WO2013038588A1

WO2013038588A1 - Communication control method, communication terminal, and network device

Info

Publication number: WO2013038588A1
Application number: PCT/JP2012/004756
Authority: WO
Inventors: 隆二杉崎; 池田　新吉
Original assignee: パナソニック株式会社
Priority date: 2011-09-16
Filing date: 2012-07-26
Publication date: 2013-03-21

Abstract

Disclosed is a technique that enables a communication terminal to perform communication setting on the basis of appropriate address setting information with respect to the communication through a PDN connection of a local IP access (LIPA). According to such technique, in a procedure in which a communication terminal (UE 100) establishes the PDN connection with respect to the network, the network notifies the UE of a connection accepting message, in which the address setting information suited to the communication of an LIPA connection is included in an option field (PCO), if the PDN connection is the LIPA connection at the time of using the PMIP. The UE performs the communication setting of the LIPA connection on the basis of the address setting information included in the PCO, and ignores the address setting information in an RA message received from the network thereafter.

Description

COMMUNICATION CONTROL METHOD, COMMUNICATION TERMINAL, AND NETWORK DEVICE

The disclosed technology is a communication control method, a communication terminal, and a network using a home access technology (LIPA (Local IP Access)) when a network-driven MIP (PMIP (Proxy Mobile IP)) is applied Relates to the device.

Currently, standardization activities for technologies used in mobile phones (also referred to as user equipment: UEs and communication terminals) are being carried out in 3GPP (The Third Generation Partnership Project: Third Generation Partnership Project). From a procedure satisfying basic functions such as a procedure, it is called a home access technology (LIPA), for example, a server in which a UE is located in a local network (for example, an in-house server that cannot be accessed from an external network or can be accessed from an external network) And a procedure for providing an access service to the home server are defined (see Non-Patent Document 1 below). This LIPA is one of the technologies defined by 3GPP, and its operation is defined in accordance with a transport protocol between core network nodes called GTP (GPRS Tunneling Protocol) or PMIP. An example of the configuration of a network (communication system) when the UE performs LIPA is shown in FIG.

In FIG. 1, a base station 210 wirelessly connected to the UE 100 (eNB (eNode B) 310 in the E-UTRAN 300, called HeNB (Home eNB) 210 in the LHN (Local HeNB Network) 200), the UE 100 on the E-UTRAN 300 The mobility management node in charge of communication line control and mobility control (the mobility management node connected to the E-UTRAN 300 is the MME (Mobility Management Entity: Mobility Management Entity) 430, the SGW that performs user data distribution control to the E-UTRAN 300 of the UE 100 ( Serving Gateway: serving gateway, MAG (Mobility Anchor Gateway) 410, etc. PGW (Packet Data Network Gateway: HA (Packet Data Network Gateway), HA (User Data Transfer) and PDN (Packet Data Network: Packet Data Network) 500 and user data transfer between the SGW 410 and path control (data path control) User Agent (Home Agent) and LMA (Local Mobility Anchor: Local Mobility Anchor), etc.) 420, LHN200 performs user data transfer and route control (data path control) between Enterprise / Residential network 600 and SGW 410, or HeNB 210. LGW to perform (Local Gat way: local gateway (220), a server that manages and holds subscription data (subscription data) of UE100 and communication context (having an interface with MME430 (for UE100 using E-UTRAN)) Shows an example of a network configuration composed of HSS (called Home Subscriber Server) 440).

In FIG. 1, when the UE 100 communicates (LIPA) with a node in the enterprise / residential network 600 via the LHN 200, the UE 100 establishes a PDN connection and an EPS bearer (referred to as EPS Bearer, bearer, etc.) with the LGW 220. To do. The UE 100 acquires an IP (Internet Protocol) address through the establishment of this PDN connection, and establishes an EPS bearer used for communication with the Enterprise / Residential network 600 (see Non-Patent Document 1 and Non-Patent Document 2 below). reference). When establishing a PDN connection, information such as the IP address assigned to the UE 100 and the address of the SGW 410 (for example, IPv6 link-local address) is treated as context information of the UE 100, and the core network (for example, in Non-Patent Documents 1 and 2). Specified EPC; Evolved Packet Core etc.) 400 entities (for example, MME, SGW, LGW). As a result, the entity of the core network 400 can transfer, for example, data transmitted from the enterprise / residential network 600 to the UE 100. The UE 100 transmits a request message (sometimes referred to as a connection request message in this specification) such as “Attach request” and “PDN connectivity request” disclosed in Non-Patent Document 1 to the network, and the LGW 220. PDN connection is established during

The procedure for establishing a PDN connection for LIPA (hereinafter referred to as a LIPA connection) is largely the same as the procedure for establishing a normal PDN connection. The difference is that the entity of the core network 400 (for example, the MME 430) aims for LIPA. And when the LIPA connection is permitted (for example, the APN (Access Point Name: access point name specified by the Attach / PDN connectivity request transmitted from the UE 100). This parameter identifies the PDN 500, and the connection of the PDN connection. (Information indicating the destination) is identified as an APN for LIPA and the UE is permitted to connect to LIPA), the Correlation I from the MME 430 to the HeNB 210 Points are mentioned to be sent. The LGW 220 and the HeNB 210 establish a communication path (direct user plane path (direct user plane path), direct path (direct path), shortcut path), which can directly exchange user data when establishing a LIPA connection. The direct path can be identified using the Correlation ID shared via the MME 430. The merit of constructing the direct path is that user data transfer can be closed by the LGW 220 and the HeNB 210, and the traffic load of the core network 400 can be reduced.

In general, in a network defined by 3GPP, the procedure for the UE 100 to acquire an IPv6 address is that the UE 100 generates an IPv6 address based on the IPv6 prefix acquired from the network (see Non-Patent Document 1 and Non-Patent Document 2). reference). The entity that notifies the UE 100 of the IPv6 prefix differs depending on whether the core network transport is GTP or PMIP. In GTP, PGW420 (LGW220 at the time of LIPA) is disclosed in Non-Patent Document 1. RA (Router Advertisement: Router Advertisement) message (also called address information notification message) is used to notify the UE 100 of the IPv6 prefix, and PMIP notifies the UE 100 of the IPv6 prefix using the RA message as disclosed in Non-Patent Document 2. To do. It should be noted that the RA message is sent in response to both a case where it is transmitted in response to an inquiry from the UE 100 (Solicated) and a case where it is periodically transmitted without being inquired from the UE 100 (Unsolicited).

The RA message is notified to the UE 100 when the PDN connection establishment is completed (after the default bearer is established). Further, the UE 100 can request an RA message by transmitting an RS (Router Solicitation) message (also called an address information request message) to the network. The PGW 420, LGW 220 (in the case of GTP), or SGW 410 (in the case of PMIP) that has received the RS message returns an RA message.

The structure of the RA message includes a source address (Source address (source address)), an end point address (Destination address (destination address)), and the like as disclosed in Non-Patent Document 3 and Non-Patent Document 4 below. It consists of IP field, ICMP (Internet Control Message Protocol) including the message type, router lifetime, etc., and Possible options field including source link layer address and prefix information.

Further, as disclosed in Non-Patent Document 3 and Non-Patent Document 4, a Link-MTU (Maximum Transmission Unit) value indicating the size of the maximum transfer unit that can be transmitted in the layer 2 link using an RA message, a router The priority level between them can also be notified.

Next, a user data transfer process when a LIPA connection is established between the UE 100 and the LGW 220 will be described.

When a LIPA connection is established, a direct path is established between the HeNB 210 and the LGW 220. At this time, for example, user data in the uplink direction sent from the UE 100 on the established LIPA connection is transferred from the HeNB 210 to the LGW 220 via the direct path. That is, the user data in the uplink direction is not transferred from the HeNB 210 to the SGW 410 of the core network 400, but is transferred directly from the HeNB 210 to the LGW 220. Similarly, in the downlink direction, the user data received by the LGW 220 from the Enterprise / Residential network 600 is not transferred to the SGW 410 of the core network 400 but is transferred from the LGW 220 to the HeNB 210 via the direct path. Thereafter, the HeNB 210 transfers the received user data in the downlink direction to the UE 100.

The above-described flow of user data in the downlink direction assumes that the UE 100 is in the CONNECTED mode (a state in which a communication bearer including a radio section has been established). When the UE 100 is in the IDLE mode (a state in which a communication bearer in the radio section is not established), the paging process disclosed in Non-Patent Document 1 or Non-Patent Document 5 is performed in order to shift the UE to the CONNECTED mode. . In order to trigger the paging process, the LGW 220 transfers the first (partial) data of the received user data in the downlink direction to the SGW 410 of the core network 400, and the SGW 410 performs the paging process disclosed in Non-Patent Document 1. To do. When the UE 100 enters the CONNECTED mode by the paging process, the downlink data addressed to the UE 100 transferred to the SGW 410 is transferred to the UE 100. That is, when the UE 100 is in the IDLE mode, only some user data is transferred via the SGW 410 of the core network 400.

As described above, user data is not normally transferred in the direction of the core network 400 (the SGW 410), but a message (also referred to as control signaling) for controlling the LIPA connection is transmitted to the MME 430 of the core network 400. For example, when the UE 100 wants to release a LIPA connection, the UE 100 transmits a PDN Connection Request message disclosed in Non-Patent Document 1 to the network. The PDN Connection Request message is transferred to the MME 430 via the HeNB 210, and processing for releasing the LIPA connection is performed.

Further, when a direct path is not established between the HeNB 210 and the LGW 220, that is, the direct path cannot be established with the LGW (the establishment is not permitted or cannot be physically established), the UE 100 enters the enterprise / residential network 600 via the base station. When trying to connect to the core network 400 only when the network operator policy permits (for example, when the connection data from the outside (MRA described below is permitted in the subscription data of the UE 100 held by the HSS 440)). Can be connected to the LGW 220 via the SGW 410 and can access the Enterprise / Residential network. In this way, the UE 100 under the HeNB of the LHN 200 accesses the Enterprise / Residential network 600 via the SGW 410 is referred to as MRA (Managed Remote Access (to home based network)) in Non-Patent Document 5. It is sometimes called RIPA (Remote IP Access), remote access, etc. In this way, user data and control signaling transmitted from the HeNB 210 to the entities of the core network 400 and the E-UTRAN 300 are the same as those of the LHN 200 shown in FIG. The data is transferred to the destination node via an (IP) backhaul 700 for connecting the core network 400.

