KR100789900B1 - Method of policy based handover for multi interface mobile node accessible to different wireless networks - Google Patents

Abstract

A handover method based on a policy of a mobile terminal having a multi-wireless interface accessible to heterogeneous wireless networks is provided to enable a provider to efficiently use resources of a wireless network as previously making a decision for handover to a mobile terminal, thus the mobile terminal can more quickly conduct handover. A policy server(200) receives a network state report message including state information on the at least current network from a mobile terminal(100). In case of state change of the current network accessed by the terminal or in case of policy change by a network operator, the policy server(200) receives a handover policy request message from the terminal. Based on the request message, the policy server transmits a handover policy response message for the terminal. Based on information of the response message, the terminal performs handover.

Description

Method of Policy Based Handover for Multi Interface Mobile Node accessible to Different Wireless Networks}

1 is a diagram of a mobile terminal having a multi-air interface receiving services of a current network by using each interface. (The old network used before the mobile terminal handover is the old network, and the new network used after the handover is the new network.)

2 is a flow chart when a mobile terminal having a single interface performs handover using Fast MIP (Mobile IP) protocol using signal strength.

3 is a flowchart when a mobile terminal having a multi-air interface performs handover based on a policy of an operator.

4 is a flow diagram when a mobile terminal with multiple air interfaces performs handover using a Network Based Localized Mobility Management (NETLMM) protocol in which a network manages mobility.

5 is a flow chart for requesting and responding to a policy message between a policy server that determines the policy and a mobile terminal that performs the policy.

6 is a form of a message used when requesting and responding to a policy between a mobile terminal and a policy server.

7 is a message in which the mobile terminal informs the policy server of information such as the type of the current (previous) network and signal strength, and a message informing the policy server of the threshold value or new network to be moved at that time. .

8 is a message form in which the policy server informs the mobile station of a new network information. (The mobile terminal may be provided with network information such as IP address and authentication key to use in the new network before performing the handover.)

Explanation of the major symbols

10: single interface mobile terminal

100: multi interface mobile terminal

200: Policy Server

210: database

300: current (old) network

310: current access point

320: current base station

330: current AR

340: current anchor node

400: new network

410: new access point

420: new base station

430: new AR

440: new anchor node

The present invention relates to a handover method based on a policy of a mobile terminal having a multi-air interface capable of accessing a heterogeneous wireless network.

In general, a mobile terminal can be divided into a single air interface having only one air interface and a multi air interface having multiple air interfaces. Recent trends have tended to move towards multiple air interfaces that can provide a wider variety of services.

On the other hand, a service provider for a mobile terminal can be divided into a service provider that provides only one type of wireless network and a service provider that provides heterogeneous wireless networks together. Recent trends show a tendency to move toward heterogeneous wireless network services that can cope with various environments and provide various services.

In addition, the mobile terminal has a characteristic of handover when crossing the boundary between an access point (AP) and an access point or between a base station and a base station.

Background Art [0002] What is conventionally studied as a handover method of a mobile terminal is a method in which a mobile terminal having a single wireless interface serviced in one type of wireless network simply performs handover using the signal strength of the wireless network.

However, this handover method is not suitable in an environment in which a mobile node having a multi-radio interface simultaneously connects various heterogeneous wireless networks and receives services while moving at high speed. In addition, simply performing the handover using signal strength is inefficient for a mobile terminal having a multi-radio interface capable of using a heterogeneous wireless network. This is because the mobile station must periodically search for all radio frequencies.

Each heterogeneous wireless network has different characteristics in terms of service area, maximum speed, and mobility support. Therefore, in the heterogeneous wireless network, the situation of the radio channel of some kind of wireless network is worse, the channel state of the other kind of wireless network is not bad. Therefore, when a failure occurs in one kind of wireless network, it is necessary to hand over the service of the mobile terminal to another wireless network. However, it is difficult to determine the radio frequency situation of all kinds of wireless networks serviced by the mobile terminal.

1 is a diagram in which a mobile terminal having a multi-radio interface receives services of a conventional network by using each interface. Here, the network used by the mobile terminal 100 before the handover is the previous network 300, and the network used after the handover is the new network 400.

