|Definition:|| 1. an assembly, obtained by frequency division multiplexing of a specified number of supergroups, normally 5, in adjacent positions in a frequency band of specified width with guard bands between supergroups|
2. a frequency band of standardized width, 1 232 kHz, in a multichannel carrier system and occupying one of a number of specified positions in the spectrum
NOTE 1 – A mastergroup is normally an assembly of 300 FDM telephone channels.
NOTE 2 – In the USA, a mastergroup is an assembly of 10 supergroups, normally 600 FDM telephone channels, with a bandwidth of 2 520 kHz.
NOTE 3 – Signals, other than those derived from an assembly of supergroups but having specified characteristics, may occupy the whole or a part of a frequency band normally assigned to a master group.