This document provides an overview of WiMAX technology. It describes WiMAX as a wireless technology that uses radio spectrum between 2-66 GHz to provide internet connectivity over long ranges of up to 50km at speeds of up to 70 Mbps. It discusses the key components of a WiMAX system including WiMAX towers and receivers. It also covers the technical aspects of how WiMAX works including modulation methods, transmission duplexing, and the use of OFDM. The document outlines the modes of WiMAX operation and benefits. It then discusses security threats to WiMAX like eavesdropping, masquerading, message modification and DoS attacks. Finally, it mentions authentication, key exchange and encryption as security techniques for WiMAX.

1. WiMAX
Santosh Ban
Electronics and Communication Engineer

2. Introduction
 WiMAX stands for Worldwide Interoperability for Microwave Access.
 WiMAX is the trade name of “IEEE 802.16 standard”.
 Radio spectrum from 10-66 GHz and 2-11 GHz for unlicensed and licensed bands
 Range up to 31 miles (50km)
 Speed up to 70 Megabits
 It is going to be an emerging technology for the future
 It is featured with Voice, Video, Real time video conferencing and other services
 It is next generation of wifi technology which allows us to connect to the internet with
higher speed and in wider range.

3. Introduction continue…
 Modulation method in the download and uplink are BPSK (Binary Phase Shift Keying), QPSK
(Quaternary Phase Shift Keying), 16-QAM, 64-QAM
 Supports two types of transmission duplexing: Time Division Duplexing (TDD) and Frequency
Division Duplexing (FDD) and supports both half and full duplex method.
 TDD- both the uplink and downlink share the same frequency but are separated on time
 FDD- both uplink and downlink communication take place at the same time but on
different frequency
 WiMAX uses OFDM (Orthogonal Frequency Division Multiplexing) technology.

4. A WIMAX system consists of
 WiMAX Tower:
 similar to the concept of cell-phone tower. Single tower can provide coverage up to 3,000 square
miles.
 WiMAX Receiver:
 it may be the small box like devices as modem and they could be build into the laptop

5. How it Works
 A subscriber sends the wireless traffic at the speed 2M-155Mbps from fixed antenna
 The base station receives the traffic signal from multiple sites and sends to the switching
center through wired or wireless using 802.16 protocol.
 The switching center sends the traffic to the ISP or PSTN (Public Switched Telephone
Network)
Switching
Center
Base
Station
ISP
Subscriber

6. Modes of Operation
 Non- Line of Sight (Data is transmitted from tower to subscriber)
 Use a lower frequency range (2-11GHz)
 Line of Sight (Data is transmitted from one tower to another tower)
 Use a higher frequency range (66GHz)

7. Benefits of WiMAX
 Speed
 Faster than broadband services
 Wireless
 Not having to lay cable reduces cost
 Easier to extend to rural and urban areas
 Broad coverage
 Much wider range of coverage area than wifi

8. THREAT ANALYSYS
o Critical threats are
o eavesdropping of management messages,
o BS or MS masquerading,
o management message modification and DoS attack.

9. Eavesdropping
 Management messages (not encrypted) can provide valuable
information (credit card no)to an attacker.
 From the user perspective, eavesdropping of management
messages may result in limited financial loss.

10. Masquerading means
 IP spoofing: send packet with false source address.
 Instead of sending packet to server, client send it to Hacker.
 record-and-playback: take out sensitive info (e.g., password), and
use later C Hacker
takes
A hacker identity of
server.
server
B client

11. What is a DoS Attack?
o The act of denying a computer user of a particular
service.( user or client not able to connect to server or
internet.)
o It involves flooding a host until it cannot respond to
legitimate traffic

12. Other Major Threats are
Jamming
 Block WiMAX by sending the radio wave of same frequency used by WiMAX which
cause enough interference
Data Traffic Modification

13. Security Technique
Authentication
Data Key Exchange
Data Encryption