1 illustrates a situation in which a mobile terminal 100 having a multi-radio interface receives a service through a base station 320 and a wireless service through an access point provided by a conventional access point 310. In the future, the network will be in the form of receiving a service using the multi-wireless interface, and the mobile terminal 100 can also use the service as the base station 320 while receiving the service as the access point 310.

When the mobile terminal 100 moves while receiving a service through the previous base station 320, if the mobile terminal 100 moves to a serviceable area using the new access point 410, it provides a service to the wireless network 400 having a high transmission speed. That may be good from the mobile terminal 100 position. There is a need for a method for the mobile terminal 100 to perform a handover by determining a network 300 and 400 situation by the operator and giving an appropriate handover policy to the mobile terminal 100. Although the signal strength of the existing network 300 that is currently connected is good, by handover to a new network 400 that can provide a better service, it is possible to provide a service to the mobile terminal 100 more effectively. .

2 is a flowchart of handover using a signal strength of an access point when a mobile terminal having a single interface receives a service through an access point of a conventional network.

First, a mobile terminal having a single air interface receives a service by using an access point or a base station of a conventional network. At this time, the mobile terminal 10 can know the signal strength of the access point, and if the signal strength falls below a certain threshold, the Fast MIP (Mobile IP) protocol or the Mobile IP protocol is operated to perform a handover of the mobile terminal 10. Will be performed. The handover of the mobile terminal 10 having a single interface can be applied by handing the mobile terminal 10 by using the signal strength. However, the mobile terminal having the multi-radio interface performs the handover only with the signal strength. There is a disadvantage in that the method does not efficiently use the entire radio resource.

Therefore, there is a need for a structure in which an operator who best understands such a situation determines a wireless network suitable for the mobile terminal and gives a handover policy to the mobile terminal. To this end, first, a roaming agreement between operators with heterogeneous networks, and a policy on usage fee and handover method are required.

The present invention is to provide a message for the network structure and access and handover policy that the operator can manage the handover of the mobile terminal.

The present invention is to provide a structure of a network for performing a handover based on the policy of the operator and a message for requesting and responding to the policy between the mobile terminal and the operator.

The present invention provides a better service to the terminal in consideration of the handover policy of the operator, the type of service currently being used by the user, the network to which the terminal subscribes or the priority of the terminal, and the network state where the mobile terminal is currently located. It is to provide a way to change the wireless access network of the mobile terminal to provide an environment.

The present invention is to provide a method for the operator to efficiently use the resources of the wireless network, to make a handover decision to the mobile terminal in advance, to perform a handover faster when the mobile terminal handovers will be.

In order to achieve the above object, a handover method based on a policy of a mobile terminal having a multi-radio interface capable of accessing a heterogeneous wireless network of the present invention can access a heterogeneous wireless network in which state information is managed by a policy server. A method for a mobile terminal having a multi-radio interface to perform a handover based on a policy between the heterogeneous wireless networks, wherein the policy server is configured to change the state of the current network to which the mobile terminal is connected. Receiving, from the handover policy request message, the policy server sending a handover policy response message to the mobile terminal based on the handover policy request message, and the handover policy response message. The mobile terminal performs handover based on A characterized in that it comprises.

The handover policy request message may include at least one of a mobile terminal and user identity information, mobile terminal location information, and a reason for a handover policy request message. The handover policy response message may include at least a hand. It is preferable to include at least one of the over performance information, the new network information to perform the handover, the additional information.

The operator policy server preferably receives a network status report message from the mobile terminal, the network status report message including at least current state information of the current network, and the operator policy server responds to the mobile terminal at least according to a change in the state of the current network. Preferably, the mobile terminal transmits a policy setting message including policy information to be performed.

<Example>

EMBODIMENT OF THE INVENTION Hereinafter, the Example of this invention is described, referring an accompanying drawing. However, even if the drawings are different, detailed descriptions of the same functions will be omitted by attaching the same reference numerals.

