March 2003

3GPP SA2

Slide 1

doc.: IEEE 802.11-03/209r0

Submission1

3GPP System – WLAN Interworking

Principles and Status

From 3GPP SA2

WWW.3GPP.ORG

Presented by Dr. Mike Ritter

CTO, Mobility Networks

March 2003

3GPP SA2

Slide 2

doc.: IEEE 802.11-03/209r0

Submission2

Background and Purpose

• Study on Interworking between 3GPP system and WLAN was initiated in service requirement group, SA1, during 2001

• Documented in Technical Report 22.934 approved in September 2002– High-level principles– different levels/scenarios of Interworking – and operational requirements for the different scenarios.

• The purpose of this presentation is to provide – Some insight into these scenarios – current status of the work in 3GPP as of February 2003– Initial thoughts in collaboration areas between IEEE and 3GPP

March 2003

3GPP SA2

Slide 3

doc.: IEEE 802.11-03/209r0

Submission3

Outline

• High-level principles

• Interworking scenarios

• Status of the Work

• Potential areas of collaboration

March 2003

3GPP SA2

Slide 4

doc.: IEEE 802.11-03/209r0

Submission4

High –level Principles• Functional split between WLAN 3GPP

system should be clearly specified

• Interworking between WLAN and 3GPP system should pose as little 3GPP specific requirements to WLAN systems as feasible

• Interworking means between WLAN access network and 3GPP system should be able to support many-to-many relationship between the two systems

• Intended to be generic for the identified WLAN technologies e.g. 802.11, Hiperlan 2, HisWAN

3GPP Home PLMN

WLAN B

Interworking Relationship

Interworking Relationship

WLAN A

3GPP Visited PLMN WLAN C

Roaming Relationship

Interworking Relationship

Interworking Relationship

UE

March 2003

3GPP SA2

Slide 5

doc.: IEEE 802.11-03/209r0

Submission5

Interworking scenarios - Concepts

• 6 Scenarios identified

• These represent steps in interworking WLAN and 3GPP networks

• Scenarios described by an incremental set of service and operational features

1: Common billing and Customer care

– No 3GPP specification work needed

2: 3GPP system based access control and charging

– IP access over WLAN for 3GPP subscribers

3: Access to 3GPP system PS based services

– e.g. Access to IMS, SMS, WAP, MMS from an Interworking WLAN

4: Service Continuity

– Non transparent service maintenance across WLAN and GPRS/UMTS access

5: Seamless service provision

– transparent service maintenance across WLAN and GPRS/UMTS access

6: Access to 3GPP CS Services

– No use cases have been identified

Concepts High level scenario descriptions

March 2003

3GPP SA2

Slide 6

doc.: IEEE 802.11-03/209r0

Submission6

Scenario 2 - 3GPP system based Access Control and Charging

• Authentication, authorisation and accounting are provided in line with that of the 3GPP network– consistent mechanism for granting access– leveraging existing 3GPP mechanisms (e.g. SIM)– facilitates consistent charging methodology

• Main features– Access Control and charging based on 3GPP control– Reuse UICC for authentication, i.e. SIM (EAP/SIM) or USIM (EAP/AKA)– Online and offline charging mechanisms (pre-pay and post-pay)– Roaming between interworking WLANs– Security of 3GPP system not compromised– Same level of security as for the access control part as for 3GPP networks– DIAMETER / RADIUS to be used for AAA– Simultaneous connections should not be precluded by the standards

March 2003

3GPP SA2

Slide 7

doc.: IEEE 802.11-03/209r0

Submission7

• To enable access to 3GPP system Packet Services through WLAN access technology – e.g. IP Multimedia Services (IMS), WAP, SMS, MBMS….

