Module - 3

Computer Fundamentals, telecommunications, and Networks

The basic system including keyboard, mouse and monitor.

Computer System

A system of interconnected computers that share a central storage system and various peripheral devices such as a printers, scanners, or routers.

Each computer connected to the system can operate independently, but has the ability to communicate with other external devices and computers.

First Generation (1940-1956) Vacuum Tubes The first computers used vacuum tubes for circuitry and magnetic drums

 for memory, and were often enormous, taking up entire rooms. They were very expensive to operate and in addition to using a great

deal of electricity, generated a lot of heat, which was often the cause of malfunctions.

First generation computers relied on machine language, the lowest-level programming language understood by computers, to perform operations, and they could only solve one problem at a time.

Input was based on punched cards and paper tape, and output was displayed on printouts.

The UNIVAC and ENIAC computers are examples of first-generation computing devices.

The UNIVAC was the first commercial computer delivered to a business client, the U.S. Census Bureau in 1951.

First generation computers

Second Generation (1956-1963) Transistors Transistors replaced vacuum tubes and ushered in the second generation of computers.

The transistor was invented in 1947 but did not see widespread use in computers until the late 1950s.

The transistor was far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors.

Though the transistor still generated a great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum tube. Second-generation computers still relied on punched cards for input and printouts for output.

Second-generation computers moved from cryptic binary machine language to symbolic, or assembly, languages, which allowed programmers to specify instructions in words.

 High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN.

These were also the first computers that stored their instructions in their memory, which moved from a magnetic drum to magnetic core technology.

The first computers of this generation were developed for the atomic energy industry.

Second generation computers

Third Generation (1964-1971) Integrated Circuits The development of the integrated circuit was the hallmark of

the third generation of computers. Transistors were miniaturized and placed on silicon chips,

called semiconductors, which drastically increased the speed and efficiency of computers.

Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitors and interfaced with an operating system, which allowed the device to run many different applications at one time with a central program that monitored the memory.

Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors.

Third generation computers

Fourth Generation (1971-Present) Microprocessors The microprocessor brought the fourth generation of computers, as

thousands of integrated circuits were built onto a single silicon chip. The Intel 4004 chip, developed in 1971, located all the components of the

computer—from the central processing unit and memory to input/output controls—on a single chip.

In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh.

Microprocessors also moved out of the realm of desktop computers and into many areas of life as more and more everyday products began to use microprocessors.

As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the Internet.

Fourth generation computers also saw the development of GUIs, the mouse and handheld devices.

Fourth generation computers

Fifth Generation (Present and Beyond) Artificial Intelligence Fifth generation computing devices, based on 

artificial intelligence, are still in development, though there are some applications, such as voice recognition, that are being used today.

The use of parallel processing and superconductors is helping to make artificial intelligence a reality. 

Fifth generation computers will radically change the face of computers in years to come.

The goal of fifth-generation computing is to develop devices that respond to natural language input and are capable of learning and self-organization.

Fifth generation computers

Classification of Computers

 According to Size According to Technology According to Purpose

According to size

Supercomputers Mainframe Computers Minicomputers Workstations  Microcomputers, or Personal Computers

Supercomputers 

Are widely used in scientific applications such as aerodynamic design simulation, processing of geological data.

Supercomputers are the most powerful computers. They are used for problems requiring complex calculations.

Because of their size and expense, supercomputers are relatively rare.

Supercomputers are used by universities, government  agencies, and large businesses.

Mainframe Computers Are usually slower, less powerful and less expensive than

supercomputers. A technique that allows many people at terminals, to access

the same computer at one time is called time sharing. Mainframes are used by banks and many business to update

inventory etc. Mainframe computers can support hundreds or  thousands of

users, handling massive amounts of input, output, and storage. Mainframe computers are used in large organizations where

many users need access to shared data and programs.  Mainframes are also used as e-commerce servers, handling

transactions over the Internet.