When the UE 100 transmits an RS message to the network in an environment where PMIP is used as a user data transport of the core network (hereinafter sometimes referred to as a PMIP environment) and a LIPA connection is established between the UE 100 and the LGW 220. The RS message is transferred from the HeNB 210 to the LGW 220 via the direct path (because the RS / RA message is handled as user data). When the LGW 220 implements the router function shown in Non-Patent Document 3, the RA message is transmitted to the UE 100 in response to the received RS message.

This is a phenomenon that occurs regardless of whether the transport protocol in the core network is GTP or PMIP. This is because the LGW 220 operates as an IP router with respect to the enterprise / residential network 600, and the operation of transmitting RA in response to the above-described RS is normally performed. However, in an environment where PMIP operates as a transport protocol, the LGW 220 does not transmit a periodic (or spontaneous) RA (that is, an unsolicited RA defined in Non-Patent Document 3). This is because the SGW 410 performs the function of the UE 100 as the next hop router (IP router) in PMIP.

At this time, as shown in FIG. 2, the UE 100 receives an RA message (solicited RA; shown as RA_1 in FIG. 2) as a reply to the RS message from the LGW 220, but on the other hand, a process of establishing a LIPA connection After the procedure is completed, an RA message periodically sent from the SGW 410 (unsolicited RA; shown as RA_2 in FIG. 2) is also received.

That is, in the PMIP environment, when the UE 100 has established a LIPA connection and the UE 100 transmits an RS message to the network, the UE 100 may receive RA messages having different contents from the LGW 220 and the SGW 410 at almost the same timing. .

When the UE 100 receives RA messages having different contents (especially, different source link local addresses), the UE 100 manages information stored in the two RA messages. Further, as disclosed in Non-Patent Document 3, the UE 100 has one piece of information stored in the RA message (for example, a Link-MTU value indicating the maximum transfer unit size that can be transmitted in the layer 2 link) per link. In such a case, the existing information is overwritten with the information stored in the last received RA message.

The RA messages sent from the two gateways (LGW 220 and SGW 410) are expected to have different information as shown in FIG. For example, RA_1 indicates a configuration example of an RA message (corresponding to RA_1 in FIG. 2) transmitted by the LGW 220 in response to the RS message from the UE 100. For example, RA_1 has a source address of 2001: db8 :: 1 and a Link-MTU value of 2000.

That is, when UE 100 can hold only one piece of information (Link-MTU value) stored in the RA message for the layer 2 link at the same time, and after receiving RA_1, RA_2 (corresponding to RA_2 in FIG. 2) When the Link-MTU value is 1500), the Link-MTU value related to the layer 2 link is overwritten from 2000 to 1500. Thereby, even when the UE 100 performs communication on the LIPA connection established with the LGW 220, the Link 100 is set to the link-MTU value (1500) specified by the RA_2, so that the UE 100 performs inefficient communication. There is a problem of being forced.

In summary, when the Link-MTU value (Link-MTU value 1) stored in the RA_1 message is larger than the Link-MTU value (Link-MTU value 2) stored in the RA_2 message (Link-MTU value 1> Link). -MTU value 2) When the UE 100 receives RA_2 later, user data is generated with reference to the Link-MTU value 2 smaller than the actual Link-MTU value 1. At this time, the size of the IP packet is smaller than the actual Link-MTU value 1, and the LGW 220 normally receives it. That is, since the difference between the Link-MTU is not noticed, the UE 100 is forced to perform inefficient communication until the next RA_1 is received.

On the other hand, when the Link-MTU value 2 notified by the RA_2 message is larger than the Link-MTU value 1 notified by the RA_1 (Link-MTU value 1 <Link-MTU value 2), the router LGW 220 enters the Enterprise / A packet exceeding the IP packet size (that is, Link-MTU value 1) that can be transferred to the Residential network 600 is received, and an error message (Packet Too) that describes a desired Link-MTU value (that is, Link-MTU value 1) is received. The IPv6 ICMP message for notifying the Big error is transmitted to the UE 100 that is the packet transmission source. In response to this, the UE 100 again sets the notified Link-MTU value 1 as the Link-MTU value of the layer 2 link, and performs proper communication (see Non-Patent Document 6).

As described above, in a situation where the SGW 410 and the LGW 220 have different link local addresses and individually send RAs to the UE 100, the RA received immediately after throwing the RS message as described above is from the LGW 220. Since it cannot be determined (because the SGW 410 may transmit RA at almost the same timing), the UE 100 can always set communication based on appropriate address setting information (information included in the RA message). Therefore, inefficient communication occurs. Even when the source addresses of RA_1 and RA_2 are the same, the UE 100 overwrites information (for example, the Link-MTU value) with the contents of the RA message received later, and the same problem occurs.

Here, although it is not impossible to determine whether the transmission source is LGW 220 or SGW 410 based on the contents of the RA message, it is necessary to change the basic protocol of IPv6, and all terminal OS (Operating System) ) Is costly and unrealistic. That is, a low cost and feasible solution is required.

Note that not all UEs 100 can transmit an RS message when establishing a connection (due to restrictions due to implementation and settings). After establishing the LIPA connection, the UE 100 receives only the RA message that the SGW 410 periodically transmits (Unsolicited). That is, there is no opportunity to obtain an RA message from the LGW, and communication settings cannot be performed based on appropriate address setting information. In particular, it is not impossible to share necessary setting information such as Link-MTU value between the LGW 220 and the SGW 410, but the conventional PMIP technology does not specify an option for transmitting such information, and it is accompanied by protocol modification. The impact (cost due to renovation of the terminal OS) is enormous and unrealistic.

In view of the above problem, according to an aspect of the disclosed technology, for example, RA messages (address information notification messages) including different address setting information are notified from two gateways (LGW 220 and SGW 410) to UE 100, respectively. In the obtaining environment, the UE 100 can always perform communication setting based on appropriate address setting information (information included in the RA message), and it is possible to suppress the occurrence of inefficient communication.

In addition, according to one aspect of the present disclosure, for example, address setting information (address information notification notified from the gateway (LGW 220) that manages the LIPA connection), for example, is particularly required for the communication terminal to perform communication via the LIPA connection. It is possible to suppress the occurrence of inefficient communication that occurs when the address setting information included in the message is overwritten by the address setting information included in the address information notification message notified from another gateway (SGW 410). Become.

Further, in the case where PMIP is used in the core network 400 and the UE 100 transmits an RS message to the network, the UE 100 receives RA messages from two gateways of the LGW 220 and the SGW 410, and correct RA message information (for example, , Link-MTU value) may not be available. According to one aspect of the present disclosure, for example, even when the UE 100 transmits an RS message to the network, it is possible to always select and use correct RA message information.

One aspect of the disclosed technique is, for example, a communication control method for performing communication control of a communication terminal connected to a network via a base station,
The communication terminal transmitting a connection request message including identification information designating a connection destination to the network;
A first gateway on the network that performs data path control of the communication terminal receives the connection request message, and performs data path control in connection with the connection destination based on the connection request message Sending a registration request message to the second gateway;
The second gateway receives the registration request message and generates address setting information to be notified to the communication terminal;
The second gateway, as a response to the registration request message, sending a registration response message including the address setting information in an option field to the first gateway;
The first gateway transmits a connection acceptance message including the address setting information in an option field to the communication terminal;
The communication terminal receiving the connection acceptance message from the network as a response to the connection request message;
The communication terminal performing communication setting with the connection destination based on the address setting information;
A communication control method.
With this method, the communication terminal can perform communication settings based on appropriate address setting information in communication with a desired connection destination network, and can suppress the occurrence of inefficient communication.

Note that the aspect of the disclosed technique may be realized by a communication terminal, a network device, or the like in addition to the communication control method described above.

In the disclosed technology, for example, in an environment where an address information notification message including different address setting information can be notified from two gateways to a communication terminal, the communication terminal always performs communication setting based on appropriate address setting information. As a result, it is possible to suppress the occurrence of inefficient communication. In addition, for example, the disclosed technology has an effect that the communication terminal can perform communication setting based on appropriate address setting information for communication via the LIPA connection, for example. In addition, for example, the disclosed technique has an effect that the address setting information can always be correctly selected and used even when the communication terminal transmits an address information request message to the network.

Note that the effects and advantages of the disclosed technology are not limited to the above, and further effects and advantages will be apparent from the disclosure of the present specification and drawings. The above-described further effects and advantages are individually provided by, for example, the various embodiments and features disclosed in this specification and the drawings, and all the effects are not necessarily limited by one aspect of the disclosed technology. And benefits need not be provided.

The figure which shows an example of the system configuration common to the 1st to 3rd embodiment of this indication technique, and the prior art The figure which shows an example of the conventional subject which this indication technique tries to solve The figure for demonstrating an example of RA message transmitted in 3rd Embodiment of a prior art and this indication technique FIG. 7 is a sequence diagram for explaining an example of a system operation according to a conventional technique and an example of a system operation assumed in the first to third embodiments of the disclosed technique; The figure which shows an example of the extended RA message in 1st Embodiment of this indication technique The figure which shows an example of a structure of UE in 1st Embodiment of this indication technique. The flowchart which shows an example of operation | movement of UE in 1st Embodiment of this indication technique. The figure which shows an example of a structure of LGW in 1st Embodiment of this indication technique The flowchart which shows an example of operation | movement of LGW in 1st Embodiment of this indication technique. The sequence diagram for demonstrating an example of operation | movement of 2nd Embodiment of this indication technique The figure which shows an example of the state transition in 2nd Embodiment of this indication technique The figure which shows an example of a structure of UE in 2nd Embodiment of this indication technique. The flowchart which shows an example of operation | movement of UE in 2nd Embodiment of this indication technique. The figure which shows an example of a structure of LGW in 2nd Embodiment of this indication technique. The flowchart which shows an example of operation | movement of LGW in 2nd Embodiment of this indication technique. The figure which shows an example of the message for notifying address setting information from LGW to SGW in 2nd Embodiment of this indication technique. Sequence diagram for explaining an example of the operation of the third embodiment of the disclosed technology The figure which shows an example of a structure of UE in 3rd Embodiment of this indication technique. The flowchart which shows an example of operation | movement of UE from step S1701 of FIG. 17 to step S1705. The flowchart which shows an example of operation | movement of UE from step S1713 of FIG. 17 to step S1717. The figure which shows an example of a structure of LGW in 3rd Embodiment of this indication technique. FIG. 17 is a flowchart showing an example of LGW operation from step S1701 to step S1703 in FIG. FIG. 17 is a flowchart showing an example of LGW operation from part of step S1707 (reception of a PBU message) to step S1711. The figure which shows the 1st example of the PBA message transmitted from LGW to SGW in 3rd Embodiment of this indication technique. The figure which shows the 2nd example of the PBA message transmitted from LGW to SGW in 3rd Embodiment of this indication technique.

