WiFi
IT 101
Zaid Shahsamand, Michael Gutierrez,
Brian Jaggassar, BryanSamson,
Shahen Desilva Udugampola
History of Wi-Fi
In 1985 the FCC allowed the opening of several bands of
the wireless spectrum. Allowing those bands to be used
without government license.
The bands were taken from the scientific, medical, and
industrial bands of the wireless spectrum.
The FCC made these bands available for communication
purposes.
Using spread spectrum technology, which spreads a
radio signal over wide range of frequencies they were
able to steer around interference from other equipment.
When Ethernet became popular vendors came to the
realization that a wireless standard was best.
History of Wi-Fi continued….
In 1988, the NCR Corporation wanted to use the
unlicensed spectrum to hook up wireless cash register,
they looked into getting a standard started.
Victor Hayes and Bruce Tuch were hired and they went
to the ICEE and created the committee known as 802.3.
Vendors took a while to agree on an acceptable
standard due to the fragmented market.
In 1997 the committee agreed on a basic specification
that allowed for a data-transfer rate of two megabits per
second.
Two technologies known as frequency hopping, and
direct-sequence transmission allowed for this data-
transfer rate.
History of Wi-Fi continued
The new standard was finally published in 1997, and engineers
immediately began working on prototype equipment that was
compliant.
Two variants 802.11b (operates in 2.4GHz band), and 802.11a
(operates in 5.8GHz band) were ratified in December 1999 and
January 2000 respectively.
Companies soon began creating 802.11b companies arose.
In August 1999 the Wireless Ethernet Compatibility Alliance (WECA)
was created with the intention to assure compatibility between
products from various vendors.
A consumer friendly name was need for this new technology and the
term “Wi-Fi” came to be.
Apple was the first to supply their computers with Wi-Fi slots on all
their laptops, thus sparking the mainstream penetration of Wi-Fi.
It’s Easy!
A wireless network that uses radio waves, just like cell phones, televisions and radios
do. In fact, communication across a wireless network is a lot like two-way radio
communication. Here's what happens:
A computer's wireless adapter translates data into a radio signal and transmits it
using an antenna.
A wireless router receives the signal and decodes it. It sends the information to the
Internet using a physical, wired Ethernet connection.
The radios used for Wi-Fi communication are very similar to the radios used for walkie-
talkies, cell phones and other devices. They can transmit and receive radio waves, and
they can convert 1’s and 0’s into radio waves and convert the radio waves back into 1s and
0s
Very useful and convenient due to accessibility and cheap prices.
Easy to use. All that’s needed is the proper hardware
devices and signal transmitters and receivers.
-Many electronic devices use
Wi-Fi due to its simple
functions.
-Companies use Wi-Fi to
create wireless network
within their company
-Phone companies such as
T-mobile use the new Wi-Fi
Hot Spots for their users to
get free calling/internet
access.
-Nintendo uses Wi-Fi to synch
their products and to use
global network usage.
Protocols and Security
Protocols
802.11a: Transmits at 5GHz and can
move up to 54 megabits of data per
second. It uses Orthogonal Frequency-
Division Multiplexing or (OFDM). This is a
more efficient coding technique that splits
that radio signal into several sub-signals
before they reach a receiver which greatly
reduces interference.
Protocols
802.11b: Transmits at 2.4 GHz and can move up
to 11 megabits of data per second. It uses
Complimentary Code Keying or (CCK) coding.
This coding is a set of 64 eight-bit code words
used to encode data that have unique
mathematical properties that allow them to be
correctly distinguished from one another by a
receiver even in the presence of substantial
noise and multipath interference. This is the
slowest and consequently the least expensive of
all the sections.
Protocols
802.11g: Transmits at 2.4 GHz like
802.11b, but can move up to 54 megabits
of data per second. This is because it
uses the Orthogonal Frequency-Division
Multiplexing coding technique. This is the
most commonly used protocol today.
