Transcript wifi technologyx

ASHWINI.B.
NISHA.B.A.
SIVA INSTITUTE OF FRONTIER TECHNOLOGY
AGENDA











History
Introduction
Wifi components
open wireless access point
solution to open wifi
Wifi walkie talkie
Merits
Demerits
Latest Inventions in wifi
References
Conclusions
What is the goal of 802.11 standard ?
To develop a Medium Access Control
(MAC) and Physical Layer (PHY)
specification for wireless connectivity
for fixed, portable and moving stations
within a local area.
3
WiFi
HISTORY
 Invention
 The Name
 Wifi Certification
Wi-Fi FUNDAMENTALS
 Wi-Fi is called Wireless Fidelity, is the wireless way to
handle networking.
 Wi-Fi enabled computers send and receive data, within the
range of a base station.
 Its just as fast as a cable modem connection.
 Allows you to access the Internet, while on the move.
Wi-Fi NETWORK
Do I need any license to use 802.11 device ?
 No , 2.4 GHz and 5.0 GHz are public available frequency !!!
7
WiFi
WiFi compnents
 A PC,




A wireless PCMCIA card, or a wireless adapter
A Network Interface
An Access Point
A valid internet connection.
Access Point (AP)
 An access point is, relaying data between connected wireless
devices in addition to a single connected wired device
WIRELESS ADAPTER
 allows a device to connect to a wireless network. These
adapters connect to devices using various interconnects such
as PCI, USB, PCMCIA
Wireless Router
 A wireless router integrates an AP, Ethernet switch, and
internal Router firmware application that provides IP Routing,
NAT & DNS forwarding through an integrated WAN interface
 It allows wired and wireless Ethernet LAN devices to connect
to single WAN device such as cable modem or DSL modem
Wireless Ethernet Bridge
 A wireless Ethernet bridge connects a wired network to a
wireless network
 This is different from an access point in the sense that an
access point connects wireless devices to a wired network at
the data-link layer
 Two wireless bridges may be used to connect two wired
networks over a wireless link, useful in situations where a
wired connection may be unavailable, such as between two
separate homes.
Range Extender
 Wireless devices connected
through repeaters will
suffer from an increased
latency for each hop.
Additionally, a wireless
device at the end of chain
of wireless repeaters will
have a throughput that is
limited by the weakest link
within the repeater chain.
Open Wireless Access Points
•Is your WiFi “Open”?
•The dangers of open WiFi
•What about the legal implications
SolutionS to “open” WiFi
One possibility:
Mac Address Filtering
• Give my access point a list of allowed clients by their Mac
Address…
• There is a problem though!
• The MAC address is the front of every packet sent,
Anyone with packet sniffing software instantly sees all the
authorized MAC addresses for the wireless network. They
capture even one packet, they've got the MAC address
that they can spoof.
SolutionS to “open” WiFi
Another possibility:
SSID Hiding
• You hide the name of your router so that people don't see it.
• It hides it only from those who aren't using packet sniffers,
hackers see it just fine.
Solutions to “open” WiFi
One last possibility:
Data Encryption
• WEP is one type of encryption
• WEP (Wired Equivalent Privacy)
• Foundation of WEP encryption is an RC4 cipher, is
extremely strong. But it was used in a very bad way.
• Thus WEP is broken!!!
SolutionS to “open” WiFi
Data Encryption
• WPA / WPA2 is the other type of encryption
• WPA (Wi-Fi Protected Access)
• WPA uses TKIP protocol along with RC4 encryption which
changes the key often enough to make it secure
•WPA2 uses AES encryption it doesn't use the RC4
encryption
Wi-Fi WALKIE-TALKIE
 These are small radios that can transmit and receive radio
signals.
 Our voice is picked up by a microphone, encoded onto a radio
frequency and transmitted with the antenna.
 Antenna, decode our voice from the radio signal and drive a
speaker.
 Signal strength is about 0.25 watts.
 Walkie-talkie is designed to handle the human voice.
Merits
 Unlike packet radio systems, Wi-Fi uses unlicensed radio spectrum
 Allows LANs to be deployed without cabling, potentially reducing the
costs of network deployment and expansion.
 Competition amongst vendors has lowered prices considerably since
their inception.
 Wi-Fi networks support roaming, in which a mobile client station such
as a laptop computer can move from one access point to another as the
user moves around a building or area.
 Many access points and network interfaces support various degrees of
encryption to protect traffic from interception.
 Wi-Fi is a global set of standards
Demerits
 Higher Power consumption as compared to some other lowbandwidth standards,
 Many 2.4 GHz 802.11b and 802.11g Access points default to
the same channel on initial startup, contributing to congestion
on certain channels.
 Wi-Fi networks have limited range.
good places to install WiFi?
Basically, any location which caters to business users, and
where people with laptops are likely to make frequent visits
is an ideal choice to install WiFi.
Airports
Hotels & Resorts
Restaurants
Coffee Shops
Bookstores
Shopping Malls
HOTSPOTS
What is a HotSpot?
 A Hotspot is a geographic area that has a readily accessible
wireless network.
 Hotspots are equipped with a Broadband Internet connection.
 One or more Access Points are provided to access the Internet
wirelessly.
 HotSpots can be setup in any public location that can support
an Internet connection.
TYPICAL Wi-Fi USERS
Now that we know about WiFi, who are the likely
users of WiFi services?






Frequent Travelers
Businessmen
Scientists & Doctors
Students and Academicians
Administrators & Technocrats
Just about anybody with a
laptop
Latest invention in wifi
 Wifi signals to electricity
 IEEE 802.16
Wifi signals to electricity
Air Energy:
Able to produce electricity
from wireless Internet
connection.Most useful
inventions for people living
in mega polises
802.11/802.16
Fi
CONCLUSION
Wireless Fidelity is common now. We are expecting more on this
technology in future. Let’s hope for that ….
REFERENCE




"WiMAX™ operators and vendors from around the world
announce new deployments, growing commitment at the 2nd
Annual WiMAX Forum® Global Congress
http://www.authorstream.com/Presentation/aSGuest83926799208-wireless-fidelity-new/
http://www.ohgizmo.com/wp-content/uploads/2010/01