Hereinafter, first to third embodiments of the disclosed technology will be described with reference to the drawings.

First, a system configuration common to the first to third embodiments of the disclosed technology will be described with reference to FIG. FIG. 1 is a diagram illustrating an example of a system configuration common to the first to third embodiments of the disclosed technology and the conventional technology.

As described above, the communication system illustrated in FIG. 1 is referred to as a base station (eNB (eNode B) 310 in E-UTRAN 300 and HeNB (Home eNB) 210 in LHN (Local HeNB Network) 200) that is wirelessly connected to UE 100. ), The MME 430 responsible for the mobility management of the UE 100, the HSS 440 holding the subscription information of the UE 100, the SGW 410 for performing user data distribution control, the PGW 420 for performing address assignment to the UE 100 and user data transfer and path control between the PDN 500 and the SGW 410 , LHN200 Enterprise / Residential network 600 and SGW410, or Enterprise / Residential network 00 to have a user data transfer and LGW220 performing routing control (data path control) between the HeNB 210. The UE 100 performs data communication with the enterprise / residential network 600 and the PDN 500 by using this communication system. In FIG. 1, the LGW 220 is illustrated as a device different from the HeNB 210, but may be physically or logically handled as one entity.

Here, the UE 100 has at least one or more communication interfaces and can be connected to a network (for example, the E-UTRAN 300 or the LHN 200). Note that the UE 100 may be connected to the illustrated network (for example, the E-UTRAN 300 or the LHN 200) simultaneously or exclusively, but only one network can be connected at the same time through one communication interface. Only. The UE 100 is connected to the communication system via a base station such as the HeNB 210 or the eNB 310, and can communicate with the PDN 500 or the enterprise / residential network 600 through the network. When the UE 100 establishes a LIPA connection with the LGW 220 of the LHN 200, entities in the core network 400 (such as the MME 430 and the SGW 410) operate to establish the LIPA connection, and the UE 100 can communicate with the enterprise / residential network 600. become.

As described above, the UE 100 can establish a LIPA connection with the LGW 220 of the LHN 200 by using a procedure established by 3GPP. In the following, the establishment of the LIPA connection will be described mainly using the network components shown in FIG. 1. However, the disclosed technique is also applicable to UTRAN (UMTS Terrestrial Radio Access Network) established by 3GPP. Applicable. In UTRAN, the base station corresponding to the above-described HeNB 210 of the LHN 200 is called an HNB and is used as a device combined with the LGW 220. Accordingly, in FIG. 1, the LGW 220 manages a plurality of HeNBs 210, but in the UTRAN, the LGW 220 and the HNB have a one-to-one relationship.

Hereinafter, an example of a system operation premised on the first to third embodiments of the disclosed technology will be briefly described with reference to FIG. FIG. 4 is an example of a system operation according to a conventional technique, and is a sequence diagram for explaining an example of a system operation premised on the first to third embodiments of the disclosed technique. Here, as an explanation example of the first to third embodiments of the disclosed technology, when the UE 100 establishes a LIPA connection with the LGW 220, a PDN connection establishment procedure is performed via the MME 430 (via the E-UTRAN 300). The implementation will be described with reference to the network connection procedure (Attach procedure) disclosed in Non-Patent Document 1 and Non-Patent Document 2.

The procedure for the UE 100 to establish a LIPA connection with the LGW 220 via the HeNB 210 of the LHN 200 (FIG. 4) is the same except for a part of the procedure for the UE 100 to establish a PDN connection with the PGW 420 via the eNB 310 of the E-UTRAN 300. . The difference in the procedure is that the MME 430 determines whether the PDN connection to be established is a LIPA connection or a conventional (non-LIPA) PDN connection (a PDN connection with the PGW 420), and the PDN connection to be established is intended for LIPA If it is, the MME 430 notifies the HeNB 210 of information (correlation ID) for establishing a direct path between the HeNB 210 and the LGW 220, and the HeNB 210 establishes a direct path between the LGW 220. It is a point to do.

The information indicating whether or not this is a LIPA connection is called Correlation ID in 3GPP, and is a part of step S401 in FIG. 4 (see Non-Patent Document 1: For example, FIG. 5.3.2 of Non-Patent Document 1). 1-1, notified to the HeNB 210 from the MME 430, and the HeNB 210 establishes a direct path with the LGW 220 using the received Correlation ID (see Non-Patent Document 1 and Non-Patent Document 2). .

As disclosed in Non-Patent Document 2, when a LIPA connection is established between the UE 100 and the LGW 220 in a PMIP environment where PMIP is used in the core network 400, an RA message for assigning an IPv6 prefix to the UE 100 is an SGW 410. Sent from. Further, as disclosed in Non-Patent Documents 1 to 3, the RA message is periodically sent from the SGW 410 to the UE 100.

Further, as disclosed in Non-Patent Documents 1 to 3, the UE 100 can transmit an RS message to the network in order to obtain an IPv6 prefix. Since this RS message is handled as user data, it is transferred from the HeNB 210 via the direct path to the LGW 220 and receives an RA message from the LGW 220.

As a result, when the UE 100 transmits an RS message to the network, as shown in FIG. 2, the UE 100 receives RA messages from two gateways (SGW 410 and LGW 220) and manages information of the two RA messages. . In addition, information (for example, the Link-MTU value) that the UE 100 can hold only for the layer 2 link is overwritten with the most recently received information, and thus inefficient communication occurs as described above. there is a possibility.

<First Embodiment>
In 1st Embodiment of this indication technique, the said subject is solved by extending RA message (RA_1 in FIG. 2) transmitted to UE100 from above-mentioned LGW220.

First, the UE 100 performs a PDN connection establishment procedure disclosed in Non-Patent Document 1 or Non-Patent Document 2 and establishes a LIPA connection with the LGW 220. Subsequently, the UE 100 transmits an RS message to the network. The RS message is transferred from the HeNB 210 to the LGW 220 via the direct path (not via the SGW 410). The LGW 220 transmits an RA message to the UE 100 in response to the received RS message.

In the first embodiment of the disclosed technique, the RA problem transmitted from the LGW 220 to the UE 100 is extended as shown in FIG. That is, in the first embodiment of the disclosed technique, information that instructs to use only the RA message transmitted from the LGW 220 in the RA message conventionally transmitted from the LGW 220 (other RA ignore instruction information and RA designation information). , Which is also referred to as RA specific information), the UE 100 can receive only the information included in the RA message (RA_1 in FIG. 2) transmitted from the LGW 220 to the UE 100 in the IP setting (configuration) related to the LIPA connection. As a result, it becomes possible to make appropriate settings by selectively using it, and the inefficient communication state described above can be avoided. The RA designation information is information for instructing to use only the RA message transmitted from the LGW 220, but ignores the RA message from the RA message transmission source (for example, the SGW 410 in FIG. 2) other than the LGW 220. It can also be interpreted as the information to be instructed.

When the UE 100 can determine the source of the RA message by referring to information (for example, a source address and a port number) stored in the conventional RA message, the source of the RA message May be used as RA designation information. Further, as RA designation information, for example, a token or ID shared between the UE 100 and the LGW 220, or information exchanged when a PDN connection is established (key information or TMSI (Temporary Mobile Subscriber Identity)) or the like may be used. Good.

When the LGW 220 establishes the PDN connection of the UE 100 and confirms that PMIP is applied to S5 or S8, which is the connection interface with the SGW 410, and that the requested PDN connection is for LIPA, In response to the RS message from the UE 100, a state is formed so that an extended RA message as shown in FIG. 5 can be transmitted. For example, the state is stored in the context information of the UE 100, and when the RS message is received later, the context information is referred to and it is determined whether to respond with the conventional RA or the extended RA. Thereafter, the UE 100 can always obtain and set correct information by trusting only the RA message in which the RA designation information is stored (that is, the extended RA message). That is, all RA messages in which RA designation information is not stored are ignored.

In order to easily explain the first embodiment of the disclosed technology, the network connection procedure (Attach procedure) has been described as an example, but other procedures for establishing a PDN connection (for example, PDN connectivity request are used). Or a procedure for establishing a PDN connection).

Next, the configuration of the UE 100 according to the first embodiment of the disclosed technology will be described with reference to FIG. FIG. 6 is a diagram illustrating an example of a configuration of the UE 100 according to the first embodiment of the present disclosure. In FIG. 6, a UE 100 is connected to a network (for example, E-UTRAN or LHN) to perform communication processing in a lower layer and packet communication processing such as IP in an upper layer, and to a RA message received as an RA message. Check whether specified information is stored and evaluate and use only RA messages in which RA specified information is stored, or information included in RA messages in which RA specified information is not stored or such It has at least an RA message processing unit 102 that ignores (drops) the RA message itself. Note that the above-described configuration of the UE 100 is an example. For example, a function for confirming whether RA designation information held by the RA message processing unit 102 is stored, and RA designation information is not stored. In some cases, it may be implemented separately from the function of ignoring information included in the RA message.

Next, the UE 100 having the configuration illustrated in FIG. 6 will be described in detail with reference to FIG. 7, focusing on the characteristic processing in the disclosed technology. FIG. 7 is a flowchart showing an example of the operation of the UE 100 in the first embodiment of the disclosed technology.

