Current & Future Opportunitiesfor Wi-Fi in a 4G World

Brough Turnerrbt@ashtonbrooke.com

broughturner@gmail.com

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ITU Vision for 3G

Satellite

Macrocell Microcell

UrbanIn-Building

Picocell

Global

Suburban

Basic TerminalPDA Terminal

Audio/Visual Terminal

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“3G” Services• 3G-324M Video telephony• Location-based services• Push-to-Talk (VoIP w/o QoS)• Rich presence (instant messaging)• Fixed-mobile convergence (FMC)• IP Multimedia Services (w/ QoS)

– Video sharing (conversational video on IP)

• Converged “All IP” networks – the Vision

Limited adoption

Limited adoption

Limited adoption

Limited adoption

Bypassed !

No traction

Too late …

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The Internet is the killer platform

• Mobile Internet access drives 3G data usage

• Future business models an open question– Walled garden – too late !– Advertising ?– Other 2-sided business

models ?

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Mobile Internet Access• For PC’s under restrictive

terms of service, e.g. no servers, no P2P, no substitution for private lines or frame relay

• AT&T: 5GB @ $60/mo• Verizon: ditto• Sprint: ditto• No US operator offers

flat rate unlimited plans

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iPhone glimmer of what’s possible

• Controlled eco-system– Apps must meet unpublished

Apple & AT&T requirements,e.g., VoIP over Wi-Fi, not 3G

• Explosive growth in mobile broadband usage

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iPhone traffic

US data traffic

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US 3G performance• Novarum Inc. (1/2010)

– Measurements in 36 cities (Anaheim, …, Boston, …, Philly, …, Raleigh, …, Tempe)

– 8-2007: 507/195 Kbps & 340 ms delay

– 12-2009: 1.5 Mbps down• Doubling < 24 months

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Increasing capacity

Operator Services

Femtocell

Wi-Fi

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Internet

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1. Add Cellsites ($$$)2. Newer radios ($$)3. More backhaul ($$$)

4. Femtocells ($$)5. Wi-Fi ($)

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Spectrum history

• 1920: Primitive radio receivers– Needed to restrict who transmits

• 1927- 1934: Origin of FCC, spectrum licensing– Ensuing decades - almost all spectrum assigned– Three bands reserved for “junk” uses

• 1985: FCC authorizes spreadspectrum communications in theISM, or “junk” bands, i.e. – 900 MHz, 2.4 GHz, 5.8 GHz

Wi-Fi History1985 FCC permits communications in “junk bands” at 900 MHz, 2.4 GHz & 5.8 GHz

1988 - 1997 IEEE bodies iterate; eventually publish first 802.11 specThree alternate solutions for 1 Mbps operation with a 2 Mbps option

1999 802.11a – 54 Mbps at 5.8 GHz using OFDM modulation

1999 802.11b – 11 Mbps at 2.4 GHz using DSSS modulation

1999 Wireless Ethernet Compatibility Alliance (WECA) formed– Focuses on interoperability and a certification program

2001 802.11d – extends the spec for other regulatory domains (EU, Japan, etc.)

2003 802.11g – 54 Mbps at 2.4 GHz using OFDM modulation

2003 WECA adopts new name: Wi-Fi Alliance

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2004 view of Wi-Fi market• Rampant growth

however…• Article in ‘The

Economist’ warns Wi-Fi under threat:

• WiMAX in wide area• WiMedia in home

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Additional highlights• 1997: FCC authorizes Unlicensed National Information Infrastructure

(U-NII) radio band providing 200 MHz more spectrum in 5 GHz band• 2003: FCC adds 255 MHz to 5 GHZ bringing total spectrum to 555 MHz• 2003-2009: Task Group n works to dramatically improve Wi-Fi

performance, in part via MIMO and Beamforming• 2007: 802.11n draft 2 products certified by the Wi-Fi Alliance• 2009: 802.11n specification approved

Wi-Fi has pioneered the commercial deployment of the

key ‘4G’ wireless technology,

i.e. OFDM, MIMO, Beamforming

In-Stat (Nov 09)

• Worldwide hotspots reach 245,000 venues in 2009• Hotspot connects increased in 2009 by 47 percent,

bringing total worldwide 1.2 billion connects• Wi-Fi handset shipments grew 50%, 2007 to 2008• Wi-Fi-enabled entertainment device (cameras,

gaming devices, and personal media players) shipments projected to increase from 108.8 million in 2009 to 177.3 million in 2013