Protocols
802.11n: Transmits optionally at 2.4 GHz or 5
GHz and can move up to 248 megabits of data
per second. It uses Multiple-Input and Multiple-
Output, or (MIMO). This is the use of multiple
antennas at both at the transmitter and receiver
to improve communication performance. It
achieves this without additional bandwidth or
transmit power by using a higher spectral
efficiency and link reliability.
Security
MAC Address Filter- This allows a user to
permit or block a list of MAC addresses for
use of your wireless router. I allow the
MAC addresses of my laptop and
Nintendo Wii only for use of my wireless
router.
Security
WEP Encryption- This stands for Wired
Equivalency Privacy. This was the
original encryption for wireless networks.
The common key lengths are currently
128- and 256-bit. The longer the key is the
harder chance a cracker would have to get
into your network.
Security
WiFi Protected Access or (WPA) which
was created by the WiFi Alliance. It uses
a TKIP algorithm which is supposed to
improve WEP encryption. It uses a pre-
Shared Key or (PSK) and RADIUS
servers.
Security
(WPA2) is the enhancement of WPA which makes the
AES-CCMP algorithm mandatory.
802.1X
Lightweight Extensible Authentication Protocol or
(LEAP)
Protected Extensible Authentication Protocol or
(PEAP)
Temporal Key Integrity Protocol or (TKIP)
Remote Authentication Dial In User Service or
(RADIUS)
WLAN Authentication and Privacy Infrastructure or
(WAPI)
Advantages and Disadvantages of
Wi-Fi.
Freedom of Wi-Fi
Wireless
Laptops can move from place to place.
Can stream files from one computer to
another.
Range is not limited by wires.
(Can connect from outdoors).
Wi-Fi and Gaming
Portable gaming systems
(Nintendo DS, Playstation Portable)
Can link with each other
for multiplayer gaming.
Wi-Fi and gaming
Can also connect to the
internet via “Hot Spot”.
- Play with others online.
- Surf the web.
- Download Media.
Wi-Fi and Gaming
Game consoles: PS3, XBOX 360, Wii have available
Wi-Fi.
Can connect to the internet wirelessly.
Can perform as a media center.
Disadvantages of Wi-Fi
Security
Bandwidth
- Use Encryption
- Slow speed at public
areas. (Campuses, Cafe)
- Install Firewalls
- Set up Wi-Fi connection
- Install Anti-Virus away from Electro
programs. Magnetic Radiating
devices. (Microwaves)
Disadvantages of Wi-Fi
Wi-Fi’s link to Autism
- November press release links Wi-Fi to Autism.
- Experiments were ran, including children exposed
to Wireless Technology (Wi-Fi, Cellphones)
- Claimed that Wi-Fi caused metal toxins to be
trapped in cells.
Expand of Wi-Fi:
Will pop up in bookstores, coffee
shops, truck stops, marinas, and
airports everywhere.
All limousines will offer Wi-Fi service for
customers on the go.
Major airlines will announce the availability of
Wi-Fi connections during flights.
The number of hotspots in the world today will
multiplying rapidly.
Worldwide hotspots will grow in the next five
years from 28,500 to 208,000.
Car-2-Car Communication:
Funded by the German
government.
The project is called Network on
Wheels (NOW).
The idea is to use 802.11a and b wireless
networks between cars that relate information
about traffic jams and road conditions to one
another.
Will help to improve road safety and efficiency.
Wi-Max Technology:
It’s an upgrade from Wi-Fi.
Range is up to 15 miles, which means that
establishing a few towers would pretty much
make the entire city connected.
Will be less tedious to use.
Mainly people living in rural and undeveloped
areas would surely benefit from it.
Ultra-Wideband:
A power-efficient radio technology.
Allows the transmission and sharing of
information between devices in a high
bandwidth spectrum.
Enables electronics to function wirelessly up to a
range of 30 feet.
One of the first wire-less products to use UWB is
the Belkin CableFree USB Hub.
Transfers data up to 100 times faster than a
Bluetooth connection.