UE 100 transmits an Attach request message according to the procedure for establishing a PDN connection defined in 3GPP (step S701 in FIG. 7). Subsequently, the UE 100 receives an Attach accept message (hereinafter also referred to as a connection acceptance message) that is a result of the network permitting Attach request (step S703 in FIG. 7). Thereafter, when the UE 100 receives the RA message, it checks whether or not RA designation information is stored in the RA message (step S705 in FIG. 7). When it is confirmed that RA designation information is stored in the RA message, the RA message information is used as usual (step S707 in FIG. 7). On the other hand, when the RA designation information is not stored, the UE 100 ignores (discards) the information included in the RA message or the RA message itself (step S709 in FIG. 7).

Next, the configuration of the LGW 220 in the first embodiment of the disclosed technique will be described with reference to FIG. FIG. 8 is a diagram illustrating an example of a configuration of the LGW 220 according to the first embodiment of the disclosed technique. In FIG. 8, the LGW 220 performs communication processing with the SGW 410 of the core network 400 and the HeNB 210 of the LHN, and performs an RA message to the communication processing unit 221 that performs packet communication processing such as IP, and the UE 100 that holds the LIPA connection in the PMIP environment. At the time of transmission (for example, when an RS message is received), it has at least an RA message processing unit 222 that processes an RA message to be transmitted to the UE 100 into an extended RA message storing RA designation information.

Next, the LGW 220 having the configuration illustrated in FIG. 8 will be described in detail with reference to FIG. 9, focusing on the characteristic processing in the disclosed technology. FIG. 9 is a flowchart illustrating an example of the operation of the LGW 220 according to the first embodiment of the disclosed technique.

The LGW 220 receives a PBU (Proxy Binding Update) message (hereinafter also referred to as a registration request message) from the SGW 410 in the PDN connection establishment procedure defined in 3GPP (step S901 in FIG. 9). At this time, as described above, when the LGW 220 uses PMIP as a transport protocol and confirms that the requested PDN connection is for LIPA, the LGW 220 responds to the RS message from the UE 100. In order to be able to transmit an extended RA message as follows, it is recorded in the context information of the UE 100 that the UE 100 is a UE 100 that holds a LIPA connection in the PMIP environment. For example, the protocol applied to the traffic transport of the UE 100 that transmitted the PDN connection establishment request in the UE context and the subscription data held by the network or the parameter in the transmitted message is PMIP, and the UE 100 If the APN stored in the PDN connection establishment request transmitted from is an APN for LIPA, it can be determined that the UE 100 holds the LIPA connection.

Note that the LGW 220 may determine that the protocol applied to the traffic transport of the UE 100 is PMIP upon receiving the PBU message (because it is already obvious). Whether or not the APN is intended for LIPA may be inquired of other network nodes such as the MME 430, or information set in advance in the LGW 220 may be used. In addition, when the LGW 220 is an operation in which only establishment of a LIPA connection is requested (for example, when the LGW 220 is an operation that accommodates only the LIPA connection), the LGW 220 is an APN for the purpose of LIPA. Can be omitted, and PDN connections related to all UEs can be handled as LIPA connections.

When the LGW 220 transmits an RA message to the UE 100 that holds the LIPA connection (that is, when an RA message is transmitted as a response to the received RS message), the LGW 220 transmits an extended RA message storing RA designation information to the UE 100 ( Step S903 in FIG. 9). Finally, the LGW 220 transmits a PBA message to the SGW 410 (step S905 in FIG. 9).

Next, a format example of an RA message (that is, an extended RA message) in which RA designation information transmitted from the LGW 220 to the UE 100 is stored will be described with reference to FIG. In the extended RA message shown in FIG. 5, the UE 100 ignores (drops) the “conventional RA message field” in which information in a normal RA message is stored and the RA message transmitted from another gateway (for example, the SGW 410). It is composed of an “RA designation information field” in which RA designation information for the purpose of instructing is stored. In the “RA designation information field”, for example, an RA message identifier for enabling the UE 100 to identify whether or not to use an RA message received thereafter, or whether the UE 100 should ignore information included in the RA message. For example, flag information (for example, bits represented by 0 or 1) is stored. When the UE 100 can determine whether or not the information included in the RA message should be ignored by referring to the IP header information stored in the RA message to identify the transmission source, the “RA designation information field” "" Can be omitted.

As described above, according to the first embodiment of the present disclosure, the UE 100 can select only the RA message from the specific gateway and ignore the RA message transmitted from the other gateway. The problem of exchanging user data using wrong parameters (for example, Link-MTU value) can be avoided. That is, the UE 100 can always obtain and set correct information by trusting only the RA message (that is, the extended RA message) in which valid RA designation information is stored.

<Second Embodiment>
In the first embodiment, the method for solving the problem by extending the RA message defined in Non-Patent Document 3 has been described. However, in the second embodiment of the disclosed technology, the message defined by 3GPP The problem is solved by extending (control signaling). Thereby, it is not necessary to change the RA message defined in the RFC of Non-Patent Document 3, and the repair cost of the terminal OS can be greatly reduced.

Hereinafter, a second embodiment of the disclosed technique will be described. FIG. 10 is a sequence diagram for explaining an example of the operation of the second embodiment of the disclosed technique. Note that FIG. 10 is based on the sequence diagram (FIG. 4) for explaining an example of the operation of the first embodiment of the disclosed technique, and thus the description of the overlapping steps is omitted.

FIG. 10 shows a procedure for establishing a LIPA connection between the UE 100 and the LGW 220. As disclosed in FIG. 4 and Non-Patent Document 1 or Non-Patent Document 2, the UE 100, for example, in a network connection procedure (Attach procedure), sends a PDN connection establishment request storing an APN that is identification information of a connection destination network. It transmits to the network (step S1001 in FIG. 10). Subsequently, in order to carry out the process for establishing the LIPA connection, the procedure disclosed in Non-Patent Document 1 and Non-Patent Document 2 is performed as in the first embodiment of the disclosed technology ( Processing from step S1002 to step S1003 in FIG. 10).

Subsequently, when the network determines that the APN indicated by the PDN connection establishment request sent from the UE 100 is an APN for LIPA to which the UE 100 is permitted to connect (when established as a LIPA connection), The LGW 220 converts the RA message information (address setting information) to be notified to the UE 100 into a PCO (Protocol Configuration) in a PBA (Proxy Binding Acknowledgment) message (which may be referred to as a registration response message in this specification). (Option) (also referred to as an option field) and returns to the SGW 410 (step S1004 in FIG. 10). By using PCO, the LGW 220 can directly notify the UE 100 of arbitrary information. The UE 100 receives the message with the PCO in which the RA message information (address setting information) is stored (step S1005 in FIG. 10). The RA message information (address setting information) notified to the UE 100 by the LGW 220 is information included in the RA_2 in FIG. 2, and the UE 100 stores the RA message information (address setting information) stored in the PCO. It is possible to appropriately set communication between the UE 100 and the LGW 220 via the LIPA connection.

Further, after receiving the message in step S1005, the UE 100 ignores (discards) all the received RA messages. Note that, as shown in FIG. 11, the UE 100 ignores all the RA messages received thereafter from the normal state in which the received RA message is processed in a normal operation (see Non-Patent Documents 1 to 3) (hereinafter, Transition to a PCO belief mode, a PCO emphasis mode, a (simply) PCO mode, an RA NAS transfer mode, a designated address mode, etc. That is, by providing a new mode for continuing to use the address setting information (the same information included in the RA message or the RA message itself) stored in the PCO, the RA message received thereafter is ignored. To. Thereby, the UE 100 maintains the communication setting using the information (address setting information) of the RA message stored in the PCO, and the information in the RA message (RA_1 in FIG. 2) notified from the SGW 410, for example. The UE 100 can be prevented from being set.

Next, the configuration of the UE 100 according to the second embodiment of the disclosed technology will be described with reference to FIG. FIG. 12 is a diagram illustrating an example of a configuration of the UE 100 according to the second embodiment of the present disclosure. In FIG. 12, a UE 100 is connected to a network (for example, E-UTRAN 300 or LHN 200), performs communication processing in a lower layer and packet communication processing such as IP in an upper layer, and a message transmitted from the network. A function for processing RA message information (address setting information) in the PCO stored in the PC as an RA message. When RA message information is stored in the PCO, a process for ignoring the RA message received thereafter is performed. When the RA message information is stored in the function, the PCO, the option field address setting information processing including the function of managing the information (mode) for maintaining the state for continuing to ignore other RA messages. It has at least part 103. Note that the configuration of the UE 100 described above is an example, and each processing function may be divided as a processing unit. For example, when RA message information (address setting information) is stored in the PCO acquired by the option field address setting information processing unit 103 described above, processing for ignoring the RA message received thereafter is performed, for example, by an RA message drop unit. In addition, the processing unit may be divided by using, for example, a mode management unit as a management process for information (mode) for maintaining a state in which other RA messages are ignored.

The option field address setting information processing unit 103 shown in FIG. 12 has received RA message information (address setting information) that is not stored in the conventional PCO as a normal IP packet. Process like information. In order to enable the UE 100 to process the RA message information (address setting information) stored in the PCO in the same way as a normal RA message, for example, the message type and the packet length may be unified. The option field address setting information processing unit 103 uses, for example, a packet filter function implemented as part of an OS (operation system) IP stack (corresponding to a part of the communication processing unit 101 in FIG. 12). be able to. Using a packet filter, it is possible to set to drop or pass an IP packet having a specific protocol number (type) received from a specific source address. For example, the RA message can be specified by setting the protocol number 58 (IPv6-ICMP) and the ICMP type 134 as a key (in addition, the reception direction may need to be set).

Next, the UE 100 having the configuration illustrated in FIG. 12 will be described in detail with reference to FIG. 13 with a focus on characteristic processing in the disclosed technology. FIG. 13 is a flowchart illustrating an example of the operation of the UE 100 according to the second embodiment of the present disclosure.

First, the UE 100 transmits a message for establishing a PDN connection (for example, an Attach request message (or a PDN connectivity request message) disclosed in Non-Patent Document 1) to the network (step S1301 in FIG. 13). The UE 100 receives an Attach Accept message transmitted from the network to the UE 100 when the PDN connection establishment procedure established by 3GPP is permitted by the network (step S1303 in FIG. 13).

