1k — 1 × 103
1M — 1 × 106
1G — 1 × 109
Bandwidth — The span of frequencies within the spectrum that is occupied by a given signal.
Channel — It is a medium of communication paths, sometimes also called link. For example, wires, optical fibres, wave guides, air, … etc.
Frequency — The number of cycles (Hertz) per second of a periodic signal.
Full-duplex system — Information can be sent by both parties simultaneously.
Half-duplex system — Information can be sent by either one of the parties to another, but only in one direction at a time.
ITU — The International Telecommunications Union. It is a union to specify the technical communication standards among different countries.
OFTA — The Office of the Telecommunications Authority. It maintains and regulates the technical standards and issues of the telecommunication industries in Hong Kong.
Simplex system — Communication can only be conducted in one direction.
Spectrum — The span of frequencies used in communication systems.
Wavelength — The distance between two adjacent peaks, or between the same points on any adjacent cycles. It is defined mathematically as: