In telecommunication

Telecommunication

Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...

, a ternary signal is a signal that can assume, at any given instant, one of three states or significant conditions, such as power

Power (physics)

In physics, power is the rate at which energy is transferred, used, or transformed. For example, the rate at which a light bulb transforms electrical energy into heat and light is measured in watts—the more wattage, the more power, or equivalently the more electrical energy is used per unit...

 level, phase

Phase (waves)

Phase in waves is the fraction of a wave cycle which has elapsed relative to an arbitrary point.-Formula:The phase of an oscillation or wave refers to a sinusoidal function such as the following:...

 position, pulse duration

Pulse duration

In signal processing and telecommunication, the term pulse duration has the following meanings:#In a pulse waveform, the interval between the time, during the first transition, that the pulse amplitude reaches a specified fraction of its final amplitude, and the time the pulse amplitude drops,...

, or frequency

Frequency

Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...

.

Examples of ternary signals are (a) a pulse that can have a positive, zero, or negative voltage value at any given instant (PAM

Pulse-amplitude modulation

Pulse-amplitude modulation, acronym PAM, is a form of signal modulation where the message information is encoded in the amplitude of a series of signal pulses....

-3), (b) a sine wave that can assume phases of 0°, 120°, or 240° relative to a clock

Clock

A clock is an instrument used to indicate, keep, and co-ordinate time. The word clock is derived ultimately from the Celtic words clagan and clocca meaning "bell". A silent instrument missing such a mechanism has traditionally been known as a timepiece...

 pulse (3-PSK

Phase-shift keying

Phase-shift keying is a digital modulation scheme that conveys data by changing, or modulating, the phase of a reference signal ....

), and (c) a carrier wave

Carrier wave

In telecommunications, a carrier wave or carrier is a waveform that is modulated with an input signal for the purpose of conveying information. This carrier wave is usually a much higher frequency than the input signal...

 that can assume any one of three different frequencies depending on three different modulation

Modulation

In electronics and telecommunications, modulation is the process of varying one or more properties of a high-frequency periodic waveform, called the carrier signal, with a modulating signal which typically contains information to be transmitted...

 signal significant conditions (3-FM

Frequency modulation

In telecommunications and signal processing, frequency modulation conveys information over a carrier wave by varying its instantaneous frequency. This contrasts with amplitude modulation, in which the amplitude of the carrier is varied while its frequency remains constant...

).
Some examples of PAM-3 line code

Line code

In telecommunication, a line code is a code chosen for use within a communications system for baseband transmission purposes...

s that use ternary signals are:

• hybrid ternary code
  Hybrid ternary code
  The hybrid ternary line code operates on a hybrid principle that combines the binary non-return-to-zero-level and the polar return-to-zero codes and thus it is called H-ternary....
  
  
• bipolar encoding
  Bipolar encoding
  In telecommunication, bipolar encoding is a type of line code . A duobinary signal is such an encoding.- Advantages :...
  
  
• MLT-3 encoding
  MLT-3 encoding
  MLT-3 encoding is a line code that uses three voltage levels...
  
   used in 100BASE-TX Ethernet
• B3ZS
• 4B3T
  4B3T
  4B3T stands for 4 Binary 3 Ternary, a line encoding scheme used for ISDN BRI interface. 4B3T represents four binary bits using three pulses.It uses three states:* + ,* 0 , and* − ....
  
   used in some ISDN basic rate interface
  Basic rate interface
  Basic Rate Interface is an Integrated Services Digital Network configuration intended primarily for use in subscriber lines similar to those that have long been used for plain old telephone service...
  
  
• 8B6T used in 100BASE-T4 Ethernet
• return-to-zero
  Return-to-zero
  For the Delp/Goudreau band, see RTZReturn-to-zero describes a line code used in telecommunications signals in which the signal drops to zero between each pulse. This takes place even if a number of consecutive 0's or 1's occur in the signal. The signal is self-clocking...
  
  
• SOQPSK-TG uses ternary continuous phase modulationhttps://dspace.byu.edu/handle/1877/58

3-PSK can be seen as falling between "binary phase-shift keying" (BPSK) which uses two phases, and "quadrature phase-shift keying" (QPSK) which uses four phases.

See also

• balanced ternary
  Balanced ternary
  Balanced ternary is a non-standard positional numeral system , useful for comparison logic. It is a ternary system, but unlike the standard ternary system, the digits have the values −1, 0, and 1...
  
  
• digital signal
  Digital signal
  A digital signal is a physical signal that is a representation of a sequence of discrete values , for example of an arbitrary bit stream, or of a digitized analog signal...
  
  
• Fast Ethernet#100BASE-T2 uses PAM-5, which, like ternary, is one of the few modulation schemes that does not use a power-of-two number of symbols.
• three-phase electric power
  Three-phase electric power
  Three-phase electric power is a common method of alternating-current electric power generation, transmission, and distribution. It is a type of polyphase system and is the most common method used by grids worldwide to transfer power. It is also used to power large motors and other heavy loads...
  
  , like 3-PSK, uses 3 phases at a single frequency and amplitude.