KR20090094499A - Method of network based vertical handover between heterogeneous networks - Google Patents

Abstract

A method of vertical handover between heterogeneous networks is provided to realize a new network based vertical handover procedure for various moving scenario of mobile nod. A mobile node notifies to a home mobile access gateway that the measured link quality is the first threshold(Th1) or less(S3). When a resources check is completed in candidate networks, the home mobile access gateway determines the corresponding PoS as a hand over candidate(S7). The home mobile access gateway requests a hand over to the mobile node(S10). According to the request of the home mobile access gateway, the mobile node performs the hand over and connects to a candidate PoS(S11).

Description

Method of network based vertical handover between heterogeneous networks}

The present invention relates to a network-based heterogeneous vertical handover method, and more particularly, to an IP in a mobile terminal using the IEEE 802.21 protocol, which is a vertical handover method of a heterogeneous network, and the IETF Proxy Mobile IPv6 protocol, which is a network-based handover method. The present invention relates to a network-based heterogeneous network vertical handover method capable of performing vertical handover between heterogeneous networks without requiring any stack addition and change for handover.

In general, vertical handover between heterogeneous networks has used IETF Mobile IPv4 or Mobile IPv6 protocol to maintain IP sessions.

The Mobile IPv4 / v6 protocol is a host-based handover scheme that requires a lot of modifications to the mobile terminal and can cause excessive load on the radio section by IP signaling.

In order to solve this problem, the IETF international standardization organization has recently standardized a network-based IP session maintenance and handover scheme called Proxy Mobile IPv6 (PMIPv6) protocol. The PMIPv6 protocol does not require any modification to the mobile terminal and is favored by many mobile operators because of the advantage of greatly reducing the load required for the wireless section.

Meanwhile, the IEEE 802.21 protocol proposes a technology for providing an event service, a command service, and an information service required for vertical handover of heterogeneous mobile terminals.

When the IEEE 802.21 standard is completed, the IEEE 802.21 technology must be used for the vertical handover request procedure to prepare an efficient handover procedure based on the standard.

However, the conventional handover method is focused on the efficient handover method in a single network in the case of the PMIPv6 protocol, and even in the research using the PMIPv6 protocol between heterogeneous networks, the IEEE 802.21 protocol is not sufficiently considered. There is this.

The present invention has been proposed to solve the above problems, and it is possible to efficiently implement a new network-based vertical handover procedure for various mobile scenarios of a mobile node using the IEEE 802.21 protocol. The purpose is to provide an over method.

According to an aspect of the present invention, there is provided an information acquisition step of acquiring a neighbor network information from a media independent information server by a home mobile access gateway to which a mobile node is connected and to which a point of service (PoS) function is added; A threshold setting step of setting, by the home mobile access gateway, two thresholds relating to link quality to the mobile node; The mobile node determines the PoS as a handover candidate by checking a resource of a PoS corresponding to a handoverable network when the current measured link quality is equal to or less than a first threshold value; Wow; A resource reservation step of the mobile node reserving a corresponding resource with the determined candidate PoS when the current measured link quality is less than or equal to a second threshold value; A mobile access step in which the mobile node accesses the candidate PoS when the home mobile access gateway requests handover to the mobile node; And a resource release step of the candidate PoS recognizing that the mobile node is connected and requesting resource release from the home mobile access gateway.

Advantageously, the candidate determining step includes: a first notifying step of the mobile node notifying the home mobile access gateway that the measured link quality is less than or equal to the first threshold value; When the home mobile access gateway notifies the mobile node of the handoverable network information, the mobile node selects a network suitable for a current requirement and notifies the home mobile access gateway; The mobile node may further include a standby step of waiting for a mobile connection by turning on an interface accessible to the selected network.

Preferably, the resource reservation step further includes a second notification step of the mobile node notifying the home mobile access gateway that the measured link quality is less than or equal to the second threshold value. When the resource reservation is made to the determined candidate PoS, the mobile node may be notified to move.

Preferably, the mobile access step may notify the determined candidate PoS when the home mobile access gateway requests a handover to the mobile node.

Preferably, the handoverable network is an access network managed by the same core network as the network to which the mobile node is connected, and the determined candidate PoS may be a visited mobile access gateway to which a PoS function is added.

