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For mobile phone technology, a mobile allocation index offset (MAIO) refers a time delay separating traffic channels.When a GSM (Global System for Mobile Communications) mobile phone is served by a cell that is hopping over a set of frequencies, the separate traffic channels hop over the allocated frequencies according to a hopping sequence number (HSN).
The first signal report format code may have been QJS. [citation needed]The U.S. Navy used R and K signals starting in 1929. [citation needed]The QSK code was one of the twelve Q Codes listed in the 1912 International Radiotelegraph Convention Regulations, but may have been in use earlier.
A tabular data card proposed for Babbage's Analytical Engine showing a key–value pair, in this instance a number and its base-ten logarithm. A key–value database, or key–value store, is a data storage paradigm designed for storing, retrieving, and managing associative arrays, and a data structure more commonly known today as a dictionary or hash table.
The frequency band is divided into smaller sub-bands. Signals rapidly change ("hop") their carrier frequencies among the center frequencies of these sub-bands in a determined order. Interference at a specific frequency will affect the signal only during a short interval. [1] FHSS offers four main advantages over a fixed-frequency transmission:
With hop-by-hop transport, chunks of data are forwarded from node to node in a store-and-forward manner. As hop-by-hop transport involves not only the source and destination node, but rather some or all of the intermediate nodes as well, it allows data to be forwarded even if the path between source and destination is not permanently connected ...
Some call sign block ranges are unassigned by the ITU, e.g. the 1AA–1ZZ and QAA-QZZ blocks. Any call sign used by an amateur in these unassigned block ranges usually had it assigned to them by a group with an unrecognized national claim. Unless otherwise noted, they have no value for DXCC awards, nor are they valid under UK license conditions ...
An antenna's impedance is different at different frequencies. An antenna tuner matches a radio with a fixed impedance (typically 50 Ohms for modern transceivers) to the combination of the feedline and the antenna; useful when the impedance seen at the input end of the feedline is unknown, complex, or otherwise different from the transceiver.
In telecommunications, especially radio communication, spread spectrum are techniques by which a signal (e.g., an electrical, electromagnetic, or acoustic) generated with a particular bandwidth is deliberately spread in the frequency domain over a wider frequency band.