1. IEEE NJ Coast Section Seminar on Wireless LAN & IP Telephony Session W3 Toward 4G Networks Ramachandran Ramjee, Ph.D. ramjee@bell-labs.com http://www.bell-labs.com/~ramjee

2. Mar 27, 2002 2 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Wide-Area Wireless Standards Evolution 3G/ IMT-2000 Capable Existing Spectrum New Spectrum IS-95-A/ cdmaOne IS-95-A/ cdmaOne IS-95-B/ cdmaOne IS-95-B/ cdmaOne IS-136 TDMA IS-136 TDMA 136 HS EDGE 136 HS EDGE GSM GSM GPRS EDGE WCDMA cdma2000 1X (1.25 MHz) cdma2000 3X (5 MHz) HSCSD 1XEV DO: HDR (1.25 MHz) 2G“2.5G”1G Analog AMPS Analog AMPS TACS

3. Mar 27, 2002 3 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Other wireless standards  802.11/802.11b - 2-11 Mbps - uses 2.4GHz spectrum  802.11a - 54 Mbps - Orthogonal Frequency Division Multiplexing (OFDM)  HiperLan2 - 50Mbps - local-area networks - uses 5GHz spectrum  Bluetooth - 720 kbps - very limited range using 2.4GHz spectrum  ARDIS - 19.2 Kbps - IBM/Motorola - slotted CSMA  MOBITEX - 9.6 Kbps - RAM mobile-slotted CSMA  CDPD - 19.2 Kbps - DSMA/CD using AMPS  Metricom - Frequency Hopped SS - 28.8 Kbps, 128 kbps upgrade - uses the ISM 900 Mhz band  iDEN - 20kbps - uses Mobile IP, supports WAP  DECT/CT2 - cordless, low-mobility - 32kbps - FDMA/TDMA  PHS - cordless system for microcell/indoor use, Japan - 128 Kbps - TDMA  iMode - 9.6 Kbps - packet data service, currently uses PDC  WAP - Wireless Application Protocol - currently circuit-switched data

4. Mar 27, 2002 4 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Observations  The ‘G’ in #G stands for Generation and typically refers to the generation of wide-area wireless network’s air interface  While the 4G air interface has not been standardized yet, a plethora of wireless standards are prevalent and will continue to co-exist  Dominant among these are CDMA2000, WCDMA, and 802.11- based systems  Today, each of these air interfaces has its own network architecture standards though the network provides similar functionality of mobility and location management *A unified network architecture based on IP that provides a common mobility and location management mechanism can serve as the 4G network of the future while different air interfaces simply plug into this network

5. Mar 27, 2002 5 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Outline  Motivation  IP Mobility –Macro-mobility: Mobile IP –Micro-mobility: HAWAII  IP Paging –HA/FA paging –Domain paging  Interworking of Wireless LANs with 3G Networks

6. Mar 27, 2002 6 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Motivation: Why IP?  Migration of wireless access networks to IP allows – Support for anticipated growth of the wireless Internet access merging of services for wireline and wireless networks merging of wireless voice and data networks – Reduced product and operational costs of IP infrastructure availability of “commodity” hardware, software, and services increased efficiency of packet-based networks for combining voice and data

7. Mar 27, 2002 7 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Industry Directions for Wireless Networking  Cellular Telecom Approach – Efforts to define wireless data networking standard (General Packet Radio Service/GPRS, UMTS) begin before full impact of Internet explosion is felt  Internet-Based Approach – Use Internet standards for networking and mobility with extensions to inter-operate and support cellular air interfaces (e.g., GPRS, CDMA) GPRS/UMTS standards begin 199019952002 153M Internet Users 1998 3M Internet Users 1994 1992 FPLMTS standards begin 1st UMTS customers

