Wireless but not clueless
Glossary
binary code. A digital coding system that uses a sequence of only two types of symbols (eg, 0 and 1) to represent data. The two symbols are called bits (an abbreviation for binary digits). For more information see How bits and bytes work (How Stuff Works, USA).
broadband. A type of data transmission in which a single wire can carry several channels of data at once. Broadband transmission provides a high rate of data transfer, defined as more than 200 kilobits per second.
cryptographic. For more information see Cryptography (Webopedia, USA)
frequency. A measure of how frequently a wave goes up and down (oscillates) or the number of waves passing by in a second. A hertz is a unit of frequency – 1 oscillation per second; a kilohertz (kHz) is 1000 hertz – 1000 oscillations per second; a megahertz is 1 million hertz – 1 million oscillations per second. For more information see Sound properties and their perception – pitch and frequency (The Physics Classroom, USA).
optical fibre. A glass thread that acts as a guide for lightwaves. Fibres used in telecommunications usually have a cladding of glass of a lower refractive index. In a communication system, several fibres are made up into a cable.
radio waves. Low frequency electromagnetic radiation. Radio waves have wavelengths ranging from less than a centimetre to as long as 100 kilometres. The hertz (Hz) is the unit of frequency and means one complete oscillation per second. Many frequencies are much higher than this so other units are used (eg, 1 megahertz (1MHz) = 1,000,000Hz).
We divide the radio wave part of the electromagnetic spectrum into bands that are allocated to different uses. These include AM radio (amplitude modulation), FM radio (frequency modulation) and CB radio (citizens' band), television, aircraft communications, satellites, mobile phones and pagers. Within each band, no two transmissions can use the same part of the spectrum – or frequency – at the same time. For this reason, each band within the radio wave spectrum, itself a part of the broader electromagnetic spectrum, must be managed carefully to ensure the best use of this limited resource.
For more information see How the radio spectrum works (How Stuff Works, USA).
router. A device located where two or more networks connect that determines the best path for forwarding the data packets.
telecommunications. The communication of information over a distance by means of radio waves, optical signals or along a transmission line.
Posted January 2007.