Preferably, when the visited mobile access gateway requests authentication to a policy server after access of the mobile node, the policy server responds to the visited mobile access gateway with a related profile including address information of a local mobility anchor; ; A tunneling step in which the visited mobile access gateway exchanges the local mobility anchor with a Proxy Binding Update (PBU) and a Proxy Binding Acknowledgement (PBA) message after the connection recognition of the mobile node, and performs tunneling; And transmitting, by the visiting mobile access gateway, a router advertisement message and data to the mobile node.

Preferably, the handoverable network is an access network managed by a core network different from the network to which the mobile node is connected, and the determined candidate PoS may be a visited mobile access gateway to which a PoS function is added.

Preferably, when the visited mobile access gateway requests authentication to a visited policy server after access of the mobile node, the visited policy server requests an authentication to a home policy server; A first response step for the home policy server to respond to the visited policy server an associated profile containing address information of a home local mobility anchor; And a second response step, wherein the visit policy server responds to the visited mobile access gateway an associated profile including the address information of the visited local mobility anchor with the address information of the home local mobility anchor.

Preferably, when the visited mobile access gateway transmits a PBU message to the visited local mobility anchor after recognizing the connection of the mobile node, the visited local mobility anchor sends a Remote PBU message including whether the mobile node is moved to the home local mobility anchor. Sending a message to the mobile terminal; A first tunneling step in which the home local mobility anchor sends a Remote PBA message as a response to the visit local mobility anchor so that tunneling between the home local mobility anchor and the visit local mobility anchor is performed; And a second tunneling step, wherein the visited local mobility anchor sends a PBA message to the visited mobile access gateway to perform tunneling between the visited local mobility anchor and the visited mobile access gateway.

Advantageously, the visited mobile access gateway may further transmit a RA message and data to the mobile node.

Preferably, the handoverable network is an access network managed by a core network different from the network to which the mobile node is connected, and the determined candidate PoS is a serving gateway having a mobility management entity (MME) function to which a PoS function is added. Can be.

Preferably, when the serving gateway requests authentication to the visited policy server after access of the mobile node, the visited policy server requests an authentication to a home policy server; A first response step for the home policy server to respond to the visited policy server an associated profile containing address information of a home local mobility anchor; And a second response step, wherein the visit policy server responds to the serving gateway a related profile including the address information of the visit local mobility anchor together with the address information of the home local mobility anchor.

Preferably, the serving gateway notifies the visited local mobility anchor that the mobile node has moved after recognizing the connection of the mobile node; Transmitting, by the visited local mobility anchor, a Remote PBU message including whether the mobile node is moved to a home local mobility anchor; A tunneling step in which the home local mobility anchor sends a Remote PBA message as a response to the visit local mobility anchor so that tunneling between the home local mobility anchor and the visit local mobility anchor is performed; The visited local mobility anchor may further include a first transmission step for transmitting an RA message and data to the serving gateway.

Preferably, the serving gateway may further include a second transmission step of transmitting an RA message and data to the mobile node.

The network-based heterogeneous vertical handover method according to the present invention provides a new network-based handover procedure for various mobile scenarios of a mobile node by using the IEEE 802.21 protocol which is a vertical handover method of a heterogeneous network. Handover is possible through a PHY / MAC stack suitable for the interface hardware already in place, so if the mobile terminal has a stack that conforms to the IEEE 802.21 protocol, it can be used for vertical handovers without the need for any network stack additions or changes for IP mobility. This has the effect of correctly maintaining the IP session.

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

1 is a schematic configuration diagram of a system for vertical handover between heterogeneous networks based on a network according to the present invention.

As shown in FIG. 1, in a system for vertical handover between heterogeneous networks based on an IEEE 802.21 protocol, a MIH Media Independent Point of Service (PoS), which is a node that performs a service defined in the IEEE 802.21 protocol, is Mobile Access Gateway (MAG) defined in PMIPv6 protocol and Mobility Management Entity (MME) defined in 3GPP LTE / SAE protocol.

Here, the mobile access gateway (MAG) and the mobility management entity (MME) are nodes that are mainly responsible for mobility management in each access network, and the mobile access gateway (MAG) is an access router located in the PMIPv6 domain. The function is added to the Access Router, and the mobility management entity (MME) performs mobility management of the mobile node.

Meanwhile, the MIH PoS also exchanges information with a Point of Attachment (PoA), which is a lower layer 1/2 connection point of a mobile terminal (MN), and includes a media independent information server (MIIS) and a local mobility anchor (LMA); It is also configured to exchange information with high-level nodes such as Local Mobility Anchor.

Here, the Media Independent Information Server (MIIS) is a server that manages various network information about heterogeneous networks serviced to users, and the Local Mobility Anchor (LMA) is a function defined in the IETF PMIPv6 protocol and all mobiles that reside in the PMIPv6 domain. Supports routing and mobility services for the terminal.

The above configuration depends on how operators configure heterogeneous networks, that is, when one or more access networks are managed in one same core network and when different core networks manage one or more access networks. It may be configured in consideration of. Here, the access network considers LTE / SAE of 3GPP and WiBro network, which has recently become a lot of issues.

FIG. 2 is a schematic diagram of a case where the system of FIG. 1 is managed on one core network.

As shown in Fig. 2, when the operator configures one core network, it manages all mobile node subscribers in one core network, and the old system and the new LTE of different access networks, for example, the WiBro network or 3GPP. / SAE keeps the system together.

In this configuration, the local mobility anchor (LMA) for operating PMIPv6 is basically configured as one. Of course, multiple local mobility anchors (LMAs) can be managed for load balancing and fault tolerance. In addition, the local mobility anchor (LMA) is tunneled to the mobile access gateway (MAG) connected to the mobile terminal unconditionally any packet transmitted by any node outside the domain to the mobile terminal that resides in the domain.

The Mobile Access Gateway (MAG) is added to an Access Control Router (ACR) or the like of a WiBro network that performs the function of an Access Router that is directly related to layer 3 general routing and IP address assignment. In addition, when a mobile node enters a domain and connects to an access router, the mobile access gateway (MAG) supports mobility by exchanging mobility-related signaling with a local mobility anchor (LMA) on behalf of the mobile node.

A Policy Server (PS) is a function defined in the IETF PMIPv6 protocol and stores a variety of information related to a mobile node. In particular, a Policy Server (PS) stores a local mobility anchor (LMA) address for providing mobility services to a mobile node. It is managed and added to AAA (Authentication, Authorization, Accounting) server.

The AAA server is a server that provides authentication, authorization, and fee calculation functions for network resource access processing and service provision of mobile nodes, and is generally located in a core network managed by an operator.

Meanwhile, in the 3GPP LTE / SAE network, since the Packet Data Network Gateway (P-GW) functions as an access router of the entire network, the Mobile Access Gateway (MAG) function serves as a serving gateway (S-GW; Serving). Local mobility anchor (LMA) added to the packet data network gateway (P-GW) itself, or local mobility anchor (LMA) in the operator network outside the packet data network gateway (P-GW) It is configured to.

A packet data network gateway (P-GW) is a gateway located between the operator's core network and the external Internet network and acts as a gateway between them, and typically performs a layer 3 access router function and delivers RA messages to mobile nodes. .

The serving gateway (S-GW) is located between the core network and the access network to perform various management of mobile nodes.

The mobility management entity (MME) cooperates with the serving gateway (S-GW) and the evolved nodeB (eNodeB) to perform mobility management of the mobile node.

NodeB is a node that performs the same function as the base station in the 3GPP network, eNodeB is a node that performs a function similar to the previous base station as a function defined in the 3GPP LTE / SAE protocol and performs an improved function.

Radio Network Controller (RNC) is a node that mainly manages the overall resources of a wireless network, and a Serving GPRS Support Node (SGSN) delivers data packets with mobile nodes in a service area. This node is responsible for packet routing and transmission, mobility management, logical link management, authentication, and charging.

In the WiBro network, a radio access system (RAS) plays a role as a base station in a WiBro service area, and an access control router (ACR) manages a radio access system (RAS) and a mobile terminal. Typically responsible for the function of an access router.

FIG. 3 is a schematic diagram of a case where the system of FIG. 1 is managed on different core networks.

As shown in FIG. 3, when two operators configure different core networks, one or more access networks are maintained in each core network.

In this configuration, each core network operates independently with PMIPv6, and local mobility anchors (LMAs) are configured independently.

Hereinafter, a method for vertical handover between heterogeneous networks based on the present invention will be described with reference to FIGS. 4 to 7.

4 is a flowchart illustrating a method for vertical handover between heterogeneous networks based on a network according to the present invention.

The method is a basic procedure to efficiently support the PMIPv6 protocol from the list of various event services, command services, and information services defined in the IEEE 802.21 protocol.

