(Long Term Evolution) The latest high-speed cellular transmission network. LTE is a 4G technology with download speeds that run the gamut from 3 to 37 Mbps worldwide (roughly 4 to 13 Mbps in the U.S.). Standardized in 2008, the first LTE smartphones appeared in 2011. See cellular generations and 3G. Available for the two major cellphone systems worldwide (GSM and CDMA), LTE was designed to provide global interoperability. However, LTE operates in more than three dozen frequency bands around the world, making it unjustifiable to build a phone that tunes in that many channels. Officially 4G In late 2010, the ITU widened its definition to include LTE (along with WiMAX and HSPA+) as bona fide 4G technologies. Previously, the ITU designated only LTE Advanced as true 4G. See LTE Advanced and AWS. LTE Architecture Is Based on IP Packets LTE changed its data structure and air interface from 3G. With LTE, both voice and data are transmitted in IP packets, known as the "Evolved Packet System" (EPS). In previous cellular networks, voice is handled by the traditional circuit-switched architecture, and data are packet switched. Defined in 3GPP Release 8, LTE uses the OFDMA-based E-UTRA air interface and Evolved Packet Core infrastructure (see EPC). See LTE architecture, 3GPP, GSM, CDMA and IP Multimedia Subsystem. LTE Technologies There are several technolgies that fall under the LTE umbrella. Unlicensed Spectrum See LTE-U. Internet of Things See LTE-for IoT. Higher Speed See LTE Advanced.