Editing Nordic Mobile Telephone (section)

=== Signaling ===
NMT voice channel is transmitted with FM (Frequency Modulation)<ref name="googlebooks-tele-illustrated">{{cite book|title=The telecommunications illustrated dictionary|author=Petersen, Julie K.|year=2002|url=https://books.google.com/books?id=b2mMzS0hCkAC&pg=PA679|publisher=CRC Press|isbn=9781420040678}}</ref> and NMT signaling transfer speeds vary between 600 and 1,200&nbsp;bits per second, using FFSK (Fast [[Frequency Shift Keying]]) modulation. Signaling between the base station and the mobile station was implemented using the same RF channel that was used for audio, and using the 1,200&nbsp;bit/s FFSK modem. This caused the periodic short noise bursts, e.g. during handover, that were uniquely characteristic to NMT sound.