WO2009000124A1 - Procede de selection de passerelle dans un reseau sans fil - Google Patents

Procede de selection de passerelle dans un reseau sans fil Download PDF

Info

Publication number
WO2009000124A1
WO2009000124A1 PCT/CN2007/003908 CN2007003908W WO2009000124A1 WO 2009000124 A1 WO2009000124 A1 WO 2009000124A1 CN 2007003908 W CN2007003908 W CN 2007003908W WO 2009000124 A1 WO2009000124 A1 WO 2009000124A1
Authority
WO
WIPO (PCT)
Prior art keywords
3gpp
network
pdn
roaming
mobile terminal
Prior art date
Application number
PCT/CN2007/003908
Other languages
English (en)
Chinese (zh)
Inventor
Zaifeng Zong
Se Wu
Jinguo Zhu
Original Assignee
Zte Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zte Corporation filed Critical Zte Corporation
Publication of WO2009000124A1 publication Critical patent/WO2009000124A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W48/00—Access restriction; Network selection; Access point selection
    • H04W48/17—Selecting a data network PoA [Point of Attachment]

Definitions

  • the present invention relates to the field of wireless communications, and more particularly to a gateway selection method in a wireless network. Background technique
  • the packet data network gateway PDN GW Packet Data Network GateWay
  • PDN GW Packet Data Network GateWay
  • PDN GWs may be multiple PDN GWs in the 3GPP evolved packet system, which are respectively connected to different PDNs. As shown in Figure 1.
  • the 3GPP evolved packet system consists of E-UTRAN (Evolved-UMTS Territorial Radio Access Network), MME (Mobility Management Entity), S-GW (Moon Service Gateway, Serving Gateway), PDN GW, HSS (Home Subscriber Server, Home Subscriber Server), 3GPP AAA Server (3GPP Authentication and Authorization Accounting Server) and other nodes.
  • the MME is responsible for control plane related operations such as mobility management, non-access stratum signaling processing, and user mobility management context management;
  • the S-GW is an access gateway device connected to the E-UTRAN, in the E-UTRAN and the PDN.
  • the data is forwarded between the GWs and is responsible for caching the paging wait data.
  • PDN GW is the border gateway of 3GPP evolved packet system (EPS) and PDN network, which is responsible for PDN access and forwarding data between EPS and PDN.
  • EPS 3GPP evolved packet system
  • the 3GPP evolved packet system provides connectivity services to two PDNs, the enterprise private network and the Internet, respectively.
  • PDN GW 1 provides connectivity to the corporate private network;
  • PDN OW 2 provides connectivity to the Internet.
  • the PDN GW selection module selects an appropriate PDN GW for the mobile terminal.
  • the HSS/AAA provides the necessary information for the PDN GW selection module.
  • the information provided to HSS/AAA is as follows:
  • the information provided by the HSS/AAA to the PDN GW selection module is either a PDN GW IP address list and an Access Point Name (APN, Access Point Name); or an APN and a selectable visited Land Mobile Network (VPLMN, visited PLM) Instructions for PDN GW.
  • APN Access Point Name
  • VPLMN visited Land Mobile Network
  • the PDN GW selection module When the HSS/AAA provides the PDN OW selection module with an indication of the APN and whether the PDN GW of the VPLMN can be selected, if the indication indicates that the PDNMN can select the PDN GW, the PDN GW selection module first attempts to select from the VPLMN according to the APN. PDN GW, if it fails, the PDN GW selection module selects the PDN GW from the home land mobile network (HPLMN) according to the APN.
  • HPLMN home land mobile network
  • the non-3GPP IP access network when non-roaming, the non-3GPP IP access network is directly connected to the PDN GW through S2a or S2b.
  • the non-3GPP IP access network When roaming, there are three scenarios for interworking between the non-3GPP IP access network and 3GPP, namely:
  • Scenario 1 The mobile terminal directly accesses the PDN from the PDN GW of the VPLMN through the non-3GPP IP access network.
  • Scenario 2 The mobile terminal cannot access from the PDN GW of the VPLMN through the non-3G P IP access network; the PDN, but the non-3GPP operator has a protocol with the HPLMN operator of the mobile terminal, and can directly access the non-3GPP access network. To the PDN GW of HPLMN.
  • Scenario 3 The mobile terminal cannot access the PDN from the PDN GW of the VPLMN through the non-3GPP IP access network, and the VPLMN does not allow the mobile terminal to directly access the PDN GW of the HPLMN, the roam between the VPLMN and the HPLMN through the non-3GPP access network.
  • the protocol stipulates that the non-3GPP access network must access the HPLMN's PDN GW via the VPLMN's Serving Gateway (S-GW).
  • the access network element of 3GPP is an enhanced packet data gateway ePDG, and the scene during roaming is shown in FIG. 2 .
  • the number 1 in the figure corresponds to the scenario 1 above, the mobile terminal directly accesses the PDN through the PDN GW located in the VPLMN; the number 2 corresponds to the scenario 2, the mobile terminal accesses the PDN through the PDN GW located in the HPLM; the number 3 corresponds to the scenario 3 above.
  • the mobile terminal accesses the PDN through the S-GW located at the VPLMN and then through the PDN GW located at the HPLMN.
