US0074l7970B2
`
`(12; United States Patent
`Shaheen
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 7,417,970 B2
`Aug. 26, 2008
`
`(54) CONFIGURING AN INTERWORKING
`WIRELESS LOCAL AREA NETWORK USER
`EQUIPMENT TO ACCESS A 3GPP SYSTEM
`
`(75)
`
`Inventor: Kamel M. Shaheen, King of Prussia, PA
`(US)
`
`(73) Assignee:
`
`InterDigital Technology Corporation,
`Wilmington, DE (US)
`
`( * ) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 421 days.
`
`(21) Appl.No.: 11/096,141
`
`(22)
`
`Filed:
`
`Mar. 31, 2005
`
`(65)
`
`Prior Publication Data
`
`US 2005/0271013 A1
`
`Dec. 8, 2005
`
`Related U.S. Application Data
`
`2004/0097232 A1
`2005/0025164 A1 *
`2006/0050667 A1 *
`2006/0165027 A1 *
`2006/0209768 A1 *
`
`5/2004 Haverinen
`......... .. 370/401
`2/2005 Kavanagh et al.
`3/2006 Verma et al.
`.............. .. 370/338
`7/2006 Heden ...................... .. 370/328
`9/2006 Yan et al.
`.................. .. 370/338
`
`FOREIGN PATENT DOCUMENTS
`
`WO
`W0
`
`03/105493
`04/006447
`
`12/2003
`I/2004
`
`OTHER PUBLICATIONS
`
`3GPP TS 23.234, “Technical Specification Group Services and Sys-
`tem Aspects; 3GPP System to Wireless Local Area Network
`(WLAN) Interworking; System Description”; 3rd Generation Part-
`nership Project; V6.0.0; Release 6; Mar. 2004; pp. 1-83.
`Third Generation Partnership Project, “Technical Specification
`Group Services and System Aspects; 3GPP system to Wireless Local
`Area Network (WLAN) interworking; System description (Release
`6),” 3GPP TS 23.234 V6.4.0 (Mar. 2005).
`
`* cited by examiner
`
`Primary Examiner—Barry W Taylor
`(74) Attorney, Agent, or Firm—Volpe and Koenig, P.C.
`
`(60) Provisional application No. 60/576,698, filed on Jun.
`2, 2004.
`
`(57)
`
`ABSTRACT
`
`(51)
`
`Int. Cl.
`(2006.01)
`H04Q 7/00
`(2006.01)
`H04Q 7/24
`(2006.01)
`H04L 1/14
`(2006.01)
`H04L 12/66
`(52) U.S. Cl.
`..................... .. 370/331; 370/338; 370/231;
`370/329; 370/352; 370/356
`(58) Field of Classification Search ............... .. 370/331,
`370/338, 231, 329, 352, 356
`See application file for complete search history.
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`A method for configuring a11 interworking wireless local area
`network (I-WLAN) user equipment (UE) to access a third
`generation partnership project (3GPP) system begins by ini-
`tiating a connection from a UE to the 3GPP system, the
`initiating step including indicating the UE’s interworking
`protocol capabilities.Authentication and authorization of the
`UE connection by the WLAN to the 3GPP system is
`requested, including indicating the UE’s interworking proto-
`col capabilities. The 3GPP system determines whether to
`accept the UE’ s request, including examining the UE’ s inter-
`working protocol capabilities. An interworking protocol is
`instantiated at the UE, whereby the UE is configured to inter-
`work with the 3GPP system.
`
`2004/0066769 A1 *
`
`4/2004 Ahmavaara et al.
`
`....... .. 370/338
`
`9 Claims, 3 Drawing Sheets
`
`3GPP SYSTEM
`AAA/HLR/AUTHENTICATION CENTER
`
`
`INTERWORKING AGREEMENT
`UE INITIATES CONNECTION
`TO 3GPP INDICATING ITS
`
`INTERWORKING PROTOCOL
`CAPABILITIES
`
`AUTHENTICATION/AUTHORIZATION
`REQUEST PROCEDURES
`
`INDICATING UE
`INTERWORKING CAPABILITIES
`
`
`
`
`
`APPLE 1011
`
`
`
`
`AUTHENTICATION/AUTHORIZATION
`ACCEPT PROCEDURES
`INCLUDING
`INTERWORKING CONFIGURATION
`
`THE UE INSTANTIATES THE PREFERRED
`
`INTERWORKING PROTOCOL CONFIGURATION
`TUNNEL ESTABLISHMENT
`PROCEDURES:
`END TO END
`OR
`GTP BASED SWITCHED TUNNEL
`
`
`
`APPLE 1011
`
`1
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`
`US 7,417,970 B2
`
`1
`CONFIGURING AN INTERWORKING
`WIRELESS LOCAL AREA NETWORK USER
`EQUIPMENT TO ACCESS A 3GPP SYSTEM
`
`CROSS REFERENCE TO RELATED
`APPLICATIONS
`
`This application claims the benefit of U.S. Provisional
`Application Ser. No. 60/576,698, filed Jun. 2, 2004, which is
`incorporated by reference as if fully set forth herein.
