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June 4, 2008
Vermelding onderdeel organisatie
1
The genesis of WiFi and its applications
CERN, Geneva, Switzerland
Ing. Vic Hayes, “Father of Wi-Fi” andDr. Ir. Wolter Lemstra
Senior Research Fellows, Delft University of Technology
Faculty Technology, Policy and ManagementSection Economics of Infrastructures
June 4, 2008 2
Outline• What is Wi-Fi?• How did Wi-Fi come about?
• Regulations US• The development of the standard• Regulations Europe
• Applications• Conclusion
June 4, 2008 3
What is Wi-Fi…
• Wi-Fi is the certification mark of the Wi-Fi Alliance• For devices working according to the IEEE 802.11
family of standards that have been tested on interoperability
• For broadband, wireless, communication between computers and access points
www.wi-fi.org
June 4, 2008 4
The Success of Wi-Fi…
The preferred means for connecting to the Internet• At home…• In the office…• In hotels, restaurants, coffee shops…• At airports, rail-way stations…• At universities…
For exchanging emails, business data, market information, and increasingly for voice (skype)
www.wi-fi.org
June 4, 2008 5
0
1000
2000
3000
4000
5000
6000
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006Year
Num
ber o
f dev
ice
appr
oval
s in
the
US
of A
915 MHz
5850 MHzU-NII
2450 MHz
1985FCC permits
Spread Spectrum in 3 bands “designated
for ISM”
June 4, 2008 6
The start of the whole exercise
• In the time of President Reagan, the policy was to minimize regulation to enable innovation
• Continued with the Carter Administration• FCC played their role by assigning three bands for the use
by devices that did not need an end-user license, provided that they used spread spectrum
• Release was in May 1985, Dr Michael Marcus was a key player
• Used the device approval graph as the background for the time axis
• Note yourself the role of IEEE 802.11
June 4, 2008 7
Spread Spectrum
• Precedence that a regulator required the use of more spectrum than needed for the data transfer• Enables more robust data transfer• Lowers interference to other users by lowering the power density
• The FCC permitted two types of Spread Spectrum:• Frequency Hopping Spread Spectrum• Direct Sequence Spread Spectrum
• Original proposal was to use overlay over other services• Too many complaints from incumbent users• FCC selects bands designated for the use of Industial, Scientific and
Medical Applications• Micro wave ovens do not complain
June 4, 2008 8
MultipathReflections add or subtract
June 4, 2008 9
MultipathReflections add or subtract
2400 2420 2440 2460 2480 250030
20
10
0
10
Frequency selective lossin dB
for 2.4 GHz bandat some indoor channel
( 100 nsec )
Frequency in MHz
June 4, 2008 10
Frequency Hopping principle
1 23 45 6 78 910 11 Frequency
Energy
Operate in one “channel”at a time for maximum300 ms.Pick channel accordingto pseudo-random code.
Channel width 1MHz, 79 channels
use all channelsbefore re-using one
By selecting patterns with pseudo random codes that have minimum interference chance, CDMA can be done, although thoses code are not“collision free”
Three sets with best patterns available
June 4, 2008 11
2400 2420 2440 2460 2480 250030
20
10
0
10
Frequency selective lossin dB
for 2.4 GHz bandat some indoor channel
( 100 nsec )
Frequency in MHz
FH protection against FadingVery limited performance in this hop
Next hop is better
June 4, 2008 12
Direct Sequence transmitterData
X11 chip code
Direct SequenceSpread Spectrum
Signal
Power
Frequency
Power
Frequency
+1-1
+1 -1 -1 -1 -1 -1+1 +1 +1 +1 +1
June 4, 2008 13
Direct Sequence receiver
Data
:11 chip code
Direct SequenceSpread Spectrum
Signal Data
Interference+11
-11
+1
-1
June 4, 2008 14
Robustness against multipath
echo
echo
peak
June 4, 2008 15
2400 2420 2440 2460 2480 250030
20
10
0
10
Frequency selective lossin dB