Minicomputers

Are smaller than mainframe, general    purpose computers, and give computing power without adding the prohibitive expenses associated with larger systems. It is generally easier to use.

Minicomputers usually have multiple terminals.

Minicomputers may be used as network servers and Internet servers.

Workstations

Workstations are powerful single-user computers.

Workstations are used for tasks that require a great deal of number-crunching power, such as product design and computer animation.

 Workstations are often used as network and Internet servers.

Microcomputers Is the smallest, least expensive of all the computers. Micro

computers have smallest memory and less power, are physically smaller and permit fewer peripherals to be attached.

 Microcomputers are more commonly known as personal computers.

 Desktop computers are the most common type of PC.  Notebook (laptop) computers are used by people who need

the power of a desktop system, but also portability. Handheld PCs (such as PDAs) lack the power of a desktop

or notebook PC, but offer features for users who need limited functions and small size.

Personal Computers(PC)

Desk Top Lap Top Palm Top PDA

According to Technology

  Analog Computers Digital Computers Hybrid Computers

According to technology

Analog Computers:- These computers recognize data as a continuous measurement of a physical property ( voltage, pressure, speed and temperature).Example: Automobile speedometer. Amplifiers

Digital Computers:- These are high speed programmable electronic devices that perform mathematical calculations, compare values and store results.

They recognize data by counting discrete signal representing either a high or low voltage state of electricity. Example: voice processing, image processing, word processing etc.

Hybrid Computers:-A computer that processes both analog and digital data. Example: Cardiology

According to Purpose General purpose Computers  Special Computers

General purpose Computers: A ‘General Purpose Computer’ is a machine that is capable of carrying out some general data processing under program control.

Refers to computers that follow instructions, thus virtually all computers from micro to mainframe are general purpose. Even computers in toys, games and single-function devices follow instructions in their built-in program.

Special purpose Computers: A computer that is designed to operate on a restricted class of problems.

Input and output devices

Input devices Keyboard Mouse Track balls Touch pads Pointing sticks Pen input Touch screen Light pen Digitizer Graphics tablet Scanner Microphone Electronic white board Video & Audio cards

Output devices Monitor Printers Audio card Plotters LCD projection panels Computer output

microfilm Speakers Facsimile (FAX)

What is System Software?

System software refers to the files and programs that make up your computer's operating system.

System files include libraries of functions, system services, drivers for printers and other hardware, system preferences, and other configuration files.

The programs that are part of the system software include assemblers, compilers, file management tools, system utilities, and debuggers. 

The system software is installed on your computer when you install your operating system. You can update the software by running programs such as "Windows Update" for Windows or "Software Update" for Mac OS X.

system software

Unlike application programs, however, system software is not meant to be run by the end user. For example, while you might use your Web browser every day, you probably don't have much use for an assembler program (unless, of course, you are a computer programmer). 

Since system software runs at the most basic level of your computer, it is called "low-level" software. It generates the user interface and allows the operating system to interact with the hardware.

System software helps use the operating system and computer system. control the operation of computer...

There are 4 types of system software- operating systems, compilers, interpreters and assemblers. Examples of system software's:

BIOS  (basic input/output system) Microsoft Windows MAC OS X Linux

Application software

Application software, also known as an application or an "app", is computer software designed to help the user to perform specific tasks.

Examples include enterprise software, accounting software, office suites, graphics software and media players.

Application software classification

Business applications:  Microsoft Office, OpenOffice.org Enterprise software:  financial systems, customer

relationship management (CRM) systems and supply-chain management software

Educational software: Deliver evaluations (tests), track progress through material, or include collaborative capabilities.

Mobile applications:  smart phones, tablet computers, portable media players, personal digital assistants and enterprise digital assistants

Product engineering software : CAD, CAE

Application software classification Command line interface : DOS, UNIX A graphical user interface (GUI) is one in which you

select command choices from various menus, buttons and icons using a mouse. Microsoft Windows, Mac OS and Ubuntu are common examples of operating systems which bundle one or more graphical user interfaces.

