Bandwidth

Bandwidth is the width of a frequency range occupied or transmitted by a signal or channel. In communications, it is a key factor in how much information a channel can carry.

Shannon–Hartley theorem: A formula giving the maximum reliable information rate of a noisy channel from its bandwidth and signal-to-noise ratio. It quantifies how bandwidth and noise jointly limit channel capacity.
Frequency: The number of cycles of a repeating event that occur per unit time, measured in hertz. Bandwidth measures the span between frequencies.
Digital subscriber line: A family of broadband technologies that transmit digital data over telephone-line pairs. DSL performance depends on the usable frequencies and line conditions.
Throughput: The actual rate at which data is successfully delivered through a system over time. Throughput is measured in delivered data per second, unlike frequency bandwidth.
Nyquist–Shannon sampling theorem: A theorem stating the sampling conditions needed to reconstruct a band-limited signal from discrete samples. It connects a signal’s highest frequency to the sampling rate needed to preserve it.
Hertz: The SI unit of frequency, equal to one cycle per second. Frequency ranges and bandwidth are commonly expressed in hertz.
Cable modem: A device that provides internet access over a cable television network’s coaxial infrastructure. Cable systems allocate frequency bands to downstream and upstream data.
Latency: The delay between initiating an action and observing its effect in a system. A wide-bandwidth connection can still have high latency.
Signal-to-noise ratio: The ratio of a signal’s power to the power of background noise, commonly expressed in decibels. It works with bandwidth to set the theoretical capacity of a noisy channel.
Fourier analysis: A family of mathematical methods that represents signals as sums or integrals of sinusoidal components. It explains how a signal can be described by its frequency components.

Linked from 26 pages