First, the home mobile access gateway (MAGh) to which the mobile node (MN) is connected obtains information about the surrounding network from the media independent information server (MIIS) (steps S1 and S1 ').

Here, the home mobile access gateway (MAGh) has a PoS function added, and the candidate PoS may be a visited mobile access gateway (MAGv) or a serving gateway (S-GW) as described below according to the configuration of the system. In FIG. 4, the mobile access gateway (MAG) to which the mobile node (MN) is connected is shown as a home mobile access gateway (MAGh) separately from the visited mobile access gateway (MAGv).

That is, when the mobile node (MN) is connected to any network, the home mobile access gateway (MAGh) requests the peripheral network information to the media independent information server (MIIS) (step S1), the media independent information server (MIIS) In response, the information is transmitted to the home mobile access gateway MAGh (step S1 ').

Next, the home mobile access gateway (MAGh) sets a threshold value on the link quality (Link Quality) to the mobile node (MN) (step S2).

Here, the threshold setting proceeds immediately after the mobile node MN is connected to an arbitrary network, and the threshold is set to two different thresholds Th1 and Th2. Thereafter, the mobile node MN moves and measures the current link quality.

If the mobile node MN has a current measured link quality less than or equal to the first threshold Th1, the mobile node MN indicates that the measured link quality is less than or equal to the first threshold Th. Home Mobile Access Gateway MAGh (Link_Going_Down Report I) is informed (step S3).

At this time, if the home mobile access gateway (MAGh) (Resource Check) to the mobile node (MN) handoverable network information (step S4), the mobile node (MN) selects a network suitable for the current requirements to the home The mobile access gateway (MAGh) is notified (step S4 ').

Next, the mobile node MN waits for the mobile connection by turning on an interface that can be connected to the selected network (Power On) (step S5).

At this time, the home mobile access gateway (MAGh) checks the resource of the PoS corresponding to the handable network (Resource Availability Check) (steps S6 and S6 '). That is, the home mobile access gateway (MAGh) checks the resources for the handoverable candidate networks.

The home mobile access gateway (MAGh) determines that the PoS is a handover candidate when resource checking is completed on the candidate networks (step S7). Here, the home mobile access gateway (MAGh) determines the handover candidate PoS in consideration of the network selected by the mobile node (MN) in step S4 '.

Next, when the mobile node MN continuously moves and measures the current link quality, and the current measured link quality is less than or equal to the second threshold Th2, the mobile node MN determines that the measured link quality is the second threshold. The home Mobile Access Gateway (MAGh) is notified (Link_Going_Down Report II) that it is equal to or smaller than the value Th2 (step S8).

Subsequently, the Home Mobile Access Gateway (MAGh) reserves the resource with the determined candidate PoS (Resource Reservation) (step S9). At this time, the home mobile access gateway (MAGh) informs the mobile node (MN) to move to the candidate PoS.

Next, the home mobile access gateway MAGh requests a handover to the mobile node MN (Step S10). At this time, the home mobile access gateway (MAGh) informs the mobile node (MN) of the candidate PoS determined in step S7.

The mobile node MN performs a handover (Link-specific Handover) at the request of the home mobile access gateway (MAGh) and is connected to the candidate PoS (step S11).

The candidate PoS recognizes (Link-Up Indication I) the connection of the mobile node (MN) when the mobile node (MN) is handed over to a new network and connected (step S12).

Next, the candidate PoS requests a resource release to the home mobile access gateway (MAGh) (step S13). That is, the candidate PoS requests the home mobile access gateway (MAGh) to release resources associated with the handed over mobile node (MN).

In this manner, network-based vertical handover using the IEEE 802.21 protocol can be performed without modification of the mobile node (MN).

On the other hand, the network-based vertical handover method can be applied in consideration of the following three mobile scenarios related to the configuration of the network.

The first is when a mobile node (MN) moves to an access network that supports a mobile access gateway (MAG) within the same core network, and the second is a mobile access gateway (MAG) between core networks with different mobile nodes (MN). Is a case of moving to a supported access network, and a third case is that a mobile node (MN) moves to an access network in which a mobile access gateway (MAG) is not supported between different core networks.

Hereinafter, a network-based heterogeneous vertical handover method for each mobile scenario will be described.

5 is a flowchart illustrating a method for vertical handover between heterogeneous networks based on a network according to a first embodiment of the present invention.

