WIMAX

(WORLDWIDE INTEROPERABILITY

FOR MICROWAVE ACCESS)

A PROJECT REPORT

Submitted by

K.PRAVEEN KUMAR (90810133034)

R.RAM KUMAR (90810133037)

In partial fulfillment for the award of the degree

of

BACHELOR OF ENGINEERING

in

ELECTRONICS AND COMMUNICATION ENGINEERING

MOUNT ZION COLLEGE OF ENGINEERING AND TECHNOLOGY

PUDUKOTTAI

ANNA UNIVERSITY: CHENNAI 600 025

APRIL 2014

ANNA UNIVERSITY: CHENNAI 600 025

BONAFIDE CERTIFICATE

Certified that this project report ―WIMAX (WORLD WIDE

INTEROPEROPILTY FOR MICROWAVE ACCESS‖, is the bonafide work of

―PRAVEEN KUMAR K (90810133034), RAM KUMAR R (90810133037),‖

who carried out the project work under my supervision.

SIGNATURE SIGNATURE

Mrs. A. TAKSALA DEVAPRIYA M.E., Mr. C.PALANIAPPAN M.E.,

HEAD OF THE DEPARTMENT SUPERVISOR,

Assistant Professor

Department of ECE, Department of ECE,

Mount Zion College of Mount Zion College of

Engineering and Technology Engineering and Technology

Pudukkottai-622507 Pudukkottai-622507

Submitted for University Project Viva-Voce held on………………………..

INTERNAL EXAMINER EXTERNAL EXAMINER

ACKNOWLEDGEMENT

First of all I thank my ALMIGHTY and my PARENTS who

had provided all my needs.

I would like to express my sincere thanks to the Chairman

Mr. JAYABARATHAN CHELLIAH, M.A. (USA), B.Ed., Mount Zion College

of Engineering & Technology, for giving me an opportunity to do the project.

I would like to express my sincere thanks to the Director

Prof. JAYSON K. JAYABARATHAN, M.Tech, Ph. D., Mount Zion College of

Engineering & Technology, for providing me various facilities needed for

successful completion of my project.

With a deep sense of gratitude I record my thanks to the

Principal Dr. P. BALAMURUGAN, Ph.D., Mount Zion College of Engineering &

Technology, for his constant encouragement throughout my project work.

I take this golden opportunity to express my heartfelt thanks to

Head of the Department of ECE, Mrs. A. TAKSALA DEVAPRIYA, M.E., for

rendering all the help and valuable suggestion to complete this project well in time.

I express my profound and heartfelt thanks to my Guide

Mr. C.PALANIAPPAN M.E., for his consistent guidance, encouragement and

support

Last but not the least I thank all my friends and family members

who directly and indirectly helped me to complete my project.

ABSTRACT

In recent years broadband wireless access (BWA) has gained special

attention. While the IEEE 802.11 technologies were very successful in indoor

wireless LAN (WLAN) applications, it was concluded that the overall design and

feature set of 802.11 WLANs were not well suited for outdoor BWA applications.

In order to meet the outdoor need, the IEEE802 committee set up a working group

to develop a new standard, for BWA applications, namely IEEE 802.16. To

promote the 802.16 standard, an industrial association, namely worldwide

interoperability for microwave access (WIMAX) forum, was formed to define the

interoperability specification between 802.16 products from different

manufacturers. A device which passes the WIMAX conformance and

interoperability testing is regarded as a WIMAX –certified device. IEEE 802.16

networks are also often referred to as a WIMAX networks. In this project, we focus

