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Integration of WLAN and Wide Area Mobile Networks. Author: Jamshid Khun-Jush Ericsson Research - Corporate Unit, Germany jamshid.khun-jush@eed.ericsson.se. Content. Wireless Data Solutions WLAN Usage Scenarios Why WLAN - GPRS/3G Interworking Interworking Level/Architecture Options
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Integration of WLAN and Wide Area Mobile Networks Author: Jamshid Khun-Jush Ericsson Research - Corporate Unit, Germany jamshid.khun-jush@eed.ericsson.se
Content • Wireless Data Solutions • WLAN Usage Scenarios • Why WLAN - GPRS/3G Interworking • Interworking Level/Architecture Options • Basics • Pros & Cons • Interworking Service Aspects and Security Challenges • Standardization
2nd Generation Cellular Complementary Wireless “Data” Solutions Wide Area Mobile Network (WAMN) Wireless Personal Area Network (WPAN) Wireless Local Area Network (WLAN) 3rd Generation cellular Mobility WLAN H2 / 11a / HiSWAN Bluetooth 11b 0,1 1 10 100 Mbps User Bitrates
Internet IWU SGSN GGSN Home/SOHO Usage Scenarios Mobile Operator WLAN WLAN WAMN WLAN Enterprise WLAN Wireless ISP Ethernet AP - AP Mobility (link level) WLAN WLAN
Why WLAN – GPRS/3G interworking? • Requirements: • needs for “global” roaming and mobility • needs for high capacity - especially at hot spots • Market: • Users of PC-type terminals as a part of the 3G operator subscriber base • 3G packet service expansion with small investment costs • New services and applications • Increased overall customer value Increased revenue stream
Why Standardized Integration? • More flexible and wider deployment • Larger market for WLAN • Exploiting world wide roaming infrastructure • More advanced interworking solutions • Support for cellular services on the WLAN segment • Platform for new service concepts
How a Single Global Interworking Standard? • WLAN – a family of technologies • Interesting in an interworking perspective • IEEE 802.11 • MMAC HiSWANa • HiperLAN2 • Challenge • A multiparty standardization issue • Remedy • Collaboration on standard harmonization • HiperLAN2- 3G Interworking spec. & HiSWANa network spec. • 3GPP feasibility study on a generic solution • Generic solution – needs wider collaboration • HiperLAN2 – 3GPP has initiated a dialogue • ETSI BRAN is in a position to play an important role • Number of collaboration points with all parties in discussion
Interworking Level/Architecture • Two basic approaches: • tight interworking (Iu-based) • loose interworking (IP-based) • Results in different characteristics and time lines, different pros & cons • Both alternatives may lead to full support of all requirements in a long term
GERAN BS BSC BS Tight Interworking: Basic Architecture Iu/ Gb 3GPP UTRAN based Node B Core GGSN/FA Network SGSN RNC ISP / Gn Iu Corporate / HSS AuC Service Gr Network HLR Gi Node B HA AAA Iuhl2 WRAN AP Signalling AP L2/ L3 IWU Switch Signalling and User data SGSN: Serving GPRS Support NodeGGSN: Gateway GSN AAA: Authentication, Authorisation and Accounting HSS Roaming partner
GGSN SGSN SGSN SGSN Iuhl2 Iu Iurhl2 Iurhl2/utr IWU IWU RNC Iubhl2 Iubhl2 Iub Node B Node B AP AP AP AP Uuhl2 Uu Dual mode Mobile Tight Interworking: Features and Elements • Iubhl2 interface for WRAN connection to the 3G core Network • Iuhl2 very similar to Iu • Iubhl2 and Uuhl2 are WLAN specific • Iurhl2 can be WLAN specific • Reuse of 3G mechanisms for mobility, QoS and security • WLAN-3G interworking unit (IWU) needed
Loose Interworking: Basic Architecture GERAN BS BSC BS 3GPP Iu/Gb UTRAN based Node B Core GGSN/FA Network SGSN RNC ISP / Gn Corporate/ Iu HSS Service AuC Gr Network HLR Gi Node B HA AAA AAA WRAN (Diameter) Wx IP AP Signalling WSN/FA AP L2/ L3 Switch Signalling and User data AAA Roaming partner
Loose Interworking: Features and Elements • “The rest of WLAN network” • IP router w/ foreign agent • Wx is the interface between the WLAN Interworking architecture and 3G • 3G integration by IETF protocols, e.g. Authentication by AAA protocols. • Home AAA server (AAAH) is a part of the HSS • Local AAA server (AAAL) is part of the WLAN interworking architecture. • Different user identities linked by HSS • unified treatment of a user wrt billing, service network functionality etc. AP Router w/ The rest of foreign IP network WLAN network agent AP AAAL HSS MT AAAH Wx with (U )SIM HLR Gr GGSN w/ RNC Node B SGSN foreign agent
Tight Interworking: Pros & Cons Pros • Fully integrated mobility management • high performance handover! • Full service & thus QoS mapping possible • Prospects for future development • No need for additional AAA functionality Cons • Will lead to a significant standardization effort! • May take some time to be deployed
Loose Interworking: Pros & Cons Pros • Adapts well to IP protocol architecture • Requires small standardization efforts in the short term • Cost for deployment and maintenance • Fast time to market • Reduced business risk Cons • Unclear service & QoS mapping • Handover performance MAY BE unsatisfactory Recommendation Go for Loose Interworking
Service Aspects in an Interworking Context • Numerous additional service concepts • A singular point of contact for the wireless user (administrational service gain) • Easier and more efficient corporate access • 3G services over WLAN access network e.g. • IP Multimedia Subsystem (IMS) • Location Based Services (LBS ) • WLAN • A Pure data network • Limitation of service offering? • Fundamental for the realization of a solution within a reasonable time • Voice service • Considered unimportant from the WLAN Side
3G Services (IMS.LBS..) Voice CS-services Voice CS-services H2/11a/HiSWANa H2/11a/HiSWANa 3G 3G Interworking Scenario • Voice service is a part of the interworking concept served by the public cellular access WLAN Services WLAN Services 3G Services (IMS.LBS..) A micro cellular network under a 3G umbrella cell
Security - Challenges • Security must be preserved within the WLAN domain as it is in the 3G network • Both for User and for Network • An obvious challenge for WLAN community • Level of protection differs in all WLAN systems • Integrity • Confidentiality • Denial of service • … • Solutions for obtaining a secure authentication in an interworking scenario Robert`s presentation
Standardization • BRAN finalized and published H2-3G Interworking requirements document • Collaboration between BRAN and 3GPP underway • 3GPP started a feasibility study on WLAN-UMTS interworking • Objective: a generic solution for all WLAN standards • Required: a wide collaboration amongst WLAN standards bodies • BRAN and Japanese MMAC collaboration started • BRAN seeks collaboration with IEEE802.11 on this issue