MILLIMETER WAVE
COMMUNICATION
Microwave cellular systems have precious little
spectrum: around 600 MHz are currently in use,
divided among operators [10]. There are two
ways to gain access to more microwave spectrum:
• To repurpose or refarm spectrum. This has
occurred worldwide with the repurposing of
terrestrial TV spectrum for applications such
as rural broadband access. Unfortunately,
repurposing has not freed up that much
spectrum, only about 80 MHz, and at a high
cost associated with moving the incumbents.
• To share spectrum utilizing, for instance,
cognitive radio techniques. The high hopes
initially placed on cognitive radio have been
dampened by the fact that an incumbent not
fully willing to cooperate is a major obstacle
to spectrum efficiency for secondary users