for 2.4 GHz bandat some indoor channel
( 100 nsec )
Frequency in MHz
DS Robustness
Sufficient information available to correlate
June 4, 2008 16
0
1000
2000
3000
4000
5000
6000
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006Year
Num
ber o
f dev
ice
appr
oval
s in
the
US
of A
915 MHz
5850 MHzU-NII
2450 MHz
1985FCC permits
Spread Spectrum in 3 bands “designated
for ISM”
NCR initiates
feasibility study
June 4, 2008 17
Initiation of feasibility study
• NCR is a manufacturer of terminals for Financial and Retail Institutions
• Retailers need to change floor plans regularly and have marble floors• Hard to change the cabling
• The availability of unlicensed spectrum opened the way to get competitive advantage by cutting the need for network cabling with wireless cash registers
• Cash registers were built on IBM PC platform• No hard disk drives so initial program load needed to be
through the network• Guess when most of the registers needed program load
June 4, 2008 18
Our first prototype
June 4, 2008 19
Second prototype
June 4, 2008 20
Saw filter
• Made at the micro-elektronic lab of TU Delft
• Part of a PhD research of Ir. Jaap Haartsen
• Now Professor Dr. Ir Jaap Haartsen at University Twente
June 4, 2008 21
0
1000
2000
3000
4000
5000
6000
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006Year
Num
ber o
f dev
ice
appr
oval
s in
the
US
of A
915 MHz
5850 MHzU-NII
2450 MHz1988IEEE 802.4lreactivated
1985FCC permits
Spread Spectrum in 3 bands “designated
for ISM”
NCR initiates
feasibility study
June 4, 2008 22
Reasons to make an industry standard
• Become an industry leader• NCR customers eventually needed to process their
business information system on IBM computers• NCR obliged to emulate IBM terminals to reach the IBM
mainframe• Always a follower, always later on the market• By leading the standards process, become the leader
• Prevent chaos in the spectrum
June 4, 2008 23
Place of standardization
• With the release of the IEEE 802.3, Ethernet, standard in 1985 and its success it was clear that the success story was in the LAN/MAN Standards Committee, LMSC or IEEE Project 802
• Work can only be done under an approved “Project Authorization Request”
• I found one that already was approved in the Token Bus protocol group IEEE P802.4. A bus structure looked pretty much feasible for radio
• However the group was already dormant and I had to take the lead to wake it up.
June 4, 2008 24
0
1000
2000
3000
4000
5000
6000
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006Year
Num
ber o
f dev
ice
appr
oval
s in
the
US
of A
915 MHz
5850 MHzU-NII
2450 MHz1988IEEE 802.4lreactivated
1985FCC permits
Spread Spectrum in 3 bands “designated
for ISM”
NCR initiates
feasibility study
NCR pro-duct dev.
NCR Product release
June 4, 2008 25
First NCR product
1990
IBM PC AT adapter withexternal antenna from a later release1 channel at 2 Mbit/s915 MHz band
June 4, 2008 26
0
1000
2000
3000
4000
5000
6000
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006Year
Num
ber o
f dev
ice
appr
oval
s in
the
US
of A
915 MHz
5850 MHzU-NII
2450 MHzJuli 1990establishment IEEE 802.11
1988IEEE 802.4lreactivated
1985FCC permits
Spread Spectrum in 3 bands “designated
for ISM”
NCR initiates
feasibility study
NCR pro-duct dev.
NCR Product release
June 4, 2008 27
Back into history• 1990• PCs were rare at meetings• Weight, including bag and
power adapter:• 8 kg
• Input/output:• 2,5” floppy • 9,6 kbit/s modem
June 4, 2008 28
0
1000
2000
3000
4000
5000
6000
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006Year
Num
ber o
f dev
ice
appr
oval
s in
the
US
of A
915 MHz
5850 MHzU-NII
2450 MHzJuni 1997
IEEE approves802.11
Juli 1990establishment IEEE 802.11
1988IEEE 802.4lreactivated
1985FCC permits
Spread Spectrum in 3 bands “designated
for ISM”1991
CEPT permits 2.4 GHz band
NCR initiates
feasibility study
NCR pro-duct dev.
