We use a time-dependent numerical model to calculate the prompt GRB emission (spectra and light curves) on a broad energy range.
The emission is modelled by combining a time-dependent radiative code, solving for electron and photon distributions, with a dynamical
code calculating the evolution of the physical conditions in the shocked regions of the outflow. The microphysics parameters and the
parameters defining the dynamical evolution are constrained by the observed spectral evolution in the standard sub-MeV energy range
as well as by Fermi/LAT observations. I will show the comparison of our results with the simulated GRB population and further
constraints it imposes in the parameter space for prompt emission. The synthetic GRB light curves and spectra are currently used in
the estimate of CTA detection rate and the optimization of observations.