telecommunication Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than that fe ...

, the term protocol-control information or PCI has the following meanings: # The queries and replies among

communication Communication (from la, communicare, meaning "to share" or "to be in relation with") is usually defined as the transmission of information. The term may also refer to the message communicated through such transmissions or the field of inquir ...

s equipment to determine the respective capabilities of each end of the communications link. # For layered systems,

information Information is an abstract concept that refers to that which has the power to inform. At the most fundamental level information pertains to the interpretation of that which may be sensed. Any natural process that is not completely random ...

exchanged between entities of a given layer, via the service provided by the next lower layer, to coordinate their joint

operation Operation or Operations may refer to: Arts, entertainment and media * ''Operation'' (game), a battery-operated board game that challenges dexterity * Operation (music), a term used in musical set theory * ''Operations'' (magazine), Multi-Ma ...

References

Reference models Telecommunications standards ISO standards ITU-T recommendations ITU-T X Series Recommendations {{telecom-stub