A first embodiment of the present invention is a vertical handover method when a mobile node (MN) moves to an access network supported by a mobile access gateway (MAG) within a same core network. Is an access network managed by the same core network as the network to which the mobile node MN is connected, and the determined candidate PoS is a visiting mobile access gateway (MAGv) to which the PoS function is added.

In the first embodiment of the present invention, the home mobile access gateway (MAGh) to which the mobile node (MN) is connected obtains an information acquisition step (step S101) of obtaining peripheral network information from the media independent information server (MIIS), and home mobile access. A threshold setting step (step S102) in which the gateway MAGh sets two thresholds relating to link quality to the mobile node MN; If the mobile node MN has a current measured link quality less than or equal to the first threshold Th1, the home mobile access gateway MAGh checks the resources of the visiting mobile access gateway MAGv corresponding to the handoverable network. A candidate determination step (steps S103 to S107) of determining the visited mobile access gateway (MAGv) as a handover candidate; Resource reservation step (step S108 ~) in which the mobile node (MN) reserves the resource to the visited mobile access gateway (MAGv) where the home mobile access gateway (MAGh) is determined if the current measured link quality is less than or equal to the second threshold. S109), and when the home mobile access gateway (MAGh) requests a handover to the mobile node (MN), the mobile node (MN) goes to the mobile access step (steps SS110 to S111) to connect to the visited mobile access gateway (MAGv). This is the same method as steps S1 to S11 in FIG. 4, and thus a detailed description thereof will be omitted.

After the mobile node MN is handed over and connected to the visited mobile access gateway (MAGv) as described above, when the visited mobile access gateway (MAGv) requests authentication (AAA Query) to the policy server PS (step S112). The policy server PS responds to the visited mobile access gateway MAGv with the relevant profile containing the address information of the local mobility anchor LMA (step S112 '). Here, the authentication request and response includes the ID of the mobile node (MN), and the profile is a profile required by the PMIPv6 protocol.

When the authentication is completed, the visiting mobile access gateway (MAGv) recognizes that the mobile node (MN) has been handed over to the access network managed by the visited mobile access gateway (step S113).

Next, the visiting mobile access gateway (MAGv) existing in the access network newly moved by the mobile node (MN) exchanges PBU and PBA messages with the local mobility anchor (LMA) after acknowledging the connection of the mobile node (MN) to the PMIPv6 protocol. The defined handover procedure is performed (steps S114 to S115). That is, the visiting mobile access gateway (MAGv) exchanges PBU and PBA messages of the PMIPv6 protocol with the local mobility anchor (LMA) by utilizing the local mobility anchor (LMA) address obtained through the AAA authentication.

Here, bidirectional tunneling is established if no tunnel is established between the visiting mobile access gateway (MAGv) and the local mobility anchor (LMA).

By the tunneling, the visiting mobile access gateway (MAGv) transmits the RA message and data to the mobile node (MN) (step S116).

As such, when the handover of the mobile node MN is normally completed, the visited mobile access gateway MAGv requests the resource release from the home mobile access gateway MAGh to release resources for the moved mobile node MN ( Step S117).

In this manner, even when the mobile node MN moves to an access network supported by the mobile access gateway MAG on the same core network, vertical handover based on the network can be performed without modification of the mobile node MN. .

6 is a flowchart illustrating a method for vertical handover between heterogeneous networks based on a network according to a second embodiment of the present invention.

The second embodiment of the present invention is a vertical handover method when the mobile node MN moves to an access network supported by a mobile access gateway (MAG) between different core networks. The network is an access network managed by a core network different from the network to which the mobile node MN is connected, and the determined candidate PoS is a visited mobile access gateway (MAGv) to which the PoS function is added.

In the second embodiment of the present invention, the procedure until the mobile node MN is connected to the visited mobile access gateway MAGv existing in the new mobile access network is the same as that of the first embodiment, and thus the description thereof is omitted here.

After the mobile node MN is handed over and connected to the visited mobile access gateway MAGv, the visited mobile access gateway MAGv requests authentication from the visited policy server PSv (step S212).

In this case, in order for AAA authentication to the network to which the mobile node (MN) is currently connected, it is necessary to obtain the result of AAA authentication to the previous network. Therefore, the visiting policy server (PSv) authenticates with the home policy server (PSh). Request (step S213).

