KR101404109B1 - Apparatus and method for handover in mobile IP networks with user policies - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a handover of a mobile IP network, and more particularly, to a handover method and system using a user policy in a Mobile IP that determines a handover of a wireless terminal based on a handover policy set by a user. Generally, the handover in the mobile IP is determined by the strength of the radio signal. However, according to the present invention, the handover is performed only when the user sets the handover signal strength according to a predetermined policy and falls below the set signal strength. Therefore, the user can determine the handover according to the purpose of use of the wireless network.

Mobile IP, handover, policy-based handover

Description

TECHNICAL FIELD [0001] The present invention relates to a handover method and system for handover in mobile IP,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a handover of a mobile IP network, and more particularly, to a handover method and system using a user policy in a Mobile IP that determines a handover of a wireless terminal based on a handover policy set by a user.

The present invention is derived from the research carried out as part of the IT growth engine technology development project of the Ministry of Knowledge Economy. [Assignment Control Number: 2006-S-061-03, Title: IPv6-based QoS Service and Terminal Mobility Supporting Router Technology Development]

The handover refers to the change of the network connection to the moved base station in order to maintain communication when the mobile terminal moves to the area of another base station after leaving the area of the serving base station.

The handover is divided into a horizontal handover in which a handover is performed in a homogeneous communication network and a vertical handover in which a handover is performed in a heterogeneous communication network. Generally, regardless of the type of handover, the handover is determined according to the strength of the radio signal of the base station. The method of determining the handover by the intensity of the radio signal is clear, but the user 's intervention is excluded due to the uniform standard application.

In addition, Mobile IP was developed in 1995, but the need for layer-2 handover and 802.11 a / b / g roaming capabilities is reduced. Therefore, mobile IP supporting vertical handover has been announced, but it is not activated due to lack of support of heterogeneous communication network.

It is an object of the present invention to provide a handover method and system using a user policy in a mobile IP for determining a handover in a mobile IP network using a user policy based on signal strength to satisfy various users' will be.

The above object can be accomplished by a mobile communication system, comprising: a first base station, receiving a handover start message for handing over from a mobile station to a second base station, receiving a handover policy of the mobile station transmitted from the first base station, Determining whether to perform handover of the mobile station based on the handover policy, receiving an authentication request of the mobile station from the second base station when handover of the mobile station is determined, And transmitting the data transmitted from the correspondent node in communication with the mobile terminal to the second base station, the method comprising the steps of: And the handover method according to the user policy in the mobile IP.

In a mobile IP network including a mobile terminal, a first base station communicating with the mobile terminal, and a second base station initiating a new communication with the mobile terminal, during communication with the first base station, A mobile terminal for releasing connection of the first base station and establishing a connection with the second base station upon receiving a response message to the handover start message, A first base station for determining a handover of the mobile station based on a handover policy transmitted from the mobile station when receiving a handover start message and a second base station for receiving a network use request message from the mobile station, 1 authentication of the mobile terminal to the first base station and authentication of the mobile terminal from the first base station When new, are achieved by a hand-over system according to the user policy in the mobile IP and a second base station that allows a network to use of the mobile station.

According to the present invention, it is possible to perform a handover according to a policy set by a user in a mobile IP network. Therefore, the user can use the mobile IP network for the purpose of use.

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

The handover method and system according to the user policy in the present mobile IP will be outlined as follows. The handover of a general mobile IP is determined based on the signal strength of the base station, and handover is determined. However, according to the present invention, the user can set a handover policy in the mobile terminal, and the established policy is transmitted when the base station and the wireless network are connected, and each base station determines whether handover is performed according to the handover policy transmitted.

1 is a block diagram illustrating a horizontal handover of a mobile IP.

