Frequency of optimum transmission
Encyclopedia
Frequency of optimum transmission, in the transmission
of radio
waves via ionospheric reflection
, is the highest effective (i.e. working) frequency
that is predicted to be usable for a specified path and time
for 90% of the days of the month. It is often abbreviated as FOT. The FOT is normally just below the value of the maximum usable frequency
(MUF). In the prediction of usable frequencies, the FOT is commonly taken as 15% below the monthly median value of the MUF for the specified time and path.
The FOT is usually the most effective frequency for ionospheric reflection of radio waves between two specified points on Earth.
Synonyms for this term include:
Transmission (telecommunications)
Transmission, in telecommunications, is the process of sending, propagating and receiving an analogue or digital information signal over a physical point-to-point or point-to-multipoint transmission medium, either wired, optical fiber or wireless...
of radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
waves via ionospheric reflection
Ionospheric reflection
Ionospheric reflection is a bending, through a complex process involving reflection and refraction, of electromagnetic waves propagating in the ionosphere back toward the Earth....
, is the highest effective (i.e. working) 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...
that is predicted to be usable for a specified path and time
Time
Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....
for 90% of the days of the month. It is often abbreviated as FOT. The FOT is normally just below the value of the maximum usable frequency
Maximum usable frequency
Maximum usable frequency describes, in radio transmission, using reflection from the regular ionized layers of the ionosphere, the upper frequency limit that can be used for transmission between two points at a specified time, independent of transmitter power...
(MUF). In the prediction of usable frequencies, the FOT is commonly taken as 15% below the monthly median value of the MUF for the specified time and path.
The FOT is usually the most effective frequency for ionospheric reflection of radio waves between two specified points on Earth.
Synonyms for this term include:
- frequency of optimum trafficTrafficTraffic on roads may consist of pedestrians, ridden or herded animals, vehicles, streetcars and other conveyances, either singly or together, while using the public way for purposes of travel...
- optimum traffic frequency
- optimum transmission frequency
- optimum working frequency