A wireless system in outdoor environment including a reconfigurable intelligent metasurface designed to perform beam-steering is presented. The metasurface unit-cell has been designed to work in the range 37-40 GHz and the designed meta-atom is insensitive to the angle of incidence until 30°. We model and evaluate the effect of interferers on the tracking performances. In particular, we model the channel including interferers and we consider the effect of interferers for different signal powers and different directions on the radiation pattern generated by the metasurface. In general, we notice that the sidelobe level increases when the number of scatterers and their power increase and also when the angle of incidence of the signals scattered from the cluster is increased. Interestingly, for certain configurations, e.g. at 225°, the radiation pattern at 50°is better than at 30°, showing that the behavior is not linear.