NCR Product release
June 4, 2008 29
Deelnemers per vergadering
0
20
40
60
80
100
120
140
90se
p91
jan91
may91
sep
92jan
92may
92se
p93
jan93
may93
sep
94jan
94may
94se
p95
jan95
may95
sep
96jan
96may
96no
v97
mar97
jul97
nov
98mar98
jul98
nov
99mar99
jul
jaar/maand
Aan
tal p
erso
nen
Aanwezigen InterimAanwezigen Plenaire
Selection MAC
Board approval 1st stdJuni 97
Technologyproposalsarriving
Sponsor ballot
July 96
WG ballotNov 94
June 4, 2008 30
1997, 1st standard approved
June 4, 2008 31
1998, Using our own product
June 4, 2008 32
0
1000
2000
3000
4000
5000
6000
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006Year
Num
ber o
f dev
ice
appr
oval
s in
the
US
of A
June 1997IEEE approves
802.11
September 1999.IEEE approves802.11a and.11b
915 MHz
5850 MHzU-NII
2450 MHzJuli 1990establishment IEEE 802.11
1988IEEE 802.4lreactivated
1985FCC permits
Spread Spectrum in 3 bands “designated
for ISM”1991
CEPT permits 2.4 GHz band
1997FCC
permits U-NII devices
1999CEPT expands 5
GHz with 255 MHz
NCR initiates
feasibility study
NCR pro-duct dev.
NCR Product release
1992CEPT permits 150
MHz in 5 GHz band
June 4, 2008 33
The group after approval of 11a and 11b
June 4, 2008 34
0
1000
2000
3000
4000
5000
6000
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006Year
Num
ber o
f dev
ice
appr
oval
s in
the
US
of A
June 1997IEEE approves
802.11
September 1999.IEEE approves802.11a and.11b
915 MHz
5850 MHzU-NII
2450 MHzJuli 1990establishment IEEE 802.11
1988IEEE 802.4lreactivated
1985FCC permits
Spread Spectrum in 3 bands “designated
for ISM”1991
CEPT permits 2.4 GHz band
1997FCC
permits U-NII devices
1999CEPT expands 5
GHz with 255 MHz
NCR initiates
feasibility study
NCR pro-duct dev.
NCR Product release
1992CEPT permits 150
MHz in 5 GHz band
Apple/Lucent deal
WECA established
June 4, 2008 35
The Success of Wi-Fi…1990 (proprietary) $ 1370.00 @ 2 Mbit/s
2007Built into every PC$ 99.99 @ 11 Mbit/s
2000 (Std)
June 4, 2008 36
Forcing market success takes time,money, perseverance and some luck
June 4, 2008 37
Price erosion
0
200
400
600
800
1000
1200
1400
1600
1985 1990 1995 2000 2005 2010
Year
US$
June 4, 2008 38
Wi-Fi came to life
• With the success of the Apple/Lucent Technologies deal the Chasm had been crossed
• WECA became Wi-Fi Alliance and built user-friendliness and user-trust
• Competition brought price reduction• Wi-Fi became attractive
• Continued progress with both spectrum rules and technology:
June 4, 2008 39
0
1000
2000
3000
4000
5000
6000
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006Year
Num
ber o
f dev
ice
appr
oval
s in
the
US
of A
June 1997IEEE approves
802.11
September 1999.IEEE approves
802.11a and.11b
915 MHz
5850 MHzU-NII
2450 MHzJuli 1990
establishment IEEE 802.11
1988IEEE 802.4lreactivated
1985FCC permits
Spread Spectrum in 3 bands “designated
for ISM”1991
CEPT permits 2.4 GHz band
1997FCC
permits U-NII devices
1999CEPT expands 5
GHz with 255 MHz
2003. WRC allocates
455 MHz co-primary spectrum
in 5 GHz band
June 2003.IEEE approves
802.11g
NCR initiates
feasibility study
NCR pro-duct dev.
NCR Product release
1992CEPT permits 150
MHz in 5 GHz band
Apple/Lucent deal
WECA established
2002 FCC permits Digital Transmission
Systems
June 4, 2008 40
Outline• What is Wi-Fi?• How did Wi-Fi come about?
• Regulations US• The development of the standard• Regulations Europe
• Applications• Conclusion
June 4, 2008 41
Kofi Annan Expresses a Bold Wi-Fi Vision
"With considerablespeed and withoutenormous investments, Wi-Fi can facilitateaccess to knowledgeand information, forexample by making useof unlicensed radio spectrum to delivercheap and fast Internet access.
—From UN Secretary-General KofiAnnan’s welcoming message to "The Wireless Internet Opportunity forDeveloping Countries" conference at UN Headquarters in New York on June 26, 2003http://w2i.com/resource_center/white_papers/p/subCat_1
Indeed, it is precisely in places whereno infrastructure exists that Wi-Fi canbe particularly effective, helpingcountries to leapfrog generations of telecommunications technology and infrastructure and empower theirpeople."