The home policy server PSh responds to the visited policy server PSv with the relevant profile containing the address information of the home local mobility anchor LMAh (step S214), and then the visited policy server PSv receives the home local mobility anchor ( The associated profile including the address information of the visited local mobility anchor LMAv together with the address information of LMAh) is returned to the visited mobile access gateway MAGv (step S215).

Here, the authentication request and response includes an ID of a mobile node (MN), and the profile is a profile required by the PMIPv6 protocol, and is transferred to a visited local mobility anchor (LMAv) of a network to which the mobile node (MN) is currently connected. Home local mobility anchor (LMAh) of the network.

The visited mobile access gateway (MAGv) recognizes that the mobile node (MN) is handed over to the access network managed by the visited mobile access gateway (MAGv) and is connected to the mobile network (step S216).

The visited mobile access gateway (MAGv) sends a PBU message to the visited local mobility anchor (LMAv) after recognition of the connection of the mobile node (MN) (step S217).

That is, the visited mobile access gateway (MAGv) transmits the PBU message of the PMIPv6 protocol to the visited local mobility anchor (LMAv) of the current network by utilizing the visited local mobility anchor (LMAv) address obtained through the AAA authentication. It also sends home local mobility anchor (LMAh) address information that was served in the previous network.

Next, when the visited local mobility anchor LMAv receives the PBU message, it transmits a Remote PBU message including whether the mobile node MN moves to the home local mobility anchor LMAh (step S218). That is, the visited local mobility anchor LMAv present in the current network notifies the home node mobility anchor LMAh of the previous network that the mobile node MN has moved.

Here, the Remote PBU message is a newly defined message that utilizes the message defined in the IEEE 802.21 protocol and the message defined in the PMIPv6 protocol to the maximum. When the mobile node (MN) moves to a different core network, This message is sent by the existing visited local mobility anchor (LMAv) to the home local mobility anchor (LMAh) existing in the previous core network.

At this time, the Home Local Mobility Anchor (LMAh) existing in the previous core network receiving the Remote PBU message is homed with respect to the ID of the mobile node (MN) to be currently processed in the Binding Cache data structure defined in the PMIPv6 protocol. Binds a Network Prefix and a Visit Local Mobility Anchor (LMAv) address that exists in the newly moved core network.

Next, the home local mobility anchor LMAh sends a Remote PBA message to the visited local mobility anchor LMAv as a response (step S219).

Here, the Remote PBA message is a newly defined message utilizing the message defined in the IEEE 802.21 protocol and the message defined in the PMIPv6 protocol, and the home local mobility anchor (LMAh) may have received the remote PBU from the visited local mobility anchor (LMAv). When sent as a response message.

At this time, the visited local mobility anchor (LMAv) receiving the Remote PBA message has a home network prefix and home for the ID of the mobile node (MN) to be processed in the binding update list data structure defined in the PMIPv6 protocol. Stores local mobility anchor (LMAh) addresses.

As such, when the Landing Local Mobility Anchor (LMAv) receives a Remote PBA message, bidirectional tunneling is formed between the Landing Local Mobility Anchor (LMAv) and the Home Local Mobility Anchor (LMAh). Set.

Next, the visited local mobility anchor (LMAv) sends a PBA message to the visited mobile access gateway (MAGv) (step S220). That is, the visited local mobility anchor (LMAv) receiving the Remote PBA message transmits the PBA message to the visited mobile access gateway (MAGv) that sent the PBU message to notify the successful mobility information binding result.

Here, bidirectional tunneling is set if no tunnel is established between the visited local mobility anchor (LMAv) and the visited mobile access gateway (MAGv).

By the tunneling, the visiting mobile access gateway (MAGv) transmits the RA message and data to the mobile node (MN) (step S221).

In other words, after the mobile node (MN) has handed over to the Landing Mobile Access Gateway (MAGv), tunneling and landing local mobility anchors between the home local mobility anchor (LMAh) of the old network and the landing local mobility anchor (LMAv) of the new network. Packets are sent from the old network to the new network using tunneling formed between the LMAv and the visiting mobile access gateway (MAGv).

As such, when the handover of the mobile node MN is normally completed, the visited mobile access gateway MAGv requests the resource release from the home mobile access gateway MAGh to release resources for the moved mobile node MN ( Step S222).

In this way, even when the mobile node MN moves from one core network to another access network where the mobile access gateway is supported, the network-based vertical handover may be performed without modification of the mobile node MN. Can be.

