In communication

Communication

Communication is the activity of conveying meaningful information. Communication requires a sender, a message, and an intended recipient, although the receiver need not be present or aware of the sender's intent to communicate at the time of communication; thus communication can occur across vast...

s and electronics

Electronics

Electronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...

, especially in telecommunications, interference is anything which alters, modifies, or disrupts a signal

Signal (electrical engineering)

In the fields of communications, signal processing, and in electrical engineering more generally, a signal is any time-varying or spatial-varying quantity....

 as it travels along a channel

Channel (communications)

In telecommunications and computer networking, a communication channel, or channel, refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel...

 between a source

Communication source

A source or sender is one of the basic concepts of communication and information processing. Sources are objects which encode message data and transmit the information, via a channel, to one or more observers ....

 and a receiver. The term typically refers to the addition of unwanted signals to a useful signal. Common examples are:

• Electromagnetic interference
  Electromagnetic interference
  Electromagnetic interference is disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source. The disturbance may interrupt, obstruct, or otherwise degrade or limit the effective performance of the circuit...
  
   (EMI)
• Co-channel interference
  Co-channel interference
  Co-channel interference or CCI is crosstalk from two different radio transmitters using the same frequency. There can be several causes of co-channel radio interference; four examples are listed here....
  
   (CCI), also known as crosstalk
  Crosstalk (electronics)
  In electronics, crosstalk is any phenomenon by which a signal transmitted on one circuit or channel of a transmission system creates an undesired effect in another circuit or channel...
  
  
• Adjacent-channel interference
  Adjacent-channel interference
  Adjacent-channel interference is interference caused by extraneous power from a signal in an adjacent channel. ACI may be caused by inadequate filtering , improper tuning or poor frequency control .ACI is distinguished from crosstalk.Broadcast...
  
   (ACI)
• Intersymbol interference
  Intersymbol interference
  In telecommunication, intersymbol interference is a form of distortion of a signal in which one symbol interferes with subsequent symbols. This is an unwanted phenomenon as the previous symbols have similar effect as noise, thus making the communication less reliable...
  
   (ISI)
• Inter-carrier interference (ICI), caused by doppler shift in OFDM modulation (multitone modulation).
• Common-mode interference
  Common-mode interference
  In telecommunication, the term common-mode interference has the following meanings:#Interference that appears on both signal leads , or the terminals of a measuring circuit, and ground....
  
   (CMI)
• Conducted interference
  Conducted interference
  In telecommunications, the term conducted interference has the following meanings:*Interference resulting from noise or unwanted signals entering a device by conductive coupling, i.e., by direct coupling....
  
  

Interference is typically but not always distinguished from noise

Electronic noise

Electronic noise is a random fluctuation in an electrical signal, a characteristic of all electronic circuits. Noise generated by electronic devices varies greatly, as it can be produced by several different effects...

, for example white

White noise

White noise is a random signal with a flat power spectral density. In other words, the signal contains equal power within a fixed bandwidth at any center frequency...

 thermal noise.

Radio resource management

Radio resource management

Radio resource management is the system level control of co-channel interference and other radio transmission characteristics in wireless communication systems, for example cellular networks, wireless networks and broadcasting systems...

 aims at reducing and controlling the co-channel and adjacent-channel interference.

See also

• Distortion
  Distortion
  A distortion is the alteration of the original shape of an object, image, sound, waveform or other form of information or representation. Distortion is usually unwanted, and often many methods are employed to minimize it in practice...
  
  
• Signal-to-Interference Ratio
  Signal-to-interference ratio
  The signal-to-interference ratio , also known as the carrier-to-interference ratio , is the quotient between the average received modulated carrier power S or C and the average received co-channel interference power I, i.e...
  
   (SIR)
• Signal to noise plus interference (SNIR)
• Inter-flow interference
  Inter-flow interference
  In wireless routing, inter-flow interference refers to the interference between neighboring routers competing for the same busy channel.The inter-flow interference routing metric is incorporated in MIC and iAWARE wireless routing protocol....
  
  
• Intra-flow interference
  Intra-flow interference
  Intra-flow interference is interference between intermediate routers sharing the same flow path.In wireless routing, routing protocol WCETT, MIC and iAWARE incorporate consideration to the intra-flow interference metric....