High-mobility III-V heterostructures are emerging and very promising materials likely to fulfil high-speed and low-power specifications for ambient intelligent applications. The main objective of this work is to theoretically explore the potentialities of MOSFET based on III-V materials with low bandgap and high electron mobility. First, the charge control is studied in III-V MOS structures using a Schrödinger-Poisson solver. Electronic transport in III-V devices is then analyzed using a particle Monte Carlo device simulator. The external access resistances used in the calculations are carefully calibrated on experimental results. The performance of different structures of nanoscale MOS transistor based on III-V materials is evaluated and the quasi-ballistic character of electron transport is compared to that in Si transistors of same gate length.