3 shows that a mobile terminal having a multi-radio interface is selected by a policy server when performing a handover. The mobile terminal 100 is connected to a wireless network 300 using a plurality of IP (Internet Protocol) addresses. It can be used independently of the 400, it is also possible to selectively use the network 400 of the better environment of the heterogeneous wireless network. This determination is determined by the operator's policy server 200, and can be applied to other things such as the user's location, the operator's policy change, the network situation change, the user's service change, and the like. The mobile terminal 100 requests a handover policy from the operator's policy server 200 when there is a signal strength attenuation, location change, or a current network state change, and the policy server 200 provides the user's subscription information and the present. The conventional handover policy is determined in consideration of the situation of the network 300, and the policy is transmitted to the mobile terminal 100. The mobile terminal 100 that has received the handover policy performs a handover to the new network 400 selected by the policy. In this case, the mobile terminal 100, the Mobile IP, Fast Mobile IP, and NETLMM (Network Based Localized Mobility Management) IETF (Internet) Engineering Task Force) allows the use of protocols that are being standardized.

4 is a flowchart when the operator uses the NETLMM protocol that can manage the mobility of the mobile terminal. The mobility management and handover protocols proposed by the IETF are a method of informing the home agent (HA) of its location by knowing that the mobile terminal 100 has moved to another new network 400. In the real world, however, a model is used to centrally manage mobility in the network, and the standard is being created by the NETLMM WG.

First, the networks 300 and 400 should be models in which one operator can manage or manage heterogeneous networks. All data coming into and going out of the operator goes through an anchor node 220 called an edge mobility anchor point (EMAP), and the ID (IMSI, NAI, etc.) of the mobile terminal 100 is connected to the anchor node 220. Unique ID of) and address have user's network location (Binding Table) information.

When there is a mobile terminal 100 that is being serviced through the access point 310 and the base station 320 in the conventional network 300, the mobile terminal 100 is referred to as the “access point 410 of the new network 400”. Perform a handover ”, and the mobile terminal 100 simply needs to change an access point according to the existing IEEE 802.11 standard.

AAR (Advanced Access Router) 340 for updating the location information of the mobile terminal 100, if it determines that the mobile terminal 100 is connected to its network, the ID of the mobile terminal 100 to the EMAP 220 And update the address. The EMAP 220 receives the mobile terminal 100 determines that the mobile terminal 100 has moved, and then the incoming messages are transmitted to the new access point 410 through tunneling. Through this, the mobile terminal 100 does not need to process a message for handover, and the operator can easily handle handover of the mobile terminal 100 by using one anchor node 220.

5 is a flowchart of a policy decision request and response between a mobile terminal and a policy server. The mobile terminal 100 has a Policy Enforcement Function (PEP) capable of executing a policy, and the Policy Server 200 has a Policy Decision Point (PDP) for determining a policy. Subscriber Profile Repository (SPR) 210 is a database that contains user profile information and information about policy decisions.

First, the mobile terminal 100 transmits a handover policy request message to the policy server 200. The policy server 200 refers to the user's subscription information and policy information in the SPR 210, and performs a handover policy using the location received from the mobile terminal 100 and the information of the legacy network 300 currently being used. The mobile station 100 transmits a handover policy response message to the mobile station 100. The mobile terminal 100 having received the handover policy selects a new network 400 to be connected according to the policy, and stores it so as to execute the received policy.

6 is a protocol message type used for policy between a mobile terminal and a policy server. It uses the Common Open Policy Service (COPS) protocol defined by the Internet Engineering Task Force (IETF), and defines it as a handover policy request message so that the mobile terminal 100 can determine a policy for a handover that did not exist previously. This message is used to request a handover policy.

The handover policy request message is for the mobile terminal 100 to give the policy server 200 information necessary for handover. In order to first identify the identity of the mobile terminal 100 may include things such as IMSI (International Mobile Subscriber Identity), IMEI (International Mobile Equipment Identity), IPv4, IPv6, MAC address, etc., the location of the mobile terminal 100 There may be a Location Area ID, Cell ID, Service Set Identifier (SSID), Extended Service Set Identifier (ESSID), etc. indicating information.

It also includes information indicating why the handover policy request message originated. This includes information that can inform the policy server 200 of this state change when the signal strength of the currently connected legacy network 300 is weakened. In addition, it includes information of the wireless network 300 that the mobile terminal 100 is currently connected and used.

The reason for sending the user's service type is that if the user is using a service such as VoIP or video conferencing, it may be better not to perform handover, and in case of a service requiring a large bandwidth, To over. This determination is based on the contents set in the operator's policy server 200, the user policy server 200, if received from the previously received policy information, such as VoIP, video conferencing, handover policy request It is also possible to follow the handover using the signal strength of the network 300 without the message.

