Long Term Evolution — Rel-8, Rel-9 (2008-2009)
First 4G standard with all-IP architecture, OFDMA, and Evolved Packet Core (EPC). LTE revolutionized mobile networks with flat architecture, low latency under 10ms, and peak rates up to 300 Mbps.
LTE (Long Term Evolution) is the first 4G mobile technology standardized by 3GPP. It was defined in Rel-8 (2008) and extended in Rel-9 (2009).
Key architectural components include the Evolved Packet Core (EPC) with MME, S-GW, P-GW, HSS, and PCRF, plus the E-UTRAN radio access network based on eNodeB base stations.
LTE uses OFDMA in the downlink and SC-FDMA in the uplink, with bandwidths from 1.4 to 20 MHz. MIMO support ranges from 2x2 to 4x4, enabling peak rates of 150-300 Mbps downlink.
Rel-9 added Home eNodeB (femtocells), eMBMS for broadcast services, location services, VoLTE via IMS, and CSFB/SRVCC for voice continuity with legacy networks.