Wi-Fi is a popular technology that allows electronic devices to connect to the internet or exchange data wirelessly using radio waves. It uses the IEEE 802.11 standards and devices must complete certification testing by the Wi-Fi Alliance to use the Wi-Fi trademark. Wi-Fi has a limited range of about 65 feet indoors but this can be extended using multiple access points. While convenient, Wi-Fi connections can be less secure than wired connections so encryption protocols are used.

1. Wi-Fi Technology

2. Definition
• Wi-Fi, also spelled Wifi or WiFi, is a popular
technology that allows an electronic device to
exchange data or connect to the internet
wirelessly using radio waves.
• The name is a trademark name, and was
stated to be a play on the audiophile term HiFi.

3. • The Wi-Fi Alliance defines Wi-Fi as any
"wireless local area network (WLAN) products
that are based on the Institute of Electrical
and Electronics Engineers' (IEEE) 802.11
standards"

4. Trademark
• Only Wi-Fi products that complete Wi-Fi
Alliance interoperability certification testing
successfully may use the "Wi-Fi CERTIFIED"
trademark.

5. Devices
• Many devices can use Wi-Fi, e.g. personal
computers, video-game consoles,
smartphones, some digital cameras, tablet
computers and digital audio players.

6. Hotspot
• Wifi hotspot has a range of about 20 meters
(65 feet) indoors and a greater range
outdoors.
• Hotspot coverage can comprise an area as
small as a single room with walls that block
radio waves, or as large as many square miles
achieved by using multiple overlapping access
points

7. Security
• Wi-Fi can be less secure than wired
connections (such as Ethernet) because an
intruder does not need a physical connection.
Web pages that use SSL are secure but
unencrypted internet access can easily be
detected by intruders

8. • Because of this, Wi-Fi has adopted various
encryption technologies. The early encryption
WEP, proved easy to break. Higher quality
protocols (WPA, WPA2) were added later.

9. Wi-Fi certification
• The IEEE does not test equipment for
compliance with their standards. The nonprofit Wi-Fi Alliance was formed in 1999 to fill
this void — to establish and enforce standards
for interoperability and backward
compatibility, and to promote wireless localarea-network technology. As of 2010, the WiFi Alliance consisted of more than 375
companies from around the world

10. Certification Process
• Specifically, the certification process requires
conformance to the IEEE 802.11 radio
standards, the WPA and WPA2 security
standards, and the EAP authentication
standard. Certification may optionally include
tests of IEEE 802.11 draft standards,
interaction with cellular-phone technology in
converged devices, and features relating to
security set-up, multimedia, and powersaving.

11. Internet access
• A Wi-Fi-enabled device can connect to the
Internet when within range of a wireless
network which is configured to permit this.
The coverage of one or more (interconnected)
access points called hotspots can extend from
an area as small as a few rooms to as large as
many square miles

12. City-wide Wi-Fi
• In the early 2000s, many cities around the
world announced plans to construct city-wide
Wi-Fi networks. There are many successful
examples; in 2004, Mysore became India's
first Wi-Fi-enabled city and second in the
world after Jerusalem. A company called
WiFiyNet has set up hotspots in Mysore,
covering the complete city and a few nearby
villages.

13. • In 2005, Sunnyvale, California, became the
first city in the United States to offer city-wide
free Wi-Fi. Minneapolis has generated $1.2
million inIn May 2010, London, UK, Mayor
Boris Johnson pledged to have London-wide
Wi-Fi by 2012. Several boroughs including
Westminster and Islington already have
extensive outdoor Wi-Fi coverage. profit
annually for its provider

14. • In May 2010, London, UK, Mayor Boris
Johnson pledged to have London-wide Wi-Fi
by 2012. Several boroughs including
Westminster and Islington already have
extensive outdoor Wi-Fi coverage.

15. Campus-wide Wi-Fi
• any traditional college campuses in the United
States provide at least partial wireless Wi-Fi
Internet coverage. Carnegie Mellon University
built the first campus-wide wireless Internet
network, called Wireless Andrew, at its Pittsburgh
campus in 1993 before Wi-Fi branding originated.
• In Europe many universities collaborate in
providing Wi-Fi access to students and staff
through the eduroam international
authentication infrastructure.

16. • In 2000, Drexel University in Philadelphia
became the United States' first major
university to offer completely wireless
Internet access across its entire campus. The
Far Eastern University in Manila is the first
university in the Philippines to implement a
campus-wide Wi-Fi coverage.

17. Advantages
• Wi-Fi allows cheaper deployment of local area
networks (LANs). Also spaces where cables
cannot be run, such as outdoor areas and
historical buildings, can host wireless LANs.
• Manufacturers are building wireless network
adapters into most laptops. The price of
chipsets for Wi-Fi continues to drop, making it
an economical networking option included in
even more devices

18. Range
• Wi-Fi networks have limited range. A typical
wireless access point using 802.11b or 802.11g
with a stock antenna might have a range of 35 m
(120 ft) indoors and 100 m (300 ft) outdoors. IEEE
802.11n, however, can more than double the
range.
• Range also varies with frequency band. Wi-Fi in
the 2.4 GHz frequency block has slightly better
range than Wi-Fi in the 5 GHz frequency block
which is used by 802.11a and optionally by
802.11n

19. Wifi Adapter

20. Wifi Module

21. Piggybacking
• Piggybacking refers to access to a wireless
Internet connection by bringing one's own
computer within the range of another's wireless
connection, and using that service without the
subscriber's explicit permission or knowledge.
• During the early popular adoption of 802.11,
providing open access points for anyone within
range to use was encouraged to cultivate wireless
community networks,particularly since people on
average use only a fraction of their downstream
bandwidth at any given time.

22. Safety
• The World Health Organization (WHO) says
"there is no risk from low level, long-term
exposure to wi-fi networks" and the United
Kingdom's Health Protection Agency reports
that exposure to Wi-Fi for a year results in the
"same amount of radiation from a 20-minute
mobile phone call"

23. • Thank You