on the performance analysis of Band Width-REQ, which allows us to focus our

attention on improving the efficiency of the BW-REQ algorithms as it is a

fundamental component for the complete analysis of the WIMAX medium access

control (MAC) protocols

TABLE OF CONTENTS

CHAPTER NO TITLE PAGENO

ABSTRACT vi

LIST OF FIGURES viii

LIST OF SYMBOLS ix

1 INTRODUCTION TO BSNL

1.1 HOW BSNL CAME IN TELECOM MARKET 1

1.2 INSTITUTIONAL FRAME WORK 2

1.3 BSNL CONTRIBUTION TO DEVELOPMENT

OF TELECOM 2

2 INTRODUCTION

2.1 ABOUT THE PROJECT 3

2.2 FUNCTIONING OF WIMAX 3

2.3 FUNCTION DIAGRAM 4

2.3.1 Usage Models of IEEE 802.16 5

2.3.2 IEEE 802.16 Specifications 5

2.4 WIMAX SETUP 6

2.5 BENEFITS OF WIMAX 6

2.6 ADVANTAGES OF WIMAX OVER 3G 7

3 LITERATURE SURVEY

3.1 BLOCK DIAGRAM OF WIMAX 8

3.2 WIRELESS COMMUNICATION 9

3.2.1 Bluetooth 9

3.2.2 Wi-Fi (Wireless Fidelity) 9

3.3.3 Wi-Fi Connectivity 10

3.3 INTERNET (WIRED/WIRELESS ACCESS) 10

3.3.1 Broadband Wireless Access Technology 11

3.4 WHAT IS WIMAX 11

3.4.1 A WIMAX System Consists of 11

3.5 WHY WIMAX IS NEEDED 12

3.5.1 How WIMAX Works? 13

3.6 WIMAX SCENARIO 13

3.7 BENEFITS TO USTOMERS 14

3.7.1 WIMAX Application 15

3.7.2 Promises 16

4 WIMAX INTERNET ACCESS

4.1 BLOCK DIAGRAM OF INTERNET CONNECTION 17

4.2 WIMAX TOWER RANGE IN BSNL 25

4.3 MODE OF OPERATION 26

4.3.1 Line-Of-Sight 26

4.3.2 Non-Line-Of-Sight 26

4.4 RANGE 26

4.5 WIMAX EQUIPMENT 27

4.6 GATEWAYS 27

4.7 INTERNET ACCESSIBILITY 29

4.8 BACKHAUL 30

4.9 TRIPLE-PLAY 30

4.9.1 MAC Layer 31

5 WIMAX TECHNOLOGY AND PROCESS

5.1 TECHNOLOGY 33

5.2 MARKET IMPACT 35

5.3 CHALLENGES AHEAD 37

5.3.1 Challenge: Conformance Test 37

5.3.2 Challenge: Orthogonal Frequency 38

Division Multiple Access Complexity

5.3.3 Challenge: Multiple-Input, Multiple-Output 38

Complexity

5.3.4 Challenge: A Tight EVM Requirement 39

5.3.5 Challenge: Receiver Performance 39

5.3.6 Terminology 40

5.3.7 Challenge: Spectral Efficiency/ Latency 41

5.3.8 Challenges: Integration with Legancy Systems 41

5.4 SOLUTIONS 41

5.5 RESEARCH AND DEVELOPMENT 42

5.6 USES 43

6 WIMAX STATUS MODULES

6.1 WIMAX SECURITY 44

6.2 SCANNING 45

6.3 NETWORK ENTRY 46

6.4 OPERATIONAL 47

6.5 DEVICE STATUS 48

7 CONCLUSION AND REFERENCES

7.1 CONCLUSION 49

7.2 REFERENCES 50

LIST OF FIGURES

FIGURE NO TITLE PAGE NO

1. Function Diagram of WIMAX 4

2. Block Diagram of WIMAX 8

3. Wi Fi Connectivity 10

4. WIMAX Tower And Receiver 12

5. Working of WIMAX 13

6. Applications of WIMAX 15

7. WIMAX Promises 16

8. Block Diagram of Internet Connection 17

9. Coverage Area of WIMAX Tower 24

10. WIMAX Tower Range In Tamil Nadu 25

11. Site Of Element Management System 25

12. Indoor Gateway 28

13. Outdoor Gateway 28

14. USB Dongle 29

15. WIMAX Network Equipment and

Devices World Wide Revenue

Forecast

35

LIST OF ABBREVIATIONS

S.NO ABBEREVIATIONS DESCRIPTIONS

1. BWA Broadband Wireless Access

2. WIMAX World Wide Inter-Operability for Microwave

Access

3. MAC Medium Access Control

4. QOS Quality of Service

5. PMP Point To Multi Point

6. BS Base Station

7. SSs Serves A Set of Subscriber Stations

8. TDMA Time Division Multiple Access

9. TDD Time Division Duplexing

10. FDD Frequency Division Duplexing

11. L2CAP Logical Link Control and Adaptation Protocol

12. PAN Personal Area Network

13. TKIP Temp Key Integrity Protocol

14. WEP Wired Equivalent Privacy

15. NLOS Non Line of Sight

16. OFDMA Orthogonal Frequency Division Multiplexing

17. WFDCLs WIMAX Forum Designated Certification

Laboratories

18. TTI Telecommunication Industry Association

19. PCT Protocol Conformance Test

20. NCT Network Conformance Test

21. RPT Radiated Performance Test

22. RCT Radio Conformance Test

23. EVM Error Vector Magnitude

24. PAPR Peak To Average Power Ratio

25. ADS Advanced Design System

26. VSA Vector Signal Analysis

27. WIFI Wireless Fidelity

28. PCMCIA Personal Computer Memory Card

International Association

CHAPTER – 1

INTRODUCTION TO BSNL

India is the fourth largest telecom market in Asia after China, Japan and South

Korea. The Indian telecom network is the eighth largest in the world.

TYPE: COMMUNICATION SERVICE PROVIDER

COUNTRY: INDIA

AVAILABLITY: NATIONAL EXCEPT DELHI & MUMBAI

OWNER: THE GOVERNMENT OF INDIA

WEBSITE: www.bsnl.co.in

1.1 HOW BSNL CAME IN TELECOM MARKET

The initial phase of telecom reforms began in 1984 with the creation of Center for

Department of Telematics (C-DOT) for developing indigenous technologies and

private manufacturing of customer premise equipment. Soon after, the Mahanagar

Telephone Nigam Limited (MTNL) and Videsh Sanchar Nigam Limited (VSNL)

were set up in 1986.The Telecom Commission was established in 1989. A crucial

aspect of the institutional reform of the Indian telecom sector was setting up of an

independent regulatory body in 1997 – the Telecom Regulatory Authority of India

(TRAI), to assure investors that the sector would be regulated in a balanced and fair

manner. In 2000, DoT corporatized its services wing and created Bharat Sanchar

Nigam Limited.

1.2 INSTITUTIONAL FRAMEWORK

It is defined as the system of formal laws, regulations, and procedures, and informal

conventions, customs, and norms, that broaden, mold, and restrain socio-economic

activity and behavior. The country has been divided into units called Circles, Metro

Districts, Secondary Switching Areas (SSA), Long Distance Charging Area

(LDCA) and Short Distance Charging Area (SDCA).

In India, DoT is the nodal agency for taking care of telecom sector on behalf of

government.

Its basic functions are:

Policy Formulation

Review of performance

Licensing

Wireless spectrum management

Administrative monitoring of PSUs

Research & Development

Standardization/Validation of Equipment

1.3 BSNL CONTRIBUTION TO DEVELOPMENT OF TELECOM

Bharat Sanchar Nigam Limited was formed in year 2000 and took over the service

providers role from DOT. BSNL’s roadmap for providing customer with access to

the latest telecommunications services without losing sight of universal service

access has been by way of utilizing optimally the existing infrastructure and

accelerating advances in technological component by innovative absorption.

CHAPTER - 2

INTRODUCTION

2.1 ABSTRACT

The IEEE 802.16 standards are considered to be among the critical broadband

wireless access (BWA) technologies in fourth- generation networks. The worldwide

interoperability for microwave access (WIMAX), which is based on this family of

standards, is designed to facilitate services with high transmission rates for data and

multimedia application in metropolitan areas. The physical (PHY) and medium

access (MAC) layers of WIMAX have been specified in the IEEE 802.16 standards.

Many advanced communication technologies such as orthogonal frequency division

multiplexing/orthogonal frequency division multiple network access and multiple

input –multiple output are embraced in standards. Supported by these modem

technologies, WIMAX is able to provide a large service coverage, a high speed data

rate, and quality of service (QoS) - guaranteeing service. Because of these features,

WIMAX is considered to be a promising alternative for last- mile BWA.

2.2 FUNCTIONING OF WIMAX

A subscriber sends a wireless traffic at speed ranging from 2M to 155M bits/sec

from a fixed antenna on a building. The base station receiver transmission from

multiple sites and sends traffic over wireless or wired links to a switching center

using 802.16 protocol. The switching center sends traffic to an ISP or the public

switched telephone network.

Two operation modes are specified in WIMAX: a mandatory point- to- multipoint

(PMP) mode and an operational mesh mode. In the PMP mode, a centralized base

Station (BS) serves a set of subscriber stations (SSs) with in the same antenna

sector in a broadcast manner. The transmission between the BS and the SSs are

realized in a frame structure by means of time division multiple access (TDMA). To

support duplexing, WIMAX defines both time division duplexing (TDD) and

frequency division duplexing (FDD). On the other hand, in the mesh mode, the SSs

are organized in an ad hoc manner.

