Wi-Fi Technology : Wi-Fi Technology By
G Sathish Reddy &
N Upendranath Agenda : Agenda What is Wi-Fi
How it works
Advantages and Limitations What is Wi-Fi ? : What is Wi-Fi ? Wi-Fi is an abbreviation for wireless-fidelity known as 802.11 wireless network.
Wi-Fi Wireless Technology that uses radio frequency to transmit data through the air.
Wi-Fi is a generic term that refers to the IEEE 802.11 communications standard for Wireless Local Area Networks (WLANs) .
Wi-Fi Network connect computers to each other ,to the internet and to the wired network. Wi-Fi standards : Wi-Fi standards IEEE 802.11b( 1999)
IEEE 802.11g(2003) Wi-Fi (802.11b) : Wi-Fi (802.11b) It operates in 2.4 GHz frequency range.
Limits to the number of Access points in range of each other, and three .
It having 1 to 11 Mbps speed ,but realistically about 4-5 Mbps.
It uses direct sequence spread spectrum technology.
It is having the range of 100-300 feet indoor and 400 -1500 feet outdoor . Wi-Fi (802.11a) : Wi-Fi (802.11a) This is operates in 5GHz frequency.
Multiple channels can be configured faster throughput and more Access points can be allocated.
It is having 6-54Mbps speed realistically about 27Mbps.
It uses the frequency division multiplexing technology.
It is having the range of 40-300feet indoor
and 100-1000feet out door. Wi-Fi (802.11g) : Wi-Fi (802.11g) It is extension of 802.11b,and shorter range than 802.11b.
Flexible because multiple channels can be combined for faster throughput, but limited to one access point.
Runs at 54Mbps ,realistically about 20-25Mbps.
It uses the frequency division multiplexing technology. Elements : Elements Access points : It is a wireless LAN transceiver or base station that are connect one or many wireless devices simultaneously to the internet.
Wi-Fi cards : they accept the wireless signals and relay information .they can be internal and external. (ex; PCI,PCMCIA)
Safe guards :firewalls and antivirus software protect networks from invited users and keep information secure. How a Wi-Fi Network Works : How a Wi-Fi Network Works A Wi-Fi hotspot is created by installing an access point to an internet connection.
An access point acts as a base station.
When Wi-Fi enabled device encounters a hotspot the device can then connect to that network wirelessly.
A single access point can support up to 30 users and can function within a range of 100 – 150 feet indoors and up to 300 feet outdoors.
Many access points can be connected to each other via Ethernet cables to create a single large network. Security : Security Wireless technology doesn’t remove any old security issues, but introduces new ones
Denial of Service Eavesdropping : Eavesdropping By default, everything is transmitted in clear text
Usernames, passwords, content ...
No security offered by the transmission medium
Different tools available on the internet
Network sniffers, protocol analysers . . .
Password collectors MITM Attack : MITM Attack Attacker spoofes a disassociate message from the victim
The victim starts to look for a new access point, and the attacker advertises his own AP on a different channel, using the real AP’s MAC address
The attacker connects to the real AP using victim’s MAC address Denial of Service : Denial of Service Attack on transmission frequecy used
Not very technical, but works
Attack on MAC layer
Spoofed deauthentication / disassociation messages
can target one specific user
Attacks on higher layer protocol (TCP/IP protocol)
SYN Flooding Advantages : Advantages Mobility.
Speed. Limitations : Limitations Interference.
Hi power consumption .