Session W3 Toward 4G Networks

1
Session W3Toward 4G Networks

• Ramachandran Ramjee, Ph.D.
• ramjee_at_bell-labs.com
• http//www.bell-labs.com/ramjee

2
Wide-Area Wireless Standards Evolution
2G
2.5G
1G
3G/ IMT-2000 Capable
Existing Spectrum New Spectrum
IS-95-A/ cdmaOne
IS-95-B/ cdmaOne
Analog AMPS
1XEV DO HDR (1.25 MHz)
IS-136 TDMA
136 HS EDGE
TACS
GSM GPRS
EDGE
GSM
WCDMA
HSCSD
3
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
Observations

• The G in G stands for Generation and typically
  refers to the generation of wide-area wireless
  networks 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
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
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
Industry Directions for Wireless Networking
1st UMTS customers
GPRS/UMTS standards begin
FPLMTS standards begin
1998
1994
1992
1990
1995
2002
3M Internet Users
153M Internet Users

• 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)

8
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
Emerging Mobile Packet Networks GPRS and UMTS
Tunneled packets using GTP
Regular routing
GGSN
Radio Access Networks
Host
Intranet

• 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

10
Emerging Mobile Packet Networks CDMA2000 and
802.11 (Mobile IPv4)
Tunneled packets using Mobile IP
HA
Regular routing
Radio Access Networks
MD
Host
Internet

• 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

11
Trends
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

12
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
Hierarchy and unique address

• 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

14
HAWAII Enhanced Mobile IP
Internet
Domain Router
MD
Local mobility
Local mobility
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

15
Power-up
16
Design Principle IIISoft-state
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

17
Failure Recovery
Domain Root Router 2
Domain Root Router 1
1
1
1.1.1.100-gt port 4, 239.0.0.1
2
R
R
4
2
4


3
3
1.1.1.100-gtport 3, 239.0.0.1
3
5
1
4
R

3
2
2
BS1
BS2
BS3
BS4
1.1.1.100-gtwireless, 239.0.0.1
1
MY IP 1.1.1.100 BS IP1.1.1.5
18
Path Setup Schemes

• 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

19
Micro-Mobility
20
Macro-Mobility
Domain Root Router 2
Domain Root Router 1
Mobile IP Home Agent 1.1.1.100-gt 1.1.2.200
1
1
2
R
R
4
2
4


3
3
1.1.2.200-gt port 3, 239.0.0.1
3
5
4
1.1.2.200-gtport 2, 239.0.0.1
6
5
1
4
R

3
2
2
BS2
BS3
BS4
1.1.2.200-gtwireless, 239.0.0.2
1
7
MY IP 1.1.1.100 BS IP1.1.2.1 COA IP1.1.2.200
21
Simulation Topology
22
Performance Audio and Video
23
Performance TCP

• 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

24
Update Rates
Network Model
Domain Router

• 39 users/sq. miles
• users moves at 112 Km/hr.
• base stations cover 7 Km2

...
Router 7
...
Mobile IP Updates at Home Agent
2
B
L
r
B
L
rn
MIP
D
B

D
B
T
16
p
M

• Varies linearly with of base stations

ltlt1, local mobility
Hawaii Updates at Domain Router
2
M-IP
B
L
rn
B
L
gr
H

D
B

D
B
T
p
16

• Varies O(BD1/2)

M
2
BD
L
r
R
B
L
rn
Hawaii
B

D
D
B

16YTR
p
aggregation
25
Performance Update Rates

• Scalability at the Domain Root Router
• Number of entries entries are from a given
  domains IP subnet -gt 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 31 and CPU utilization ratio is
  91.

26
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
Changes from Mobile IP (rfc2002)

• 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)

28
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
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
What is Paging?

• 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

31
IP Paging Outline

• Motivation
• IP Paging Architectures
• Performance
• IETF Standardization (SeaMoby Working Group)
• Summary

32
Paging in wireless networks (1) GPRS, UMTS
Tunneled packets using GTP
Regular routing
GGSN
Host
Intranet

• 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

33
Paging in wireless networks (2) CDMA2000,
Mobile IP
Tunneled packets using Mobile IP
HA
Regular routing
MD
Host
Internet