7 is a flowchart illustrating a method for vertical handover between heterogeneous networks based on a network according to a third embodiment of the present invention.

The third embodiment of the present invention is a vertical handover method when the mobile node MN moves between different core networks to an access network in which the mobile access gateway (MAG) is not supported. The possible network is an access network managed by a core network different from the network to which the mobile node (MN) is connected, and the determined candidate PoS is a serving gateway (S-GW) having a mobility management entity (MME) function with PoS capability. If it is.

The third embodiment of the present invention provides a serving gateway (S) in which a mobile node (MN) exists in a new moved access network, except that the visited mobile access gateway (MAGv) is configured as a serving gateway (S-GW). Since the procedure from the GW) to the AAA authentication is the same as in the second embodiment, the description thereof is omitted here.

When the serving gateway (S-GW) completes the AAA authentication of the mobile node (MN), the serving gateway (S-GW) informs that the mobile node (MN) has been moved to the visiting local mobility anchor (LMAv) (Link-Up Indication). II) (step S317).

At this time, the serving gateway (S-GW) uses the visited local mobility anchor (LMAv) address obtained through AAA authentication in steps S312 to S314 to transfer the mobile node MN to the visited local mobility anchor (LMAv). Notify me.

Next, as in steps S218 and S219 of the second embodiment, the visited local mobility anchor LMAv transmits a Remote PBU message including whether the mobile node MN is moved to the home local mobility anchor LMAh (step S218). In operation S318, the mobile node MN is notified of the fact of movement.

The Home Local Mobility Anchor (LMAh) sends a Remote PBA message as a response to the Visit Local Mobility Anchor (LMAv) (step S319), forming a bidirectional tunneling between the Visit Local Mobility Anchor (LMAv) and the Home Local Mobility Anchor (LMAh). If no tunnel is set, bidirectional tunneling is set.

By tunneling, the visited local mobility anchor LMAv sends the RA message and data to the serving gateway S-GW (step S320).

Next, the serving gateway S-GW transmits the RA message and data to the mobile node MN (step S321).

That is, after the mobile node (MN) has handed over to the serving gateway (S-GW), tunneling between the home local mobility anchor (LMAh) of the old network and the landing local mobility anchor (LMAv) of the new network, and LTE / SAE Packet forwarding in the network is used to transfer packets from the old network to the new network.

As described above, when the handover of the mobile node MN is normally completed, the serving gateway S-GW requests resource release from the home mobile access gateway MAGh to release resources for the mobile node MN. Step S322).

In this way, even when the mobile node MN moves from one core network to another without access to the mobile access gateway MAG, network-based vertical handover is performed without modification of the mobile node MN. can do.

1 is a schematic configuration diagram of a system for vertical handover between heterogeneous networks based on a network according to the present invention;

FIG. 2 is a schematic structural diagram of a case where the system of FIG. 1 is managed on one core network. FIG.

3 is a schematic structural diagram of a case where the system of FIG. 1 is managed on different core networks;

4 is a flowchart illustrating a method for vertical handover between heterogeneous networks based on a network according to the present invention.

5 is a flowchart illustrating a method for vertical handover between heterogeneous networks based on a network according to a first embodiment of the present invention.

6 is a flowchart illustrating a method for vertical handover between heterogeneous networks based on a network according to a second embodiment of the present invention.

7 is a flowchart illustrating a method for vertical handover between heterogeneous networks based on a network according to a third embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

MN: Mobile Node MAG: Home Mobile Access Gateway

LMA: Local Mobility Anchor MIIS: Media Independent Information Server

PS: Policy Server S-GW: Serving Gateway

Claims (14)

