Signals in the time and frequency domains. Propagation of radio frequencies. Noise, large-scale path loss, small scale fading and multipath. Modulation techniques for mobile radio. Capacity of wireless channels. Error correction principles and techniques. Multiple access techniques (TDMA, CDMA, OFDM) and interference in wireless networks. Main subsystems of mobile telephony networks. Examples of existing wireless standards including IEEE 802.11 (WiFi), 3G, 4G.