The 3GPP Release 8 standard specifies the 4G Evolved Packet System (EPS), which includes the E-UTRAN (access network also known as LTE) and EPC (core network also known as SAE).
System Architecture Evolution (SAE) is the evolution of the GPRS Core Network. It is a simplified architecture where the intelligence is in the access network instead of the core network. It is an all-IP Network and supports higher throughput and lower latency radio access networks, including E-UTRA (LTE and LTE-Advanced air interface), 3GPP legacy systems (GERAN or UTRAN) and non-3GPP systems (WiMAX or cdma2000).
The EPS, also known as LTE, is designed to provide high data rates and low latency using a flat, all-IP network architecture. The EPS is standardized to provide all services including mobile broadband data, high-quality voice, and multimedia services.
Downlink peak data rates provided by LTE up to 100Mb/s and 50Mb/s in the uplink. It operates in both TDD and FDD modes and it has a scalable bandwidth up to 20MHz, covering 1.4, 3, 5, 10, 15 and 20MHz. The usage of OFDMA (SC-FDMA in the uplink) and MIMO technic increase spectral efficiency over 3 times.