  • the PDN GW selection method defined in the 3GPP evolved packet system can only select scene 1 during roaming, and cannot distinguish between scene 2 and scene 3. Summary of the invention
  • the technical problem to be solved by the present invention is to provide a gateway selection method in a wireless network, which can solve the problem of selecting a PDN GW from a 3GPP evolved packet system EPS during roaming.
  • the technical solution adopted by the present invention is a gateway selection method in a wireless network, which includes the following steps:
  • the roaming 3GPP AAA proxy determines whether the UE data link must be forwarded via the roaming network according to the roaming protocol, and adds the second indication information as the second indication information to the non-3GPP IP access.
  • the network, the authentication result further includes packet data network gateway PDN GW selection information that the home 3GPP AAA server joins;
  • the non-3GPP IP access network selects a PDN GW for the UE according to the PDN GW selection information, and if the selected PDN GW is located at the home location, the non-3GPP IP access network determines to establish user data according to the second indication information. Whether the link needs to access the PDN GW of the home location through the serving gateway S-GW of the roaming place.
  • gateway selection method in the wireless network may further have the following features:
  • the PDN GW selection information in the step (b) includes an access point name and first indication information, and the first indication information represents whether the PDN GW of the roaming network is allowed to be selected for the mobile terminal.
  • gateway selection method in the wireless network may further have the following features:
  • Step (c) is further divided into the following steps:
  • the non-3GPP IP access network attempts to select the PDN GW for the mobile terminal according to the access point name in the roaming 3GPP network;
  • the non-3GPP IP access network attempts to select the PDN GW from the roaming 3GPP network, the non-3GPP IP The access network selects a PDN GW for the mobile station based on the WLAN access point name W-APN;
  • the non-3GPP IP access network attempts to select the S-GW for the mobile terminal in the roaming 3GPP network.
  • the gateway selection method in the wireless network provided by the present invention may also have the following features: when the mobile terminal accesses the 3GPP network from the trusted non-3GPP IP access network, the non-3GPP IP access network The gateway device selects the PDN GW of the 3GPP network for the mobile terminal; when the mobile terminal accesses the 3GPP network from the untrusted non-3GPP IP access network, the enhanced packet data gateway ePDG selects the PDN GW of the 3GPP network for the mobile terminal.
  • the gateway selection method in the wireless network provided by the present invention may also have the following features:
  • the roaming protocol in step (b) is a roaming agreement between the roaming network operator and the home network operator.
  • the gateway selection method in the wireless network provided by the present invention may also have the following features:
  • the gateway device and the ePDG in the non-3GPP IP access network are moved according to the W-APN and the first indication information and the second indication information.
  • the terminal selects the PDN GW and the S-GW of the 3GPP network.
  • the gateway selection method in the wireless network of the present invention can distinguish between scenario 2 and scenario 3 in which the non-3GPP IP access network communicates with the 3GPP during roaming, and solves the problem that when the mobile terminal UE roams, the mobile terminal is from the non-3GPP IP access network.
  • 1 is a cross-sectional architecture diagram of a 3GPP evolved packet system and a non-3GPP IP access network when non-roaming;
  • FIG. 2 is a scenario diagram of interworking between a 3GPP evolved packet system and a non-3GPP IP access network during roaming;
  • Figure 3 is a flow chart of an embodiment of the present invention.
  • the present invention provides a method for distinguishing between scene 2 and scene 3 based on the selection method of the PDN GW defined in the 3GPP evolved packet system.
  • the 3GPP AAA proxy located in the VPLMN decides whether to select scenario 1 or scenario 3 when the PDN GW is located in the HPLMN according to the roaming protocol between the VPLMN and the HPLMN.
  • the 3GPP AAA proxy brings this decision to the non-3GPP IP access network in the authentication result.
  • the non-3GPP IP access network selects the PDN GW based on the APNs and flags obtained from the HSS/3GPP AAA system during the authentication process.
  • This embodiment describes a procedure for the 3GPP AAA authentication system to provide the required information of the PDN GW for the non-3GPP IP access network when the mobile terminal UE accesses the 3GPP service through the non-3GPP access network for the first time.
  • the 3GPP AAA authentication system After the 3GPP AAA authentication system successfully authenticates the mobile terminal, the 3GPP AAA authentication system carries the PDN GW selection information to the non-3GPP IP access network in the AAA authentication accept message. Wherein, the 3GPP AAA Server located in the home network sends the selection to the PDN GW selection module.
