ALEVEL ICT UNIT 1: Connection

Microwave

are used to transmit satellite television and for mobile phones. over a long distance

Laser

is an optical communication technology that uses light propagating in free space to wirelessly transmit data for telecommunications or computer networking.

ISP

"Internet Service Provider." provides access to the Internet. Whether you're at home or work, each time you connect to the Internet, your connection is routed through an ISP. This normally costs a monthly fee for them to use it

GSM

A mobile phone signal (also known as reception and service) is the signal strength (measured in dBm) received by a mobile phone from a cellular network (on the downlink).

Radio waves

are used to transmit television and radio programs. over a moderate distance

Satellite

facilitates communications, as radio, television, and telephone transmissions, by means of the reflection or the amplification and retransmission of signals between stations on earth or in space.

Broadband

high-speed data transmission in which a single cable can carry a large amount of data at once. The most common types of Internet broadband connections are cable modems (which use the same connection as cable TV) and DSL modems (which use your existing phone line).

Digital

information stored using ones and zeros. Computers are digital machines because they can only read information as on or off (1 or 0). This method of computation, also known as the binary system, may seem rather simplistic, but can be used to represent incredible amounts of data.

Fibre cable connections

is a high-speed data transmission medium. It contains tiny glass or plastic filaments that carry light beams. Digital data is transmitted through the cable via rapid pulses of light. example transatlantic telecommunications cables between the U.S. and Europe are fiber optic

Coaxial cable

is a type of cable that has an inner conductor surrounded by a tubular insulating layer, surrounded by a tubular conducting shield. Many coaxial cables also have an insulating outer sheath or jacket.

Twisted pair cables

is a type of wiring in which two conductors of a single circuit are twisted together for the purposes of canceling out electromagnetic interference (EMI) from external sources, they can be shielded and unshielded

Bluetooth

is a wireless technology standard for exchanging data over short distances from fixed and mobile devices, and building personal area networks, weak connection if far away from connection source.

XDSL

is similar to ISDN as both operate over existing copper telephone lines and both require the short runs to a central telephone office (usually less than 20,000 feet). XDSL offers much higher speeds - up to 32 Mbps for upstream traffic, and from 32 Kbps to over 1 Mbps for downstream traffic.

infrared waves

is used to transmit information from remote controls. over a short distance

Modem

modulates outgoing digital signals from a computer or other digital device to analog signals for a conventional copper twisted pair telephone line and demodulates the incoming analog signal and converts it to a digital signal for the digital device.

Wi-Fi

the standard way computers connect to wireless networks to allow them to revive and send data. Nearly all modern computers have built-in Wi-Fi chips that allows users to find and connect to wireless routers.

Switch

used to network computers together. typically small, flat boxes with 4 to 8 Ethernet ports. These ports connect to computers, cable or DSL modems. High-end switches can have more than 50 ports and often are rack mounted. this has more control over sending information than a hub

Copper wires

uses electrical signals to pass data between networks. There are three types of copper cable: coaxial, unshielded twisted pair and shielded twisted pair.

ISDN

(Integrated Services Digital Network) a set of communication standards for digital transmission of voice, video, data, and other network services. Can provide connection speeds up to 64 kbps 124 kbps and uses the telephone line.

ASDL

(asymmetric digital subscriber line) can provide connection speeds up to 24 mbps and uses the telephone line.

3G/4G

4G is the fourth generation of wireless mobile telecommunications technology, succeeding 3G. Potential and current applications include amended mobile web access, IP telephony, gaming services, high-definition mobile TV, video conferencing, and 3D television. (microwaves)

analog

A dial-up modem converts digital signals from a computer to analogue signals that are then sent down the telephone line. (cannot make a call if connected to the internet).

Hub

a device that allows multiple computers to communicate with each other over a network. It has several Ethernet ports that are used to connect two or more network devices together. Each computer or device connected to the hub can communicate with any other device connected.