2.3 FUNCTION DIAGRAM

Figure 2.1 Function Diagram

2.3.1 USAGE MODELS OF IEEE 802.16

Fixed

IEEE 802.16 standards

Portable

IEEE 802.16-2004 standard( revises and replace)

IEEE 802.16a and 802.16REVd version)

Mobile

IEEE 802.16e

2.3.2 IEEE 802.16 SPECIFICATIONS

802.16a

Uses the licensed frequencies from 2 to 11GHZ

Supports mesh network

802.16b

Increases spectrum to 5 and 6 GHZ

Provides QoS(for real time voice and video

Service)

802.16c

Represents a 10 to 66 GHZ

802.16d

Improvement and fixes for 802.16a

802.16e

Address on mobile

Enable high speed signal handoff necessary for

communication with users moving at vehicular speed

2.4 WIMAX SETUP

Setup a WiMAX base station

WiMAX enabled computer or upgrade computer to add WiMAX

capability

Service provider issues encryption code that would give access to the base

station

Base station would beam data to computer via radio signals

For local network, WiMAX base station would send data to a WiMAX

enabled switch which would then send the data to other computers on that

network.

WiMAX tower

Similar in concept to cell phone tower- a single WiMAX BS can provide

coverage to a very large area as big as 30 miles

WiMAX receiver

The receiver could be a small box or PCMCIA card, or they could be built

into a laptop

2.5 BENEFITS OF WIMAX

Speed

Faster than broadband service

Wireless

Not having to lay cables reduces cost

Easier to extend to suburban and rural areas

Broad coverage

Much wider coverage than Wi-Fi hotspots

2.6 ADVANTAGES OF WIMAX OVER 3G

WiMAX is important for mobile broadband wireless, as it completes 3G by

providing higher performance for data with more than 1 Mbps downstream to allow

connection of laptops and PDAs WiMAX technology is the solution for many types

of high- bandwidth applications at the same time across long distances and will

enable service carriers to converge the all-IP-based network for triple – play

services data, voice and video.

CHAPTER – 3

LITERATURE REVIEW

3.1 BLOCK DIAGRAM OF WIMAX

Figure

3.1 Block Diagram of WIMAX

Wireless Communication

Bluetooth/Wi-Fi/WiMAX

Internet

WiMAX – Introduction

How WiMAX Works

WiMAX Scenario

Benefits of WiMAX

Advantages of WiMAX over Wi-Fi

Uses of WiMAX

Promises

3.2 WIRELESS COMMUNICATION

Blue tooth-personal area network

Wi-Fi- local area network

WiMAX- wide area network

3.2.1 Bluetooth

IEEE 802.15

Personal area network(PAN)

Using 2.4 GHZ ISM band- 79 channels

Non –licensed spectrum

Frequency hopping spread spectrum and time division duplex

Coverage -1 to 10 meter

Point to multipoint

Data transfer rate 721 kbps

L2CAP – logical link control and adaptation protocol

3.2.2 Wi-Fi (Wireless Fidelity)

IEEE 802.11 b/g/u

Wireless LAN

Using 2.4 GHZ ISM band-11 channels

Non- licensed spectrum

Single access point(hot spot)

Direct sequence spread spectrum

Data transfer rate 11mbps

TKIP- temp key integrity protocol

WEP(wired equivalent privacy) and WPA (Wi-Fi protocol

access) - provide security by encrypted information

Coverage - 10 to 100 meter (30 feet)

3.3.3WI-FI Connectivity

Figure 3.1 Wi-Fi Connectivity

3.3 INTERNET (WIRED/ WIRELESS ACCESS)

Broadband access

Uses DSL or cable modem at home

WIFI

Uses WIFI routers at home and hotspots on the road

Dial up connection

GSM 2.5G (GPRS), 2.75G (EDGE). 3G (HSDPA), 4G (LTE)

CDMA 1x- EVDO

3.3.1 BROADBAND WIRELESS ACCESS TECHNOLOGY

Broadband access through wire is too expensive and Wi-Fi coverage is very

sparse

The BWA technology (WIMAX) promises

High speed of broadband services

Wireless rather than wired

Broad coverage

3.4 WHAT IS WIMAX?

WIMAX stands for worldwide interoperability for microwave access

WIMAX refers to broadband wireless networks that are based on the IEEE

802.16 standards, which ensures compatibility and interoperability between

broadband wireless access equipment

WIMAX which will have a range of up to 31 miles, is primarily aimed at

making broadband network access widely available without the expanse of

stringing wires (as in cable access broadband) or the distance limitations of

digital subscriber line.

3.4.1 A WIMAX SYSTEM CONSISTS OF

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 3,000

square miles.

A WiMAX receiver- the receiver and antenna could be a small box r personal

computer memory card, or they could be built in to a laptop the way Wi-Fi

access is today.

WIMAX TOWER WIMAX RECEIVER

Figure 3.2 Wimax Tower and Receiver

3.5 WHY WIMAX IS NEEDED

A service provider, network operator or an enterprise, WiMAX enables you to

deliver the differentiated high- speed and high- bandwidth data services your

customer’s value. Fixed WiMAX is ideally suited for:

Broadband access to underserved areas, and extending DSL/cable modem

services to rural areas

Replacing more expensive means of broadband access such as DSL, cable

modem services, and satellite TV.

Backhauling traffic for wireless service provider or cable operators at a

reduced cost

Interconnecting and backhauling WiFi hot zones built on wireless mesh

network solution(for instance Nortel)

Enabling ISPs, cable and satellite operators to deliver existing through a new

channel

Providing robust, secure bandwidth for data traffic and communication for

financial and educational institutions, municipalities and in-the-field military

or public safety institutions.

3.5.1 How WIMAX Works?

Figure 3.3 Working of WIMAX

3.6 WIMAX SCENARIO

Consider a scenario where a WiMAX –enabled computer is 10 miles away

from the WiMAX base station. A special encryption code is given to

computer to gain access to base station

The base station would beam data from the internet required for the computer

The user would pay the provider monthly fee for using the service. The cost

of this service could be much lower than the current high- speed internet-

subscription fees because the provider never had to run cables.

The WiMAX protocol is designed to accommodate several different methods

transmission, one of which is voice over internet protocol(VoIP)

If WiMAX –compatible computers become very common, the use of VoIP

could increase dramatically. Almost anyone with laptop could make VoIP

calls.

