Post on 05-Apr-2018
7/31/2019 Parwez Wifi
1/26
Wi-Fi Technology
7/31/2019 Parwez Wifi
2/26
Wireless Technology is an alternative to WiredTechnology, which is commonly used, forconnecting devices in wireless mode.
Wi-Fi Network connect computers to each other, tothe internet and to the wired network.
Wi-Fi works on physical and data link layer.
7/31/2019 Parwez Wifi
3/26
The purpose of Wi-Fi is to hide complexity by enablingwireless access to applications and data, media and streams.
The main aims of Wi-Fi are the following: make access to information easier
ensure compatibility and co-existence of devices
eliminate complex cabling
eliminate switches, adapters, plugs, pins and connectors
7/31/2019 Parwez Wifi
4/26
The term Wi-Fi suggests Wireless
Fidelity, resembling the long-
established audio-equipmentclassification term high fidelity (in
use since the 1930s ) or Hi-Fi (usedsince 1950).
7/31/2019 Parwez Wifi
5/26
The technology used in Wi-Fi is easiest to understand in terms of radio.It is quite similar to walkie-talkies, the only difference being in the
strength of signals.
An ordinary walkie-talkie can handle only limited data in the range of
1000 bits per second, and operate at 49 MHz. In the case of Wi-Fi
radios, the signal strength is much more, so they can handle much
higher data rates. Wi-Fi radios typically operate at a frequency of
2.4GHz.
There are three versions of Wi-Fi radios currently available- the ones
that work with, 802.11b
802.11g
802.11a
While the first two- 802.11b and 802.11g- transmit 2.4 GHz, the radios
operating at 802.11a standard can transmit at 5GHz.
7/31/2019 Parwez Wifi
6/26
Appeared in late 1999
Operates at 2.4GHz radio spectrum
11 Mbps (theoretical speed) - within 30 m Range
4-6 Mbps (actual speed) 100 -150 feet range
Most popular, Least Expensive
Interference from mobile phones and Bluetooth devices whichcan reduce the transmission speed.
7/31/2019 Parwez Wifi
7/26
Introduced in 2001
Operates at 5 GHz (less popular)
54 Mbps (theoretical speed)
15-20 Mbps (Actual speed)
50-75 feet range
More expensive
Not compatible with 802.11b
7/31/2019 Parwez Wifi
8/26
Introduced in 2003
Combine the feature of both standards (a,b)
100-150 feet range
54 Mbps Speed
2.4 GHz radio frequencies
Compatible with b
7/31/2019 Parwez Wifi
9/26
7/31/2019 Parwez Wifi
10/26
Access Point (AP) - The AP is a wireless LAN transceiver orbase station that can connect one or many wireless devicessimultaneously to the Internet.
Wi-Fi cards - They accept the wireless signal and relayinformation. They can be internal and external.(e.g PCMCIACard for Laptop and PCI Card for Desktop PC)
Safeguards - Firewalls and anti-virus software protect networksfrom uninvited users and keep information secure.
7/31/2019 Parwez Wifi
11/26
Basic concept is same as Walkie talkies.
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 up to 300 feet.
Many access points can be connected to each other via
Ethernet cables to create a single large network.
7/31/2019 Parwez Wifi
12/26
7/31/2019 Parwez Wifi
13/26
The client communicate through Access Point.
BSA-RF coverage provided by an AP.
ESA-It consists of 2 or more BSA.
ESA cell includes 10-15% overlap to allow roaming.
7/31/2019 Parwez Wifi
14/26
AP is not required.
Client devices within a cell can communicate directly with
each other.
It is useful for setting up of a wireless network quicklyand easily.
7/31/2019 Parwez Wifi
15/26
This is used to connect a LAN in one building to a LANs in
other buildings even if the buildings are miles apart. These
conditions receive a clear line of sight between buildings. The line-of-sight range varies based on the type of wireless
bridge and antenna used as well as the environmental conditions.
7/31/2019 Parwez Wifi
16/26
Wi-Fi is composed of three main sectors:
Home (individual residences and apartment buildings)
Public (Round about 70,000 hotspots through out the world)
Enterprise (corporations, universities, office parks)
7/31/2019 Parwez Wifi
17/26
7/31/2019 Parwez Wifi
18/26
Home
Small Businesses
Large Corporations & Campuses
Health Care
Wireless ISP (WISP)
Travellers
7/31/2019 Parwez Wifi
19/26
Service Set Identifier (SSID)
Wired Equivalent Privacy (WEP)
Wireless Protected Access (WPA)
IEEE 802.11i
WEP and WPA are encryption protocols that you can choose fromin your router's firmware.
Wi-Fi Protected Access (WPA), a subset of the upcoming 802.11i
security standard, will replace the flawed Wired Equivalent Privacy(WEP).
Without your SSID, people will not be able to join your Wi-Fihotspot.
7/31/2019 Parwez Wifi
20/26
Mobility
Ease of Installation
Flexibility
Cost Reliability
Security
Use unlicensed part of the radio spectrum
Roaming Speed
7/31/2019 Parwez Wifi
21/26
Interference
Degradation in performance
High power consumption
Limited range
7/31/2019 Parwez Wifi
22/26
7/31/2019 Parwez Wifi
23/26
7/31/2019 Parwez Wifi
24/26
7/31/2019 Parwez Wifi
25/26
7/31/2019 Parwez Wifi
26/26