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ABI Research (August 2009)

• ABI projects 1 billion Wi-Fi chips in 2011• Global shipments of Wi-Fi-enabled cell phones

to double between 2009 and 2011– 144 million in 2009 to 300 million in 2011

• 90% of smart phones Wi-Fi capable by 2014

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Increasing capacity

Operator Services

Femtocell

Wi-Fi

1

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4

Internet

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1. Add Cellsites ($$$)2. Newer radios ($$)3. More backhaul ($$$)

4. Femtocells ($$)5. Wi-Fi ($)

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Femtocells: too little, too late• Primary users of 3G/4G data also have Wi-Fi

– Laptops, smart phones• Corporate IT prefers Wi-Fi they control• Consumers deploying Wi-Fi anyway

– For PCs, for gaming, for home media– Pay extra to help carrier improve their network?

• Femtocell’s only value may be voice coverage

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What’s next?• Wireless tipping point

– 5 GHz becomes as valuable as 2.4 GHz or 700 MHz– Spatial reuse → incredible density increments

• Wi-Fi leads the way– Leveraging Moore’s law and existing 802.11n spec.– Task Grp ac – Very high throughput <6GHz (2012?)

New biz ops!

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Spectrum MythTV Spectrum is “beach front” spectrum

• Based on legacy technology, not physics!– Travels farther thru the air – No!– Thru windows – roughly the same– Goes thru masonry – yes, this is better …

Free space path loss

But this equation encapsulates two effects:① Actual path loss② Receiving antenna aperture (assumed to be ½ wavelength)

Seems to say more , more loss

5 GHz photons go just as far as 700 MHz photons !

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Refraction and reflections

Shorter wavelength - more reflections, refraction “MultiPath” “Ghosts” if a single receiver

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MIMO: Multiple Input Multiple Output

• Multiple paths improve link reliability and increase spectral efficiency (bps/Hz), range & directionality

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Rich Indoor MIMO Multipath

Wall

Reflector

Moving reflector

Direct ray

Tx

Rx

Reflector

Source: Fanny Mlinarsky, Octoscope

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Municipal Multipath Environment

Source: Fanny Mlinarsky, Octoscope

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Multiple channels per chipLike CPU cores …• 2x2 MIMO – 2008• 4x4 MIMO – 2010-11then• 8 radios, 16 radios?, …

how to use silicon?

Better and better beam-forming !

Intel

Fujitsu

AMD

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Beamforming• Select among multiple predefined antenna elements

– Widely used with single radios (2G, 3G, Wi-Fi – Vivato, Ruckus Wireless)

• Adaptive antenna arrays– Dynamically compute phase and amplitude for each antenna element– Adapts for desired signal while also reducing interference

8 antenna elementsspread over 3.5 λs, i.e. ~18 cm, or < 7.5” at 5.8 GHz

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Beamforming~2014: >300 Mbps Wi-Fi to ~1 Km at mass market prices ?

4x4 MIMOwith 8-12 antenna elements

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Commercial beamforming Wi-Fi beams, before silicon support …• Vivato (’02-’06)

– Technical success, but expensive – Connect with 11g clients up to 2 km– Vivato-to-Vivato up to 18 km

• Ruckus Wireless (today) – 12 elements – selectively switched to

two channels on 2x2 silicon– Dramatically outperforms conventional

2x2 systems

• 11n wireless networking solutions in silicon• Founded 2006; customers include Netgear• 4x4 MIMO with beamforming

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TVWS – Beach-front Property?• MIMO antenna element

separation >= ½ wavelength– 2.1 meters at 70 MHz– 21 cm at 700 MHz

• But only– 2.5 cm for 5.8 GHz Wi-Fi

Wavion Networks

D-Link DAP-2553

Ruckus Wireless

Wi-Fi• Stationary clients or

pedestrian motion

• Data centric (VoIP an afterthought)

• Wide-open market, many vendors, many market segments, many customers

3G / 4G• Supports mobile use

at auto speeds

• Voice centric (voice revenues still king)

• 4-6 vendors, 1 application,<700 customers

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Wi-Fi markets evolving• Well established in enterprises and on campus• Mesh products emerge to fill coverage gaps

– Aruba Networks, BelAir Networks, Bluesocket, Cisco, Clearsite Communications, Firetide, Locust World, Meraki, Mesh Dynamics, Motorola, Nortel, Open-Mesh, Packet Hop, Ruckus Wireless, SkyPilot Networks, Strix and Tropos