3.7 BENEFITS TO CUSTOMERS

Range of technologies and service level choice from both fixed and

wireless broadband operations

DSL – like services at DSL price but with portability

Rapidly declining fixed broadband prices

No more DSL ―installation‖ fees from incumbent

3.7.1 WIMAX Application

Figure 3.4WIMAX Application

3.7.2PROMISES

CHAPTER – 4

WIMAX INTERNET ACCESS

4.1 BLOCK DIAGRAM OF INTERNET CONNECTION

Figure 4.1 Block Diagram of Wimax connections

ASN Access Service Network

Access Service Network (ASN) and

Connectivity Service Network (CSN)

The ASN consists of the WiMAX base stations and the ASN Gateway (ASNGW).

Whereas, the CSN is at the core of the network providing control and management

functions such as IMS, DHCP, FTP and AAA.

A key element of the ASN is the ASNGW, which controls and aggregates the traffic

from a large number of WiMAX base stations. An IEEE 802.16e-2005 compliant

network may be deployed without an ASN-GW providing the wireless access

network is used for fixed and nomadic applications only.

AAA Server (Authentication, Authorization and Accounting)

An AAA server is a server program that handles user requests for access to

computer resources and, for an enterprise, provides authentication, authorization,

and accounting (AAA) services. The AAA server typically interacts with network

access and gateway servers and with databases and directories containing user

information. The current standard by which devices or applications communicate

with an AAA server is the Remote Authentication Dial-In User Service (RADIUS).

Overview of IMS AAA Server AAA Functions

Authentication

Authentication requests are transported using either the RADIUS or Diameter

protocol. The clients for these authentications are Diameter or RADIUS equipment

providing network access, as well as Packet Data Gateways (PDGs) which initiate

authentication when the subscriber sends a tunnel creation request. The attributes

used for EAP-SIM or EAP-AKA authentication are retrieved from an HSS via

Diameter Wx, or from an HLR (Home Location Register) via Diameter to RADIUS

proxy to SBR SIM Server (requires the Juniper Networks SBR SIM server).

The authentication and transport encoding is entirely standards-based. Hence, the

IMS AAA Server supports clients developed for previously existing EAP-SIM

deployments, such as the Juniper Networks Odyssey Access Client or other

standards-compliant clients connecting to a standards-compliant 802.1x access

point. In this manner, the IMS AAA Server meets the WLAN 3GPP Interworking

goal of supporting existing network deployments.

Authorization

Authorization requests are issued by either the WLAN access device or the

Packet Data Gateways (PDG).

RADIUS or Diameter-based WLANs request authorization of network access for

the WLAN UE. This authorization is typically performed together with the

authentication, and takes the form of authorization attribute value pairs (AVPs)

returned with the RADIUS Access-Accept packet. For Diameter, a Diameter-EAP-

Answer message would be returned with the Result-Code set to

DIAMETER_SUCCESS. This message would also include the appropriate

authorization AVPs required for the service requested.

A PDG requests authorization separately from the authentication request. For

example, the WLAN UE might initiate a tunnel towards the PDG, which results in

an authentication and tunnel establishment. If the same WLAN UE requests an

additional tunnel in the same session, authentication need not be performed.

Instead, the additional tunnel will be granted without full authentication being

required. The PDG can request authorization of W-APNs in subsequent

authorization requests.

The primary profile data used for these policy decisions is downloaded from the

HSS, however the IMS AAA Server also supports local policy storage

Accounting

Both online charging and offline charging functionality is defined in 3GPP TS

23.234. This implementation of the IMS AAA Server supports the offline charging

functionality, implemented by a Diameter interface carrying charging events

towards the Charging Data Function (CDF). It is the CDF that has the responsibility

of integrating these charging events into Charging Data Records (CDRs.)

Accounting information is generated and reported for Direct IP Access and for the

tunnels used in WLAN 3GPP IP Access.

The WLAN AN is responsible for generating and reporting WLAN access usage to

the appropriate 3GPP system (for example, the visited network in the roaming case

and home network in the non-roaming case).

A WLAN can issue an Accounting-Request whenever it chooses, for example upon

establishing a successful connection. Each time an Accounting-Request message

arrives at the IMS AAA Server, an accounting transaction begins. During this

transaction, the server handles the message by examining the Acct-Status-Type and

other attributes within the message, and taking the appropriate action.

For WLAN Direct IP Access in the HPLMN, the IMS AAA Server reports

(accounting) charging data to the home Offline Charging System. For WLAN

Direct IP Access in a roaming situation, you can configure the routing of charging

data using the explicit routing feature of the IMS AAA Server. Using this feature

you can route the charging data to either the visited network's CDF or to the

downstream CDF in the subscribers home network.

Broadband Remote Access server/ BNG

A broadband remote access server (BRAS, B-RAS or BBRAS) routes traffic to and

from broadband remote access devices such as digital subscriber line access

multiplexers (DSLAM) on an Internet service provider's (ISP) network. BRAS can

also be referred to as a Broadband Network Gateway (BNG).

The BRAS sits at the core of an ISP's network, and aggregates user sessions from

the access network. It is at the BRAS that an ISP can inject policy management and

IP Quality of Service (QoS).

The specific tasks include:

Aggregates the circuits from one or more link access devices such as

DSLAMs

Provides layer 2 connectivity through either transparent bridging or PPP

sessions over Ethernet or ATM sessions

Enforces quality of service (QoS) policies

Provides layer 3 connectivity and routes IP traffic through an Internet service

provider’s backbone network to the Internet

A DSLAM collects data traffic from multiple subscribers into a centralized point so

that it can be transported to a switch or router over a Frame Relay, ATM, or

Ethernet connection.

The router provides the logical network termination. Common link access methods

include PPP over Ethernet (PPPoE), PPP over ATM (PPPoA) encapsulated

sessions, bridged ethernet over ATM or Frame Relay (RFC 1483/RFC 1490), or

just plain ethernet. In the case of ATM or Frame Relay based access, individual

subscribers are identified by Virtual Circuit IDs. Subscribers connected over

ethernet-based remote access devices are usually identified by VLAN IDs or MPLS

tags. By acting as the network termination point, the BRAS is responsible for

assigning network parameters such as IP addresses to the clients. The BRAS is also

the first IP hop from the client to the Internet.

Element Management System

An element management system (EMS) consists of systems and applications

for managing network elements (NE) on the network element-management layer

(NEL) of the Telecommunications Management Network (TMN) model.

