System Architecture Evolution (aka SAE) is the core network architecture of 3GPP’s LTE wireless communication standard.
SAE is the evolution of the GPRS Core Network, with some differences:
simplified architecture
all-IP Network (AIPN)
support for higher throughput and lower latency radio access networks (RANs)
support for, and mobility between, multiple heterogeneous access networks, including E-UTRA (LTE and LTE Advanced air interface), 3GPP legacy systems (for exampleGERAN or UTRAN, air interfaces of GPRS and UMTS respectively), but also non-3GPP systems (for example WiMAX or cdma2000)