June 4, 2008 42
Examples Wi-Fi applications
Equador www.postalportals.nl
Nepal
USA, South CaliforniaDenmark
Berlin, Germany
www.nepalwireless.net
www.sctdv.net/
www.diirwb.net/
freifunk.net/community
June 4, 2008 43
18 km
32 km
Going to Nepal
June 4, 2008
Vermelding onderdeel organisatie
44
Nepal Wireless Networking ProjectRun by Himanchal Higher Secondary School, Myagdi
Mahabir Pun, 2006
June 4, 2008 45
Background
• No roads• No means of electronic communication -
even post offices• No clinics• Not enough teachers in government schools• No means of selling farm products• Trying to kill these birds with one stone
June 4, 2008 46
Mahabir Pun, 2006
June 4, 2008 47
One of the nodes in Nepal
Mahabir Pun, 2006
June 4, 2008 48
Uses of the Nepal Network
• E-mail, Internet Browsing, Chatting• Post messages, announcements, stories, etc in the
bulletin board
Mahabir Pun, 2006
June 4, 2008 49
Uses of the Nepal Network
• Local PC-PC telephone system• STD and ISTD call through Nepal Telecom Line
Mahabir Pun, 2006
June 4, 2008 50
Uses of the Nepal Network
• Reference materials for students and teachers• Live tele-teaching
Mahabir Pun, 2006
June 4, 2008 51
Uses of the Nepal Network
• Telemedicine with Om Hospital in Pokhara
Mahabir Pun, 2006
June 4, 2008 52
Uses of the Nepal Network
• Local e-commerce• Access to price information:
• No cheating with prices
June 4, 2008 53
Final remark Nepal Network
• More information: http://www.nepalwireless.net/• 5 Full time jobs, 3 part time jobs
• Mahabir Pun - Team Leader
• Presentation to Parliament resulted in de-licensing of spectrum
• won the Ramon Magsaysay award 2007 for his work in setting up and using the Nepal Wireless Network
Mahabir Pun, 2006
June 4, 2008 54
Going to Djursland
June 4, 2008 55
Also in developed countriesIn Denmark 95 % of the people live within a Broadband
distribution pointThey are connected to 1600 DSL exchangesTo connect the last 5 % (rural areas) they need an additional
4600 DSL exchangesNo economic forces to install thoseIn Djursland 25 % of the population could not be connected
June 4, 2008 56
Roll out an IEEE 802.11 network
Purple: within 1.5 km from antennaOrange: within 3 km from antennaYellow: within 5 km from antenna
5000 connected householdsISP get all business to InternetWithout any investment in infrastructure
Nielsen, DIIRWB, 2006
June 4, 2008 57
Wi-Fi is changing economics
Nielsen, DIIRWB, 2006
• If incumbent operators can not or will not provide Internet access…
• Citizens and Villagers can and will step in
• Wi-Fi based Wireless Community Initiatives
• Typical examples:• Djursland Denmark• AirJaldi Tibet/India• Mérida Venezuela
Purple: within 1.5 km from antennaOrange: within 3 km from antennaYellow: within 5 km from antenna
June 4, 2008 58
Shaped by users
• The original Wireless-LAN moved from:• Corporate Networking to Private Networking• Private Domain use to Public domain use• From Free to a Fee to Free• Corporate investments to Operator investment to
Community investments• In-door to Out-door• Stationary to Nomadic
• WLAN enables closing of the “Digital Divide”:• In Developing countries in Developed countries
June 4, 2008 59
Outline• What is Wi-Fi?• How did Wi-Fi come about?
• Regulations US• The development of the standard• Regulations Europe
• The Dutch roots• Applications• Conclusion
June 4, 2008 60
Conclusion
• The success of Wi-Fi can be traced back to• The change in Government policy, i.e. the 1985 decision
of the FCC to allow unlicensed spectrum• The standardization effort of the IEEE 802.11 WG• The global availability of harmonized spectrum, and• The work of the Wi-Fi Alliance
• Freedom triggered user innovation• Triggered social compassion
June 4, 2008 61
• Stay tuned for more information on "the genesis of Wi-Fi and the road toward global success" in a forthcoming edited book by Lemstra, Groenewegen, Hayes and many others.