As recommended by ITU-T, the element management system's key functionality is

divided into five key areas - fault, configuration, accounting, performance and

security (FCAPS). Portions of each of the FCAPS functionality fit into the TMN

models. Northbound, the EMS interfaces to network management systems and or

service management systems depending on the deployment scenario. Southbound,

the EMS talks to the devices.

An element management system manages one or more of a specific type of

telecommunications network element. Typically, the EMS manages the functions

and capabilities within each NE but does not manage the traffic between different

NEs in the network. To support management of the traffic between itself and other

NEs, the EMS communicates upward to higher-level network management systems

(NMS) as described in the telecommunications management network layered

model. The EMS provides the foundation to implement TMN–layered operations

support system (OSS) architectures that enable service providers to meet customer

needs for rapid deployment of new services, as well as meeting stringent quality of

service (QoS) requirements. The TeleManagement Forum common object request

broker architecture (CORBA) EMS–to–NMS interface heralds a new era in OSS

interoperability by making the TMN architecture a practical reality.

Tier II switch

It is a network aggregation switch.

BTS – Base Transceiver Station

A Base Transceiver Station (BTS) is a piece of equipment that facilitates wireless

communication between user equipment (UE) and a network. UEs are devices like

mobile phones (handsets), WLL phones, computers with wireless Internet

connectivity. The network can be that of any of the wireless communication

technologies like GSM, CDMA, wireless local loop, Wi-Fi, WiMAX or other wide

area network (WAN) technology.

BTS is also referred to as the radio base station (RBS), node B (in 3G Networks)

or, simply, the base station (BS). For discussion of the LTE standard the

abbreviation eNB for evolved node B is widely used.

Though the term BTS can be applicable to any of the wireless communication

standards, it is generally associated with mobile communication technologies like

GSM and CDMA. In this regard, a BTS forms part of the base station subsystem

(BSS) developments for system management. It may also have equipment for

encrypting and decrypting communications, spectrum filtering tools (band pass

filters), etc. antennas may also be considered as components of BTS in general

sense as they facilitate the functioning of BTS. Typically a BTS will have several

transceivers (TRXs) which allow it to serve several different frequencies and

different sectors of the cell (in the case of sectored base stations).

A BTS is controlled by a parent base station controller via the base station control

function (BCF). The BCF is implemented as a discrete unit or even incorporated in

a TRX in compact base stations. The BCF provides an operations and maintenance

(O&M) connection to the network management system (NMS), and manages

operational states of each TRX, as well as software handling and alarm collection.

The basic structure and functions of the BTS remains the same regardless of the

wireless technologies.

Coverage Area of WIMAX Tower

Figure 4.2 coverage Area of Wimax Tower

Frequencies used in BSNL for WIMAX Services.

2652.5 MHz

2647.5 MHz

2642.5 MHz

2637.5 MHz

Wimax Tower Range in Tamil Nadu

Figure 4.3 Wimax Tower Range in Tamil Nadu

Site in Element Management System

Figure 4.4 Site Element Management systems

4.3 Mode of Operation

4.3.1 Line-of-Sight

A fixed dish antenna points straight at the WiMAX tower from a rooftop or

pole.

The line-of-sight connection is stronger and more stable, so it's able to send a

lot of data with fewer errors.

It use higher frequencies, with ranges reaching a possible 66 GHz.At higher

frequencies, there is less interference and lots more bandwidth. & 30-mile

radius

4.3.2 Non-Line-of-Sight

A small antenna on a computer connects to the tower

Uses 2 GHz to 11 GHz frequency range.

It is limited to a 4-to-6 mile radius. WiFi sort of service

4.4 Range

Designed to handle many users spread out over kilometers

Designed to tolerate greater multi-path delay spread(signal reflections)up to

10.0 micro seconds

PHY and MAC designed with multi-mile range in mind

WIMAX should be able to handle up to 70 megabits per second.

WIMAX will blanket a radius of 30 miles (50 km) with wireless access.

The increased range is due to the frequencies used and the power of the

transmitter

4.5 WIMAX Equipment

There are numerous devices on the market that provide connectivity to a WIMAX

network. These are known as the "subscriber unit" (SU) or CPE (Customer

it is also called the wimax modem. Premises Equipment)

Some Connecting Device

Gateways

Dongles

4.6 GATEWAYS

WIMAX gateway devices are available as both indoor and outdoor versions from

several manufacturers.

Indoor gateways

Outdoor gateways

4.6.1 INDOOR GATEWAY

It is of non-line of sight operation

It is a Portable device

Indoor gateways are convenient but radio losses that mean subscriber may

need to be significantly closer to the base station Range up to 3.5 km

Figure 4.5 Indoor gateway of Wimax used in BSNL

4.6.2 OUTDOOR GATEWAYS

It is Line of sight operation

The Range up to 15 km

It is of Fixed operation

Figure 4.6 Outdoor gateway of Wimax used in BSNL

4.6.3 USB DONGLE

Range up to 1 km (From BTS)

Non line of sight operation

Portable

Compact

Its provides connectivity to a Wimax network

Figure 4.6 Wimax USB Dongle

4.7 Internet Access

WIMAX can provide at-home or mobile Internet access across whole cities or

countries. In many cases this has resulted in competition in markets which typically

only had access through an existing incumbent DSL (or similar) operator.

Additionally, given the relatively low associated with the deployment of a WIMAX

network (in comparison with 3G,HSDPA, XDSL,HFC or FTTX), it is now

economically viable to provide last-mile broadband Internet access in remote

locations.

4.8 BACKHAUL

WIMAX can provide at-home or mobile Internet access across whole cities

or countries. In many cases this has resulted in markets which typically only had

access through an existing incumbent DSL (or similar) operator. Additionally,

given the relatively low costs associated with deployment of a WIMAX network (in

comparison with 3G, HSDPA, XDSL, HFC or FTTX), it is now economically

viable to provide last-mile broadband Internet access in remote locations.

4.9 TRIPLPE-PLAY

WIMAX supports the technologies that make triple-play service offerings

possible (such as Quality of Service and Multicasting).

On May 7, 2008 in the United States, Sprint Nextel, Google, Intel, Comcast, Bright

House, and Time Warner announced a pooling of an average of 120 MHz of

spectrum and merged with Clear wire to market the service. The new company

hopes to benefit from combined services offerings and network resources as a

springboard past its competitors. The cable companies will provide media services

to other partners while gaining access to the wireless network as a Mobile virtual

network operator to provide triple-play services.