A third party server side application that the user may choose to install in his or her account on a social media site or other Web 2.0 web site, for example a face book app.

Operating systems A part of system software O/S is a program which monitors ,controls

and maintains the computer. All computer systems have an operating

system. Currently, there are three dominate typical user operating systems. Macintosh OS, Microsoft Windows OS, Linux.

Functions

Process management Resource management File management Communication management Security management Memory management

Process management

All process from start to shut down Booting Open Save Install Copy Print Send ..etc.

Resource management

Installing drivers required for input, output, memory, power, communication devices.

Coordinating among peripherals.

File management

Names, Folders Locations, Attributes, - Size, type, modified, protection,

password etc.

Communication management

User- application s/w- hardware. Connects one computer to another using

LAN/WAN. Command interpretation. Downloading/uploading

Memory management

Primary RAM-ROM Secondary – hard disk, CD, DVD, Pen drive

Etc.

Security management

Virus management Alert messages Dialogue boxes Firewall Password/ Access protection

Features of Operating Systems Software and hardware management Constant API Execution of programs Interruptions Managing memory Networking Security

Software and hardware management The operating system is the bridge between

computer hardware and software and makes the communication between them possible.

Also communication between different software's in the computer is also taken care by operating system.

Constant API

Application Program Interface (API) is a software that allows different applications that run on a computer to work on other computers also.

But they should have same operating system. So it is very vital to have consistent API in the operating system.

Execution of programs

Programs running in the computer are completely dependent on the operating system.

But program execution is a tough process. The multitasking and multithreading features of the operating system are dependent upon the type of program execution feature of O.S.

Interruptions

Interruption may happen at any time while using the computers. So the operating system should allow and handle many numbers of interrupts.

Whenever an interruption occurs, the operating system should respond to it by saving and stopping the current execution and work on the new execution.

This is the most hard-hitting process for the operating system.

Managing memory

The operating system provides the memory for the programs that are executed at any moment.

So the operating system should have good memory allocation facility to execute the programs smoothly.

The prioritization and allocation of memory to the applications running should be taken care by the operating systems.

Networking

Today computers are nothing without internet connection or some network connection. This is the age of networking.

So if computers are connected to a network, the there should be definitely communication between one computer and another.

So the operating system is what makes it possible for one computer to communicate with other computers.

Security Security is the important feature that should be looked

for in an operating system. An operating system in the computer takes care of all security issues of computer and data in it.

Log in passwords, firewall settings, and every such aspect related to security depends on the ability of the operating system.

Some of the computers in network may involve in file sharing, and other data sharing. So it is important in such cases to have powerful secured operating systems.

Telecommunications and Networks

Business Application Trends Telecommunications networks now play

a vital and pervasive role in Web-enabled… E-business processes Electronic commerce Enterprise collaboration Other applications that support operations,

management, and strategic objectives

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The Internet

A network of networksPopular uses

E-mail Instant messaging Browsing the World Wide Web Newsgroups and chat rooms

The Internet Revolution

The Internet has become a global information superhighway Millions of smaller, private networks operating independent of, or

in harmony with, each other 10 servers in 1991 to over 46 million today Sustained growth in excess of 1 million servers per month No central computer system No governing body Based on common standards

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Internet Service Providers

ISP A company that specializes in providing easy access

to the Internet For a monthly fee, provides software, user name,

password, and Internet access ISPs themselves are connected to one another

through network access points One ISP can easily connect to another to obtain

addresses of websites or user nodes

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Internet Applications

Most popular Internet applications and uses E-mail Instant messaging Browsing the Web Newsgroups Chat rooms Publish opinions, subject matter, creative work Buy and sell Downloading (data, software, reports, pictures, music, videos)

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Business Use of the Internet

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Business Value of the Internet

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Intranets Within an organization Uses Internet technologies Business value of Intranets

Used for information sharing, communication, collaboration, & support of business processes.

