Channel Partitioning MAC protocols: FDMA
FDMA: frequency division multiple access
channel spectrum divided into frequency bands
each station assigned fixed frequency band
unused transmission time in frequency bands go idle
example: 6-station LAN, 1,3,4 have pkt, frequency bands 2,5,6 idle
TDM (Time Division Multiplexing): channel divided into N time slots, one per user; inefficient with low duty cycle users and at light load.
FDM (Frequency Division Multiplexing): frequency subdivided.