• 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

34
Why IP paging?

• 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

35
IP Paging Goals

• 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

36
IP Paging Architectures
HA initiates page

• Uniform mobility management
• wireless LANs, outdoor

Old FA initiates page
Any router initiates page

• 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

37
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
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
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
Router operation
Routing Paging entry entry State Operation YES
YES Active Regular Forwarding YES NO Active No
paging support NO NO Null Forward if default
route exists, else
discard NO YES Standby Paging If (packet
arrives from DRR or I am DRR) If (node
is base station or no refresh from
downlink port or queuesize lt threshold)
Initiate paging else
Forward to port in paging entry
Endif else Forward along default
route Endif
41
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
Paging
Domain Root Router 2
Domain Root Router 1
1
1
R
2
R
4
2
4


3
3
1.1.1.100-gt port 3, 239.0.0.1
Buffer
1.1.1.100-gtport 3, 239.0.0.1
5
1
R
4

3
2
1
1
4
BS1
BS2
BS3
BS4
1.1.1.100-gtwireless, 239.0.0.1
2
3
2
MY IP 1.1.1.100 BS IP1.1.1.2
43
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
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
IP Paging Reliability Results
Home Agent
Domain Model
Mobile IP Model
Internet
R
DR/HA
IP Paging Area
46
IP Paging Reliability Results
HA
47
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 hosts 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
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
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
Integrated Wireless Access Networks
The next wave of Internet access will be through
high-speed wireless packet access

• 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

Service Provider Home Network
Roaming Agreements
Local Area Wireless Hotspot/Enterprise
Wide Area Wireless
4G Wireless?
51
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
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
Public Wireless Access NetworksWhy 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 providers 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

54
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 providers subscribers on network
• Improving the subscribers 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
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
Approach 1Peer-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

57
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

HLR
Access Network
3G Core Network
AAA
M-IP Agent
Internet
3G Gateway
802.11 Air Interface
802.11 Air Interface
802.11 BS
802.11 BS
802.11 BS
802.11 BS
Integrated 3G/802.11 Network
58
Complete Service Picture
Accounting/ Billing
Applications/ Content
Accounting
Applications/ Content
Wireless Carrier Network
Corporate Network
Roaming Broker
Authentication
Mobility/ Roaming Agreements
VPN
Authentication
Network Support
3G Access
Wayport Airport/ Enterprise
3G Access
Wireless Access
Wayport Airport/ Enterprise
MobileStar Starbucks Store-front
802.11
Handoff Possibilities
802.11
Intratech Intranetwk Handoff
Intratech Internetwk Handoff
Intratech Internetwk Handoff
Intratech Internetwk Handoff
Intertech Internetwk Handoff
Intratech Intranetwk Handoff
One Bill from Wireless Carrier/ Bundled Data
Package
Seamless Mobility/Roaming for Subscriber/ Negotia
ted Rates with Partners
Uninterrupted Applications Streaming, Email,
Corporate VPN, Web
Subscriber Service
Terminal Possibilities
Dual Interface
Built-in 802.11
Combined Air Card
59
802.11/3G Integration Architecture using
Peer-to-Peer Approach and IP mobility
Home network (3G carrier)
Billing Servers
PDSN or GGSN
PCF or SGSN
Access Router
Local AAA
3G Wireless Access
802.11 Gateway
BSC
Hot-spot 802.11
BS
BS
802.11 Access Points
Dual-mode terminal w/ MobileIP client
60
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
What is 802.1X?
Home Network
802.11 Network
Local AAA
802.11 Access Point
EAP support

• 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

62
EAP-SKE scheme for 802.11 Security
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
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-salga
  relli-pppext-eap-ske-00.txt

Performs Authentication, Generates Encryption
key and key material
Internet
802.11 Gateway
Radius exchange
802.1X/EAPOL exchange over air
Algorithm to construct encryption key from
passed key material
63
Roaming Agreements Among 802.11 Service Providers
Home network (3G carrier)
Same backend infrastructure Supports 3G and 802.11
Billing Servers
Roaming Agreement
Large 802.11WISP Service Provider (e.g. Wayport)
Roaming Agreement
802.11WISP Service Aggregator
Shared Revenue Settlement DB
Shared Revenue Settlement DB
802.11 Gateway
802.11 Gateway
802.11 Gateway
Large 802.11 WISP (Wayport)
Small 802.11 WISP(Company Y)
Small 802.11 WISP(Company X)
802.11 Access Points
802.11 Access Points
802.11 Access Points
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QoS Features for 802.11
Goal Offering per user levels of service and
fairness to subscribers in 802.11 networks

• 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

802.11 QoS over air
10 Mbps
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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

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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