TDMA
From The RadioReference Wiki
Time Division Multiple Access (TDMA) is a generic name for digital transmission formats that subdivides a (12.5 kHz) channel into a fixed number of time slots (usually 2) during which digital data and voice is transmitted, on and off in increments of millisecond. Those on and off durations - allow the 12.5 kHz to be used by two unique-groups of users simultaneously, effectively making it into a usable 2 channels/slot; hence, the time-divided, multi-user accessible, naming.