4G is a wireless system designed to provide high throughput and wide area coverage using a packet-switched network. It uses technologies like OFDM and UWB to achieve high data rates of up to 20 Mbps for mobile users traveling at speeds up to 200 km/hr. 4G will implement a single worldwide IP-based core network to provide uniform multimedia services across heterogeneous access networks. It aims to seamlessly integrate existing mobile technologies through an all-IP infrastructure for improved scalability to meet growing demands for wireless data.