A modem whose modulated output signal has an essential frequency spectrum that is limited to that which can be wholly contained within, and faithfully transmitted through, a voice channel with a nominal 4-kHz bandwidth . ( 188 ) Note: High frequency (HF) modems are limited to operation over a voice channel with a nominal 3-kHz bandwidth.
NARROWBAND MODEM
Meaning of NARROWBAND MODEM in English
Telecommunication standard terms English vocab. Английский словарь стандартных телекоммуникационных терминов. 2012