8. Mar 27, 2002 8 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Clash of models  Telecom/cellular model Approach: Extend current wireless circuit-based infrastructure to support wireless internet data – Flexibility at the cost of complexity and efficiency (e.g. X.25 support in GPRS, PPP support in CDMA) + Rich functionality through experience (e.g., paging, micro- mobility)  Internet model Approach: Extend current internet data-based infrastructure to support wireless internet data + Simplicity using IP (support other protocols, e.g. X.25, through tunneling if necessary) – Missing functionality (e.g., paging, micro-mobility)

9. Mar 27, 2002 9 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Emerging Mobile Packet Networks: GPRS and UMTS  Compatible with cellular telecom networks + may be deployed leveraging existing infrastructure – requires separate advances from the Internet  Specialized nodes manage mobility and forward packets + requires no changes to fixed hosts or intermediate routers – results in tunneling and triangular routing – special failure recovery mechanisms needed  Inter-SGSN handoffs always managed by GGSN – high update overhead – slow handoffs Intranet MD SGSN GGSN Host Regular routing Tunneled packets using GTP Internet SGSN Radio Access Networks

10. Mar 27, 2002 10 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Emerging Mobile Packet Networks: CDMA2000 and 802.11 (Mobile IPv4)  Compatible with regular IP networks and hosts + most Internet advances apply  Specialized agents manage mobility and forward packets + requires no changes to fixed hosts or routers – results in tunneling and triangular routing – special failure recovery mechanisms needed  Handoffs always managed by Home Agent – high update overhead – slow handoffs MD FA HA Host Internet Regular routing Tunneled packets using Mobile IP FA Radio Access Networks

11. Mar 27, 2002 11 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Trends  Local and Wide-area wireless data networks – high and low mobility users  IP functionality in access network elements including base stations – homogeneous IP-based access network  Diverse applications – quality of service support necessary * Mobility has to be processed locally Trends

12. Mar 27, 2002 12 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Micro-mobility: Design Goals  Scalability – process updates locally  Limit disruption – forward packets if necessary  Efficiency – avoid tunneling where possible  Quality of Service (QoS) support – local restoration of reservations  Reliability – leverage fault detection mechanisms in routing protocols  Transparency – minimal impact at the mobile host

13. Mar 27, 2002 13 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony  Hierarchy through domains – Mobile-IP for movement between domains – HAWAII Path Setup for movement within domain  Users retain their unique IP address while moving within a domain – Home address could be dynamically assigned – Co-located care-of address used in foreign domain * Unique and unchanging address limits updates to Home Agent and simplifies QoS support in the network Hierarchy and unique address

14. Mar 27, 2002 14 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony HAWAII: Enhanced Mobile IP  Distributed control: Reliability and scalability – host-based routing entries in routers on path to mobile  Localized mobility management: Fast handoffs – updates only reach routers affected by movement  Minimized or Eliminated Tunneling: Efficient routing – dynamic, public address assignment to mobile devices Domain Router RR RRRR Domain Router RR RRRR Local mobility Mobile IP Internet MD

15. Mar 27, 2002 15 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony HAWAII Mobile IP Internet 1.1.1.100->port 4, 239.0.0.1 1.1.1.100-> port 3, 239.0.0.1 1.1.1.100->wireless, 239.0.0.1 R 2 3 1 R 1 2 3 4 5 MY IP: 1.1.1.100 BS IP:1.1.1.5 1 R 2 3 4 R 1 2 3 4 5 R 2 3 1 4 4 Domain Root Router 2 Domain Root Router 1 5 BS1 2 3 4 5 BS2BS3BS4 1 Power-up

16. Mar 27, 2002 16 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Design Principle III:Soft-state  Host-based routing entries maintained as soft-state  Base-stations and mobile hosts periodically refresh the soft-state  HAWAII leverages routing protocol failure detection and recovery mechanisms to recover from failures * Recovery from link/router failures Soft-State

17. Mar 27, 2002 17 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony HAWAII Mobile IP Failure Recovery Internet 1.1.1.100->port 3, 239.0.0.1 1.1.1.100-> port 4, 239.0.0.1 1.1.1.100->wireless, 239.0.0.1 R 2 3 1 R 1 2 3 4 5 MY IP: 1.1.1.100 BS IP:1.1.1.5 1 R 2 3 4 R 1 2 3 4 5 R 2 3 1 4 4 Domain Root Router 2 Domain Root Router 1 5 BS1 2 3 BS2BS3BS4 1

18. Mar 27, 2002 18 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony  Host-based routing within the domain  Path setup schemes selectively update local routers as users move  Path setup schemes customized based on user, application, or wireless network characteristics * Micro-mobility handled locally with limited disruption to user traffic Path Setup Schemes

19. Mar 27, 2002 19 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony HAWAII Mobile IP Internet 1.1.1.100->port 3 (4), 239.0.0.1 1.1.1.100-> port 3, 239.0.0.1 R 2 3 1 R 1 2 3 4 5 MY IP: 1.1.1.100 BS IP:1.1.1.2 R 2 3 4 R 1 2 3 4 5 R 2 3 1 4 4 Domain Root Router 2 Domain Root Router 1 5 BS1 23 4 1.1.1.100->wireless, 239.0.0.1 15 BS2BS3BS4 1.1.1.100->port 1(wireless), 239.0.0.1 1 Micro-Mobility

20. Mar 27, 2002 20 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony MY IP: 1.1.1.100 BS IP:1.1.2.1 COA IP:1.1.2.200 Internet 1.1.2.200->port 2, 239.0.0.1 1.1.2.200-> port 3, 239.0.0.1 1.1.2.200->wireless, 239.0.0.2 HAWAII Mobile IP R 2 3 1 R 1 2 3 4 5 1 R 2 3 4 R 1 2 3 4 5 R 2 3 1 4 4 Domain Root Router 2 Domain Root Router 1 5 BS1 2 3 4 5 BS2BS3BS4 1 Mobile IP Home Agent: 1.1.1.100-> 1.1.2.200 6 7 Macro-Mobility

21. Mar 27, 2002 21 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Simulation Topology

22. Mar 27, 2002 22 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Performance: Audio and Video

23. Mar 27, 2002 23 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony  TCP - Web transfers in Mobile IP: Interaction between Tunneling and TCP Path MTU discovery results in 1 round trip wasted for each object.  TCP - File transfers: 5- 15% improvement over Mobile IP Performance: TCP

24. Mar 27, 2002 24 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Update Rates Domain Router Router 1... BS1 BS-20... BS1 BS20 39 users/sq. miles users moves at 112 Km/hr. base stations cover 7 Km 2 Network Model T BL BL M DB DB 16 2      IP  16YT R BDBD L RBL T BL BL H B DDB M DB DB 16 2 2           Mobile IP Updates at Home Agent: Hawaii Updates at Domain Router: Hawaii M-IP <<1, local mobility aggregation Router 7 – Varies linearly with # of base stations – Varies O(B D 1/2 )

25. Mar 27, 2002 25 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Performance: Update Rates  Scalability at the Domain Root Router – Number of entries: entries are from a given domain’s IP subnet -> perfect hashing for route lookup. – Number of updates: updates for Mobile IP varies linearly with the number of base stations in domain whereas in HAWAII, updates vary with the square root of number of base stations in domain.  Based on FreeBSD implementation, for a typical network configuration, update ratio of Mobile IP to HAWAII is 3:1 and CPU utilization ratio is 9:1.

26. Mar 27, 2002 26 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Standardization: IETF SeaMoby Working Group  Draft-seamoby-ietf-mm-problem-01.txt identifies the goals for a new IETF micro-mobility protocol:  Mobility without changing routable IP address  Use Mobile IP for inter-domain mobility  Use Mobile IP for signaling from the mobile host  IP version neutral  Optimized routing  Plug & Play  Inter-technology/heterogeneous mobility support  Inter-operate with existing QoS protocols * HAWAII appears an excellent fit! * Work is in IRTF now.

27. Mar 27, 2002 27 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony  Previous Foreign Agent Notification Extension (Route Optimization draft)  NAI extension (NAI draft)  Mobile challenge-response extension (Challenge Response draft)  NAI in foreign agent advertisements to detect domain changes (Private addresses draft)  Register with foreign agent while using co-located addresses  Allow split Mobile-IP registrations at the foreign agent (regionalized tunnel draft) Changes from Mobile IP (rfc2002)

28. Mar 27, 2002 28 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony HAWAII: Benefits Summary  Scalability through reduced updates as micro-mobility transparent to home agents  Limited disruption of traffic as Path Setup Schemes are optimized for the environment  Efficiency through reduced data packet header overhead as no tunneling in a (large) home/power-up domain  Ease of QoS support: unique address  Reliability through soft-state  Transparency to hosts that use Mobile IP  Integration with existing wireless infrastructure

29. Mar 27, 2002 29 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Outline  Motivation  IP Mobility –Macro-mobility: Mobile IP –Micro-mobility: HAWAII * IP Paging –HA/FA paging –Domain paging  Interworking of Wireless LANs with 3G Networks

30. Mar 27, 2002 30 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Mobile Host State Diagram  “Idle” mobile hosts update network less frequently than “active” mobile hosts  Network has only approximate location information for idle mobile hosts * Network determines the exact location by paging to deliver packets What is Paging?

31. Mar 27, 2002 31 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony IP Paging Outline  Motivation  IP Paging Architectures  Performance  IETF Standardization (SeaMoby Working Group)  Summary

32. Mar 27, 2002 32 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Paging in wireless networks (1): GPRS, UMTS  Paging for voice initiated differently (MSC) from data (SGSN) + may be deployed leveraging existing infrastructure – requires separate mechanisms  Specialized nodes, protocols (BSSGP) manage paging + requires no changes to intermediate routers – separate advances from other paging protocols – special failure recovery mechanisms needed Intranet MD SGSN GGSN Host Regular routing Tunneled packets using GTP Internet SGSN Radio Access Networks

33. Mar 27, 2002 33 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Paging in wireless networks (2): CDMA2000, Mobile IP  Paging for voice initiated differently (MSC) from data (RAN/MSC) + may be deployed leveraging existing infrastructure – requires separate mechanisms – No paging in Mobile IP  Specialized nodes, protocols (IS2001) manage paging + requires no changes to fixed hosts or routers – separate advances from other paging protocols – special failure recovery mechanisms needed MD FA HA Host Internet Regular routing Tunneled packets using Mobile IP FA Radio Access Networks

34. Mar 27, 2002 34 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony As wireless access networks migrate to IP, IP paging allows  common infrastructure to support different wireless technologies –seamless merging of LAN/WAN –avoids duplication of paging protocols, resulting in cost savings  deployment of sophisticated paging algorithms –leverages the support of multicast, if available –user-customized paging areas Why IP paging?

35. Mar 27, 2002 35 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony  Efficiency limit updates from mobile host when idle to conserve battery power  Scalability push paging initiation closer to base station  Reliability allow paging initiation to occur at any router/base station (no single point of failure)  Flexibility allow for fixed, hierarchical, or user-defined paging areas IP Paging Goals

36. Mar 27, 2002 36 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony IP Paging Architectures Internet Home Agent Foreign Agent Foreign Agent Foreign Agent R R R Domain Paging Area Mobile IP Paging Area 3 Options: Home Agent Paging – Home agent buffers packets and initiates page to all Foreign Agents – Can be controlled by corporate network – Does not scale Foreign Agent Paging – Last active Foreign agent buffers packets and initiate paging – Distributes load Domain Paging – Fully distributed, very scaleable and reliable Uniform mobility management – wireless LANs, outdoor Old FA initiates page HA initiates page Any router initiates page

37. Mar 27, 2002 37 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Home Agent (HA) Paging  Centralized at HA  Simple implementation  Issues/concerns –Inefficient signaling: long delays if HA far from mobile host –Scalability at HA –Multicast-based addressing of paging area needs global visibility, scalability of paging areas