Web publishing Comparatively easy, attractive, & lower cost alternative for

publishing & accessing multimedia business information

The Role of Intranets Many companies have sophisticated and

widespread intranets, offering… Detailed data retrieval Collaboration Personalized customer profiles Links to the Internet

Intranets use Internet technologies Web browsers and servers TCP/IP network protocols HTML publishing and databases

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Intranets

Intranets are protected by… Passwords Encryption Firewalls

Customers, suppliers, and other business partners can access an intranet via extranet links

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Business Value of Intranets

Intranets support Communications and collaboration Business operations and management Web publishing Intranet portal management

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Intranets as Information Portals

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Extranets

Network links that use Internet technologies to interconnect the firm’s intranet with the intranets of customers, suppliers, or other business partners Consultants, subcontractors, business

prospects, & others

Extranets (continued)

Business value Improve communication with customers and

business partners Gain competitive advantage in

Product development Cost savings Marketing Distribution Leveraging their partnerships

Extranets

Network links that use Internet technologies to connect the intranet of a business to the intranets of another

Virtual Private Networks Direct private network links, or private secure Internet

links between companies Unsecured Extranet

Link between a company and others via the Internet, relying on encryption of sensitive data and firewall security systems

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Extranet Connectivity

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Business Value of Extranets Web browser technology makes customer

and supplier access to intranets easier and faster

Another way to build and strengthen strategic relationships

Enables and improves collaboration between a business, customers, and partners

Facilitates online, interactive product development and marketing

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Telecommunications Network Model

A telecommunications network is any arrangement where A sender transmits a message To a receiver Over a channel Consisting of some sort of medium

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Telecommunications Network Model

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Telecommunications Network Components

Terminals Any input/output device that uses networks

to transmit or receive data Telecommunications processors

Devices that support data transmission, reception Telecommunications channels

Media over which data are transmitted, received Computers

All sizes and types

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Network Component Alternatives

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Types of Communications Networks

Primary types of communications networks Wide Area Local Area Metropolitan Area Virtual Private Client/Server Peer-to-peer

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Wide Area Network (WAN) Telecommunication network that covers a

large geographic area

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Local Area Network (LAN) Connects computers within a limited physical

area, such as an office, classroom, or building

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Metropolitan Area Network  A metropolitan area network (MAN) is a computer network that usually

spans a city or a large campus. A MAN usually interconnects a number of local area networks (LANs) using

a high-capacity backbone technology, such as fiber-optical links, and provides up-link services to wide area networks (or WAN) and the Internet.

Virtual Private Networks (VPN) Used to establish secure intranets and extranets

The Internet is the main backbone network Relies on network firewalls, encryption, and

other security features to build a “pipe” through the Internet

Creates a private network without the high cost of a separate proprietary connection

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Virtual Private Network

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Client/Server Networks Clients

End user personal computers or networked computers

Servers Used to manage the networks

Processing Shared between the clients and servers Sometimes called a two-tier architecture

Larger computer systems are being replaced with multiple client/server networks

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Client/Server Network

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Peer-to-Peer Networks Central Server Architecture

P2P file-sharing software connects all PCs to a central server

When a PC requests a file, the server searches

all active peers on the network The server sends the requesting PC a list of

links to all active peers who have the file Clicking a link connects the two PCs and

automatically transfers the file to the requesting PC

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Peer-to-Peer Networks

Pure Peer-to-Peer Architecture No central directory or server File-sharing software connects one PC to

another online user When you request a file, the software searches every

online user and sends you a list of active file names Clicking a link automatically transfers the file from that

user’s hard drive to yours

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Central Server Peer-to-Peer Networks

Advantages Can better protect the integrity and security

of the content and users of the network Disadvantages

Directory server can be slowed or overwhelmed by too many users or technical problems

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Peer-to-Peer Network Diagrams

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Network TopologyThe network topology defines the way in which computers, printers, and other devices are connected. A network topology describes the layout of the wire and devices as well as the paths used by data transmissions.

