Wi-Fi and WiMAX are wireless networking technologies that use radio waves and have standards specified by IEEE. Wi-Fi provides short range connectivity using technologies like 802.11b, 802.11a, 802.11g and 802.11n. WiMAX is a wireless broadband technology that provides longer range connectivity using standards like 802.16 and 802.16e. Both have advantages like mobility and convenience but Wi-Fi has limitations in range and speed while WiMAX installations have higher costs.

1. Presented By,
S.J.
VIT University, Chennai.

2. 
 Both the technology
- work on wireless networks.
- have their own standards specified by IEEE.
 The evolution of wireless LAN started with the introduction
of the 802.11b standard in 1999.
 In the same year, the 802.11a started introduced the
Orthogonal Frequency Division Multiplexing (OFDM).
 In 2003, "the best" of both standards were joined to the
802.11g standard
 Wi-MAX was standardized as 802.16 by Wi-MAX forum, in
2001.
Standard’s Overview

3. 
 Wi-Fi is wireless networking technology that uses radio
waves to provide wireless high-speed Internet and
network connections.
 A common misconception is that the term Wi-Fi is short
for "wireless fidelity," however this is not the case. Wi-Fi is
simply a trademarked phrase that means IEEE 802.11x.
 It is wireless LAN technology which provides narrow
range of connectivity.
 Establishes a standard for interoperability and backward
compatibility.
Wi-Fi Overview

4. 
 Wi-Fi technology used ratio technologies that transmits
and receive data at high speed.
 Standards specified by IEEE.
•IEEE 802.11b
•IEEE 802.11a
•IEEE 802.11g
•IEEE 802.11n
Wi-Fi’s-IEEE standard

5. 
Comparison of Wi-Fi Standards

6. 
 Introduced in 2009.
 Improve network throughput over 802.11a and
802.11g
 300 Mbps speed.
 Multi input and multiple output (MIMO) added.
 40MHz channel to the PHY, and frame aggregation
to the MAC layer.
 2.4/5GHz radio frequencies.
IEEE 802.11n

7.  AP based technology
(Infrastructure mode)
 Peer-to-Peer technology
(Ad-Hoc mode)
 Point-to-Multipoint Bridge topology.
Wi-Fi Network Architecture

8. 
 Wi-Fi setup contains one or more
access point and client
 AP broadcasts SSID via beacons, every 100ms.
 Beacons transmitted at 1Mbps.
 Client can communicate at least at 1Mbps.
 Connections to AP(same SSID) is decided on basis of
signal strength.
 Connection criteria and roaming is open to client.
 Wi-Fi has same properties as that of non switched
Ethernet network.
How Wi-Fi Works?

9.  There are two signaling frequencies currently used by Wi-Fi
networks:
 2.4 GHz - Comprises of
- 14 channels
- bandwidth 20 to 22 MHz (ISM band)
- Bluetooth, microwaves, telephones, garage door openers,
etc.
 5 GHz - Comprises of
- 13 channels
- bandwidth 20 MHz (U-NII band)
- Less crowded as compared to 2.4GHz.
 The "Wi-Fi CERTIFIED" trademark can only be used by Wi-Fi
products
 range of about 20 meters in indoor and greater at outdoor.
 It uses WEP, WPA, WPA2
Salient Features

10. 
 Convenience
 Mobility
 Productivity
 Deployment
 Expandability
 Cost
Advantages

11. 
 Security
 Range
 Reliability
 Speed
Disadvantages

12. 
 WIMAX is an IP based, wireless broadband access
technology that provides performance similar to 802.11/Wi-
Fi networks with the coverage and QOS of cellular
networks.
 WI-MAX refers to “Worldwide Interoperability for
Microwave Access”.
 It is wireless MAN technology which provides broadband
range of connectivity.
 A standard based technology that enable the delivery of last
mile wireless broadband access as an alternative to cable and
DSL
 Establishes standard that provides fixed and mobile Internet
Access.
Wi-MAX Overview

13. 
 Standards specified by IEEE.
•IEEE 802.16
•IEEE 802.16a
•IEEE 802.16e
Wi-MAX’s-IEEE standards

14. 
Comparison of Wi-MAX standards

15. 
Wi-MAX Architecture

16. 
 When a user send data from a subscriber device to a base station then that
base station broadcast the wireless signal into channel which is called
uplink and base station transmit the same or another user is called
downlink.
 The base station of WiMAX has higher broadcasting power, antennas and
enhanced additional algorithms.
 When signal transmit form user to WiMAX base station or base to user
(WiMAX receiver) the wireless channel faces many attenuation such as
fraction, reflection, refraction, wall obstruction etc.
 OFDMA that prohibit interfering and be multiplexed also makes possible
power prioritization for various sub carriers according to the link quality.
 WiMAX is providing quality of service (WiMAX QoS) which enables high
quality of data like VoIP or TV broadcasts.
 WiMAX technology support various protocol such as VLAN, ATM, IPv4
Ethernet etc.
How Wi-MAX works

17.  Two forms of wireless services
 Non line of Sight.
 Line of Sight.
 OFDM based physical layer
 Very high field data rates-74Mbps
 Scalable bandwidth(1.25,5,10MHz) and data rate
 Adaptive modulation and coding.
 Link Layer retransmission.
 Robust Security.
 Support for advance antenna techniques
Salient Features

18. 
 Single station can serve hundreds of users.
 Much faster deployment of new users comparing to
wired networks.
 Speed of 10 Mbps at 10 kilometers with line-of-site.
 It is standardized, and same frequency equipment
should work together.
Advantages

19. 
 Line of site is needed for longer connections
 Weather conditions like rain could interrupt the
signal.
 0ther wireless equipment could cause interference.
 Multiplied frequencies are used.
 WiMAX is very power intensive technology and
requires strong electrical support.
 Big installation and operational coast.
Disadvantages

20. 
 Yota is the largest WiMAX network operator in the
world.
 By the end of 2008 there were 350,000 WiMAX
subscribers in Korea.
 As of October 2010, the WiMAX Forum claimed over
592 WiMAX networks deployed in over 148 countries,
covering over 621 million subscribers.
 By February 2011, the WiMAX Forum cited coverage of
over 823 million people, and estimate over 1 billion
subscribers by the end of the year.
Current Deployments

21. 
Comparison Between Wi-Fi and WiMAX