38. Mar 27, 2002 38 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Foreign Agent (FA) Paging  Initiated at previously attached FA  Distributed among different foreign agents in paging area  Simple implementation  Efficient: paging restricted to local domain  Issues/concerns –Reliability when previous FA crashes –Requires FA deployment

39. Mar 27, 2002 39 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Domain Paging  Initiated at any node (router/base station) in path from mobile to root router  Completely distributed among different nodes in domain  Highly scalable, reliable to node failures  Efficient: paging restricted to local domain  Issues/concerns –implementation complexity –router support

40. Mar 27, 2002 40 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Router operation Routing Paging entryentryStateOperation YESYESActiveRegular Forwarding YESNOActiveNo paging support NONONullForward if default route exists, else discard NOYESStandbyPaging: If (packet arrives from DRR or I am DRR) If (node is base station or no refresh from downlink port or queuesize < threshold) Initiate paging else Forward to port in paging entry Endif else Forward along default route Endif

41. Mar 27, 2002 41 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Implementation  All three paging protocols implemented in FreeBSD  Paging protocol processing in user space, data forwarding in kernel space  Paging implementation does not affect fast path performance - use of virtual interfaces  Implementation used to measure processing load of different paging tasks - results to drive large scale simulation

42. Mar 27, 2002 42 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony MY IP: 1.1.1.100 BS IP:1.1.1.2 Internet 1.1.1.100->port 3, 239.0.0.1 1.1.1.100-> port 3, 239.0.0.1 R 2 3 1 R 1 2 3 4 5 R 2 3 4 R 1 2 3 4 5 R 2 3 1 4 4 Domain Root Router 2 Domain Root Router 1 5 BS1 4 1 1 1.1.1.100->wireless, 239.0.0.1 2 3 BS2BS3BS4 1 2 Buffer HAWAII Paging Data Paging

43. Mar 27, 2002 43 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Scalability (latency)  Simulation parameters –36-90 zones per domain –paging area size = 6 –real, synthetic traces –processing times from implementation  HA paging needs 5 processors for comparable performance  FA paging scalable  Domain paging supports highest paging load

44. Mar 27, 2002 44 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Scalability (updates)  Large Paging Area size results in fewer updates but increases latency due to higher paging processing load  In FA/HA paging, updates can occur due to movement or when user is paged and found at new location  In Domain paging, updates are only due to movement - results in least number of updates

45. Mar 27, 2002 45 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony IP Paging – Reliability Results Internet Home Agent IP Paging Area R FA R R DR/HA R R R R R R Mobile IP Model Domain Model

46. Mar 27, 2002 46 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony IP Paging – Reliability Results Domain HA FA DomainHA

47. Mar 27, 2002 47 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Standardization: IETF SeaMoby Working Group  Draft-ietf-seamoby-paging-problem-statement-02.txt identifies need for IP paging (now RFC 3132)  Draft-ietf-seamoby-paging-requirements-02.txt identifies following requirements (now RFC 3154): – minimize impact on host’s power consumption – on receiving page, host must re-establish layer three link – efficient utilization of layer two, if available – support existing mobility protocols – flexible support for different paging areas – allow arbitrary mapping between paging areas, subnets – robust against failures, packet losses * FA, Domain paging suitable candidates!

