WiFi Technology

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Wi-Fi TechnologyNCC Workshop, 2003Kent Lundgren
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Outline

• Introduction and Scope
• Wi-Fi Protocols
• Wi-Fi vs. Bluetooth
• Wi-Fi vs. Cellular
• Hotspot Drivers
• Hotspot Players
• Backhaul
• WISPs
• Wi-WAN Solution
• Conclusions

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Wi-Fi Introduction

• Simple, cheap and ubiquitous
• Great solution for
• Home LAN
• Office LAN
• Periodic Event LAN, conferences, trade shows
• When applied to a large area Internet service
  business, challenges arise
• Access Points get very large in number.
• Build-out, Management Maintenance become
  exponentially complex.
• Internet Access operating cost dwarfs equipment
  cost.

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Wi-Fi Market Size
U.S. Europe
Number of Users (millions)
Revenue ( millions)
Users growing from 600K to 21.5M in US
Revenue growing from 134M to 3B in US
The Analysys Group, 2002 Europe 2007 is Harris
Estimate
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802.11 (Wi-Fi) Protocol Comparison
802.11i temporal key integrity protocol may
replace WEP 802.11x
authentication protocol
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Pluses Minuses
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Recommendations

• Do not use home-brewed 802.11a/b/g systems
  outdoors. Expect severe interference from those
  who do at 2.4 GHz.
• 802.11as biggest advantage, generous spectral
  allocation (in the US), outweighs its
  disadvantages.

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Different Markets Roles
high power long range

• Bluetooth
• Designed for quick, seamless, short-range
  networks
• Features low power consumption, small protocol
  stack,robust data voice transfer
• Cheap price
• Good choice for WPAN (Wireless Personal Area
  Networks)
• 802.11
• Designed for infrequent mobility, IP-based data
  transmission
• Medium range and high data rate
• At least 10x the price of bluetooth
• Good choice for WLAN

medium power medium range
low power short range

• WPAN
• BT
• HomeRF

x0M
xKM
x00M
IEEE 802.11
GSM, CDMA, GPRS, etc.
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Wi-Fi vs. Cellular

• Cellular comes from the Telecom World
• Slow standardization and long product lifecycle
  (decades)
• Circuit switched
• Trunk lines and exchanges are digital TDM
• 2.5G/3G data networks are hybrid approaches
• Circuit-switched voice
• Packet data
• Wi-Fi comes from the Networking World
• Rapid product life cycles
• Internet is the backbone, with a wireless edge
• IP from the core to the edge
• Contention-based MAC lowers client cost
• IP is the dominant networking standard, while
  FDDI, Token Ring, Frame Relay, ATM have had
  limited impact

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Wi-Fi Cellular Voice and Data
Cellular
2.5/3G
802.11
WLAN
Voice
Data
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Hot Spot Drivers

• Wi-Fi CPE is will be free
• Integrated into next generation PCs and PDAs
• Very different from other access solutions
• Access business cases normally very sensitive to
  CPE costs
• Mobility/Portability is a killer application in
  itselfwe learned that from voice
• Early adopters are business users
• They can pay
• They have no other roaming data communications
  options
• Except 3G. but what and where is it?
• Killer application is remote corporate LAN
  access
• Adoption of 802.11a
• Big speed jump, lots more spectrum

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Anticipated Wi-Fi Deployment

• Phase 1 - Early deployments, isolated sites
• Airports, the odd hotel, convention halls
• low user density low speed user access rates
  (primarily 802.11b)
• Phase 2 - Full deployments network build-outs,
  coverage driven
• Consolidations to gain coverage and broader
  service portfolios, fixed and mobile carriers get
  involved
• Dependable coverage and availability
• Advanced roaming services agreements
• Stable, predictable pricing

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Hot Spot Players
Optional Roaming Intermediary Broker or
Settlement Services
Agreement
Agreement
Home Entity (such as Users Corporation or
Service Provider)
WISP Hotspot Operator
Global Roaming AAAServices Network
Roaming RADIUS NETwork Server
Central Policy / Authentication Database
AAA ROAMing Server
VPN / AAAServer
AAA / RADIUS Proxy Server
Hotspots
Mobile / Nomadic User
Home Entities Definition who the Mobile /
Nomadic User has a billing relationship and
account with (may not be a Wireless Hot Spot
Operator) Examples are Corporations,
Carriers, and WISPs Themselves

• Maintain security association with their
  nomadic user (Authentication, Authorization, and
  Accounting)
• Additional roaming revenues from users
  without having to deploy WLAN infrastructure

