LTE is a first-generation 4G (4th generation) cellular networking technology based on original 3G (3rd generation) technologies that can reach speeds of around 100Mbit/s, reduced latency, scalable bandwidth capacity, and backwards compatibility with existing GSM and UMTS technology. GPP engineers named the technology "Long Term Evolution" because it represents the next step (4G) in a progression from GSM, a 2G standard, to UMTS, the 3G technologies based upon GSM.
The upper layers of LTE are based upon TCP/IP, and support mixed data, voice, video and messaging traffic. LTE uses OFDM (Orthogonal Frequency Division Multiplexing) and, in later releases, MIMO (Multiple Input Multiple Output) antenna technology similar to that used in the IEEE 802.11n wireless local area network (WLAN) standard.
Further evolution steps will be taken within a few years, with 5G (5th generation) scheduled to be released around 2020/2021, or possibly earlier. Each generation seems to have about a 10 year span between releases.