  • the WLAN required WLAN access point name (W-APN, WLAN APN), and whether or not the indication of the roaming PDN GW can be selected.
  • the roaming 3GPP AAA Proxy determines whether the data link of the mobile terminal is necessary according to the roaming protocol. Forwarded via roaming 3GPP network.
  • a UE User Equipment, a mobile terminal
  • the non-3GPP access network performs access authentication on the UE, where the network element includes a UE, a non-3GPP access network, a 3GPP AAA Proxy, a 3GPP AAA server, and an HSS.
  • the 3GPP AAA Server is the authentication executor.
  • the HSS provides the user's authentication vector and subscription information, and the 3GPP AAA Proxy and the non-3GPP access network are responsible for transmitting the required authentication between the UE and the 3GPP AAA Server. Signaling
  • the UE After the UE is successfully authenticated by the 3GPP AAA Server, send an authentication accept message to the 3GPP AAA Proxy according to the subscription information provided by the HSS, and send the user W-APN and the first indication information of whether the user is allowed to access from the roaming PDN GW.
  • the indication in 1) is inserted as an option into the authentication accept message;
  • the 3GFP AAA Proxy intercepts the 303-step authentication accept message.
  • the 3GPP AAA Proxy determines whether the data link of the UE to the PDN must be forwarded through the roaming network according to the roaming agreement between the roaming network operator and the home network operator, and sets the second indication information according to the decision (indication 2 in the figure) 305, 3GPP AAA Proxy appends the indication 2 to the authentication accept message, and forwards the authentication accept message to the non-3GPP access network;
  • the non-3GPP access network selects the PDN GW according to the W-APN, the indication 1 and the indication 2 in the authentication accept message.
  • the selection process of the above step 306 further includes the following steps:
  • the PDN GW selection module obtains the selection information of the PDN GW, including the W-APN, the indication 1 and the indication 2, and starts the selection process of the PDN GW;
  • This embodiment is a case where the trusted non-3GFP and the 3GPP are intercommunicated, that is, the UE is registered from the trusted non-3GPP IP access network, and the PDN GW selection module is located in the gateway device in the non-3GPP access network.
  • the PDN GW and the S-GW are selected by the gateway device based on the PDN GW selection information obtained from the 3GPP AAA authentication system.
  • PDN GW selection module first determines the indication 1 , if the indication 1 indicates that the PDN GW can be selected from the roaming place, step 403 is performed, otherwise, step 404 is performed;
  • the PDN GW selection module attempts to resolve the PDN GW from the roaming ground according to the W-APN, if the parsing is successful, step 405 is performed, otherwise, step 404 is performed;
  • the non-3GPP access network attempts to resolve the PDN for the UE from the home network according to the W-APN.
  • step 406 if the parsing is successful, the IP address of the PDN GW is obtained from the home network, step 406 is performed, otherwise, step 410 is performed;
  • the non-3GPP access network initiates a link establishment request to the PDN GW of the roaming network, if requested Successfully establishes a user data link to the PDN GW of the roaming network, otherwise, step 410 or 404 is performed;
  • step 406 judgment indication 2, if the indication 2 indicates that the network must be forwarded through the roaming, step 407 is performed, otherwise, step 408 is performed;
  • the non-3GPP access network for the UE to try to select the S-GW in the roaming 3GPP network; if the resolution is successful, go to step 409, otherwise, go to step 410;
  • the non-3GPP access network attempts to establish, for the UE, a user data link to the PDN GW located in the home network. If the request is successful,
  • the non-3GPP access network initiates a user data link request to the S-GW, and brings the IP address and the W-APN information of the selected PDN GW to the S-GW. If the request is successful, the S-GW establishes the slave. The user data link to the PDN GW, and the two links are mapped for subsequent data forwarding, otherwise step 410 is performed;
  • the user data link fails to be established.
  • the UE access fails, and the UE sends an access failure information.
  • the PDN In another embodiment, such as when the UE registers from an untrusted non-3GPP IP access network, the PDN
  • the GW selection module is located in the ePDG.
  • the PDN GW and the S-GW are selected by the ePDG based on the PDN GW selection information obtained from the 3GPP AAA authentication system.
  • the flow of the above embodiment is equally applicable to this case.
  • the gateway selection method in the wireless network of the present invention can distinguish between scenario 2 and scenario 3 in which the non-3GPP IP access network communicates with the 3GPP during roaming, and solves the problem that when the mobile terminal UE roams, the mobile terminal is from the non-3GPP IP.
  • the access network accesses the problem of selecting the PDN GW in the 3GPP evolved packet system EPS.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Security & Cryptography (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

L'invention concerne un procédé de sélection de passerelle dans un réseau sans fil. Lorsque l'équipement utilisateur est en itinérance, il accède à l'EPS 3GPP à partir d'un réseau d'accès IP 3GPP; pendant l'authentification d'accès, un mandataire AAA 3GPP dans les réseaux visités décide si les données d'équipement utilisateur doivent être transmises par le réseau visité et ajoute la décision sous la forme d'une deuxième indication au résultat d'authentification qui contient les informations de sélection de la passerelle PDN ajoutée par le serveur AAA 3GPP dans le réseau domestique, puis transmet le résultat d'authentification au réseau d'accès IP non 3GPP; enfin, le réseau d'accès IP non 3GPP sélectionne une passerelle PDN pour l'équipement utilisateur en fonction des informations de sélection de passerelle PDN. Si la passerelle PDN se trouve dans le réseau domestique, le réseau d'accès IP non 3GPP décide s'il faut passer par la passerelle S dans le réseau visité pour accéder à la passerelle PDN dans le réseau domestique, en fonction de la deuxième indication. Les scénarios 2 et 3 pour l'intercommunication entre le réseau d'accès non 3GPP et le réseau 3GPP pendant l'itinérance peuvent être différenciés par le procédé selon l'invention. Ledit procédé permet de résoudre le problème de la sélection de passerelle PDN lorsque le terminal mobile en itinérance accède à l'EPS 3GPP à partir du réseau d'accès IP non 3GPP.
PCT/CN2007/003908 2007-06-22 2007-12-29 Procede de selection de passerelle dans un reseau sans fil WO2009000124A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN200710127743.5 2007-06-22
CNA2007101277435A CN101330740A (zh) 2007-06-22 2007-06-22 一种无线网络中的网关选择方法