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Hot Spot Players, cont.
Optional Roaming Intermediary Broker or
Settlement/Clearinghouse
Agreement
Agreement
Home Entity (such as Users Corporation or
Service Provider)
WISP Hotspot Operator
Global Roaming AAAServices Network
Roaming RADIUS NETwork Server
Central Policy / Authentication Database
AAA ROAMing Server
VPN / AAAServer
AAA / RADIUS Proxy Server
Hotspots
Mobile / Nomadic User

• Provides Home Entities with aggregated WLAN
  secure hotspot locations for their users
• Provides WISP Hotspot Operators with
  aggregated customer base of already
  provisioned nomadic users

Roaming Intermediaries Definition
participate in the Authentication and Accounting
Process between multiple Hotspot Operators and
various Home Entities Examples are Remote
Access (dialup) Providersand Settlement
(cellular) Carriers/Providers
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Hot Spot Players, cont.
Optional Roaming Intermediary Broker or
Settlement Services
Agreement
Agreement
Home Entity (such as Users Corporation or
Service Provider)
WISP Hotspot Operator
Global Roaming AAAServices Network
Roaming RADIUS NETwork Server
Central Policy / Authentication Database
AAA ROAMing Server
VPN / AAAServer
AAA / RADIUS Proxy Server
Hotspots
Mobile / Nomadic User

• Providing WLAN access attracts customers
• Roaming brings additional revenues without cost
  of customer acquisition / provisioning
• Cost sensitive infrastructure build out

WISP Hotspot Operators Definition deploys
public access WLAN networks (e.g., Wi-Fi) and
public access control gateway functionality
Example locations airports, restaurants, hotel
rooms, company lobbies, conference rooms,
apartments
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Hot Spot Players, cont.
Optional Roaming Intermediary Broker or
Settlement Services
Home Entity (such as Users Corporation or
Service Provider)
Hotspot Operators Network Operations Center
Global Roaming AAAServices Network
Roaming RADIUS NETwork Server
AAA ROAMing Server
Central Policy / Authentication Database
VPN / AAAServer
AAA / RADIUS Proxy Server
Firewall VPN Server
NomadicUser
Hotspot 2
Hotspot 1
Cell 2
Cell 1
Cell 1
Wireless Access Point
Wireless Access Point
Wireless Access Point
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Hot Spot Challenges

• Security
• Quality of Service
• Roaming/Billing
• Revenue Model
• Backhaul

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Typical Indoor Hot Spot Configuration

• High Speed Backhaul is required to avoid
• traffic flattening
• poor performance of VoIP, VIDoIP, etc
• poor user experience

• Traffic is not Pier-2-Pier Within the HotSpot
  (as is the case with LANs)
• Aside from stat-gain, all traffic in the HotSpot
  is Egress/Ingress through the HotSpot BackHaul
  Link
• No local caching or mail serving

.... or wireline backhaul alternative
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Hot Spot Backhaul Bottleneck
E1/DSL Backhaul (1Mbps)
Wifi Bandwidth ( 10Mbps) 802.11a/b blend
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Wired vs. Wireless Backhaul

• Wired bandwidth is expensive when you can get it.
• Licensed wireless is less costly, reliable, more
  flexible and scales well.
• Supplied by emerging Wireless Wide Area Network
  (Wi-WAN) operators, aka Wireless ISPs (WISPs)

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WISP (Wi-WAN) Market Segments
Residential SOHO
) ) ) ) ) ) ) ) )
MTU Building Access
) ) ) ) ) ) ) ) ) ) ) )
) ) ) ) ) ) ) ) ) ) ) )
Cellular Backhaul
) ) ) ) ) ) ) ) ) ) ) )
) ) ) ) ) ) ) ) ) ) ) )
) ) ) ) ) ) ) ) )
E1 / Fractional E1 Business Services
Backhaul of Wi-Fi Hot Spots
LE WISP Backhaul
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Wi-WAN Using Modified Wi-Fi Extension Outdoors

• Licensed 3.5 GHz for reliable line-of-site
  backhaul
• Modified Wi-Fi gives WISPs a) better reach, b)
  higher throughput, and c) solution to hidden
  node problem..

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Conclusions

• Higher bandwidth and generous spectral
  allocations (in the US) favor 802.11a.
• Standard Wi-Fi is problematic outdoors.
• Residential market is exploding now.
• Office market will grow when security is enhanced
  (802.11i), boosting 802.11a.
• Hotspot market will grow as roaming, billing,
  authentication, revenue model, and backhaul
  challenges are met.
• Licensed wireless is best solution for Wi-Fi
  backhaul.