The policy server 200 receiving the information of the mobile terminal 100, based on the registration information and handover policy information of the user brought from the SPR (210), the network 400 most suitable for the current user mobile terminal (100) ), A handover policy response message is sent to the mobile terminal 100. The handover policy response message includes the decision of the operator policy server 200 for the handover. In particular, the mobile terminal 100 may include information of the new network 400 to perform the handover, and may set the boundary value of the network to the mobile terminal 100 to give the threshold value for the handover. . In addition, by handing information such as IP address and security (authentication) of the new network 400 to perform the handover to the mobile terminal 100, the handover can be performed quickly.

The network status report message of FIG. 7 indicates that the mobile terminal 100 informs the policy server 200 of the signal strength of the network 300 currently being used and the state of the current network 300. It is a data that can be referred to for monitoring the status of the current network (300). In addition, the threshold value of the handover in the policy information sent by the policy server 200 to the mobile terminal 100 through the policy setting message defines what action to take when the signal strength of the network 300 falls below the threshold value. do.

Although the mobile terminal 100 may receive a handover policy response message by sending a handover policy request message before performing the handover, the mobile terminal 100 may perform a handover. If there is a policy setting message such as “Do a handover at any time” or “Use a specific network 400 when receiving any service”, perform a policy quickly using a predetermined connection and handover policy. can do.

FIG. 8 shows a policy server giving a mobile station information of a new network to use after handover, and may send a security (authentication) key value and additional information including an IP address to be used by the mobile station 100. Using such a message, the mobile terminal 100 may have information necessary for handover in advance before handover.

As mentioned above, although this invention was demonstrated based on the Example, this invention is not limited to this, It is a matter of course that the person of ordinary skill in the art belongs to the scope of the present invention by various modifications. .

The effects of the present invention described above are as follows.

First, since the user's mobile terminal does not need to know all the surrounding wireless environment, when the mobile terminal having the multi-radio interface performs handover using the signal strength, the mobile terminal must periodically search all the radio frequencies. There was a problem, but using the above invention can solve this problem.

Second, by effectively using a variety of wireless networks managed by the operator, it is possible to provide the optimal service for the user, it is possible for the operator to a variety of billing system and additional services.

Third, since the operator can manage the handover of the mobile terminal and the access network, the operator can perform the handover of the mobile terminal more quickly and efficiently manage the entire wireless network resources.

Claims (5)

A mobile terminal having a multi-radio interface capable of accessing a heterogeneous wireless network in which state information is managed by a policy server, wherein the mobile terminal performs handover based on a policy between the heterogeneous wireless networks. Receiving, by the policy server, a network status report message including status information of at least a current network from the mobile terminal; Receiving, by the policy server, a handover policy request message from the mobile terminal when the state of the current network to which the mobile terminal is connected or when the policy is changed by a network operator; Sending, by the policy server, a handover policy response message to the mobile terminal according to the handover policy request message; Performing the handover by the mobile terminal based on the information of the handover policy response message Handover method based on the policy of the mobile terminal having a multi-wireless interface that can be connected to a heterogeneous wireless network comprising a. The method according to claim 1, The handover policy request message includes at least one of a mobile station and user identity information, mobile terminal location information, and a reason for a handover policy request message. Handover method based on mobile terminal policy. The method according to claim 1, The handover policy response message includes at least one of handover performance information, new network information to be handed over, and additional information. A policy of a mobile terminal having multiple wireless interfaces that can access a heterogeneous wireless network. Based handover method. delete A mobile terminal having a multi-radio interface capable of accessing a heterogeneous wireless network in which state information is managed by a policy server, wherein the mobile terminal performs handover based on a policy between the heterogeneous wireless networks. Sending, by the policy server, a policy setting message to the mobile terminal, the policy setting message including policy information to be performed by the mobile terminal according to at least the current state change or policy change of the current network; Based on the information in the policy setting message, when the state of the current network changes or when the policy changes, the mobile terminal performs a handover Handover method based on the policy of the mobile terminal having a multi-wireless interface that can be connected to a heterogeneous wireless network comprising a.

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