Some analysts questioned how the deal will work out: Although fixed-

mobile convergence has been a recognized factor in the industry, prior attempts to

form partnerships among wireless and cable companies have generally failed to lead

to significant benefits to the participants. Other analysts point out that as wireless

progresses to higher bandwidth; it inevitably competes more directly with cable and

DSL, inspiring competitors into collaboration. Also, as wireless broadband

networks grow denser and usage habits shift, the need for increased backhaul and

media service will accelerate, therefore the opportunity to leverage cable.

4.9.1 MAC (Media Access Control) Layer

The WIMAX MAC uses a scheduling algorithm for which the subscriber station

needs to compete only once for initial entry into the network. After network entry

is allowed, the subscriber station is allocated an access slot by the base station. The

time slot can enlarge and contract, but remains assigned to the subscriber station,

which means that other subscribers cannot use it. In addition to being stable under

overload and over- subscription, the scheduling algorithm can also be more

bandwidth efficient. The scheduling algorithm also allows the base station to

control Quality of Service (QOS) parameters by balancing the time-slot

assignments among the application needs of the subscriber station of WIMAX

applications is the ability to generate, detect, demodulate, and troubleshoot PHY

layer signals.

Along with the forthcoming standardization, WIMAX has the potential to

substitute 3G and become a promising 4G. WIMAX has its distinct identity as

either a stand-alone solution for incumbent and competitive fixed network operators

or as complementary radio access solution for established 2G and 3G cellular

network operators. Fixed-line operators, on the one hand, many consider WIMAX

as a viable alternative to ass mobility to the service portfolio, leveraging their huge

subscriber base, in particular in countries where 3G licensing is delayed or not

affordable.

WIMAX deployment is in the planning stages and it might take 3-5 years in

providing reasonable coverage in well-populated areas. WIMAX may initially be

relegated to college campuses and larger corporate campuses where people are less

mobile and costs containment is important. Network, for example, can reduce

latency and free the base station to manage more of the additional, complex tasks

associated with network management. Also, the flexibility to dynamically allocate

spectrum comes at the price of tremendous signaling complexity.

As a result, the base station must manage the constantly changing data requirements

of multiple antennas (for MIMO) and a wide range of mobile stations traveling at

potentially high speeds. The signaling must be flexible enough to manage these

issues. Further, the designers and service providers must be able to verify the

performance of the network under realistic traffic conditions both before and after

deployment.

CHAPTER - 5

WIMAX TECHNOLOGY AND PROCESS

5.1 TECHNOLOGY

The fixed version of WiMAX provides non- line – of – sight (NLOS)

transmission to stationary devices using the 2-11 GHZ frequencies, higher

frequencies require line of sight. Fixed WiMAX trade mark provides a high

throughput broadband connection at speeds up to 75 Mbps over a distance as far as

30 miles. It is based on orthogonal frequency division multiplexing (OFDM), uses

multiple pilot tones and support modulations ranging from BPSK to 64 QAM.

WiMAX system can use variable bandwidths from 1 to 28 MHZ with 256

subcarriers (192 data subcarriers) in either licensed or unlicensed spectrum. It can

be used for a variety of applications including a ―last mile‖ broadband connection,

hotspot cellular backhaul, and high- speed enterprise connectivity for businesses.

The mobile version of WiMAX is an extension for mobile use in the 2-6 GHZ band

(see the table). It allows WiMAX technology to be built into notebook computers

and other mobile devices.

Table 5.1 Comparison of 802.16 Wireless Technologies

MOBILE

WIMAX 2.0

MOBILE

WIMAX

FIXED WIMAX

Standard 802.16m 802.16e 802.16d(802.16-

2004)

Usage WMAN Portable WMAN

Portable

WMAN Fixed

Throughput Over 300Mbps

(100 MHz BW)

Up to 30Mbps

(10MHz BW)

Up to75 Mbps

(20MHz BW)

Range Typical 1-3 miles Typical 1-3

miles

Typical 4-6 miles

Frequency Sub 6GHz 2-6 GHz Sub 11 GHz

Helping to promote and facilitate deployment of broadband wireless

networks based on the IEEE 802.16 standard is the industry –led organization

known as the WiMAX forum. Formed in 2001, it is working towards this goal by

certifying compatibility and interoperability of broadband wireless products.

Certification takes place via the WiMAX forum certified testing and certification

program at one of five WiMAX forum designated certification laboratories

(WFDCLs).these include: AT4 wireless in Spain and the United States,

telecommunications technology association in Korea, the china academy of

telecommunications research in china, and advanced data Technology Corporation

in Taiwan.

5.2 MARKET IMPACT

While WiMAX technology is increasingly being embraced by countries worldwide,

there is little doubt that the global economic downturn has had an impact on its

deployment, in some cases slowing down or even delaying planned roll outs. Never

the less, the telecommunication industry association (TTI) projects a bright future

for the technology with an annual growth rate that increase 34 percent in the next

three years alone.

Figure 5.2 WIMAX Revenue Forecast

This table, courtesy of infinities, highlights the growth in WiMAX equipment

revenue through 2013.In the first quarter of 2009, EMEA (Europe, the Middle East,

Africa) and Asia Pacific were the hotbeds of WiMAX activity, led by the Middle

East, India and particularly Africa.

WiMAX allows for infrastructures growth in underserved markets and is

today considered the most cost-effective means of delivering secure and reliable

bandwidth capable of supporting business critical, real-time application to the

enterprise, institutions and municipalities. It has proven itself on the global stage as

a very effective last mile solution. In the United States though, licensed spectrum

availability and equipment limitations have held up early WiMAX adaption. In fact,

while there are currently 1.2+ million WIMAX subscribers worldwide, only about

11,000 of these are from the United States.

Future growth in this market will be driven by wireless ISPs like clear wise who

intends to cover 120-million covered POPs in 80 markets with WIMAX by the end

of 2010. Growth will also be driven by the availability of the 3.65-GHZ spectrum

that the FCC opened up this past year. Although the potential for WIMAX in U.S

market looks good, analysts believe that its real opportunity lies in emerging market

like India & Pakistan where the mobile phone has achieved greater than 50%

penetration .Pakistan is currently among the first countries in the world to roll out a

functional Wimax service. India’s planned rollout expected sometime next year

comes in response to a government requirement that 20 million broadband lines be

in services by 2010.