When the mobile terminal 100 moves from the home network 110 to the visited network 120, the mobile terminal 100 transmits a handover start message to the home agent 115 included in the home network 110. When the handover is started, the link between the home agent 115 and the mobile terminal 100 is released, and the mobile terminal 100 sends a network start message to the foreign agent 125 of the visited network 120. The foreign agent 125 allocates a temporary address 123 to be used by the mobile terminal 100 and the mobile terminal stores the temporary address 123 in the terminal and uses the visited network 120. At this time, a connection tunnel 130 is created between the home agent 115 and the foreign agent 125, and data for the mobile terminal 100 transmitted from the correspondent node 140 to the home agent 115 is transmitted to the connection tunnel 130 to the mobile terminal 100.

2 is a configuration diagram showing a vertical handover of the mobile IP.

The vertical handover is the same as that of the horizontal handover shown in FIG. However, there is a difference that the visited network 250 is included in the coverage of the home network 200 and handover is possible between different types of networks.

3 is a configuration diagram of a handover priority policy message to be used in a user policy based handover to be described later.

The handover priority policy message can be configured as a field type of a packet, but it can be configured as a message type in order to flexibly cope with the development of the network.

The handover priority policy message includes a priority 301, a network device name 303 of the first and second base stations, a signal strength 305, a transmission rate 307, a transmission cost 309, (311) and a policy-based handover signal strength (313).

The item of priority (301) indicates a priority of the handover consideration of the mobile terminal. The items of priority (301) include transmission cost priority, transmission rate priority, and network stability priority. Transmission cost priority refers to a method of continuing to use a lower-cost network connection as long as the network is maintained, taking into consideration the connection with the network with lower data transmission cost, in preference to the signal strength. Transmission speed priority refers to a method of continuing to use a faster network as long as the speed is guaranteed in the network, taking into account the connection of the network with the faster data rate to the signal strength. Network Stability First of all, the stability of the entire network is taken into consideration over the signal strength, and the method of maintaining the use of the network with better stability of the network is maintained.

The network device name 303 indicates the network equipment name of the base station currently in communication.

The signal strength 305 represents the current radio signal strength of the base station indicated by the network device name 303.

The transmission rate 307 represents the current network transmission rate of the base station indicated by the network device name 303.

The transmission cost 309 represents the data transmission cost of the base station indicated by the network device name 303. In the case of a network provided free of charge, the value of this item is set to zero.

The device name 311 recognized by the OS refers to the device name recognized by the operating system for the device name indicated by the network device name 303. [

The policy-based handover signal strength 313 indicates a criterion for determining handover when the signal strength of the network equipment currently connected by the policy stored in the priority order 301 falls below the value of this item.

4 is a flowchart of a user policy based handover method according to an embodiment of the present invention.

One embodiment of the network used in this flowchart is a home network and a visited network, and the coverage of the home network is wider than the coverage of the visited network. The stability, speed and data transmission cost of the network are both more efficient for the home network.

When the mobile terminal enters the home network service available area, the home agent of the home network transmits a beacon signal to the mobile terminal (S101). Upon receiving the beacon signal, the mobile terminal requests the home agent to use an address to be used in the home network (S103), the home agent attempts authentication of the mobile node, and if the authentication is successful, the home agent stores the handover policy transmitted by the mobile node, and transmits an address to be used by the mobile node to the mobile node (S105). The mobile station stores the received address (S107)

In addition, the foreign agent (FA) of the visited network transmits a beacon signal indicating that the mobile terminal is in the service available area of the visited network (S109). The mobile terminal receiving the beacon signal transmits the beacon signal to the foreign agent (S111). The foreign agent requests the home agent to authenticate the mobile terminal (S113). If the foreign agent succeeds in the authentication (S115), the foreign agent transmits the handover (S117), and transmits the temporary address to be used by the mobile node to the mobile node (S119). The mobile node stores the received temporary address and uses the visited network (S121)

If the mobile terminal moves and the signal strength changes (S123, S131, S139), it is determined whether or not the handover is performed according to the handover policy.

