Challenges of Global Roaming

Transcription

1 Challenges of Global Roaming Syed S. Husain WP1/SSG Chair Motorola, USA Systems Rio de Janeiro, Brazil 1

2 Outline Global roaming - Definition & Requirements Technical Areas of Concern Ongoing Standards Efforts An Assessment Summary 2

3 Global Roaming Definition Global Roaming: Offer seamless services by hiding network and radio access differences from the users. Note: Global Roaming does not only mean that one has to travel far. Within a small geographic area global roaming requirements also apply. 3

4 Global Roaming Requirements Travel Service High BW Wired Service Service WLAN Interactive Game Cellular Network Cellular Network Office Highway Convention Center Train User 4

5 Global roaming Requirements Multi-mode user equipment to support diverse access technologies Multi-homed user equipment to support multiple IP addresses Support of Enhanced services VHE/IN, UPT, IP Multimedia Mobility management across multiple service provider domains Location management Service portability Authentication, Authorization and Accounting QoS / bandwidth management (wired to wireless) Interoperability using single subscription 5

6 Diverse Wireless Access Technologies ITU Approved 3G/IMT-2000 Radio Standards: CDMA Multi-carrier (cdma2000) 1xEV-DO CDMA TDD (Universal Terrestrial Radio Access) CDMA TDD (TD- SCDMA) W-CDMA (UTRA FDD) UWC-136 (FDD) Digital Enhanced Cordless Telecommunications (DECT) WLAN IEEE Series HIPERLAN Bluetooth 6

7 Evolution of Mobile Services (IP Multimedia Services) Information and Content (Non-Voice) CONTENT CONNECTIVITY MOBILITY PERSONAL PEOPLE CONNECTIVITY LOCATION Direct Link to a Person Always on, IP-based Knowledge of Location Internet Intranet / Extranet Customized Infotainment Multimedia Messaging Service Locationbased Services 7

8 Evolution of Mobile Services (Multiple Service Providers) Supporting Networks Service Platforms 3rd Party Service Platforms External UE/CPE Local Access Network Core/ Transport/ Backbone Network 8

9 Multiple Dimensions of Mobility -Low latency & low packet loss handoff -Handoff between heterogeneous networks -Paging to locate device -AAA -Path optimization Access Router Internet IP Multimedia Domain Context Transfer Access Router Access Network 1 Access Network 2 Macro Mobility Micro-mobility Examples of Access Technologies: 3GPP, 3GPP2, , Bluetooth, fixed IP Seamless mobility New Note: This could use mobility mechanisms as defined in IETF 9

10 Security Challenges Case 1: Roaming between same network type, same generation Example, ANSI-41 (2G) to ANSI-41 (2G) A derivative of user secret (SSD) is passed between networks Case 2: Roaming between same network type, different generations Example, UMTS (3G) to GSM (2G) Backwards compatible if security mechanism is unchanged If security mechanism is enhanced, translation is TBD Case 3: Roaming between dissimilar networks Example, ANSI-95 to GSM Either assign a dual subscription to the user, or Translate security parameters between networks Case 4: Roaming between cellular-based networks and IP-based networks Example, WLAN to UMTS Methods are being studied 10

11 Security Tiers IP Multimedia Services and Applications IP Multimedia Subsystem Access IP Service Access IP-Access Network IMS-Access Network Internet Wireless Access Core Network Radio-Access Network Core Network 11

12 Interoperability Services Plane Voice Services Multimedia Services Transport Plane IPv4/IPv6 transition SCTP to TCP/IP MTP to M3UA MTP/SCCP to SUA Control Plane Session Control (e.g., SIP, H.323, ISUP, BICC, PSTN) Mobility Management (e.g., ANSI 41, MAP, Mobile IP) 12

13 Overview of Standards Development Technical Areas ITU-T 3GPP 3GPP2 IETF Services Plane SG2, SSG SA1, SA2, CN1, CN5 TSG-N SIMPLE, IMPP Transport Plane SSG, SG11, SG13 SA2, CN3 TSG-A ROHC, DIFFSERV Control Plane SSG, SG13 SA2, CN1, CN4 TSG-N, TSG-P SIP, MMUSIC, IPTEL Mobility Mgmt SSG, SG11 SA2, CN1, CN4 TSG-P, TSG-N MOBILEIP, SEAMOBY Security SG7, SSG SA3, T3 TSG-S WG4, TSG-P, AHAG AAA, RADIUS, IPSec, AVT Interoperability SSG CN3 TSG-N PINT Codec SA4 TSG-C UIM (Smart Card) T3 TSG-S 13

14 An Assessment (Convergence Opportunities) Common Network Layer Common Physical Layer All Services Transport IP AT/ PPP SONET/SDH Fiber/WDM Common Services API 14

15 An Assessment (Gap Analysis and Technological Barriers) Radio system compatibility UIM portability Inter-system operability Service portability Billing/charging Numbering plans Authentication & privacy 15

16 Conclusions Global roaming is a key requirement for IMT-2000 and beyond systems Ease of Interoperability between different networks is demanded by users Global UIM based on a common UIM-MT interface is needed Standards are needed to address critical issues of global roaming 16