- 업종: Telecommunications
- Number of terms: 29235
- Number of blossaries: 0
- Company Profile:
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.
In radio communications, pertaining to the band of frequencies approximately between 3 MHz and 30 MHz. Note: "Shortwave" is not a term officially recognized by the international community.
Industry:Telecommunications
In radio communications, one of the three major subdivisions of a message, namely the heading, the text, or the ending. Note: Each message part may have separate components and each component may have elements and contents. 2. In cryptosystems, text that results from the division of a long message into several shorter messages of different lengths as a transmission security measure. Note: Message parts are usually prepared in such a manner as to appear unrelated externally. Statements that identify the parts for assembly at reception are encrypted in the texts.
Industry:Telecommunications
In radio communications, one of a (theoretically infinite) number of a concentric ellipsoids of revolution which define volumes in the radiation pattern of a (usually) circular aperture. Note 1: The cross section of the first Fresnel zone is circular. Subsequent Fresnel zones are annular in cross section, and concentric with the first. Note 2: Odd-numbered Fresnel zones have relatively intense field strengths, whereas even numbered Fresnel zones are nulls. Note 3: Fresnel zones result from diffraction by the circular aperture.
Industry:Telecommunications
In radio communications, a device for connecting several receivers or transmitters to one antenna in such a way that the equipment impedances are properly matched to the antenna impedance.
Industry:Telecommunications
In radio communications systems, pertaining to a station that is transmitting a carrier, whether or not the carrier is modulated. 2. In a radio station, pertaining to a particular source of modulation, such as a specific microphone, that is connected, i.e., is capable of modulating the carrier.
Industry:Telecommunications
In radio communications systems, pertaining to a station that is completely shut down, i.e., that is not transmitting any signal, not even an unmodulated carrier. 2. In a radio station, pertaining to a particular source of modulation, such as a specific microphone, that is disconnected, i.e., is no longer capable of modulating the carrier. Note: The carrier may continue unmodulated or it may be modulated by another signal source.
Industry:Telecommunications
In radio communication, diversity transmission and reception in which four independently fading signals are used. Note: Quadruple diversity may be accomplished through the use of space, frequency, angle, time, or polarization multiplexing, or combinations of these.
Industry:Telecommunications
In radio broadcasting, a frequency assigned for the exclusive use of one entity. 2. In networking, a signal path that provides its full bandwidth for a user's service. Note: No control or signaling is performed on this path.
Industry:Telecommunications
In radio and television transmission, pertaining to an arrangement in which programs are directly transmitted to specific users and not broadcast to the general public. 2. In telecommunications, a circuit dedicated to specific users. 3. A completed electrical circuit.
Industry:Telecommunications
In radar systems, a device that isolates the receiver from the transmitter while permitting them to share a common antenna. Note 1: A duplexer must be designed for operation in the frequency band used by the receiver and transmitter, and must be capable of handling the output power of the transmitter. Note 2: A duplexer must provide adequate rejection of transmitter noise occurring at the receive frequency, and must be designed to operate at, or less than, the frequency separation between the transmitter and receiver. Note 3: A duplexer must provide sufficient isolation to prevent receiver desensitization.
Industry:Telecommunications