Subsequently, the UE 100 confirms whether RA message information (address setting information) is stored in the PCO (option field) of the received Attach Accept message (step S1305 in FIG. 13). When it is determined that RA message information (address setting information) is stored in the PCO (option field), the UE 100 normally receives RA message information (address setting information) stored in the PCO (option field). It is processed as a message (address setting information) (RA message periodically transmitted from the gateway or RA message for the RS message) (step S1307 in FIG. 13). Subsequently, the UE 100 continues to ignore the RA message received thereafter (changes to a mode in which the RA message information stored in the PCO continues to be trusted (designated address mode)) (step S1309 in FIG. 13).

The step of processing the RA message information (address setting information) stored in the PCO in step S1307 as the address setting information stored in the normal RA message and the step of changing to the designated address mode in step S1309 are as follows: The execution order may be changed. Further, when the UE 100 acquires the mode switching information from the PCO, the UE 100 transits to a mode for operating the present invention, and performs setting of a packet filter, which will be described later. That is, after setting the packet filter, the RA message is not received unless a specific link local address is used as the source address. In other words, by appropriately setting the packet filter, there is no need to explicitly distinguish between the two modes described above, that is, the selection is made implicitly, so step S1309 can be omitted.

Next, the configuration of the LGW 220 in the second embodiment of the disclosed technique will be described with reference to FIG. FIG. 14 is a diagram illustrating an example of a configuration of the LGW 220 according to the second embodiment of the present disclosure. In FIG. 14, the LGW 220 performs communication processing with the SGW 410 of the core network 400 and the HeNB 210 of the LHN 200, and when the communication processing unit 221 that performs packet communication processing such as IP and the network determines that the LIPA connection is established in the PMIP environment The address setting information storage unit 223 stores at least RA message information (address setting information) in the PCO of the PBA message transmitted to the SGW 410.

Also, when establishing a PDN connection, it is assumed that the LGW 220 has previously assigned an IPv6 prefix as address setting information to the UE 100 using the PCO. At this time, when the LGW 220 transmits an RA message (address information notification message) in response to the RS message (address information request message) received from the UE 100 via the HeNB 210 through the direct path, a new IPv6 prefix is assigned to the UE 100. Instead, an IPv6 prefix management unit (not shown in FIG. 14) for acquiring and re-notifying the same IPv6 prefix assigned previously may be provided.

The IPv6 prefix management unit (not shown in FIG. 14) uses a function unit (managing an IPv6 prefix assigned to the UE 100 using an address pool) that has an LGW that supports GTP, and that manages the IPv6 prefix. Can do. As a result, even when the LGW 220 transmits an RA message that responds to an RS message in a PMIP environment, the prefix is centrally managed by the address pool. The IPv6 prefix can be correctly re-notified.

Further, the address setting information storage unit 223 illustrated in FIG. 14 stores RA message information (address setting information) in the PCO. Furthermore, in order to make the information (address setting information) of the RA message stored in the PCO handled in the same way as the information of the normal RA message in the UE 100 (the UE 100 can be identified as RA message information) Thus, for example, the message type, packet length, etc. may be standardized, or special information (flag) may be added.

Next, the LGW 220 having the configuration illustrated in FIG. 14 will be described in detail with reference to FIG. FIG. 15 is a flowchart illustrating an example of the operation of the LGW according to the second embodiment of the present disclosure.

The LGW 220 receives the PBU message from the SGW 410 during the PDN connection establishment procedure defined in 3GPP as in the first embodiment of the disclosed technology (step S1501 in FIG. 15). When the LGW 220 determines that the received PBU message is the establishment of the LIPA connection in the PMIP environment (for example, the PDN connection is established in the UE context or the subscription data held by the network or the parameter in the transmitted message) When the protocol type (GTP or PMIP) of the UE that transmitted the request indicates PMIP, and the APN stored in the PDN connection establishment request transmitted from the UE is an APN for LIPA), conventional Then, RA message information (address setting information) (for example, IPv6 prefix etc.) to be assigned to the UE 100 is generated (step S1503 in FIG. 15).

Note that the LGW 220 may determine that the protocol applied to the traffic transport of the UE 100 is PMIP by receiving the PBU message (since it is already obvious). Whether or not the APN is intended for LIPA may be inquired of other network nodes such as the MME 430, or information set in advance in the LGW 220 may be used. In addition, when the LGW 220 is an operation in which only establishment of a LIPA connection is requested (for example, when the LGW 220 is an operation that accommodates only the LIPA connection), the LGW 220 is an APN for the purpose of LIPA. Can be omitted, and PDN connections related to all UEs can be handled as LIPA connections.

Also, the LGW 220 confirms whether or not the direct path can be applied to the UE 100 (that is, whether user data can be transferred without going through the SGW 410), and when the direct path can be applied to the UE 100, the UE 100 RA message information (address setting information) that was about to be assigned may be generated.

Subsequently, the LGW 220 stores the generated RA message information (address setting information) in, for example, a PCO (option field) of a PBA message that is a reply to the PBU message, and transmits the same to the UE 100 via the SGW 410 (see FIG. 15 step S1505).

Next, a format example of a message using an option field in which RA message information (address setting information) notified from the LGW 220 to the SGW 410 in step S1004 in FIG. 10 is stored will be described with reference to FIG. The message shown in FIG. 16 is composed of an address setting information option that is a feature of the present application, in addition to the basic header and option field conventionally used. The address setting information option notifies address setting information for preventing the UE 100 from using an RA message transmitted from another gateway.

As described above, according to the second embodiment of the present disclosure, the UE 100 uses the RA message information (address setting information) stored in the PCO of the message received by the UE 100 in the PDN connection establishment procedure, and the UE 100 By making it possible to ignore the RA message transmitted from the UE 100, it is possible to avoid the problem that the UE 100 exchanges user data using an incorrect parameter (for example, Link-MTU value). In addition, by using the conventional technology defined by 3GPP, it is possible to solve the problem while considering the impact on the existing system.

<Third Embodiment>
In the third embodiment of the disclosed technology, the UE 100 that holds the LIPA connection needs information (for example, Link-MTU value) of the RA message transmitted from the SGW 410 (for example, other HeNB or E- A method of exchanging user data using a correct RA message information while maintaining a LIPA connection even when handing over to a UTRAN eNB or the like) will be described.

FIG. 17 is a sequence diagram for explaining an example of the operation of the third embodiment of the disclosed technique. In the third embodiment of the present disclosure, in addition to the method of storing RA message information (address setting information) in the PCO of the second embodiment, the RA message newly received by the UE 100 is reflected. Information (hereinafter also referred to as mode switching information or mode switching instruction) for instructing whether or not it should be determined is stored in the PCO.

Hereinafter, a third embodiment of the disclosed technology will be described with reference to FIG.

First, similarly to the first and second embodiments of the disclosed technology, the UE 100 establishes a message for establishing a PDN connection (for example, an Attach request message disclosed in Non-Patent Document 1 or a PDN connectivity request). Message) is transmitted to the network (step S1701 in FIG. 17). If the APN stored in the message for establishing the PDN connection in step S1701 (Attach / PDN connectivity request message) is an APN for the purpose of LIPA, the network (for example, the MME 430) is identified and a request is made. Is permitted by the network, the LGW 220 adds RA message information (in the optional field) of the PBA message, which is a response to the PBU message from the SGW 410, as in the second embodiment of the present disclosure. Address setting information) and mode switching instruction (for example, link-local address (also called link local address, LL address, LL address), or special flag information, or ID, or reply and stores the token, etc.) (step S1703 in FIG. 17).

The link-local address is used as a source address of the RA message transmitted from the SGW 410 to the UE 100, and is an address provided from the LGW 220 to the SGW 410. By using this existing field (a field for storing a source address) to notify a mode switching instruction (for example, a link-local address), it is not necessary to provide a new field. When the network wants to explicitly instruct the UE 100 to switch the mode, the special flag information, ID, token, and the like described above may be stored in a new field and notified to the UE 100. Hereinafter, in order to easily describe the third embodiment of the disclosed technology, a case where a link-local address is used as a mode switching instruction will be described as an example.

The UE 100 that has received the message (Attach Accept message) including the RA message information (address setting information) and the PCO in which the mode switching instruction is stored, will receive the RA message thereafter, as in the second embodiment of the present disclosure. Is switched to a state (designated address mode) for ignoring (discarding) (step S1705 in FIG. 17).

Thereafter, it is assumed that the UE 100 performs a handover to another base station (step S1707 in FIG. 17). In the third embodiment of the present disclosure, for ease of explanation, it is assumed that the UE 100 performs a handover to another HeNB in the same LHN. The policy for the UE 100 to handover to another base station and the processing until the PBU message is transmitted from the SGW 410 to the LGW 220 in the handover procedure (see

Non-Patent Documents

1, 2, 7, etc., in FIG. 17, the handover procedure ( Steps S1707) collectively illustrated) and the like do not affect the technology of the present disclosure and will not be described. For convenience of explanation, a handover to another HeNB in the same LHN will be described, but the technique of the present disclosure can be similarly implemented even for a handover to another HeNB of another LHN or an eNB on E-UTRAN. it can.

In the handover procedure stipulated by 3GPP, when the LGW 220 determines that the user data path of the LIPA connection is switched (or switched) via the SGW 410 (for example, in the subscription data of the UE, on the direct path under the handover destination HeNB In the case where the specification is such that LIPA is prohibited or the PBU for route switching is received from the SGW 410 (step S1709 in FIG. 17), the LGW 220 notifies the UE 100 in step S1703. The same LL address is stored in the link local address option of the PBA message transmitted from the LGW 220 to the SGW 410, and transmitted to the SGW 410 (step S1711 in FIG. 17).

In response to this, the SGW 410 sets the LL address stored in the received link local address option of the PBA as its own link local address in the bearer with the UE 100, and transmits an RA message with the LL address as the source address to the UE 100. (Step S1713 in FIG. 17). This operation is the same as the conventional SGW operation disclosed in Non-Patent Document 2, and the present invention can be realized with the implementation cost suppressed by using the conventional operation particularly with respect to the SGW 410. Note that the SGW 410 separately manages the link local address obtained by PBA at the time of handover as described above, without setting it as its own link local address in the bearer with the UE 100. Also good. This is because when the UE 100 returns to the LHN 200 again and the route of the LIPA connection is changed, the link local address used before can be used immediately without performing a new configuration. This can contribute to reduction of handover time.