• Mesh node as bridge from outdoor to indoor

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Muni Wi-Fi• Wireless broadband access networks

– Take 2; recovering from early Metro Wi-Fi– Dozens of US cities now succeeding

• Cities bring real estate, look to save current $– Communications for police & other city services

• But strong pressure for “free” in some form– 40% of APs are open (espc. Consumer APs)

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Variations on Free• Retail business giveaway

– Coffee shops, restaurants, hotels, retail– Harvard Sq. Business Association

• Sponsorship – locations, events

• Carrier supported– e.g. Cablevision’s

Optimum Wi-Fi

By kumasawa

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More free Ad supported • Didn’t work in 2005; working now…

– Costs way down; usage and interest up• Freerunr in UK (& NL, RS, ZA)

– Splash screens, limited duration free periods, …• JiWire in US – Ad platform for free Wi-Fi

– Used by Microsoft Bing nationwide Wi-Fi offer• Sputnik in US – Ad supported model growing

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100x mesh performance coming• Wi-Fi mesh performance has been extremely limited

– Multi-path limited link capacity & favored 2.4 GHz – Single radios with omni antennas mean all links share one

20 MHz channel, so mesh capacity drops ~x2 per node

• Pt-to-pt links = dramatic increase in mesh capacity– Directional antennas today; software beamforming soon

• Multi-radio mesh nodes– Separate channels for each link; note: there are eleven

40 MHz channels available at 5 GHz

Enterprise design adapted for BB

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ILEC price umbrella• Cost of Internet transit @ urban IXPs

– <$4 /Mbps /month (multi-Gbps quantities)– <$9 /Mbps /month (<=100 Mbps)

• Elsewhere, even 1 block away, very expensive– T1 $299, 5Mbps $599, 10 Mbps $1299 /month– This is $120-$200 /Mbps /month 20x-50x markup

• Fosters wireless bypass– WISPs operating 20%-50% under ILEC price umbrella

Wireless ISPs• > 2000 WISPs, in fast growing segment

– Most use license-exempt spectrum

– Mix of pre-WiMAX, WiMAX and, increasingly, Wi-Fi gear

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Wi-Fi for wireless broadband• WISPs already use license-exempt spectrum

– Sometimes with a few licensed microwave links• 11g & 11a, rapidly migrating to 11n technology

– Performance advantage is significant• Dramatically lower cost

– 5x or more vs WiMAX or pre-WiMAX systems– Increasing reliability, similar performance

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Ubiquiti targets Wireless ISPs

Point-to-point$180-$600

Point-to-multipoint~$240 & $88

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Example Wi-Fi Pt-2-Pt LinkUbiquiti BULLET-M5-HP With 28dbi Grid Antenna 802.11n

Purchased through distribution:

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Community WISP, Inc.

• Wireless broadband Internet access for all of Brevard County

• Served from 4 locations

• 900 MHz, 2.4 GHz & 5 GHz, i.e. all license-exempt spectrum

• 30/10 Mbps in many areas

• Expanding into Volusia and Seminole counties

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Summary• Wi-Fi will dominate 3G/4G data offload

– Triple play operators already bundling “free” Wi-Fi– 3G/4G service providers will follow

• Eventually, high speed Wi-Fi will be the norm– 3G/4G coverage, merely a fallback

• Wi-Fi fosters resurgence in independent ISPs– Wireless ISPs offering wireless broadband access

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Thank You

Brough Turnerbroughturner@gmail.comrbt@ashtonbrooke.com

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Credits, References• Image credits, beyond those noted in-line…

– Office building facade: http://commons.wikimedia.org/wiki/User:Beek100– Laptop icon: http://www.flickr.com/photos/ichibod/– Microwave oven: http://www.flickr.com/photos/code_martial/

• Other useful references– Novarum Inc. measurements: http://www.novarum.com/publications.php

– NIST Electromagnetic Signal Attenuation in Construction Materials http://fire.nist.gov/bfrlpubs/build97/PDF/b97123.pdf

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802.11n in-the-field• Ken Biba:

– The King is Dead, Long Live the King: 802.11n dramatically improves Wi-Fi outdoors

– Real world measurements show muni Wi-Fi networks outperform WiMAX and cellular

• Tom’s Hardware– Reviews Ruckus Wireless 11n access point with beamforming,

http://www.tomshardware.com/reviews/beamforming-wifi-ruckus,2390.html

• Net, net – it really works!