Standard frequency and time signal service (short: SFTS) is, according to Article 1.53 of the International Telecommunication Union's (ITU)

Radio Regulations Radio regulation refers to the regulation and licensing of radio in international law, by individual governments, and by municipalities. International regulation The International Telecommunication Union (ITU) is a specialized agency of the Unit ...

(RR),ITU Radio Regulations, Section IV. Radio Stations and Systems – Article 1.53, definition: ''standard frequency and time signal service'' "A radiocommunication service for scientific, technical and other purposes, providing the transmission of specified frequencies, time signals, or both, of stated high precision, intended for general reception".

Classification

In accordance with ''ITU Radio Regulations'' (article 1) variations of this ''radiocommunication service'' are classified as follows:
Standard frequency and time signal service (article 1.53) * Standard frequency and time signal-satellite service In general this ''radiocommunication service '' uses radio stations as follows: *Standard frequency and time signal stations (article 1.95)

Standard frequency and time signal-satellite service

Standard frequency and time signal-satellite service (short: SFTSS) is, according to ''Article 1.54'' of the International Telecommunication Union's (ITU)

(RR), defined as ''A radiocommunication service using space stations on earth

satellite A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...

s for the same purposes as those of the standard frequency and time signal service''. An example to this were experiments of time synchronisation (Global Transmission Services GTS-2) onboard International Space Station. However, in accordance to the ubiquitous availability, GNSS-satellite signals will be used in practice (see also: GPS disciplined oscillator).

Frequency allocation

The allocation of radio frequencies is provided according to ''Article 5'' of the ITU Radio Regulations (edition 2012).''ITU Radio Regulations, CHAPTER II – Frequencies, ARTICLE 5 Frequency allocations, Section IV – Table of Frequency Allocations'' In order to improve harmonisation in spectrum utilisation, the majority of service-allocations stipulated in this document were incorporated in national Tables of Frequency Allocations and Utilisations which is with-in the responsibility of the appropriate national administration. The allocation might be primary, secondary, exclusive, and shared. *primary allocation: is indicated by writing in capital letters (see example below) *secondary allocation: is indicated by small letters ; Example of

frequency allocation Frequency allocation (or spectrum allocation) is the part of spectrum management dealing with the designation and regulation of the electromagnetic spectrum into frequency bands, normally done by governments in most countries. Because radio pr ...

Time signals in use

The following are the known HF time signal stations currently operational.

United States

The Standard Time and Frequency Signal (STFS) is a

Radiocommunication service Radio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to ...

providing the transmission of specified

frequency Frequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio ...

and

time Time is the continuous progression of existence that occurs in an apparently irreversible process, irreversible succession from the past, through the present, and into the future. It is a component quantity of various measurements used to sequ ...

signal, of stated high precision, intended for general reception in the United States and beyond. The radio signals are broadcast on very precise carrier frequencies by the U.S. Naval Observatory and the

National Institute of Standards and Technology The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into Outline of p ...

(NIST), formerly the National Bureau of Standards (NBS). The technical specification of that particular service is in line to the provisions of the International Telecommunication Union's (ITU)

(RR)

References

External links

NIST Time and Frequency Division

NPL India Time and Frequency Standards
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