Specifically, the SGW 410, for example, transmits the RA (RA_2) in FIG. 3 to the UE 100 before receiving the notification of the LL address from the LGW 220, but after receiving the notification of the LL address from the LGW 220 (see FIG. 17 step S1713), for example, RA (RA_3) in FIG. RA_2 and RA_3 have different RA message source addresses, and 2001: db8 :: 3 set as the source address in RA_3 is notified to the UE 100 as a mode switching instruction, for example, in step S1703 of FIG.

The UE 100 that has received the RA message storing the LL address (notified to the UE 100 in step S1703 in FIG. 17) that is the mode switching instruction and the mode switching instruction (LL address) stored in the PCO received in step S1703. Then, it is confirmed whether or not the source address of the RA message received in step S1713 matches (step S1715 in FIG. 17).

When the mode switching instruction (LL address) acquired from the PCO in the message received in step S1703 (Attach Accept message) matches the source address of the RA message received in step S1713, the UE 100 receives the RA message received in step S1713. Alternatively, the communication interface (or LIPA connection) is set using the address setting information included in the RA message received thereafter (step S1717 in FIG. 17).

It should be noted that the state for using the RA message received by UE 100 after step S1717 (referred to as RA belief mode, RA priority mode, (simply) RA mode, free address mode, normal state (or normal mode), etc.). By providing, it can be clearly distinguished from the designated address mode. In order to selectively switch the two modes of the designated address mode and the normal mode by the UE 100, for example, special flag information for switching the mode to the RA message may be provided as the mode switching instruction. This eliminates the need for the LGW 220 to newly generate an LL address that has been distributed in advance by the PCO, and the UE 100 correctly switches between the two modes based on the acquired flag information, and information included in the received RA message. It is possible to determine whether to use or ignore (discard).

Further, for example, a token may be used as another form of realizing the mode switching instruction. In this case, the LGW 220 notifies the SGW 410 of the token notified to the UE by the PCO, and the SGW 410 stores the token in a predetermined option in the RA and notifies the UE 100. The UE 100 determines whether the token acquired from the PCO of the message (Attach Accept message) received in step S1703 in FIG. 17 matches the token acquired from the predetermined option of the RA message received in step S1713 in FIG. Check. Only when the tokens match, the address setting information stored in the received RA message is used. Otherwise, the address setting information stored in the RA message is ignored (discarded).

Thereby, the UE 100 can evaluate the RA message transmitted from the SGW 410 only when the RA message is required (when accessing the LGW 220 via the SGW 410), and maintains the established LIPA connection (ie, reconnection). Handover) can be performed.

Next, the configuration of the UE 100 according to the third embodiment of the disclosed technology will be described with reference to FIG. FIG. 18 is a diagram illustrating an example of a configuration of the UE 100 according to the third embodiment of the present disclosure. In FIG. 18, the communication processing unit 101 and option field address setting information processing unit 103 shown in FIG. 12 (the description is omitted here), and the period or state in which the address setting information acquired from the PCO is used (that is, specified) Address switching mode) and a mode switching unit 104 that switches a period or state (normal mode) in which the received RA message is used without being ignored (discarded). Note that the configuration of the UE 100 described above is an example.

As described above, the mode switching unit 104 illustrated in FIG. 18 includes mode switching information (for example, LL address and token) received by the PCO of the message (Attach Accept message) received in step S1703 of FIG. This is a functional unit that checks whether or not the RA message information (for example, source address, token, etc.) received in step S1713 in FIG. 17 matches and switches the mode.

Similarly to the UE 100 according to the second embodiment of the present disclosure, the additional part (mode switching unit 104) illustrated in FIG. 18 includes, for example, an OS (operation system) IP stack (in FIG. 18, the communication processing unit 101). The packet filter function implemented as a part of the above can be used. Using a packet filter, it is possible to set to drop or pass an IP packet having a specific protocol number (type) received from a specific source address. For example, the RA message can be specified by setting the protocol number 58 (IPv6-ICMP) and the ICMP type 134 as a key (in addition, the reception direction may need to be set). Furthermore, since the RA from the LL address can be captured by adding the setting using the LL address acquired through the PCO as the source address first, the mode switching unit 104 of the UE 100 changes to the designated address mode. In addition, by performing the setting as described above for the packet filter, only the corresponding RA message (that is, the RA message with the LL address as the source address) can be evaluated thereafter. Other received RA messages are discarded.

Next, the UE 100 having the configuration illustrated in FIG. 18 will be described in detail with reference to FIG. 19 and FIG. 20, focusing on the characteristic processing in the disclosed technology. FIG. 19 is a flowchart illustrating an example of the operation of the UE 100 from step S1701 to step S1705 in FIG. 17 according to the third embodiment of the present disclosure. FIG. 20 is a flowchart illustrating an example of the operation of the UE 100 from step S1713 to step S1717 in FIG. 17 according to the third embodiment of the present disclosure.

Hereinafter, the operation of the UE 100 from step S1701 to step S1705 in FIG. 17 will be described first with reference to FIG.

First, the UE 100 transmits a message for establishing a PDN connection (for example, an Attach request message (or a PDN connectivity request message) disclosed in Non-Patent Document 1) to the network (step S1901 in FIG. 19). The UE 100 receives an Attach Accept message (or a PDN connectivity Accept message) that is transmitted when the PDN connection establishment procedure specified in 3GPP is correctly processed by the network (step S1903 in FIG. 19).

The UE 100 confirms whether address setting information and mode switching information are stored in the PCO (option field) of the received Attach Accept message (step S1905 in FIG. 19).

When the address setting information and the mode switching information are stored in the PCO (option field), the UE 100, as in the second embodiment of the present disclosure technique (that is, as in step S1307 in FIG. 13), Address setting information stored in the PCO (option field) is processed as address setting information stored in a normal RA message (address information notification message) (step S1907 in FIG. 19). In step S1909 in FIG. 19, similarly to step S1309 in the second embodiment of the disclosed technology, the transition is made to a designated address mode in which the RA message (address information notification message) received thereafter is ignored. In the third embodiment of the disclosed technology, mode switching information is extracted and held (stored) from a PCO (option field). (Step S1909 in FIG. 19).

Next, the operation of the UE 100 from step S1713 to step S1717 in FIG. 17 will be described using FIG.

The UE 100 hands over to another HeNB or eNB (in particular, a HeNB that is not permitted to use a direct path with the LGW 220 or the macro base station eNB 301 arranged in the E-UTRAN 300), and then performs an RA message (address information notification). Message) is received from the network (step S2001 in FIG. 20). At this time, the UE 100 switches the RA message (address information notification message) switching information (for example, the source address and token) received in step S2001 and the mode switching information (LL address or the information stored in step S1909 in FIG. 19). It is confirmed whether the tokens and the like match (step S2003 in FIG. 20). If the compared information matches, the UE 100 updates the setting of the communication interface (or LIPA connection) using the RA message received in step S2001 (or the RA message received thereafter) (step in FIG. 20). S2005). As described above, by using the two modes of the designated address mode and the normal mode in the UE 100, for example, instead of using the LL address as the mode switching information, special flag information having a small number of bits, for example, is used. By adding, it is possible to switch the mode whether or not to use the RA message (address information notification message). Thereby, since desired information can be transmitted with few resources, it is advantageous in terms of resource efficiency.

Next, the configuration of the LGW 220 according to the third embodiment of the disclosed technique will be described with reference to FIG. FIG. 21 is a diagram illustrating an example of the configuration of the LGW according to the third embodiment of the present disclosure. In FIG. 21, the LGW 220 generates and manages mode switching information in order to selectively switch between the two modes in the communication processing unit 221 and the address setting information storage unit 223 illustrated in FIG. Based on this, at least a mode switching processing unit 224 that controls the SGW 410 using a PBA message at a predetermined timing to transmit the mode switching information to the UE 100 is provided.

Also, in the third embodiment of the disclosed technology, as in the second embodiment of the disclosed technology, in the PDN connection establishment procedure, the LGW 220 has already assigned the IPv6 prefix to the UE 100 via the SGW 410. When assigned, the RS message (address information request message) transmitted from the UE 100 is transferred from the HeNB through the direct path. At this time, even when the LGW 220 transmits an RA message (address information notification message) in response to the received RS message (address information request message), the assigned IPv6 prefix is assigned to the UE 100 without assigning a new IPv6 prefix. An IPv6 prefix management unit (not shown in FIG. 21) for specifying correctly may be held.

The mode switching processing unit 224 illustrated in FIG. 21 generates and manages mode switching information (for example, a source address and a token) stored in the option field of the PBA message transmitted from the LGW 220 to the SGW 410 in step S1703 in FIG. When it is determined that the LIPA connection route is via the SGW 410 in step S1711 of FIG. 17, mode switching information (for example, a source address and a token) is stored in the option field of the PBA message. It is also a functional part. The mode switching processing unit 224 can use a message for causing the LGW 220 to set or change the LL address for the SGW 410. For example, a PBA message that is transmitted as a response to a received PBU message, a PBA message that is transmitted spontaneously without receiving a PBU message, or a binding that aims to prompt the SGW 410 to transmit a PBU A Revoke message can be used. When these LGWs 220 use an existing message to instruct setting / change of an LL address, the existing parameters (for example, Error cause) may be used as they are, or new parameters may be defined. .

Further, in the third embodiment of the disclosed technique, the SGW 410 extracts the LL address from the PBA message option field transmitted from the LGW 220 and sets the source address of the RA message (address information notification message) to be transmitted to the UE 100. It is assumed that it is set.

Next, the LGW 220 having the configuration illustrated in FIG. 21 will be described in detail with reference to FIGS. 22 and 23, focusing on characteristic processing in the disclosed technology. FIG. 22 is a flowchart illustrating an example of the operation of the LGW 220 from step S1701 to step S1703 in FIG. 17 according to the third embodiment of the present disclosure. FIG. 23 is a flowchart illustrating an example of the operation of the LGW 220 from step S1707 in FIG. 17 (reception of a PBU message) to step S1711 in the third embodiment of the present disclosure.

Hereinafter, the operation of the LGW 220 from step S1701 to step S1703 in FIG. 17 will be described first with reference to FIG.