When the policy of network stability is set, if the signal of the visited network falls below the handover start threshold signal (S125), the foreign agent performs handover to the home agent. Then, the mobile terminal uses the home network (S127)

When the transmission cost priority policy is set, if the signal of the visited network falls below the handover start threshold signal (S133), the foreign agent performs handover to the home agent. Thereafter, the mobile terminal uses the home network (S135)

When the transmission speed priority policy is set, if the signal of the visited network falls below the handover start threshold signal (S139), the foreign agent performs handover to the home agent. Then, the mobile terminal uses the home network (S141)

Figure 5 is an embodiment of the present user policy based handover method.

In this embodiment, it is assumed that the transmission cost per packet of the home network is 1 won, the transmission speed is 2Mbps, the transmission cost per packet of the visited network is free, and the transmission speed is 10Mbps. Assuming that packet loss occurs when the signal strength of the visited network is 5, the threshold signal strength for initiating the handover is 5 when the network stability priority policy is followed. Assuming that the signal strength of the visited network is equal to 2 and the transmission speed of the home network and the visited network become equal to each other, when the transmission rate priority policy is followed, the threshold signal sequence for initiating the handover becomes 2. Lastly, when the signal strength of the visited network is 1, since the packet is often lost in the visited network, the communication itself becomes difficult. Therefore, when the transmission cost priority policy is followed, the threshold signal intensity for initiating the handover becomes 1.

Therefore, when the mobile station uses the visited network and uses the network stability priority policy, when the mobile station moves and moves to the third region 520 or more, which is the case where the signal strength becomes 5 or less, do.

In addition, when the mobile terminal uses the visited network and uses the transmission rate priority policy, handover proceeds when the mobile terminal moves to four zones (530) where the transmission speeds of the home network and the visited network are equal to each other.

Finally, when the mobile terminal is using the visited network and the transmission cost priority policy is used, when the signal strength of the home network and the visited network becomes 1 or less (5 regions, 5) when leaving the visited network, Handover is in progress.

6 is a data flow and a structure of a user policy based handover method according to an embodiment of the present invention.

The home agent 602 transmits a beacon signal indicating that the mobile terminal 600 has entered the service coverage area of the home network to the mobile terminal 600. (610) The mobile agent 600, having received the beacon signal of the home agent 602, The home agent 602 transmits an address assignment request and a handover policy stored in the mobile terminal to the home agent 602 in the form of a message described in FIG. The home agent 602 performs the mobile terminal authentication process 614 and stores the handover policy of the mobile terminal 600. If the authentication of the mobile terminal 600 is successful, Assigns a network address to be used by the mobile terminal 600 and transmits the network address to the mobile terminal 600. In step 616, the mobile terminal 600 allocated the address starts the wireless network in the home network, And starts communication with the correspondent node 606 via the network 620. [ )

When the mobile terminal 600 in communication with the home agent 602 enters the service coverage area of the visited network, the foreign agent 604 transmits a beacon signal indicating that the mobile terminal 600 has entered the service coverage area of the visited network The mobile terminal 600 receiving the beacon signal of the foreign agent 604 transmits the address assignment request and the handover policy stored in the mobile terminal 600 to the foreign agent 604 (632) The foreign agent 604 having received the address assignment request and the handover policy requests the home agent 602 to authenticate the mobile terminal 600 to authenticate the mobile terminal 600 The home agent 602 having received the authentication request of the foreign agent 604 determines whether to perform a handover according to the handover policy of the mobile terminal 600 and transmits the authentication result of the mobile terminal 600 to the foreign agent (604) (636) Upon receiving the authentication result from the home agent 602, the foreign agent 604 assigns a temporary use address to the mobile terminal 600. (638) And initiates communication with the correspondent node 606 using a tunnel formed between the home agent 602 and the foreign agent 604. In operation 640,

7 is a block diagram of a mobile terminal of a handover system according to a user policy in a mobile IP, which is an embodiment of the present invention.

The wireless terminal includes a transmission / reception unit 701, a user policy processing unit 703, and a user policy storage unit 705.

