Editing Communications system (section)

===By technology===
A [[Duplex (telecommunications)|duplex communication system]] is a system composed of two connected parties or devices which can communicate with one another in both directions. The term ''duplex'' is used when describing communication between two parties or devices. Duplex systems are employed in nearly all communications networks, either to allow for a communication "two-way street" between two connected parties or to provide a "reverse path" for the monitoring and remote adjustment of equipment in the field. An [[Antenna (radio)|antenna]] is basically a small length of a conductor that is used to radiate or receive electromagnetic waves. It acts as a conversion device. At the transmitting end it converts high frequency current into electromagnetic waves. At the receiving end it transforms [[electromagnetic waves]] into electrical signals that is fed into the input of the receiver. several types of antenna are used in communication.

Examples of communications subsystems include the [[Defense Information Systems Agency|Defense Communications System]] (DCS).