Network Topologies

Bus Local processors share the same bus, or

communications channel Tree is a variation which ties several bus

networks together

Ring Topology

Introduction to Computer Networks

A frame travels around the ring, stopping at each node. If a node wants to transmit data, it adds the data as well as the destination address to the frame. The frame then continues around the ring until it finds the destination node, which takes the data out of the frame.

Single ring – All the devices on the network share a single cable Dual ring – The dual ring topology allows data to be sent in both directions.

Star & Tree Topology

Introduction to Computer Networks

The star topology is the most commonly used architecture in Ethernet LANs. When installed, the star topology resembles spokes in a bicycle wheel.Larger networks use the extended star topology also called tree topology. When used with network devices that filter frames or packets, like bridges, switches, and routers, this topology significantly reduces the traffic on the wires by sending packets only to the wires of the destination host.

Mesh TopologyThe mesh topology connects all devices (nodes) to each other for redundancy and fault tolerance. It is used in WANs to interconnect LANs and for mission critical networks like those used by banks and financial institutions. Implementing the mesh topology is expensive and difficult.

Introduction to Computer Networks

Applications of NetworksResource Sharing

Hardware (computing resources, disks, printers)Software (application software)

Information SharingEasy accessibility from anywhere (files, databases)Search Capability (WWW)

CommunicationEmailMessage broadcast

Remote computingDistributed processing (GRID Computing)

Bluetooth devices Bluetooth is a telecommunication signal

used within a 100 m range. Bluetooth exists in many products, such as

telephones, the Wi-Fi, PlayStation 3, and recently in some high definition watches, modems and headsets.

The technology is useful when transferring information between two or more devices that are near each other in low-bandwidth situations.

Bluetooth is commonly used to transfer sound data with telephones (i.e., with a Bluetooth headset) or byte data with hand-held computers (transferring files).

Bluetooth protocols simplify the discovery and setup of services between devices.

Bluetooth devices can advertise all of the services they provide. This makes using services easier because more of the security, network address and permission configuration can be automated than with many other network types.

Easier and Better Life with Bluetooth To connect all your office peripherals

wirelessly (Printer, Scanner, Fax) To send still or video images from any

location to any location To connect your wireless headset to

your mobile phone To unlock/lock the door, open/close the

entry way light or air-conditioner automatically, upon arriving at home.

Products for ApplicationFig.1 IBM’s Bluetooth wireless card Fig.2 3Com’s Ultra–small Bluetooth

for their ThinkPad PCs USB adapter

Fig.3 Ericsson’s Bluetooth Phone Adapter attaches the Bottom of the cellular phone

Products for ApplicationFig.4 The world’s first Bluetooth Fig.5 Ericsson’s Bluetooth headset in

headset—and matching base action station—from GN Netcom

Products for ApplicationFig.6 Ericsson’s Wrist Companion Fig.7 IBM’s digital jewelry prototype Bluetooth Watch

Fig.8 IBM’s a prototype Bluetooth Fig.9 Anoto’s Wireless pen connects medic alert bracelet and watch via Bluetooth to your PC

Advantages of Bluetooth Frequency Hopping Low power & cost Low overhead Voice/Data support Ad-hoc networking

Disadvantages of Bluetooth Slower speeds Connection in busy environments Range Security? Limit of 8 devices

WI-Fi Wi-Fi is a traditional Ethernet network, and requires configuration

to set up shared resources, transmit files, and to set up audio links (for example, headsets and hands-free devices).

Wi-Fi uses the same radio frequencies as Bluetooth, but with higher power, resulting in a stronger connection. Wi-Fi is sometimes called "wireless Ethernet."

This description is accurate, as it also provides an indication of its relative strengths and weaknesses.

Wi-Fi requires more setup but is better suited for operating full-scale networks; it enables a faster connection, better range from the base station, and better security than Bluetooth.

Strengths of Wi-Fi Simplicity and ease of deployment given that it uses

unlicensed radio spectrum which does not require regulatory approval.