• Main features – Service invocation should be the same as for 3GPP radio access

networks– Cater for WLAN QoS (where supported)– Interoperability with 3GPP APN (Access Point Name)– Service level roaming, i.e. access home services from a visited

WLAN– Tunnelling to be used for carrying data from WLAN to 3GPP

home network

Scenario 3 - Access to 3GPP system PS based services

March 2003

3GPP SA2

Slide 8

doc.: IEEE 802.11-03/209r0

Submission8

Scenario 5 - Seamless services• To allow seamless handover between WLAN and 3GPP access

technologies– change of service shall be no greater than that which may occur during

intra-3GPP system handover– i.e. it shall not be noticeable to the user

Scenario 4 - Service Continuity

To allow the terminal to move between WLAN and 3GPP access technologies

continuity of access to the same servicesno need for the user/UE to re-establish the servicethe change of access may be noticeable to the user

March 2003

3GPP SA2

Slide 9

doc.: IEEE 802.11-03/209r0

Submission9

3GPP proposals stage 2 proposals (R6)

architecture (as of Jan 2003)

3GPP Home Network

3GPP Visited NW Intranet /Internet

HSS

OCS

C Gw

CCF

3GPPAAAproxy

Wr/ Wb

Wx

Wo

Wf

WLAN Access Network(with or without anintermediate network

WLAN

UE

Wr/Wb

Wf

HLR

D’/Gr’

Bordergateway

(Opt)Wn

Packetdata

gateway

Wi

Wi

Wn

Packetdata

gateway

3GPPAAAServer

Wi - Interface to public data network

Wn - Tunnelled data through intermediate networks

Wr - Wireless LAN authentication (i/f to 3GPP)

Wb - Wireless LAN charging (i/f to 3GPP)

Wx - Authentication (HSS)

D’/Gr’ - Authentication (HLR)

Wb - Wireless LAN charging

Wo - On-line charging system

Wf - Charging gateway function

Packetdata

network

Packetdata

network

C Gw

CCF

March 2003

3GPP SA2

Slide 10

doc.: IEEE 802.11-03/209r0

Submission10

Status in 3GPP • SA1 – Service Requirements

– Defines the relevant service requirement (work in progress)

– TR 21.905 (vocabulary), TR 22.934 (feasibility), TS 22.101 (service principles), TS 22.129 (handover), TS 22.105(Service capabilities), TS 22.133

• SA2 – Systems and Architecture– Release 6 (standards frozen mid-2003)

• addresses scenario 2 and scenario 3

• limitation for scenario 3 because of time constraints

• specified in 3GPP draft TS 23.234

– Release 7 (standards frozen mid/end 2004)• addresses scenarios 4 and 5

• mobility scenarios discussed in draft TR 23.934

• possible solution involves use of mobile IP

• location of home agent and address assignment to be resolved

March 2003

3GPP SA2

Slide 11

doc.: IEEE 802.11-03/209r0

Submission11

Status in 3GPP –Continued

• SA3 - Security– Specifies WLAN / 3GPP Interworking security requirements (work in progress)– Some outstanding issues with regards to protecting user identity– Specification in draft TS 33.234

• SA5 - Telecom management– Specifies charging related interfaces/architecture (work in progress)– Related specifications in TS 32.200 series

• CN groups (core network)– Protocol definition – CN4 will have the primary responsibility (work not yet started)

March 2003

3GPP SA2

Slide 12

doc.: IEEE 802.11-03/209r0

Submission12

Potential areas of collaboration with IETF

• EAP (SIM/AKA)– identified in the IETF dependencies list

• AAA– Diameter EAP application already identified in the IETF

dependencies list

• Mobile IP– Discussion on mobility support in scenario 4 and 5– use of MIPv6– interworking IPv4 / IPv6 (3GPP IMS is IPv6)

March 2003

3GPP SA2

Slide 13

doc.: IEEE 802.11-03/209r0

Submission13

Functionalities needed in WLAN

• Ability to authenticate and authorize (using RADIUS / Diameter)

• Ability of WLAN to filter outbound traffic based on destination

• Ability to terminate network based tunnel• Ability to apply SBLP / QoS• Ability to collect and provide charging

information (using RADIUS / Diameter)

March 2003

3GPP SA2

Slide 14

doc.: IEEE 802.11-03/209r0

Submission14

Functionalities needed in WLAN

terminal Authentication

Authorization

Charging

QoS / SBLP

Wr

Wb

TBD Interface

Tunnel Termination

Wn

March 2003

3GPP SA2

Slide 15

doc.: IEEE 802.11-03/209r0

Submission15

Areas of Concern

• Consistency of user experience in WLANs– ability of WLAN to provide service continuity

across multiple access points for various types of real time and non real time services

March 2003

3GPP SA2

Slide 16

doc.: IEEE 802.11-03/209r0

Submission16

Thank you