![]() ![]() The PDE-1 pages and dials in POCSAG, 2-tone, 5-tone, DTMF and Pulse Tone.1382: ST/PAA/TPA/1382, specification of a data and signalling transmission system from the 'Centre National d'Etudes de Telecommunications' of France Telecom.SYNCHRONIZATION: indication of a RadioRaft state in which a right bits pattern, characteristic of a mode, has been detected. ![]() SPACE: data level 0 of a signal corresponding to the highter frequency.SHIFT: frequency displacement of FSK signal within the lower and the higher frequencies.POCSAG: Post Office Code Standardization Advisory Group.The process makes the data signal varies one or several parameters (amplitude, phase, frequency) of one or several 'carriers' that form the transmitted signal. MODULATION: transformation of a data signal into a signal compatible with a transmission circuit.MODEM: modulator/demodulator (only the demodulator function of a modem is needed for RadioRaft).MARK: data level 1 of a signal corresponding to the lower frequency.INTERFACE: circuit transforming the audio signal from the speaker into the same but square signal compatible with the electric levels RS232 of serial COM ports.GPS: Global Positioning System (or Satellite). ![]() GMDSS: Global Maritime Distress and Safety System.In GMDSS, mode specified by recommendation ITU-R M.493-6. DFSK: Direct Frequency Shift Keying (no subcarrier).The unit 'baud' comes from the name of the French engineer Baudot who created the first 5 elements telegraph in the 19th century. Not equal to 'BPS', because some types of modulation (for example MFSK) allows transmission of several bits simultaneously. the opposite of the duration of the smallest transmitted element (for example, 50bauds corresponds to 20 ms elements). BAUD: unit for the modulation rate, e.g.ARINC: Aeronautical Radio, INC, 2551 Riva Road, Annapolis, MAryland 21401, USA. ![]()
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