The processing from step S2201 to step S2203 in FIG. 22 is the same as the processing from step S1501 to step S1503 in FIG. Subsequently, when the LGW 220 detects that the LIPA connection path of the UE 100 is changed (for example, when the characteristic of the LIPA connection (link) is changed as in the case where the LIPA connection path is changed via the SGW 410 due to handover), Mode switching information for causing the UE 100 to use the RA message (address information notification message) is generated (step S2205 in FIG. 22). Thereafter, the LGW 220 stores the address setting information generated in step S2203 and the mode switching information generated in step S2205 in the option field of the PBA message, and transmits them to the SGW 410 (step S2207 in FIG. 22).

Next, the operation of the LGW 220 from step S1707 (reception of a PBU message) to step S1711 in FIG. 17 will be described with reference to FIG.

When the UE 100 is handed over to another HeNB or eNB (here, to be HeNB for the sake of simplicity), the LGW 220 receives the PBU message from the SGW 410 (step S2301), and the HeNB that is the handover destination performs the LIPA of the UE 100. It is determined whether or not the direct path can be applied to the UE 100, such as whether or not the direct path is allowed to be established for the connection, or whether or not the direct path already exists (FIG. 23). Step S2303). When the direct path cannot be applied to the connection of the UE 100, a connection via the SGW 410 (that is, a LIPA connection for remote access) is established.

In step S2303, when the LGW 220 detects that the direct path cannot be applied to the connection of the UE 100 (when it is determined to be a connection via the SGW 410), the LGW 220 stores it in the PCO of the Attach Accept message in step S1703 and stores it in the UE 100. Using the notified mode switching information, a process for selecting an RA message is started. That is, a message instructing to use the mode switching information is transmitted to the SGW 410 (step S2305 in FIG. 23). The instruction to the SGW 410 is performed by storing mode switching information in the option field of the PBA message and transmitting it to the SGW 410, for example. The SGW 410 that has received the PBA message notifies the UE 100 of the mode switching information, and the UE 100 can evaluate the RA message (address information notification message) without ignoring it and use it for setting the LIPA connection (remote access). . In addition, in order to notify the mode switching information to the UE 100, the mode switching information may be notified to the UE 100 using the source address (Link-local address) of the RA message (address information notification message). By using the link-local address, it is not necessary to use a new parameter or a new message for notifying the UE 100 of the mode switching information. That is, since the existing RA message can be used, the implementation cost can be suppressed. Moreover, when the user data path of the LIPA connection of UE100 is not changed, LGW220 transmits normal PBA to SGW410 (step S2307).

Next, referring to FIG. 24A and FIG. 24B, the PBA message (and the Attach / PDN connectivity Accept message reaching UE 100) transmitted from LGW 220 to SGW 410 in step S1703 of FIG. 17 (FIG. 24A) and FIG. A format example of the PBA message (FIG. 24B) transmitted from the LGW 220 to the SGW 410 in step S1711 will be described.

The PBA message shown in FIG. 24A is composed of an address setting information option and a mode switching information option, which are features of the present application, in addition to the basic header and option fields used conventionally. The address setting information option notifies address setting information for preventing the UE 100 from using an RA message (address information notification message) transmitted from another gateway. The mode switching information option stores information for using the RA message (address information notification message) received when the LIPA connection route of the UE 100 is changed without being ignored. As described above, the information stored in the “mode switching information field” includes the source address (Link-local address) of the RA message (address information notification message), special flag information for switching the mode, or It may be an ID or a token.

FIG. 24B is composed of a mode switching information option, which is a feature of the present application, in addition to the basic header and option field conventionally used.

As described above, according to the third embodiment of the present disclosure, the UE 100 uses the RA message information (address setting information) acquired from the PCO of the message received by the UE 100 in the procedure for establishing the PDN connection, and the UE 100 receives information from another gateway. By enabling the transmitted RA message (address information notification message) to be ignored, it is possible to avoid the problem that the UE 100 exchanges user data using an incorrect parameter (for example, Link-MTU value). Further, by using the mode switching information, the base station (HeNB or eNB) that is the handover destination of the UE 100 does not permit the UE 100 to make a direct path to the LGW 220, or the base station that is the handover destination of the UE 100 When the LIPA connection is switched via the SGW 410, such as when there is no direct path between the (HeNB or eNB) and the LGW 220, the UE 100 uses the RA message (address information notification message) information (address setting information) from the SGW 410. Can be used. As a result, it is possible to avoid the problem that the UE 100 exchanges user data using an incorrect parameter (for example, Link-MTU value). In addition, the third embodiment of the disclosed technology, as in the second embodiment, uses the conventional technology established by 3GPP, and solves the problem while considering the impact on the existing system. Can be solved.

When the LIPA connection of the UE 100 is switched from via the SGW 410 to the direct path with the HeNB, the LGW 220 initially notifies the SGW 410 when the LIPA connection via the direct path is established (that is, at least the one notified to the UE 100 by the PCO) A different link local address) is notified to the SGW 410 again. For the notification from the LGW 220 to the SGW 410, the above-described PBA, Binding Revoke message, or the like can be used. As a result, even when the UE 100 is handed over to any base station, the IP configuration of the connection in the UE 100 can always be correctly performed, the transmission efficiency can be improved, and the user benefit can be increased.

Further, in the above description, the description has been made on the assumption that the UE 100 has two states of the designated address mode and the normal mode. However, particularly when the process according to the present invention is implemented using a packet filter, the state is changed. It may be one. That is, when the UE 100 acquires mode switching information from the PCO, the UE 100 transits to a mode in which the present invention is operated, and performs packet filter setting and the like. That is, after setting the packet filter, the RA message is not received unless a specific link local address is used as the source address. That is, by setting a packet filter, the two modes described above are implicitly selected. Therefore, in the implementation of the present invention, the two modes described above are not necessarily essential.

Further, in one aspect of the disclosed technology, the communication terminal performs a handover to another base station different from the base station to which the communication terminal is connected;
The first gateway transmitting a second registration request message to the second gateway based on the handover;
The second gateway receives the second registration request message, and determines whether data transfer between the communication terminal and the connection destination is switched to data transfer via the first gateway by the handover. Steps,
When the data transfer between the communication terminal and the connection destination is switched to the data transfer via the first gateway by the handover, the address setting included in the address information notification message received by the communication terminal is received by the second gateway. Transmitting a second registration response message including mode switching information for validating information in an option field to the first gateway;
The first gateway receives the second registration response message and transmits an address information notification message including the mode switching information to the communication terminal;
The communication terminal receives the address information notification message including the mode switching information, and sets communication with the connection destination based on the address setting information included in the address information notification message including the mode switching information. The step of updating,
Furthermore, you may have.

Further, in one aspect of the disclosed technology, in the step of generating the address setting information, the second gateway performs mode switching for validating the address setting information included in the address information notification message received by the communication terminal. Generate more information,
In the step of transmitting the registration response message to the first gateway, the second gateway further inserts the mode switching information in an option field of the registration response message,
In the step of transmitting the connection acceptance message to the communication terminal, the first gateway further inserts the mode switching information in an option field of the connection acceptance message,
In the step of receiving the connection acceptance message, when the communication terminal receives from the network the connection acceptance message in which the mode switching information is further inserted into the option field including the address setting information, the mode switching information May be further held.

In one aspect of the disclosed technology, when the communication terminal receives the address information notification message including the mode switching information from the network, the mode switching information included in the address information notification message is the connection information. Confirming whether the mode switching information included in the option field of the acceptance message matches the mode switching information held by the communication terminal;
If they match, updating the communication settings with the connection destination based on the address setting information included in the address information notification message,
Furthermore, you may have.

Also, in one aspect of the disclosed technology, one of the link local addresses of the first gateway is used for the mode switching information, and one of the link local addresses of the first gateway is used as a source address of the address information notification message. May be used.

Further, in one aspect of the disclosed technology, the communication terminal sets communication with the connection destination based on the address setting information included in the address information notification message, and then notifies the address information from the network. When another address information notification message different from the message is received, the method further includes a step of updating the setting of communication with the connection destination based on the address setting information included in the other address information notification message. May be.

Moreover, in one aspect of the disclosed technique, the address setting information generated by the second gateway may include information of an address information notification message to be notified from the second gateway to the communication terminal.

In one aspect of the disclosed technology, the connection request message and the connection acceptance message may be messages defined in a packet data network connection establishment procedure.

Further, in one aspect of the present disclosure, the registration request message and the registration response message may be a proxy binding update message and a proxy binding acknowledgment message defined by proxy mobile IP, respectively.

Further, in one aspect of the disclosed technology, the communication terminal sets communication with the connection destination based on the address setting information, and then includes address setting information included in an address information notification message received from the network. May be further included.

Further, in one aspect of the disclosed technology, the second gateway confirms whether proxy mobile IP is applied as a mobility control protocol of the communication terminal, and the proxy mobile IP is used as the mobility control protocol of the communication terminal. Is applied, the address setting information may be generated, and a registration response message including the address setting information in an option field may be transmitted to the first gateway.

Further, in one aspect of the present disclosure, the second gateway confirms whether or not the connection to the connection destination by the communication terminal is a local IP access, and the connection to the connection destination by the communication terminal is In the case of the local IP access, the address setting information may be generated and a registration response message including the address setting information in an option field may be transmitted to the first gateway.

Further, according to one aspect of the disclosed technology, the second gateway can establish a direct path that does not pass through the first gateway between the base station to which the communication terminal is connected and the second gateway. If the direct path can be established, the address setting information may be generated, and a registration response message including the address setting information in an option field may be transmitted to the first gateway.

Further, one aspect of the disclosed technology is a network device that functions as a gateway on a network to which a communication terminal connects via a base station, for example,
Means for performing data path control in connection between a connection destination designated by the communication terminal and the communication terminal;
A registration request message transmitted based on a connection request message including identification information for designating the connection destination transmitted from the communication terminal to the network, wherein the communication terminal performs data path control of the communication terminal. Means for receiving the registration request message sent from the gateway of
Means for generating address setting information to be notified to the communication terminal;
As a response to the registration request message, means for transmitting a registration response message including the address setting information in an option field to the another gateway;
Have
When the another gateway transmits a connection acceptance message including the address setting information in an option field to the communication terminal, the communication terminal receives the connection acceptance message from the network as a response to the connection request message. A network device that sets communication with the connection destination based on the address setting information may be included.
With this configuration, the communication terminal can perform communication settings based on appropriate address setting information in communication with a desired connection destination network, and can suppress the occurrence of inefficient communication.

