This document compares the 3G and 4G mobile communication technologies of UMTS and LTE. UMTS (3G) uses WCDMA technology and has a maximum theoretical downlink speed of 42Mbps, while LTE (4G) uses OFDM and more advanced MIMO schemes, providing much higher maximum theoretical downlink speeds of 100Mbps with the ability to reach 1Gbps. The document outlines the network architectures and standards of UMTS and LTE. It also lists the objectives of 4G networks in providing improved quality of service, mobility, bandwidth and a fully IP-based network compared to 3G technologies.