Telecommunications

Telecommunications

Communicating and transmitting

information electronically- - - - - - - -

(includes transmitting data, text, pictures,

voice and video over long distance)

How Do We Tele-Communicate?

Phone

Voice mail

Cell phone—also includes texting

Fax—a document generated by using a facsimile machine

Email—transmission of messages and files using a computer network

Instant messaging

Methods of Telecommunication

Social networking sites—websites that provide a virtual community in which people with a shared interest may communicate

Telecommuting—the action of working from home using a computer and telecommunications media

Intranet—a company’s private computer network

e-commerce/e-business—buying/selling merchandise or conducting business on the Internet

Methods of Telecommunication

Audio conferencing—Communication between three or more sites that are linked by a voice-only telecommunications medium

Video conferencing—Communicate in real time via video with two or more people at different locations

Telecommunications & Networks

At the heart of telecommunications is the ability to “network” computers together . . .

And at the heart of networks is the media through which communication

flows: wires, telephone lines, or wireless signals.

NetworksA group of two or more

computers linked together

Benefits

Instant communication

Information sharing

Hardware sharing

Software sharing

Network ComponentsServer—the computer at the center of a network that

manages network resources; more powerful than a desktop computer

Client—any computer on a network that relies on a server for resources, i.e. email, etc.

computers that are connected and ready to receive and/or transmit data are said to be online,

as opposed to a stand-alone computer: a computer that is not connected to a network

Classification by Coverage

Local Area Network—a network that spans a relatively small area; typically is confined to a single building or several buildings

WAN—a network that geographically spans a large area; typically includes 2 or more LANs

There are several variations of WANs

A popular WAN used by large businesses is the VPN

Virtual Private Network

VPN—a private network that uses a public network (usually the Internet) to connect remote sites or users together.

Instead of using a dedicated, real-world connection such as leased line, a VPN uses "virtual" connections routed through the Internet from the company's private network to the remote site or employee.

What media is used to connect computers

to a network or to the Internet?

Two categories of media

Wired Media

Wireless Media

A computer will need a network interface card (NIC)

to connect to a network or the Internet.

Wired MediaTwisted pair cable—cable that consists of two independently

insulated wires twisted around one another. Twisted pair is the least expensive type of wire

Coaxial cable—a type of wire that consists of a center wire surrounded by insulation and then a grounded shield of braided wire. Coaxial cables are frequently used by cable TV companies.

Fiber optic cable—a technology that uses glass (or plastic) threads (fibers) to transmit data. Fiber optics provide the best quality but is expensive to install and the cable is more fragile and difficult to splice

Wireless MediaMicrowave

Satellite

Infrared (remote controls)

Cellular

Wi-Fi (radio waves)

Bluetooth (short-range radio waves)

How is information transmitted to and

from your computer on a network or the Internet?

Modems—phone, cable, DSL

Satellites—provides high speed access for rural, remote areas or mobile vehicles and boats; transmits electromagnetic signals

T Lines—a digital high-speed long-distance telephone line that is capable of carrying multiple types of signals across the line; T-1 / T-4 lines are currently available; typically large companies and organizations qualify