Further, in one aspect of the disclosed technique, the communication terminal is a registration request message transmitted based on a handover performed to another base station different from the base station, and transmitted from the another gateway. Means for receiving a registration request message;
Means for determining whether or not data transfer between the communication terminal and the connection destination is switched to data transfer via the another gateway by the handover;
In order to validate the address setting information included in the address information notification message received by the communication terminal when data transfer between the communication terminal and the connection destination is switched to data transfer via the other gateway by the handover Means for transmitting a second registration response message including the mode switching information in the option field to the another gateway,
The another gateway receives the second registration response message and transmits an address information notification message including the mode switching information to the communication terminal, so that the communication terminal includes the address information including the mode switching information. A notification message may be received, and a communication setting with the connection destination may be updated based on the address setting information included in the address information notification message including the mode switching information.

Further, one aspect of the disclosed technique is, for example, a communication terminal connected to a network via a base station,
Means for transmitting a connection request message including identification information designating a connection destination to the network;
As a response to the connection request message, a connection acceptance message including address setting information to be notified to the communication terminal by the gateway on the network performing data path control in connection with the connection destination is received from the network. Means,
Means for setting communication with the connection destination based on the address setting information;
You may include the communication terminal which has.
With this configuration, the communication terminal can perform communication settings based on appropriate address setting information in communication with a desired connection destination network, and can suppress the occurrence of inefficient communication.

Further, according to one aspect of the disclosed technology, when an handover is performed and a connection is made to another base station different from the base station, an address information notification message including mode switching information indicating that the address setting information is valid is received. In this case, the information processing apparatus may further include means for updating the setting of communication with the connection destination based on the address setting information included in the address information notification message.

It should be noted that the above aspects of the disclosed technology can be combined as appropriate.

In addition to the communication control method, the communication terminal, and the network device, one aspect of the present disclosure provides a method that is executed by the communication terminal and the network device, a program that causes a computer to execute the method, and the program It may be realized by a recorded recording medium or the like.

Also, each functional block and each processing unit used in the description of the above embodiment may be realized by hardware, software, or a combination thereof. For example, the functional blocks included in each device illustrated in FIGS. 6, 8, 12, 14, 1, 21, etc., or each processing unit having an equivalent function may be a hardware such as a CPU and a memory of an arbitrary computer. It may be realized by wear. Further, each functional block and each processing unit may be realized by causing a computer to execute a program in which operations related to each function are described.

Further, the functional blocks used in the description of the embodiment of the presently disclosed technique are typically realized as an LSI (Large Scale Integration) that is an integrated circuit. These may be individually made into one chip, or may be made into one chip so as to include a part or all of them. Here, LSI is used, but depending on the degree of integration, it may be called IC (Integrated Circuit), system LSI, super LSI, or ultra LSI.

Also, the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.

Furthermore, if integrated circuit technology that replaces LSI emerges as a result of advances in semiconductor technology or other derived technology, it is naturally also possible to integrate functional blocks using this technology. For example, biotechnology can be applied.

The disclosed technology allows a communication terminal to always perform communication setting based on appropriate address setting information in an environment where an address information notification message including different address setting information can be notified from two gateways to the communication terminal. The effect that it becomes possible to suppress the occurrence of inefficient communication, the effect that the communication terminal can perform communication setting based on appropriate address setting information for communication via the LIPA connection, communication Even in the case where the terminal transmits an address information request message to the network, there is an effect that correct address information notification message information can be always selected and used. For example, when a PMIP is applied, a home access technology (local IP Applicable to technology when using (Access) It is.

Claims

A communication control method for performing communication control of a communication terminal connected to a network via a base station,
The communication terminal transmitting a connection request message including identification information designating a connection destination to the network;
A first gateway on the network that performs data path control of the communication terminal receives the connection request message, and performs data path control in connection with the connection destination based on the connection request message Sending a registration request message to the second gateway;
The second gateway receives the registration request message and generates address setting information to be notified to the communication terminal;
The second gateway, as a response to the registration request message, sending a registration response message including the address setting information in an option field to the first gateway;
The first gateway transmits a connection acceptance message including the address setting information in an option field to the communication terminal;
The communication terminal receiving the connection acceptance message from the network as a response to the connection request message;
The communication terminal performing communication setting with the connection destination based on the address setting information;
A communication control method.
The communication terminal performs handover to another base station different from the base station to which the communication terminal is connected;
The first gateway transmitting a second registration request message to the second gateway based on the handover;
The second gateway receives the second registration request message, and determines whether data transfer between the communication terminal and the connection destination is switched to data transfer via the first gateway by the handover. Steps,
When the data transfer between the communication terminal and the connection destination is switched to the data transfer via the first gateway by the handover, the address setting included in the address information notification message received by the communication terminal is received by the second gateway. Transmitting a second registration response message including mode switching information for validating information in an option field to the first gateway;
The first gateway receives the second registration response message and transmits an address information notification message including the mode switching information to the communication terminal;
The communication terminal receives the address information notification message including the mode switching information, and sets communication with the connection destination based on the address setting information included in the address information notification message including the mode switching information. The step of updating,
The communication control method according to claim 1, further comprising:
In the step of generating the address setting information, the second gateway further generates mode switching information for validating the address setting information included in the address information notification message received by the communication terminal,
In the step of transmitting the registration response message to the first gateway, the second gateway further inserts the mode switching information in an option field of the registration response message,
In the step of transmitting the connection acceptance message to the communication terminal, the first gateway further inserts the mode switching information in an option field of the connection acceptance message,
In the step of receiving the connection acceptance message, when the communication terminal receives from the network the connection acceptance message in which the mode switching information is further inserted into the option field including the address setting information, the mode switching information The communication control method according to claim 1, further comprising:
When the communication terminal receives the address information notification message including the mode switching information from the network, the mode switching information included in the address information notification message is included in the option field of the connection acceptance message. Checking whether the communication terminal matches the mode switching information, and
If they match, updating the communication settings with the connection destination based on the address setting information included in the address information notification message,
The communication control method according to claim 3, further comprising:
The communication according to claim 4, wherein one of the link local addresses of the first gateway is used for the mode switching information, and one of the link local addresses of the first gateway is used for a source address of the address information notification message. Control method.
After the communication terminal sets communication with the connection destination based on the address setting information included in the address information notification message, another address information notification message different from the address information notification message from the network. 5. The communication control method according to claim 4, further comprising a step of updating a communication setting with the connection destination based on address setting information included in the another address information notification message.
The communication control method according to claim 1, wherein the address setting information generated by the second gateway includes information of an address information notification message to be notified from the second gateway to the communication terminal.
The communication control method according to claim 1, wherein the connection request message and the connection acceptance message are messages defined in a packet data network connection establishment procedure.
The communication control method according to claim 1, wherein the registration request message and the registration response message are a proxy binding update message and a proxy binding acknowledgment message defined in proxy mobile IP, respectively.
The communication terminal further includes a step of ignoring address setting information included in an address information notification message received from the network after setting communication with the connection destination based on the address setting information. The communication control method described in 1.
The second gateway checks whether proxy mobile IP is applied as a mobility control protocol of the communication terminal, and when the proxy mobile IP is applied as a mobility control protocol of the communication terminal, the address The communication control method according to claim 1, wherein setting information is generated and a registration response message including the address setting information in an option field is transmitted to the first gateway.
The second gateway checks whether the connection to the connection destination by the communication terminal is a local IP access, and when the connection to the connection destination by the communication terminal is the local IP access, 2. The communication control method according to claim 1, wherein address setting information is generated, and a registration response message including the address setting information in an option field is transmitted to the first gateway.
The second gateway confirms whether or not a direct path that does not pass through the first gateway can be established between the base station to which the communication terminal is connected and the second gateway, and establishes the direct path The communication control method according to claim 1, wherein if possible, the address setting information is generated and a registration response message including the address setting information in an option field is transmitted to the first gateway.
A network device that functions as a gateway on a network to which a communication terminal connects via a base station,
Means for performing data path control in connection between a connection destination designated by the communication terminal and the communication terminal;
A registration request message transmitted based on a connection request message including identification information for designating the connection destination transmitted from the communication terminal to the network, wherein the communication terminal performs data path control of the communication terminal. Means for receiving the registration request message sent from the gateway of
Means for generating address setting information to be notified to the communication terminal;
As a response to the registration request message, means for transmitting a registration response message including the address setting information in an option field to the another gateway;
Have
When the another gateway transmits a connection acceptance message including the address setting information in an option field to the communication terminal, the communication terminal receives the connection acceptance message from the network as a response to the connection request message. A network device for setting communication with the connection destination based on the address setting information.
Means for receiving the registration request message transmitted from the another gateway, the registration request message transmitted based on a handover performed by the communication terminal to another base station different from the base station;
Means for determining whether or not data transfer between the communication terminal and the connection destination is switched to data transfer via the another gateway by the handover;
In order to validate the address setting information included in the address information notification message received by the communication terminal when data transfer between the communication terminal and the connection destination is switched to data transfer via the other gateway by the handover Means for transmitting a second registration response message including the mode switching information in the option field to the another gateway,
The another gateway receives the second registration response message and transmits an address information notification message including the mode switching information to the communication terminal, so that the communication terminal includes the address information including the mode switching information. The network device according to claim 14, wherein the network device receives a notification message and updates a communication setting with the connection destination based on the address setting information included in the address information notification message including the mode switching information.
A communication terminal connected to a network via a base station,
Means for transmitting a connection request message including identification information designating a connection destination to the network;
As a response to the connection request message, a connection acceptance message including address setting information to be notified to the communication terminal by the gateway on the network that performs data path control in connection with the connection destination is received from the network. Means,
Means for setting communication with the connection destination based on the address setting information;
Having a communication terminal.
When an address information notification message including mode switching information indicating that the address setting information is valid is received when a handover is performed to connect to another base station different from the base station, the address information notification message is displayed. The communication terminal according to claim 16, further comprising means for updating a communication setting with the connection destination based on the address setting information included.