48. Mar 27, 2002 48 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Summary  IP-based wireless access networks - efficient, cost-effective  IP paging allows common infrastructure to support different wireless interfaces including CDMA, GPRS, wireless LAN etc.  Proposed three paging architectures: each has its applicability – HA paging useful in small networks with complete administrative control – FA paging simple, scalable, easily deployable – Domain paging scalable, flexible, reliable, most efficient  Future work – Standardization – Flexible and user-specific paging mechanisms

49. Mar 27, 2002 49 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Outline  Motivation  IP Mobility –Macro-mobility: Mobile IP –Micro-mobility: HAWAII  IP Paging –HA/FA paging –Domain paging * Interworking of Wireless LANs with 3G Networks

50. Mar 27, 2002 50 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Integrated Wireless Access Networks  Ubiquitous access to Internet and applications  Always-on high speed packet data access  Islands of multi-technology RF access networks connected to core IP network Core IP Network Radio Access Network Radio Access Network Service Provider “Home” Network Billing Authentication Mobility Service Provider “Home” Network Billing Authentication Mobility Roaming Agreements Radio Access Network The next wave of Internet access will be through high-speed wireless packet access Wide Area Wireless Local Area Wireless Hotspot/Enterprise 4G Wireless?

51. Mar 27, 2002 51 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Overview  Goal –Integrate 802.11 and wide-area wireless networks  Motivation –Ability to choose 802.11 where available (substantial cost-bandwidth advantage) –3G/802.11 integration can enhance existing wireless services and offer new services.  Approach –Integrate 802.11 with CDMA2000 &/or UMTS access networks for data service  Benefits seamless mobility wider application spectrum lower access/transport cost for high bandwidth services

52. Mar 27, 2002 52 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Background Infrastructure 802.11 Network – low cost, high-data rate (11Mbps  54Mbps) – unlicensed spectrum  potential interference – short range – ORiNOCO, Apple, Cisco, etc. 2G/2.5G/3G Network – high cost, low data rate (153kbps  2Mbps) – licensed spectrum  less interference – long range – Lucent, Nortel, Nokia, Ericsson, etc. End device Various new devices being announced E.g. VisorPhone (Handspring) includes PDA with 2G+ capability: mobile phone, messaging, internet access,... Palm and Motorola announced PDA with GPRS (2.5G) capability NeoPoint, Sony, etc. claim 802.11/CDMA or 802.11/GSM prototypes Observations Dissimilar networks and infrastructure Need for current end devices and applications to adapt between one network type and another

53. Mar 27, 2002 53 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Public Wireless Access Networks: Why are they different?  Security is a major concern where a wireless shared medium is used in a public environment –More susceptible to eavesdropping and man-in-the-middle attacks –Not behind firewall of friendly colleagues –Secure access into the enterprise  Accessing service on other provider’s networks –Roaming agreements, global roaming, shared revenue agreements –Perform authentication and accounting for roaming subscribers  Mobility –Efficient, seamless handoff of data sessions while moving across networks  Authentication –User authenticates to the network –Authentication at different layers: L2, L3, VPN, HTTPS  Integrated service across different air-interface technologies  Management and Home policy –Distribute per user home policy and QoS levels of service to roamed networks –Minimize exchanges with home network through efficient protocols and optimizations  QoS/ Levels of Service –Air interface contention, fair network usage, and alleviating congestion in hot spot areas –Cannot statically configure based on IP addresses  Mobile Client Software –Mask complexities from the user: configuration, reauthentication, network selection

54. Mar 27, 2002 54 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Challenges for Public Wireless Data Access  Security is a major concern where a wireless shared medium is used in a public environment  Enabling roaming across networks –enable integrated service across different air-interface technologies (e.g. 802.11 and 3G networks) –Perform authentication and accounting for roaming subscribers –Shared revenue arrangements to allow other service provider’s subscribers on network  Improving the subscriber’s experience –Minimizing subscriber interaction when roaming across networks and networks using different air interface technologies –One-time user authentication –Automatic client terminal configuration for network  Being able to offer levels of service, fair network usage, and alleviating network congestion in hot spot areas

