LTE - High-speed cellular data transmission network

Definition of:LTE
(Long Term Evolution) The latest high-speed cellular data transmission network. LTE is a 4G technology, surpassing the speeds of the widely used 3G networks. Apple aficionados eagerly awaited the iPhone 5 because it was the first iPhone to support LTE.

Available for the two major cellphone systems worldwide (GSM and CDMA), LTE is envisioned to provide global interoperability. However, LTE operates in more than three dozen frequency bands, making it difficult to build a phone that can tune in that many channels.

Approved in 2008 with download speeds up to 173 Mbps, LTE uses a different air interface and packet structure than 3G. See cellular generations and 3G.

LTE - From 3G to 4G Officially
The ITU previously designated LTE-Advanced (LTE-A) as the true 4G evolution. However, in late 2010, it widened its definition to include regular LTE, along with WiMAX and HSPA+, as bona fide 4G technologies since they are faster than 3G. See IMT-Advanced.

E-UTRA/OFDMA, IP and IMS
LTE uses the Evolved UMTS Terrestrial Radio Access (E-UTRA) air interface, which is based on OFDMA and is a departure from CDMA and the TDMA used in GSM (see GSM and CDMA). In addition, rather than proprietary packet structures, LTE is based entirely on IP packets, and voice travels over IP (VoIP). The IP part of LTE is called "Evolved Packet System" (EPS), which was previously called "System Architecture Evolution" (SAE). LTE was defined by the 3G Partnership Project in the 3GPP Release 8 specification. See IP Multimedia Subsystem.