An information acquisition step of acquiring a neighboring network information from a media independent information server by a home mobile access gateway to which a mobile node is connected and to which a point of service (PoS) function is added; A threshold setting step of setting, by the home mobile access gateway, two thresholds relating to link quality to the mobile node; The mobile node determines the PoS as a handover candidate by checking a resource of a PoS corresponding to a handoverable network when the current measured link quality is equal to or less than a first threshold value; Wow; A resource reservation step of the mobile node reserving a corresponding resource with the determined candidate PoS when the current measured link quality is less than or equal to a second threshold value; A mobile access step in which the mobile node accesses the candidate PoS when the home mobile access gateway requests handover to the mobile node; And a resource release step of requesting resource release to the home mobile access gateway in response to the candidate PoS recognizing that the mobile node is connected. The method of claim 1, The candidate determination step, A first notifying step of the mobile node notifying the home mobile access gateway that the measured link quality is less than or equal to the first threshold value; When the home mobile access gateway notifies the mobile node of the handoverable network information, the mobile node selects a network suitable for a current requirement and notifies the home mobile access gateway; And waiting for the mobile node to wait for the mobile connection by turning on an interface that is accessible to the selected network. The method of claim 1, The resource reservation step further includes a second notification step of the mobile node notifying the home mobile access gateway that the measured link quality is less than or equal to the second threshold value. And wherein the home mobile access gateway notifies the mobile node to move upon resource reservation with the determined candidate PoS. The method of claim 1, In the mobile access step, the home mobile access gateway notifies the determined candidate PoS when handover request is made to the mobile node. The method according to any one of claims 1 to 4, The handable network is an access network managed by the same core network as the network to which the mobile node is connected, and the determined candidate PoS is a visited mobile access gateway to which a PoS function is added. Handover method. The method of claim 5, wherein When the visited mobile access gateway requests authentication to a policy server after accessing the mobile node, the policy server responds to the visited mobile access gateway with an associated profile including address information of a local mobility anchor; A tunneling step in which the visited mobile access gateway exchanges the local mobility anchor with a Proxy Binding Update (PBU) and a Proxy Binding Acknowledgement (PBA) message after the connection recognition of the mobile node, and performs tunneling; And transmitting, by the visiting mobile access gateway, a Router Advertisement message and data to the mobile node. 2. The method according to any one of claims 1 to 4, The handable network is an access network managed by a core network different from the network to which the mobile node is connected, and the determined candidate PoS is a visited mobile access gateway to which a PoS function is added. Handover method. The method of claim 7, wherein An authentication request step of, when the visiting mobile access gateway requests authentication to a visiting policy server after access of the mobile node, the visiting policy server requests authentication to a home policy server; A first response step for the home policy server to respond to the visited policy server an associated profile containing address information of a home local mobility anchor; And a second response step, wherein the visit policy server responds to the visited mobile access gateway a related profile that includes the address information of the visited local mobility anchor together with the address information of the home local mobility anchor. Network-Based Heterogeneous Vertical Handover Method. The method of claim 7, wherein When the visited mobile access gateway transmits a PBU message to the visited local mobility anchor after recognizing the connection of the mobile node, the visited local mobility anchor transmits a remote PBU message including whether to move the mobile node to a home local mobility anchor. Sending a message; A first tunneling step in which the home local mobility anchor sends a Remote PBA message as a response to the visit local mobility anchor so that tunneling between the home local mobility anchor and the visit local mobility anchor is performed; And a second tunneling step, wherein the visited local mobility anchor transmits a PBA message to the visited mobile access gateway to perform tunneling between the visited local mobility anchor and the visited mobile access gateway. Vertical Handover Method between Heterogeneous Networks The method of claim 7, wherein And transmitting, by the visited mobile access gateway, the RA message and data to the mobile node. 2. The method according to any one of claims 1 to 4, The handoverable network is an access network managed by a core network different from the network to which the mobile node is connected, and the determined candidate PoS is a serving gateway having a mobility management entity (MME) function to which a PoS function is added. Network-based heterogeneous vertical handover method. The method of claim 11, An authentication request step of, when the serving gateway requests authentication to a visit policy server after access of the mobile node, the visit policy server requests authentication to a home policy server; A first response step for the home policy server to respond to the visited policy server an associated profile containing address information of a home local mobility anchor; And a second response step, wherein the visit policy server responds to the serving gateway a related profile including the address information of the visit local mobility anchor with the address information of the home local mobility anchor. Vertical handover method of heterogeneous networks. The method of claim 11, A mobile notifying step of the serving gateway notifying the visited local mobility anchor that the mobile node has moved after recognizing the connection of the mobile node; Transmitting, by the visited local mobility anchor, a Remote PBU message including whether the mobile node is moved to a home local mobility anchor; A tunneling step in which the home local mobility anchor sends a Remote PBA message as a response to the visit local mobility anchor so that tunneling between the home local mobility anchor and the visit local mobility anchor is performed; And a first transmission step of the visited local mobility anchor transmitting an RA message and data to the serving gateway. The method of claim 11, And a second transmission step of the serving gateway to transmit an RA message and data to the mobile node.

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