Wireless communication systems are nowadays employed in many elds. The research effort beneath this work is to investigate one of the main issues in a radio communication system: interference. Devices operating in the 2.4 GHz ISM band are considered and, in particular, wireless sensors networks compliant to IEEE 802.15.4 standard are used to evaluate performance indices in the presence of interference. A complete perspective involving theoretical formulas, simulations and experimental results is given. The purpose of the work is to understand interference phenomena, using a real life test bed...