Noise level

	Email		Print
	Bookmark		Link

Noise level

In telecommunication

Telecommunication

Telecommunication is the assisted Transmission of Signal over a distance for the purpose of communication. In earlier times, this may have involved the use of smoke signals, Drum , Semaphore line, flag signals or heliograph....
, noise level is the noise power

Noise power

In telecommunication, the term noise power has the following meanings:# The measured total noise per Bandwidth unit at the input or output of a device when the signal is not present....
, usually relative to a reference.

In atmospheric sound transmission, noise level is the noise power
Noise power

In telecommunication, the term noise power has the following meanings:# The measured total noise per Bandwidth unit at the input or output of a device when the signal is not present....
of the longitudinal sound wave relative to a point of reference.

Note: Noise level is usually measured in decibel
Decibel

The decibel is a logarithmic units of measurement that expresses the magnitude of a physical quantity relative to a specified or implied reference level....
s (dB) for relative power or Watts for absolute power. A suffix is added to denote a particular reference base or specific qualities of the measurement.

Discussion

Ask a question about 'Noise level'

Start a new discussion about 'Noise level'

Answer questions from other users

Full Discussion Forum

Encyclopedia

In telecommunication
Telecommunication

Telecommunication is the assisted Transmission of Signal over a distance for the purpose of communication. In earlier times, this may have involved the use of smoke signals, Drum , Semaphore line, flag signals or heliograph....
, noise level is the noise power
Noise power

In telecommunication, the term noise power has the following meanings:# The measured total noise per Bandwidth unit at the input or output of a device when the signal is not present....
, usually relative to a reference.

In atmospheric sound transmission, noise level is the noise power
Noise power

In telecommunication, the term noise power has the following meanings:# The measured total noise per Bandwidth unit at the input or output of a device when the signal is not present....
of the longitudinal sound wave relative to a point of reference.

Note: Noise level is usually measured in decibel
Decibel

The decibel is a logarithmic units of measurement that expresses the magnitude of a physical quantity relative to a specified or implied reference level....
s (dB) for relative power or Watts for absolute power. A suffix is added to denote a particular reference base or specific qualities of the measurement. Examples of noise-level measurement units are dB(A)
A-weighting

A Weighting curve is a graph that is used to 'weight' measured values of a variable according to their importance in relation to some outcome. The most commonly know example is in sound level measurement where a specific set of weighting curves known as A, B, C and D weighting are often used....
, dBm
DBm

For other uses, see DBMdBm is an abbreviation for the power ratio in decibels of the measured power referenced to one milliwatt . It is used in radio, microwave and fiber optic networks as a convenient measure of absolute power because of its capability to express both very large and very small values in a short form....
, dBm0
DBm0

dBm0 is an abbreviation for the power in dBm measured at a zero transmission level point.dBm0 is a concept used in audio/telephony processing since it allows a smooth integration of analog and digital chains....
, dBrn
DBrn

The symbol dBrn or dB is an abbreviation for decibels above reference noise.Weighted noise power in dB is referred to 1.0 picowatt....
, dBrnC
DBrnC

dBrnC represents an audio level measurement, typically in a telephone circuit, relative to the level of circuit noise, with the measurement of this level frequency-weighted by a standard C-message weighting filter....
, dBrn(f₁ - f₂), dBrn(144-line
Line (electrical engineering)

In electrical engineering, a line is, more generally, any electrical network of an electrical system. This electric circuit loop , consists of electrical elements connected directly by conductor terminals to other devices in series....
). Noise levels are usually viewed in opposition to signal level
Signal level

In a communications system, the signal level is the Signalling Power or intensity at a specified point and with respect to a specified reference level, e.g., 1 mW....
s and so are often seen as part of a signal-to-noise ratio
Signal-to-noise ratio

Signal-to-noise ratio is an electrical engineering measurement, also used in other fields , defined as the ratio of a signal power to the noise power corrupting the signal....
. Telecommunication systems strive to increase the signal level to noise level ratio in order to effectively transmit data. In practice, if the transmitted signal falls below the level of the noise (often designated as the noise floor
Noise floor

In signal theory, the noise floor is the measure of the signal created from the sum of all the noise sources and unwanted signals within a measurement system....
) in the system, data can no longer be decoded at the receiver. Noise levels in telecommunication systems are a product of both internal and external sources to the system including shot noise
Shot noise

Shot noise is a type of electronic noise that occurs when the finite number of particles that carry energy, such as electrons in an electronic circuit or photons in an optical device, is small enough to give rise to detectable statistical fluctuations in a measurement....
, thermal noise, and ambient electromagnetic interference
Electromagnetic interference

Electromagnetic interference is an unwanted disturbance that affects an electrical circuit due to either electromagnetic conduction or electromagnetic radiation emitted from an external source....
.