Publications (1)

Publication Number Publication Date
WO2009000124A1 true WO2009000124A1 (fr) 2008-12-31

Family

ID=40185164

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2007/003908 WO2009000124A1 (fr) 2007-06-22 2007-12-29 Procede de selection de passerelle dans un reseau sans fil

Country Status (2)

Country Link
CN (1) CN101330740A (fr)
WO (1) WO2009000124A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101945456A (zh) * 2009-07-08 2011-01-12 中兴通讯股份有限公司 一种andsf提供接入网协议选择功能的方法和系统
CN102137487A (zh) * 2010-12-31 2011-07-27 华为技术有限公司 一种选择服务网关实体的方法及设备

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101483929B (zh) * 2008-01-08 2011-06-01 华为技术有限公司 非3gpp接入网关获知与策略决策实体交互方式的方法及装置
CN101784027B (zh) * 2009-01-19 2014-03-12 中兴通讯股份有限公司 紧急会话切换方法及系统
CN101789912B (zh) * 2009-01-23 2012-06-27 华为技术有限公司 更新分组数据网络网关信息的方法、装置及系统
CN101720119B (zh) * 2009-05-27 2012-06-13 中兴通讯股份有限公司 一种实现pdn连接选择的方法及系统
CN101909368B (zh) * 2009-06-08 2012-06-27 上海贝尔股份有限公司 无线网络安全解决方法和设备
CN102696268B (zh) * 2009-11-05 2016-03-30 华为技术有限公司 因特网协议地址的通知方法、系统及设备
MX2013008150A (es) 2011-01-14 2013-09-13 Nokia Siemens Networks Oy Soporte de autenticacion externo sobre una red no confiable.
CN102781004B (zh) * 2011-05-10 2017-05-24 中兴通讯股份有限公司 一种选择网关的方法及装置
CN103428798B (zh) * 2012-05-22 2016-09-21 华为终端有限公司 网关选择方法、服务器、用户设备、网关及分组数据系统
CN105873024B (zh) * 2015-01-21 2019-09-06 中国移动通信集团辽宁有限公司 一种lte网络中解析网关的方法及装置
US10237795B2 (en) * 2015-10-11 2019-03-19 Qualcomm Incorporated Evolved packet data gateway (EPDG) reselection
EP3244588B1 (fr) * 2016-05-10 2021-06-23 Nokia Solutions and Networks Oy Support de noyau dédié des réseaux d'accès wlan
US11528592B2 (en) * 2020-08-03 2022-12-13 Mediatek Inc. Apparatuses and methods for robust moving between a roaming 3GPP network and a non-3GPP network

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1358040A (zh) * 2000-12-12 2002-07-10 华为技术有限公司 蜂窝系统虚拟漫游及互通的实现方法与系统
US20040114611A1 (en) * 2002-12-17 2004-06-17 O'connell Pete Call-routing apparatus, and associated method, for providing local call handling functions in a communication network
US20040228347A1 (en) * 2001-08-09 2004-11-18 Tuija Hurtta Enabling active pdp contexts in additional plmns according to home operator information and/or subnetwork information

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1358040A (zh) * 2000-12-12 2002-07-10 华为技术有限公司 蜂窝系统虚拟漫游及互通的实现方法与系统
US20040228347A1 (en) * 2001-08-09 2004-11-18 Tuija Hurtta Enabling active pdp contexts in additional plmns according to home operator information and/or subnetwork information
US20040114611A1 (en) * 2002-12-17 2004-06-17 O'connell Pete Call-routing apparatus, and associated method, for providing local call handling functions in a communication network

