Long Term Evolution, or LTE, is a 4G mobile network standard for high-speed data. It was developed by 3GPP and first deployed in 2009. It offered a major jump over 3G. Download speeds went from a few megabits to tens or hundreds of megabits. Latency dropped. It made mobile video and apps practical.

LTE uses OFDMA for downlink and SC-FDMA for uplink. It uses MIMO antennas for higher capacity. It supports flexible bandwidth from 1.4 MHz to 20 MHz. LTE Advanced added carrier aggregation, higher-order MIMO, and relay nodes. LTE Advanced Pro pushed speeds further.

LTE characteristics

• All-IP network: packet-switched only
• OFDMA: efficient use of spectrum
• MIMO: multiple antennas for capacity
• Low latency: about 20 milliseconds
• Widely deployed: global standard

LTE is the most successful mobile standard ever. It covers most of the world. It is the fallback when 5G is not available. It will remain in service for years. 5G gets the attention. LTE does the work.