ABSTRACT
The simplest cellular systems use Frequency Division Multiplexing (FDM), which gives each conversation its own waveband, just like a radio station. For example, the analog A merican Mobile Phone System (AMPS), still the most widely used wireless standard in the United States, gives each user 30KHz. This limits the number of calls to the number of 30KHz frequencies available: If an operator has a license for 1OM Hz of spectrum, it can support at most 111 calls per cell.
