  Sensitivity of future far infrared 10m class space telescopes will be limited
by a confusion noise created by distant galaxies. Our primary goal is to create
a model that will allow us to estimate the confusion noise parameters of the
Millimetron mission. We construct a model of the Cosmic Infrared Background
(CIB) aimed at exploring the methods of prediction and reduction of the
confusion noise. The model is based on the publicly available eGALICS
simulation. For each simulated galaxy we construct a spectral energy
distribution with the help of the GRASIL code. To put our model in the context
of the current CIB investigations, we compare the outputs of the model with the
available observational data and with three other models. One is a well known
"backwards evolution" model of Bethermin et al. 2011 and two others are based
on a simple mass-luminosity (M-L) relation applied to simulated dark matter
halo catalogs. We conclude that our model reproduces the observational data
reasonably well. All four models show significant differences in the
predictions of the distribution of sources on the flux-redshift plane,
especially at high redshifts. We give estimations of the confusion noise based
on number counts (source density criterion, probability of deflection criterion
etc.) and based on the analysis of the simulated maps. We show that resolution
effects influence the number counts curves and noise estimations.