Cost of rolling out this wireless solution is low. Users are able to be mobile for up to 300 feet from the

access point. There are many Wi-Fi compatible products that are

available at a low cost and can inter-operate with other network technologies.

Wi-Fi clients can work seamlessly in other countries with minimal configuration.

Weaknesses of Wi-Fi

Limited level of mobility. Susceptible to interference. Designed technically for short-range

operations and basically an indoors technology.

Security is a concern.

Bluetooth vs. Wi-Fi IEEE 802.11 in networking Bluetooth and Wi-Fi have many applications in today's offices,

homes, and on the move: setting up networks, printing, or transferring presentations and files from PDAs to computers. Both are versions of unlicensed wireless technology.

Wi-Fi is intended for resident equipment and its applications. The category of applications is outlined as WLAN, the wireless local area networks. Wi-Fi is intended as a replacement for cabling for general local area network access in work areas.

Bluetooth is intended for non resident equipment and its applications. The category of applications is outlined as the wireless personal area network (WPAN). Bluetooth is a replacement for cabling in a variety of personally carried applications in any ambience.

What is WiMax?

WiMax (Worldwide Interoperability for Microwave Access) is a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL.

The technology is specified by the Institute of Electrical and Electronics Engineers Inc., as the IEEE 802.16 standard.

WiMAX Technology WiMAX is expected to provide fixed , nomadic, portable

and, eventually, mobile wireless broadband connectivity without the need for direct line-of-sight (LOS) with a base station.

In a typical cell radius deployment of three to ten kilometers, WiMAX Forum Certified systems can be expected to deliver capacity of up to 40 Mbps per channel, for fixed and portable access applications.

Mobile network deployments are expected to provide up to 15 Mbps of capacity within a typical cell radius deployment of up to three kilometers.

Why is it Interesting? Simultaneously support hundreds of businesses and

thousands of homes with speed connectivity. Promise of potential low cost and flexibility in building

broadband networks. Scalability, as extra channels and base stations can be

added incrementally as bandwidth demand grows. Support for both voice and video as well as Internet

data. Semiconductor vendors envisage WiMax-enabled chips

appearing in PCs in 2006 and in notebook computers and PDAs by 2007

Relation of Wi-Fi and WiMax

WiMax eliminates the constraints of Wi-Fi. Unlike Wi-Fi, WiMax is intended to work

outdoors over long distances. WiMax is a more complex technology and has to

handle issues of importance such as Quality and service, guarantees, carrier-class reliability.

WiMax is not intended to replace Wi-Fi. Instead, the two technologies complement each other.

WiMax is well suited to offer both fixed and mobile access

How WiMax Works WiMax can provide 2 forms of wireless service:

- Non-LOS, Wi-Fi sort of service, where a small antenna on a computer connects to the tower. Uses lower frequency range (2 to 11 GHz). - LOS, where a fixed antenna points straight at the WiMax tower from a rooftop or pole. The LOS connection is stronger and more stable, so it is able to send a lot of data with fewer errors. Uses higher frequencies, with ranges reaching a possible 66 GHz.

Through stronger LOS antennas, WiMax transmitting stations would send data to WiMax enabled computers or routers set up within 30 (3,600 square miles of coverage) mile radius.

WiMax Applications

According to WiMax Forum it supports 5 classes of applications:

1. Multi-player Interactive Gaming.2. VOIP and Video Conference3. Streaming Media4. Web Browsing and Instant Messaging5. Media Content Downloads

WiMax Advantages in a Nutshell

Robust, reliable carrier class “last-mile” technology with QoS

For many types of high-bandwidth applications- at the same time, across long distances

Enabling new applications that improve daily life

WiMax Success Factors

It is crucial that WiMax becomes an important building block to enable fixed/mobile convergence and to ensure its success.

Ability to offer ease of use is crucial to the success of WiMAX service providers

Success of WiMAX may depend on the ability to combine fixed and mobile access over the same infrastructure

End of Module-3

Thank You.