55. Mar 27, 2002 55 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Infrastructure Challenges  Authentication, Authorization, and Accounting (AAA) –3G networks use Home Location Register (HLR) and AAA servers to perform authentication of link-layer and network-layer sessions –802.11 networks have their own link-layer authentication mechanisms  Perform separate administration or Merge user authentication profiles  Mobility –3G networks allow for hierarchical mobility management with link-layer handoff, micro-mobility and macro-mobility support –802.11 networks support link-layer mobility and IP mobility mechanisms  Perform IP mobility or use 3G mobility mechanisms in 802.11  Quality of Service (QoS) support –Large disparity in bandwidth availability between 3G and 802.11 –3G networks, unlike 802.11, are designed and engineered for QoS  End device adaptation and QoS support in 802.11 Two approaches to address these challenges: . Interconnect 3G networks with 802.11 using IP: peer-to-peer integration . Integrate 802.11 into 3G networks: access network integration

56. Mar 27, 2002 56 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Approach 1:Peer-to-Peer Integration  Overview –Different administrative domains connected through IP –Cross domain roaming is supported by using standard IP mobility, AAA  Advantages –Easy to build (works today!) –Fits All-IP philosophy  Disadvantages –Requires Mobile IP in end device for seamless roaming –Potentially slower handoff and inefficient data path Intranet/Internet AAA HLR 802.11 Wireless 3G Network AAA M-IP Agent M-IP Agent Public/Enterprise Data Network BS 3G Air Interface BS 3G Air Interface Access Network 3G Core Network 802.11 Air Interface 802.11 AP 802.11 AP 802.11 Air Interface 802.11 AP 802.11 AP

57. Mar 27, 2002 57 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Approach 2: Access Network Integration  Overview –Operate 802.11 clusters under the same 3G access network –Mobility, AAA supported by same mechanisms in 3G network  Advantages –Faster handoffs and more efficient transport –Integrated HLR/AAA  Disadvantages –Customized 3G Gateway necessary for each network (CDMA, UMTS) results in high cost Internet Integrated 3G/802.11 Network M-IP Agent BS 3G Air Interface BS 3G Air Interface Access Network 3G Core Network 802.11 Air Interface 802.11 BS 802.11 BS 802.11 Air Interface 802.11 BS 802.11 BS AAA HLR 3G Gateway

58. Mar 27, 2002 58 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Complete Service Picture Wireless Carrier Network 3G Access MobileStar Starbucks “Store-front” Wayport Airport/ Enterprise Wayport Airport/ Enterprise Terminal Possibilities Applications/ Content Authentication Accounting Mobility/ Roaming Agreements Corporate Network Applications/ Content Accounting/ Billing Authentication VPN 3G Access Handoff Possibilities Intertech Internetwk Handoff Intratech Intranetwk Handoff Intratech Intranetwk Handoff Intratech Internetwk Handoff Intratech Internetwk Handoff Intratech Internetwk Handoff Roaming Broker Seamless Mobility/Roaming for Subscriber/ Negotiated Rates with Partners One Bill from Wireless Carrier/ Bundled Data Package Uninterrupted Applications: Streaming, Email, Corporate VPN, Web Dual Interface Built-in 802.11 Combined Air Card Subscriber Service Wireless Access Network Support 802.11 Built-in 802.11 3G data card Internet

59. Mar 27, 2002 59 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Home AAA Home Agent Hot-spot 802.11 Access Router 802.11 Access Points 802.11 Gateway “Home” network (3G carrier) BS 3G Wireless Access BSC PCF or SGSN Local AAA PDSN or GGSN Internet Dual-mode terminal w/ MobileIP client 802.11/3G Integration Architecture using Peer-to- Peer Approach and IP mobility Billing Servers

60. Mar 27, 2002 60 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Industry 802.11 Security Status  Problems with existing products –Same shared static key used for encryption –Weak encryption through RC4 and short keys –User access is not authenticated to network servers –Proprietary solutions do not interoperate  802.11i Working Group Solutions –Per packet authentication –Temporary encryption keys and frequent rekeying –Stronger AES encryption and longer keys –Adoption of 802.1X standard

