Long Term Evolution (LTE) is the next-generation air interface in the Universal Mobile Telecommunications System (UMTS) family of radio access technologies. It is defined in the 3rd Generation Partnership Project (3GPP)'s Release 8 set of specifications.
The defining characteristics of LTE are peak downlink speeds of at least 100 Mbit/s and uplink speeds of at least 50 Mbit/s, low latency (less than 10 milliseconds round trip), and a flat, all-IP architecture.
NTT DoCoMo Inc., TeliaSonera AB, and Verizon Wireless have plans to launch LTE networks in 2010, which would make them the first commercial networks in the world. But LTE devices are not expected to be widely available until 2011 at the earliest.
LTE follows 3G technologies Wideband Code Division Multiple Access (WCDMA) and High-Speed Packet Access (HSPA) and is commonly referred to as "4G." But it is technically not 4G.
LTE is a next-generation wireless technology, not only for GSM and UMTS operators, but also for traditional CDMA operators: BCE Inc. (Bell Canada), KDDI Corp., Telus Corp., and Verizon have each chosen to migrate from CDMA-based technologies to LTE for next-generation mobile broadband. In addition, China Mobile Communications Corp. also plans to follow the LTE migration path from the homegrown Chinese 3G standard, TD-SCDMA.