wireless technology

2. Wi-Fi
Wi- Max
BY
ANUSRUTHI P P SASIKUMAR

3. Wi-Fi





Stands for Wireless Fidelity.
Brand licensed by the Wi-Fi Alliance.
Wi-Fi is a local area network technology that was
originally thought to replace the thousands of
miles of LAN cables.
Wireless Local Area Networks (WLAN)
Based on IEEE 802.11

4. IEEE

In 1997, the Institute of Electrical and Electronic Engineers
(IEEE) drafted the 802.11 standard for wireless local area
networking.

In 1999, networking hardware companies accepted the
standard and began manufacturing products using the 802.11b
protocol which operated in the 2.4 GHz range and was capable
of transmitting at speeds of 11 Mbps.

The 802.11a protocol was also released in 1999, operating at
5.8 GHz with transmissions speeds of 54 Mbps, but its cost was
prohibitively high.

5. IEEE Wireless Standards
Wireless Standard
802.11b
802.11g
802.11a
Frequency Range
2.4 – 2.4835 GHz
2.4 – 2.4835 GHz
5.725 - 5.850 GHz
Max Speed
11 MBPS
54 MBPS
54 MBPS
Max Encryption
128 bit WEP
128 bit WEP
152 bit WEP
256 bit AES
Discrete Channels
3
3
8
Natively Compatible
802.11b, 802.11g
802.11b, 802.11g
802.11a
Potential user
Entry level and home
networks
Larger networks, small
business
Large business
concerned with security

6. Sample Wi-Fi Illustration

7. Wireless network design
Any wireless network can be thought of as a combination of
one or more of these types of connections:
• Point-to-Point
• Point-to-Multipoint
• Multipoint-to-Multipoint

8. Point to Point
The simplest connection is the point-to-point link. These links
can be used to extend a network over great distances.

9. Point to Multipoint
When more than one computer communicates with a
central point, this is a point-to-multipoint network.

10. Multipoint to Multipoint
When any node of a network may communicate with any
other, this is a multipoint-to-multipoint network (also
known as an ad-hoc or mesh network)

11. WLAN Architecture—Ad Hoc Mode
 Ad-Hoc mode: Peer-to-peer setup where clients can connect to each other
directly. Generally not used for business networks.

12. Ad Hoc Structure
Mobile stations communicate to each other
directly.
It’s set up for a special purpose and for a
short period of time. For example, the
participants of a meeting in a conference
room may create an ad hoc network at the
beginning of the meeting and dissolve it when
the meeting ends.

13. WLAN Architecture--Mesh
 Mesh: Every client in
the network also acts as
an access or relay point,
creating a “selfhealing” and (in
theory) infinitely
extensible network.
 Not yet in widespread
use, unlikely to be in
homes.

15. Wi-max
WiMAX uses radio microwave technology to provide wireless
internet service to computers and other devices that are equipped
with WiMAX compatible chips for example PDA’s, cell phones etc.
It works more or less like cellular network technology.
The theoretical range of WiMAX is up to 30 miles and achieves
data rates up to 75 Mbps
WiMAX operates in similar manner as Wi-Fi but with two very
convincing differences as compared to Wi-Fi, these are :
o Data rate
o Data range

16. WIMAX / IEEE 802.16
Wimax networks refer to broadband wireless networks that
are based on the IEEE 802.16 standard, which ensures
compatibility and interoperability between broadband
wireless access equipment .

The IEEE 802.16 standards
define how wireless traffics
move
between
subscriber
equipment and core networks.

WiMAX was designed for the
transmission of multimedia
services (voice, Internet, email,
games and others) at high data
rates.
Source: SHASHI JAKKU

17. Features
Use microwave for the wireless transfer of data.
Specifies a frequency band in the range between 2 GHz to
66 GHz.
For high speed wireless networking.
Basically, Wimax is a wireless internet service that is
capable of covering a wide geographical area by serving
hundreds of users at a very low cost.
Uses OFDM ,good for multipath environments.
It includes TDD and FDD duplexing support.
Flexible channel sizes (3.5 MHz,5 MHz,10MHz)
An easy and fast system to install.
Leading to low installation cost, when compared to fiber
,cable or DSL deployments.

18. 802.16 STANDARDS
802.16.1
: (10-66 GHz, line-of-sight, up to
134Mbit/s).
802.16.2 : (minimizing interference between
coexisting WMANs).
802.16a : (2-11 Ghz, Mesh, non-line-ofsight).
802.16b : (5-6 Ghz).
802.16c : (detailed system profiles).
P802.16e : (Mobile Wireless MAN).

19. WIMAX System
A WIMAX TOWER
 Similar in concept to a cell-phone tower - A single WiMAX
tower can provide coverage to a very large area as big as
~8,000 square km.
A WIMAX CLIENT TERMINAL
 The terminal receiver and antenna could be a small box or
Personal Computer Memory card, or they could be built
into a laptop.

20. WI MAX SYSTEM
WIMAX System