61. Mar 27, 2002 61 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony What is 802.1X?  Framework for port-based network access control  Allows authentication & key derivation through EAP schemes –Extensible Authentication Protocol (RFC 2284) –Reuse RADIUS infrastructure to carry EAP frames –Avoids preconfiguration of encryption keys at user terminals  Standard is not specific to wireless or 802.11  Allows 802.11 Access Points to support many different EAP schemes –802.11 working group did not mandate particular EAP scheme Internet Local AAA Home AAA “Home” Network 802.11 Access Point 802.11 Network 802.1X EAPOL Radius w/ EAP-Message Radius Direct to HAAA or through Broker AAA EAP support

62. Mar 27, 2002 62 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony EAP-SKE scheme for 802.11 Security Home AAA Home Agent 802.11 Gateway Internet “Home” Network  EAP-SKE (Shared Key Exchange) solution –Authenticate user to Home AAA with minimal protocol exchange –Provide mutual authentication –Home-AAA dynamically generates and distributes per- user per-session keys –Use separate keys for authentication and encryption; keys are never passed over the air –Commonality with MobileIP and 3GPP2 standards Use same authentication credentials Use same keyed hash function (HMAC-MD5) –Works with 802.1X, the accepted standard for initiating authentication with 802.11 access points  EAP-SKE IETF draft –http://search.ietf.org/internet-drafts/draft-salgarelli-pppext- eap-ske-00.txt Performs Authentication, Generates Encryption key and key material 802.1X/EAPOL exchange over air Radius exchange Algorithm to construct encryption key from passed key material Goal : dynamically establish security relationship between user and public 802.11 access points with no prior configuration and no subscription with owner of 802.11 network

63. Mar 27, 2002 63 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Home AAA Home Agent “Home” network (3G carrier) Internet Roaming Agreements Among 802.11 Service Providers Billing Servers 802.11 Access Points 802.11 Gateway Large 802.11WISP Service Provider (e.g. Wayport) Broker AAA Shared Revenue Settlement DB 802.11 Access Points 802.11 Gateway 802.11 Access Points 802.11 Gateway Roaming Agreement Large 802.11 WISP (Wayport) 802.11WISP Service Aggregator Broker AAA Shared Revenue Settlement DB Roaming Agreement Small 802.11 WISP (Company X) Small 802.11 WISP (Company Y) Same backend infrastructure Supports 3G and 802.11

64. Mar 27, 2002 64 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony QoS Features for 802.11 802.11 QoS over air Gold Service User Silver Service User Bronze Service User 10 Mbps Home AAA Home Agent 802.11 Gateway IP QoS on access bottleneck Edge Router Access Router 10 Mbps Internet  Need QoS functionality in two spots of possible congestion –IP QoS on oversubscribed access link –QoS for 802.11 air interface  Per user Level of Service policy obtained from Home AAA database in AAA protocol exchange –dynamic rate limiting  Gateway maps user population in 802.11 cells for achieving fairness and preserving service level guarantees  DiffServ packet marking and traffic policing –Gateway can mark packets even with Mobile IP tunnels –Home agent marks packets for 802.11 destined traffic Goal : Offering per user levels of service and fairness to subscribers in 802.11 networks

65. Mar 27, 2002 65 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Integration Summary  802.11/3G integration provides choice of wireless internet access while allowing seamless mobility  IP-based peer-to-peer interworking Solution easily extends to other types of wireless access –HDR, 802.11a, OFDM, Hiperlan2  Adapting CDMA2000 standards (security, accounting, mobility) for the 802.11 environment allows client software and backend servers can support both networks  Commonality across CDMA2000 and UMTS for integration with 802.11 –UMTS needs to have support for IETF protocols

66. Mar 27, 2002 66 IEEE NJ Coast Section seminar on Wireless LAN & IP Telephony Conclusion  IP-based wireless access networks are efficient and cost- effective  Combination of HAWAII for micro-mobility and Mobile IP for macro-mobility supports seamless and scalable handoffs  IP paging allows common infrastructure to support different wireless interfaces including CDMA, GPRS, Wireless LAN etc.  802.11/3G integration provides choice of wireless internet access while allowing seamless mobility