`
`FIELD OF INVENTION
`
`The present invention relates to configuring an interwork-
`ing wireless local area network (I-WLAN) user equipment
`(UE). More particularly, the present invention relates to a
`method and an apparatus for configuring an I-WLAN UE to
`access a 3GPP based packet switched (PS) system via an
`I-WLAN.
`
`BACKGROUND
`
`Currently, there are several WLAN interworking schemes
`with 3GPP systems (UMTS). In one scheme, the end to end
`tunnel approach, the UE establishes a tunnel with the 3GPP
`based system ending at a Packet Data Gateway (PDG). The
`tunnel goes through a WLAN Gateway (WAG) without being
`terminated at the WAG (and is transparent to the WAG). This
`scheme has been standardized as a preferred configuration
`that all I-WLAN UEs must implement.
`The second scheme is the switched tunneling approach,
`which involves establishing two turmels between the PDG
`and the UE at the WAG. The first turmel between the WAG and
`
`the PDG uses existing 3GPP based general packet radio ser-
`vice (GPRS) tunneling protocol (GTP) and the second tunnel
`follows the normal IP tunneling protocol.
`A third interworking scheme is the Generic Access
`approach, which involves the tunneling of the trafiic from the
`3GPP system to the 3GPP-based UE via the I-WLAN. In this
`scheme, the I-WLAN acts as a pseudo 3GPP Node B inter-
`working with the 3GPP system at the radio access network
`(RAN) level. The traffic passes through the I-WLAN access
`point (AP) to the I-WLAN UE which decodes the trafiic back
`to 3GPP formats and passes it to the 3GPP-based terminal.
`The existence of these schemes creates potential conflicts
`regarding the preferred mode of operation. For example: 1)
`the UE is capable of supporting all of the configurations, but
`does not know what configuration is supported by the net-
`work; 2) the UE is only capable of supporting one scheme (for
`example, the end to end tunneling architecture), but the net-
`work is configured to use another interworking scheme (for
`example, the switched tunneling solution); 3) the UE and the
`network are capable of supporting all schemes, but currently
`there is no way to communicate the preferred mode of opera-
`tion between the two sides.
`
`These schemes are different in terms of operational proto-
`cols and parameters. The end result is that multiple tech-
`niques or schemes may be used to support I-WLAN inter-
`working with 3GPP systems (cellular in general), which
`mandates that the UE should either support all of these
`schemes or some mechanism to decide which scheme is being
`supported at the infrastructure level and then configures the
`UE to operate in accordance with the supported scheme.
`During the set-up, there should be procedures to inform the
`UE of the network configuration, such that it uses the right
`interworking protocol.
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`SUMMARY
`
`According to the present invention, a UE initiates connec-
`tion to a 3GPP system via an I-WLAN while indicating the
`UE’s interworking configuration capabilities. An I-WLAN
`indicates the UE’s interworking configuration capabilities to
`the 3GPP system while requesting authentication and autho-
`rization. The 3GPP system informs the UE regarding the use
`of interworking configurations. The UE chooses a preferred
`interworking configuration of the 3GPP system.
`A method for configuring an interworking wireless local
`area network (I-WLAN) user equipment (UE) to access a
`third generation partnership project (3GPP) system begins by
`initiating a connection from a UE to the 3GPP system, the
`initiating step including indicating the UE’s interworking
`protocol capabilities. Authentication and authorization of the
`UE connection by the WLAN to the 3GPP system is
`requested, including indicating the UE’s interworking proto-
`col capabilities. The 3GPP system determines whether to
`accept the UE’ s request, including examining the UE’ s inter-
`working protocol capabilities. An interworking protocol is
`instantiated at the UE, whereby the UE is configured to inter-
`work with the 3GPP system.
