- Industry: Telecommunications
- Number of terms: 29235
- Number of blossaries: 0
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ATIS is the leading technical planning and standards development organization committed to the rapid development of global, market-driven standards for the information, entertainment and communications industry.
As used in legal documents, the latest (i.e., as of the document date) ITU Radio Regulations to which the United States is a party.
Industry:Telecommunications
Assigned numbers are numbers working in the PSTN under an agreement such as a contract or tariff at the request of specific end users or customers for their use, or numbers not yet working but having a customer service order pending. Numbers that are not yet working and have a service order pending for more than five calendar days shall not be classified as assigned numbers (FCC 00-104 §52. 15 (f) (1) (iii). )
Industry:Telecommunications
Associated COMSEC items interacting to provide a single means of encryption or decryption.
Industry:Telecommunications
Association established between two higher layer entities for which information is transmitted between both entities.
Industry:Telecommunications
Asynchronous transfer mode (ATM) layer protocol control information that precedes user data.
Industry:Telecommunications
Asynchronous transmission in which a start pulse and a stop pulse are used for each symbol. 2. Signaling in which each group of code elements corresponding to an alphanumeric character is (a) preceded by a start signal that serves to prepare the receiving mechanism for the reception and registration of a character and (b) followed by a stop signal that serves to bring the receiving mechanism to rest in preparation for the reception of the next character.
Industry:Telecommunications
At a discontinuity or impedance mismatch, e.g., in a transmission line, the ratio of the incident power to the reflected power. Note 1: Reflection loss is usually expressed in dB. Note 2: The reflection loss, Lr, is given by where Z1 and Z2 are the respective impedances, and the vertical bars designate absolute magnitude. 2. In an optical fiber, the loss that takes place at any discontinuity of refractive index, especially at an air-glass interface such as a fiber endface, at which a fraction of the optical signal is reflected back toward the source. Note: This reflection phenomenon is also called "Fresnel reflection loss," or simply, "Fresnel loss. " At normal incidence, the fraction of reflected power is expressed by the formula, where n1 and n2 are the respective indices of refraction.
Industry:Telecommunications
At a discontinuity or impedance mismatch, e.g., in a transmission line, the ratio of the incident power to the reflected power. Note 1: Reflection loss is usually expressed in dB. Note 2: The reflection loss, Lr, is given by where Z1 and Z2 are the respective impedances, and the vertical bars designate absolute magnitude. 2. In an optical fiber, the loss that takes place at any discontinuity of refractive index, especially at an air-glass interface such as a fiber endface, at which a fraction of the optical signal is reflected back toward the source. Note: This reflection phenomenon is also called "Fresnel reflection loss," or simply, "Fresnel loss. " At normal incidence, the fraction of reflected power is expressed by the formula, where n1 and n2 are the respective indices of refraction.
Industry:Telecommunications
At a given azimuth, the minimum distance between the transmitting station and the closest point of return to the Earth of a transmitted wave reflected from the ionosphere.
Industry:Telecommunications
At a given data-signaling rate or modulation frequency, operating wavelength, and effective noise bandwidth, the radiant power that produces a signal-to-noise ratio of unity at the output of a given optical detector. Note 1: Some manufacturers and authors define NEP as the minimum detectable power per square root bandwidth. When defined this way, NEP has the units of watts per (hertz) 1/2. Therefore, the term is a misnomer, because the units of power are watts. Note 2: Some manufacturers define NEP as the radiant power that produces a signal-to-dark-current noise ratio of unity. The NEP measurement is valid only if the dark-current noise dominates the noise level.
Industry:Telecommunications