By 2012 alone, springboard Research estimates that there will be 15.8- million

WIMAX subscribers in India close to 47 percent of total subscribers in the entire

Asia Pacific region.

Perhaps some of the biggest planned deployments of WIMAX through will come

from south Asia. According to springboard Research, WIMAX services revenues in

south Asia will grow from an estimated $85 million in 2007 to approximately $5.5

billion by 2012. Likewise the estimated number of Foxed and mobile Wimax

subscribers is expected to grow from 230, 00 in 2007 to 33.9 million by 2012, with

mobile WIMAX services garnering the majority of revenues and subscribers.

5.3 CHALLENGES AHEAD

Despite its growing market approval many factors conspire to make Wimax

system design challenging, including consumers, who today demand greater range,

faster data rates and lower price-points. The 802.16 specification itself also poses

challenges as if forces engineers to face many different system considerations in

term of RF requirement and architecture. Will the WIMAX system be deployed as

Time Division Duplexing (TDD), Frequency Division Duplexing (FDD) or half-

duplex FDD? Will it be based on a super heterodyne or direct-conversion RF

architecture? Ineffectively addressing any one of these challenges threatens to

hamper the proliferation of WIMAX and directly lies into the success of a WIMAX

product. Some of the key engineering challenges that now exist include:

5.3.1 Challenge: Conformance Test

Interoperability issues commonly plague new technology at introduction.

Conformance testing whether Protocol Conformance Test (PCT), Network

Conformance Test (NCT), Radiated Performance Test (RPT), or Radio

Conformance Test (RCT) plays a critical role in addressing this challenge. Not only

does it help alleviate interoperability issues with other WIMAX equipment, it also

ensures a positive end-user experience for consumers. NCT, for example, like PCT,

RCT and RPT, it is a vital part of the WIMAX Forum certification process, testing

conformance above the MAC layer to verify internet protocol layer signaling and

messaging to and from the subscriber device. The availability of rigorous and

efficient network test solutions is therefore a must for ensuring successful delivery

of WIMAX technologies. The key, of course, is in having early access to

conformance tests well advance of commercial service.

5.3.2 CHALLENGE: ORTHOGONAL FREQUENCY DIVISION

MULTIPLE ACCESS (OFDMA) COMPLEXITY

OFDMA is the digital modulation scheme employed by mobile WIMAX. It uses

OFDMA technology in an innovative way to allocate the RF spectrum more

effectively to more users. While this provides a very ―granular‖ way to dissect

bandwidth and charge for service, the standard and signal structure are extremely

complex, creating a number of challenges. To begin with, as the expected and

required services from WIMAX networks expand, ever greater demand will be

placed on the processors in both the base and mobile stations. Additional processor

strain will come from services providers using dynamically allocated subcarriers to

allocate spectrum resources. And while WiMAX’s complex signal structure

provides network operators with the flexibility they need, its associated cost puts

enormous strain on the power amplifier (PA) Another challenge stems from

WIMAX’s utilization of non-traditional frequency re-use schemes which can create

inter-cell interference, especially at the edges of the cell-just when a critical hand

off needs to occur.

5.3.3 CHALLENGE: MULTIPLE- INPUT MULTIPLE- OUTPUT

(MIMO) COMPLEXITY

MIMO technology uses multiple antennas at both the transmitter and receiver to

improve communication performance. Because it allows more bits/hertz to be

transmitted in a given bandwidth, the technology improves spectral efficiency

which, in turn, allows service provider to flexible configure communication service

and not just peak data rates. While MIMO offers increased signal robustness and

capacity improvements, those benefits come at the cost of increased complexity for

both the base station and the mobile station, placing large demands on processing

power and antenna design.

5.3.4 CHALLENGE: A TIGHT EVM REQUIREMENT

The 802.16 standard specifies that error vector magnitude (EVM) be held to -

31 DB, based on a 1% packet error rate. While this error rate, and a stringent

receiver noise figure (7 DB maximum), help contribute to WiMAX’s larger range,

having to meet the EVM target has a number of implications. For example, all the

system blocks must be more linear and phase noise must be considerably better than

in an 802.11 design, impacting the synthesizer and resulting in a longer settling

time. The PA is also impacted by the tight EVM requirement. In WiMAX systems,

Pas must deliver more power, be more linear, and be able to handle a high peak- to

– average power ratio (PAPR) about 10DB. Consequently, they consume more

power and are less efficient. As a result, Considerable effort must be made to

develop higher efficiency, more linear PAs, especially for mobile applications

where power consumption is critical.

5.3.5 CHALLENGE: RECEIVER PERFOMANCE

Nearly all WiMAX – enabled devices have two receiver and many capable of

MIMO reception in several frequency bands, commonly 2.3 GHZ and 2.5 GHZ.

This is added complexity challenges the designer to find space to adequate separate

two receiver antennas in the mobile station (MS) and thereby ensure signal

recovery. Also, the need to differentiate the multiple data streams from the received

signals places increased demands on the processor. WiMAX design must therefore

be thoroughly evaluated to ensure success in the conformance test process, and to

verify the device will operate in the electromagnetically harsh and dynamic world

in which it will work. Unfortunately, the wide range of wanted and unwanted

signals, combined with the many nested feedback loops, makes receiver design one

of the most difficult challenges in the mobile WiMAX cellular system. In fact,

many consider this task one of the hardest in modern radio design, forcing designers

to deal with everything from hardware performance and current consumption to

memory and algorithm complexity constrains, while recovering some highly

complex MIMO signals suffering from linear and non- linear distortions.

One of the specific challenges designer’s face results from the 802.16

specifications support of sub channelization. This means that instead of transmitting

on all 192 data subcarriers, the base station (BS) can transmit on just a subset for a

given user. Using the same amount of power over fewer carriers can result in

greater range for a system, but because the subcarriers are spaced more closely

together, tightly requirement exists for phase noise and timing jitter. Also, higher-

performance synthesizers must be utilized. Another challenges stems from the fact

that WiMAX systems rely on multipath to provide NLOS coverage. The receiver

used in the system are especially susceptible to phase noise, timings jitter and

frequency mismatch/synchronization. This can create a challenging situation, given

the already tight requirement for phase noise and jitter ass specified in the standard.

Improving the receiver performance will help by also improving its range and data

rate. If receiver performance is not adequate addressed, the range and data rate of

the WiMAX system will be adversely impacted, as will the price.