`A system for configuring an interworking wireless local
`area network (I-WLAN) user equipment (UE) to access a
`third generationpartnership project (3 GPP) system includes a
`UE, a WLAN, and a 3GPP system. The UE includes initiating
`means for initiating a connection request to the 3GPP system;
`first indicating means for indicating the interworking proto-
`col capabilities of the UE to the WLAN; and instantiating
`means for instantiating a selected interworking protocol. The
`WLAN includes second indicating means for indicating the
`interworking protocol capabilities of the UE to the 3GPP
`system. The 3GPP system includes first determining means
`for determining whether to accept a connection request from
`the UE; second determining means for determining the inter-
`working protocol capabilities ofthe UE and the 3GPP system;
`and selecting means for selecting an interworking protocol to
`be used between the UE and the WLAN.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`A more detailed understanding ofthe invention may be had
`from the following description of a preferred embodiment,
`given by way ofexample, and to be understood in conjunction
`with the accompanying drawings, wherein:
`FIG. 1 is a block diagram oftwo interworking protocols by
`which an I-WLAN UE can access a 3GPP system;
`FIG. 2 is a diagram of a third interworking scheme by
`which an I-WLAN UE can access a 3GPP system; and
`FIG. 3 is a flow diagram a method for configuring an
`I-WLAN UE to access a 3GPP system in accordance with the
`present invention.
`
`DETAILED DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`
`Hereafier, a user equipment (UE) includes, but is not lim-
`ited to, a wireless transmit/receive unit (WTRU), a mobile
`station, a fixed or mobile subscriber unit, a pager, or any other
`type ofdevice capable of operating in a wireless environment.
`When referred to hereafter, a base station includes, but is not
`limited to, a Node B, a site controller, an access point, or any
`other type of interfacing device in a wireless environment.
`FIG. 1 is a block diagram of two systems using interwork-
`ing protocols by which an I-WLAN UE can access a cellular
`system, such as a 3GPP system. Although the following is
`
`5
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`

`
`US 7,417,970 B2
`
`3
`described in conjunction with a 3GPP system, it can also be
`used with other cellular systems, such as 3GPP2, GPRS/
`EDGE, etc. A system 100 utilizing the end to end tunnel
`protocol includes a 3GPP system packet data gateway (PDG)
`102, which provides the connection between a 3GPP network
`and a WLAN. The PDG 102 communicates with a first
`WLAN 104 via an end to end IP tunnel 106. The tuimel 106
`
`is created through a WLAN gateway (WAG) 108, which is the
`interface between the WLAN 104 and a 3GPP network. A
`WLAN UE 110 communicates with the 3GPP network
`
`through the WLAN 104, the tunnel 106, and the PDG 102. In
`the system 100, the tunnel 106 extends from the PDG 102
`down to the WLAN UE 110.
`
`A system 120 utilizes the switched tunneling protocol
`(general packet radio service (GPRS) tunneling protocol
`(GTP)). The system 120 includes a 3GPP system gateway
`GPRS support node (GGSN) 122 that communicates via a
`GTP tunnel 124 with a WAG 126. The WAG 126 communi-
`cates via an IP tuimel 128 with a second WLAN 130. A
`WLAN UE 132 communicates with the 3GPP network
`
`through the WLAN 130, the IP tunnel 128, the WAG 126, the
`GTPtu1mel 124, and the GGSN 122. The system 120 utilizes
`two tunnels: the GTP tunnel 124 between the GGSN 122 and
`the WAG 126 and the IP tunnel 128 between the WAG 126 and
`the WLAN UE 132. It is noted that in this instance, the use of
`the PDF and the GGSN are interchangeable.
`FIG. 2 is a diagram of the Generic Access interworking
`protocol 200. FIG. 2 shows the overall architecture for a
`3GPP system where a WLAN 202 is connected directly to a
`serving GPRS support node (SGSN) 204. The WLANAP acts
`as an alternative RAN, in parallel with a GSM EDGE radio
`access network (GERAN) 206 and a UMTS terrestrial radio
`access network (UTRAN) 208. The WLAN 202 may also be
`connected to a media gateway (MGW) 210 where the IP-
`based trafiic is to be provided. The 3GPP traffic coming out of
`the SGSN 204 and directed toward the WLAN 202 is tuimeled
`
`using an IP tunnel and is transported over the WLAN 202 to
`a WLAN UE. The WLAN UE then de-turmels the IP data (i.e.,
`3GPP trafiic) and forwards it towards the 3GPP-based UE for
`processing. The WLAN 202 acts as a pipe for the 3GPP
`traffic.
`
`Other interworking scenarios between a 3GPP system and
`a WLAN UE are also possible. The systems 100, 120, and 200
`are exemplary, and other interworking scenarios can be used
`in the context of the present invention.
`FIG. 3 is a flow diagram of a method 300 for configuring an
`I-WLAN UE to access a 3GPP system in accordance with the
`present invention. The method 300 uses the WLAN UE 302,
`a WLAN 304, and the 3GPP system 306 which includes an
`authentication, authorization, and accounting (AAA) server
`and a home location register (HI R).