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
3GPP: "3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; GPRS enhancements for E-UTRAN access (Release 8)", 3GPP TS 23.401 V1.0.0, May 2007 (2007-05-01), pages 11 *
3GPP: "3rd Generation Partnershp Project; Technical Specification Group Services and System Aspects; Architecture Enhancements for non-3GPP accesses: Release 8", 3GPP TS 23.402 V0.5.0, May 2007 (2007-05-01), pages 10, 18, 35 - 37 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101945456A (zh) * 2009-07-08 2011-01-12 中兴通讯股份有限公司 一种andsf提供接入网协议选择功能的方法和系统
WO2011003313A1 (fr) * 2009-07-08 2011-01-13 中兴通讯股份有限公司 Procédé et système permettant à une fonction de découverte et de sélection de réseau d'accès (andsf) de fournir une fonction pour sélectionner un protocole de réseau d'accès
CN102137487A (zh) * 2010-12-31 2011-07-27 华为技术有限公司 一种选择服务网关实体的方法及设备
CN102137487B (zh) * 2010-12-31 2013-11-06 华为技术有限公司 一种选择服务网关实体的方法及设备
US9392529B2 (en) 2010-12-31 2016-07-12 Huawei Technologies Co., Ltd. Method and device for selecting serving gateway entity
US9838247B2 (en) 2010-12-31 2017-12-05 Huawei Technologies Co., Ltd. Method and device for selecting serving gateway entity

Also Published As

Publication number Publication date
CN101330740A (zh) 2008-12-24

Similar Documents

Publication Publication Date Title
WO2009000124A1 (fr) Procede de selection de passerelle dans un reseau sans fil
JP6148294B2 (ja) 相異なるワイヤレス通信アーキテクチャ間のモビリティのための資源管理
EP1693988B1 (fr) Procede de selection par un terminal d'abonne de la passerelle de paquets de donnees dans un reseau local sans fil
US8315227B2 (en) GTP for integration of multiple access
CN101141822B (zh) 一种无线网络的网关选择方法
EP1693995B1 (fr) Procédé d'application d'une authentification d'accès d'un utilisateur wlan
JP2020506588A (ja) 信頼できないネットワークを用いたインタワーキング機能
JP2019521607A (ja) Ｐｄｕセッション確立手順を処理する方法及びａｍｆノード
WO2007019771A1 (fr) Méthode de contrôle d’accès d’un utilisateur changeant de réseau à visiter, son unité et son système
WO2009094837A1 (fr) Procédé de sélection d'un serveur à fonction de règles de politiques et de facturation dans une situation sans itinérance
WO2013016968A1 (fr) Procédé et système d'accès, et point d'accès intelligent mobile
WO2009086734A1 (fr) Procédé pour sélectionner une entité à fonction de règles de politique et de facturation dans le scénario sans itinérance
WO2005039110A1 (fr) Analyse du traitement d'acces a un service selectionne dans un reseau local radio
WO2011015140A1 (fr) Procédé, système et appareil pour radiomessagerie de télécommunication mobile
WO2010081329A1 (fr) Procédé et système pour réguler des ressources de réseau pendant une procédure de migration de flux de services
WO2013017098A1 (fr) Procédé, dispositif et système pour l'accès d'un équipement utilisateur à un réseau fédérateur de transmission par paquets évolué
WO2009135371A1 (fr) Procédé de détermination de mode de connexion de réseau
WO2011015001A1 (fr) Procédé et système pour accéder, via un réseau local sans fil, à un réseau d’accès
WO2008009227A1 (fr) Procédé destiné à un terminal utilisateur accédant à un système de télécommunication, et système de télécommunication correspondant
WO2009046598A1 (fr) Procédé pour établir une porteuse dédiée pour un terminal utilisateur
WO2008154874A1 (fr) Procédé et système permettant d'établir un tunnel dans le réseau en évolution
WO2014040552A1 (fr) Procédé et système de notification d'informations de position dans un réseau d'accès
WO2010054560A1 (fr) Procédé et système de mise en œuvre d’un accès multiple
WO2013016967A1 (fr) Procédé et système d'accès, et point d'accès intelligent mobile
CN1845523B (zh) 互通无线局域网中实现服务质量协商的方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 07855908

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 07855908

Country of ref document: EP

Kind code of ref document: A1