MOTOTRBO
From The RadioReference Wiki
MOTOTRBO is a Motorola digital radio product marketed primarily to business/industrial users. The format uses Time Division Multiple Access (TDMA). A single 12.5 kHz channel is able to carry two conversations. This makes the format equivalent to digital radios that use Frequency Division Multiple Access (FDMA) to achieve 6.25 kHz channel spacing.
No scanner can monitor this digital format.