5.3.6 TERMINOLOGY

WiMAX refers to interoperability implement of the IEEE 802.16 family of

wireless network standards ratified by the WiMAX forum. (Similarly, Wi-Fi refers

to interoperable implement of the IEEE 802.11 wireless LAN standards certified by

the Wi-Fi alliance.) WiMAX forum certification allows vendor to sell fixed or

mobile products as WiMAX certified, thus ensuring a level of interoperability

with other certified products, as long as they fit the same profile.

5.3.7 CHALLENGE: SPECTRAL EFFICIENCY/ LATENCY

The overall complexity of mobile WiMAX, along with its high dynamic air

interface requirements a significant amount of optimization and management.

Enabling the MS to make some decision about engaging on the network. For

example, can reduce latency and free the base station to manage more of the

additional, complex tasks associated with network management. Also, the

flexibility to dynamic allocate spectrum comes at the price of tremendous signaling

complexity. As a result, the base station must manage the constantly changing data

requirements of multiple antennas (for MIMO) and a wide range of mobile stations

travelling a potentially high speed. The signaling must be flexible enough to

manage these issues. Further, the designers and service providers must be able to

verify the performance of the networks under realistic traffic conditions both before

and after deployment.

5.3.8 CHALLENGES: INTEGRATION WITH LEGACY SYSTEMS

WiMAX networks must be able to integrate in to existing cellular networks,

providing seamless connectivity and user experience. Of course designing this in to

the network operation, base station and mobile station is a challenge task since

WiMAX’s modulation scheme is so very different from legacy systems.

5.4 SOLUTIONS

Agilent technologies – as a member and active participant in the WiMAX forum—

is at the forefront of the emerging WiMAX market, first coming market with a

WiMAX – based solution in November 2004. With its innovative technology,

unrivalled expertise and outstanding customer support, it has quickly established

itself as a premier test and measurements leader in WiMAX. Bolstered by

overwhelming market acceptance, and with its ability to understand the engineering

challenges facing its customer in the WiMAX area, agilent is continuing to deliver a

broad range of solutions to the market. Agilent today offers the largest breadth of

WiMAX design and the test solution spanning the entire lifecycle from R&D,

design verification, pre- conformance, conformance and manufacturing, through

network deployment service assurance- for fixed and mobile WiMAX, WiBro, and

including support for wave 2 and MIMO. These up-to- date. Comprehensive

solutions provide engineers the reliable, repeatable and consistent results they need

to deploy WiMAX devices, networks and services.

5.5 RESEARCH AND DEVELOPMENT

WiMAX technology continues to evolve product development, however,

cannot always wait for standards to stabilize. To aid in this process, Agilent delivers

a complete, integrated R&D design and test environment including simulation,

characterization and evolution tools. As an example Agilent advanced design

system (ADS) wireless design library for fixed and mobile WiMAX, 89601A

service vector signal analysis (VSA) software. PSA service high performance

spectrum analyzer and E6651A mobile WiMAX test set offers analysis of

component and system performance, there by streamlining the design of WiMAX

designs

5.3.7 USES

The bandwidth and range of WIMAX make it suitable for the following potential

applications:

Providing portable mobile broadband connectivity across cities and countries

through a variety of devices.

Providing a wireless alternative to cable and digital subscriber line (DSL) for

―last mile‖ broadband access.

Providing data, telecommunications (VOLP) and IPTV services (triple play).

Providing a source of Internet connectivity as part of a business continuity

plan. Smart grids and metering.

CHAPTER-6

WIMAX STATUS MODULES

6.1WIMAX SECURITY

This module refers the accessing user is permitted to access the network.

The accessing user is authenticated or not it can be verified by the administrator.

The username and password will be confirmed through backend.

6.2 SCANNING

The scanning state is referred it searches the nearest base station to connect

the network. Longtime scanning is continued the user cannot be unauthorized to

access the connection so it is needed the troubleshooting process. It will help to

detect what problem has been occurred.

6.3NETWORK ENTRY

This module refers entered in to the base station and it is identified the id of nearest

base station and the transmitting, receiving signal does not match the required range

so it also be unauthorized to connect the network. When network entry operation is

done then it will go to the operational state.

6.4 OPERATIONAL

This operational state is the final state, when no errors are arised operational

state appeared. The required signal range of WIMAX is to be detected in this state.

The network will be connected without any errors.

6.5DEVICE STATUS

For the data transferring the IP will be assigned. The individual MAC ID fixed for

individual MODEM using this id the ADMIN will be troubleshooting when the

problem has been arised.

CONCLUSION

WIMAX is intended to make point – to- multipoint broadband network

access widely available, without the expanse and distance limitations associated

with wired options. Critical to this emerging technology and the overall success.

CHAPTER-7

CONCLUSION AND REFERNCES

7.1CONCLUSION

WIMAX is intended to make point-to- multipoint broadband network access

widely available, without the expense and distance limitations associated with wired

options. Critical to this emerging technology and the overall success of WIMAX

applications is the ability to generate, detect, demodulate, and troubleshoot PHY

layer signals.

Along with the forthcoming standardization, WIMAX has the potential to

substitute 3G and become a promising 4G. WIMAX has its distinct identity as

either a stand-alone solution for incumbent and competitive fixed network operators

or as complementary radio access solution for established 2G and 3G cellular

network operators. Fixed-line operators, on the one hand, may consider WIMAX as

a viable alternative to add mobility to the service portfolio, leveraging their huge

subscriber base, in particular in countries where 3G licensing is delayed or not

affordable. WIMAX deployment is in the planning stages and it might take 3-5

years in providing reasonable coverage in well-populated areas. WIMAX may

initially be relegated to college campuses and larger corporate campuses where

people are less mobile and costs containment is important.

REFERENCES

IEEE802.16-2004

Alcatel white Paper: WIMAX , making ubiquitous high-speed data

services a reality.

Intel White Paper: Understanding WIMAX and 3G for

Portable/Mobile Broadband Wireless.

WIMAX Forum: www.wimaxforum.Scom

http://en.wikipedia.org/wiki/wiMax

K. Fazek and S. Kaiser, Multi-Carrier and Spread Spectrum

Systems:

From OFDM and MC-CDMA to LTE and WIMAX and

WIMAX, 2nd

Edition, John Wiley & Sons, 2008.

M. Ergen, Mobile Broadband-Including WIMAX.

and LTE, Springer, NY,2009 ISB

Prashant Sharma (2009). ―Facts About WIMAX and Why Is It

―The Future of Wireless Broadband‖‖. Tech Pluto blog. Retrieved

August 26, 2011.

Linux Wireless Subsystem(80211) by Rami Rosen.