 1 is receiving service through the AP 1 (2) in the subnet A 10.

The MN 1 receives the packet data through the LMA 6, the MAG_old 4 and the AP 1 2 in steps S501 to S503 and provides the ACK message to the AP1 2 when the packet data is normally received (S504).

However, if the packet data provided through the LMA 6, the MAG_old 4 and the AP1 2 are not normally received, the MN 1 does not provide an ACK message to the AP1 2 (S505 to S508).

Then, if the ACK message is not received from the MN 1 for a set time after the packet data transmission, the AP1 (2) generates a NoAck message and transmits the NoAck message to the MAG_old 4 to notify the mobility of the MN 1 (S509).

Upon receiving the NoAck message from the AP1 (2), the MAG_old (4) determines that the MN (1) has moved from the subnet A (10) to another subnet and starts data buffering accordingly (S510).

Apart from this, the AP1 2 performs an operation to confirm whether the MN 1 has actually moved to another subnet or an error on the data link although the MN 1 has been informed of the movement of the MN 1 through the NoAck message . That is, the AP1 (2) attempts to retransmit the packet data after the NoAck message is transmitted for the maximum number of times (S511) and determines whether an ACK message is received from the AP1 (2) (S512, S513). Of course, the retransmission is repeatedly performed the maximum number of times, but when an ACK message is received or the number of retries is exceeded, retransmission is stopped (S514).

Upon receiving the ACK message by the retransmission, the AP1 (2) determines that the MN (1) has not moved to another subnet and transmits an Init_Buffer message to the MAG_old (4) And deletes the data stored in the buffer in the meantime (S515, S516).

On the other hand, the MAG_old 4 which is buffering data receives the Flush message from the MAG_new 5 of the subnet B 20 newly accessed by the MN 1 during data buffering (S517 and S518) (5) to the MAG_new (5) (step S519).

The embodiments of the present invention described above are not only implemented by the apparatus and method but may be implemented through a program for realizing the function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded, The embodiments can be easily implemented by those skilled in the art from the description of the embodiments described above.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

1 is a data flow diagram illustrating a mobility management method according to the PMIPv6 protocol according to a conventional example.

2 is a simplified block diagram of a PMIPv6 network to which the present invention is applied.

3 is a flowchart illustrating a method of detecting mobility in an AP in a current subnet according to an embodiment of the present invention.

4 is a flowchart illustrating a data processing method corresponding to mobility detection in a MAG of a current subnet according to an embodiment of the present invention.

5 is a general data flow diagram of a network-based mobility detection method and a corresponding data processing method according to an embodiment of the present invention.

Claims (7)

In a network to which the PMIPv6 (Proxy Mobile Internet Protocol version 6) protocol is applied, A first step in which a first access point (AP) located in a subnet A of the first IP transmits first packet data to a mobile terminal serving in its own station and waits for a response thereof; And And a second step of notifying a first MAG (Mobile Access Gateway) of the subnet A of a mobile notification message informing that the mobile terminal moves to another subnet if there is no response message from the mobile terminal during the setup response waiting time, Detection method. The method according to claim 1, A third step of determining whether a response message is received by attempting to retransmit the first packet data after transmitting the mobile notification message; and if the response message to the first MAG is received, And a fourth step of transmitting a move notification cancel message indicating that the mobile communication terminal does not move to the mobile communication terminal. 3. The method of claim 2, And a fifth step of receiving second packet data to be transmitted next to the first packet data from the first MAG after transmitting the mobile notification cancel message, and providing the second packet data to the mobile terminal. In a network to which the PMIPv6 (Proxy Mobile Internet Protocol version 6) protocol is applied, A first step in which a first MAG located in a subnet A of a first IP transmits first packet data to a first AP of its own station; A second step of starting data buffering upon receiving a move notification message informing movement of the mobile terminal from the first AP to another subnet; A third step of providing the buffered data to the second MAG upon receiving a buffering data request message from a second MAG located in a subnet B of the second IP during the data buffering; And And a fourth step of stopping the data buffering and deleting the buffered data when the move notification cancel message of the mobile terminal is received from the first AP during the data buffering. 5. The method of claim 4, And stopping the data buffering and deleting the buffered data when the set buffer time elapses during the data buffering. The method according to claim 4 or 5, Wherein the second step comprises sequentially buffering subsequent packet data starting from the first packet data. The method according to claim 6, Wherein the second MAG is a MAG located in a subnet B of a second IP handed over from the subnet A by the mobile terminal.

Images