`The WLAN 304 a11d the 3GPP system 306 exchange an
`interworking agreement (step 310). The interworking agree-
`ment is a service profile of the WLAN 304 and the 3GPP
`system 306, and specifies parameters such as the level of
`interworking, whether the user is allowed to access certain
`services, the bit rate, etc.
`The UE 302 initiates a connection to the 3GPP system 306
`and in the connection signaling indicates its interworking
`protocol capabilities (step 312). The WLAN 304 forwards the
`authentication and authorization request procedures to the
`3GPP system 306, indicating the UE’s interworking protocol
`capabilities (step 314).
`The 3GPP system 306 performs authentication and autho-
`rization acceptance procedures,
`including identifying the
`interworking configuration supported by the 3GPP system
`306 to the WLAN 304 and the UE 302 (step 316). The 3GPP
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`system 306 indicates to the UE 302 the supported interwork-
`ing protocol and directs the UE 302 to use it.
`The UE 302 instantiates the preferred interworking proto-
`col configuration (step 318). If the UE 302 can support both
`configurations, the 3GPP system 306 directs the UE 302 to
`use its preferred mode of operation. If the UE 302 is capable
`only of supporting the end to end tunneling architecture and
`the 3GPP system 306 can support both modes of operation,
`then the 3GPP system 306 may accept the UE’s attachment
`request and provides the services using the end to end tu1mel-
`ing solution. If the UE 302 and 3GPP system 306 do not
`support the same configuration, then the 3GPP system 306
`must reject the UE’s attachment request and indicate to the
`UE 302 that the configuration request during the attachment
`procedure (step 312) is not supported.
`The WLAN 304 initiates tunnel establishment procedures
`(either end to end tunneling or GTP based switched tunnel-
`ing) with the 3GPP system (step 320).
`The method 300 allows for the exchange of information
`during attachment of the UE 302 regarding which type of
`tunneling to expect. Because each type of tunneling has dif-
`ferent set-up procedures, the exchange of information sim-
`plifies the interworking set-up.
`Although the features and elements of the present inven-
`tion are described in the preferred embodiments in particular
`combinations, each feature or element can be used alone
`(without the other features and elements of the preferred
`embodiments) or in various combinations with or without
`other features and elements of the present invention.
`
`What is claimed is:
`
`1. A method for configuring a user equipment (UE) to
`access a third generationpaitnership project (3GPP) network,
`comprising:
`initiating a connection from the UE to the 3GPP network,
`including indicating the UE’s interworking protocol
`capabilities;
`requesting authentication and authorization ofthe UE con-
`nection to the 3GPP network, including indicating the
`UE’s interworking protocol capabilities;
`determining whether to accept the UE’ s request, including
`examining the UE’s interworking protocol capabilities;
`and
`
`instantiating an interworking protocol, whereby the UE is
`configured to interwork with the 3GPP network,
`wherein the interworking protocol is selected from the
`group consisting of: end to end tunneling, switched tun-
`neling, and generic access.
`2. The method according to claim 1, wherein if the UE
`supports all protocols, then said instantiating includes the
`3GPP network directing the UE to use the 3GPP network’s
`preferred protocol.
`3. The method according to claim 1, wherein if the UE
`supports one protocol, then said instantiating includes using
`the protocol supported by the UE.
`4. The method according to claim 1, wherein if the UE and
`the 3GPP network do not support the same protocol, then said
`determining includes the 3GPP network rejecting the UE’s
`connection request.
`5. A user equipment (UE), comprising:
`an initiating device configured to initiate a connection
`request to a third generation partnership project (3 GPP)
`network;
`
`6
`
`

`
`US 7,417,970 B2
`
`5
`an indicating device configured to indicate interworking
`protocol capabilities of the UE to an interworking wire-
`less local area network (I-WLAN) wherein the I-WLAN
`indicates the interworking protocol capabilities of the
`UE to the 3GPP network; and
`an instantiating device configured to instantiate a selected
`interworking protocol,
`wherein the interworking protocol is selected from the
`group consisting of:
`end to end tunneling, switched tunneling, and generic access.
`6. The UE according to claim 5, wherein said instantiating
`device instantiates an interworking protocol selected by the
`3GPP network.
`
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`
`6
`7. The UE according to claim 6, wherein ifthe UE supports
`more than one interworking protocol, then said instantiating
`device instantiates an interworking protocol preferred by the
`3GPP network.
`8. The UE according to claim 6, wherein ifthe UE supports
`only one interworking protocol, then said instantiating device
`instantiates the interworking protocol supported by the UE.
`9. The UE according to claim 5, wherein if the UE and the
`3GPP network do not support the same interworking proto-
`col, then the 3GPP network rejects the connection request
`made by said initiating device.
`*
`*
`*
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`*
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`*
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`7