The transmission / reception unit 701 is a device for transmitting / receiving various data to / from the wireless network.

When the user sets a handover policy, the user policy processing unit 703 detects the signal strength corresponding to the selected policy and synthesizes the information of the currently used network to generate a handover priority policy message. The generated message is transmitted to the base station through the transmitting / receiving unit together with the request message when requesting the network address to use the wireless network.

The storage unit 705 physically stores the handover priority selected by the user. The user can always change the handover priority for smooth network utilization.

8 is a block diagram of a base station of a handover system according to a user policy in a mobile IP, which is an embodiment of the present invention.

The base station can operate as a home agent and a foreign agent, and includes a transmission / reception unit 801, a user policy collection unit 803, and a handover determination unit 805.

The base transceiver unit 801 is a device for transmitting / receiving various data to / from the mobile terminal.

The user policy collection unit 803 collects and stores a handover priority policy message transmitted by the mobile station for each mobile station while requesting an address for network use.

The handover decision unit 805 refers to the vertical handover priority policy for each mobile station stored in the user policy collection unit 803 and decides whether to perform handover of the mobile station.

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, but, on the contrary, It will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention.

1 is a block diagram showing a horizontal handover of a mobile IP,

2 is a configuration diagram showing a vertical handover of the mobile IP,

3 is a configuration diagram of a handover priority policy message to be used in a user policy based handover,

4 is a flowchart of a user policy based handover method,

5 illustrates an embodiment of a user policy based handover method,

6 illustrates a structure and a data flow diagram of a user policy-based handover method,

7 is a block diagram of a mobile terminal of a handover system according to a user policy in a mobile IP,

8 is a block diagram of a base station of a handover system based on a user policy in a mobile IP.

Claims (10)

In a first base station, a mobile terminal receives a handover start message for handing over to a second base station; Determining whether the mobile station is handed over based on a handover policy based on a user policy of the mobile station transmitted at the first access of the mobile station to the first base station; Receiving an authentication request of the mobile terminal from a second base station if handover of the mobile terminal is determined; Transmitting authentication to the mobile station to the second base station; And And transmitting data transmitted from a correspondent node in communication with the mobile terminal to the second base station. The method according to claim 1, Wherein the first base station and the second base station include a network in which the coverage of the first base station is narrower than the coverage of the second base station. The method according to claim 1, Wherein the handover policy includes handover start signal strength based on priority, device name, signal strength, speed, cost, or priority. The method of claim 3, Wherein the priority includes a network speed priority, a data transmission cost priority, or a network stability priority. In a mobile IP network including a mobile terminal, a first base station communicating with the mobile terminal, and a second base station initiating new communication with the mobile terminal, The base station transmits a handover start message to the first base station while performing communication with the first base station, and upon receiving a response message to the handover start message, disconnects the first base station, A mobile terminal for establishing a connection with two base stations; A first base station for determining a handover of the mobile station based on a handover policy transmitted from the mobile station when the handover start message is received from the mobile station; And When receiving a network use request message from the mobile terminal, the first base station requests authentication of the mobile terminal, and upon receiving authentication of the mobile terminal from the first base station, permits network use of the mobile terminal And a second base station. 6. The method of claim 5, Wherein the mobile terminal stores a handover policy according to a setting of a user and transmits the handover policy together with the network use request. 6. The method of claim 5, Wherein the first base station and the second base station store the handover policy transmitted together with the mobile terminal when the mobile terminal requests to use the network. 6. The method of claim 5, Wherein the first base station and the second base station are user policies in a Mobile IP in which coverage of the first base station is narrower than coverage of the second base station. 6. The method of claim 5, Wherein the handover policy includes handover start signal strength based on priority, device name, signal strength, speed, cost, or priority. 10. The method of claim 9, The handover system according to user policy in Mobile IP, wherein the priority includes network speed priority, data transmission cost priority, or network stability priority.

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