LTE: Long Term Evolution

Long Term Evolution, or LTE, is an entirely new radio platform technology with specifications approved by the 3GPP in January 2008, and initial deployment planned in 2010. LTE uses Orthogonal Frequency Division Multiple Access (OFDMA) on the downlink, which is well suited to achieve high peak data rates in high spectrum bandwidth. LTE is part of the GSM evolutionary path beyond 3G, following EDGE, UMTS, HSPA (HSDPA and HSUPA combined) and HSPA Evolution (HSPA+). Although HSPA and its evolution is strongly positioned to be the dominant mobile data technology for the next decade, it is important to evolve the GSM family of standards toward the future. The HSPA Evolution will provide the stepping-stone to LTE for many operators.

LTE uses Orthogonal Frequency Division Multiple Access (OFDMA) on the downlink and single Carrier Frequency Division Multiple Access (SC-FDMA) on the uplink. LTE assumes a full Internet Protocol (IP) network architecture and is designed to support voice in the packet domain. It incorporates top-of-the-line radio techniques to achieve performance levels beyond what will be practical with CDMA approaches, particularly in larger channel bandwidths. However, in the same way that 3G coexists with Second Generation (2G) systems in integrated networks, LTE systems will coexist with 3G and 2G systems. Multimode devices will function across LTE/3G or even LTE/3G/2G, depending on market circumstances.

LTE is expected to provide:

• Downlink peak theoretical data rates up to 326 Mbps with 20 MHz bandwidth
• Uplink peak theoretical data rates up to 86 Mbps with 20 MHz bandwidth
• Operation in both FDD and TDD modes
• Scalable bandwidth up to 20 MHz, covering 1.4 MHz, 2.5 MHz, 5 MHz, 10 MHz, 15 MHz and 20 MHz.
• An increase in spectral efficiency of two to four times that of HSPA Release 6
• Reduced latency to 10 msec round-trip time between user equipment and the base station and to less than 100 msec transition time from inactive to active.

LTE will address the market needs of at least the next decade, after which time operators might deploy Fourth Generation (4G) networks using LTE technology as a foundation.

Additional Information

New Clearwire announces 'Clear' brand (FierceWireless, December 1, 2008)

LTE exceeding 3GPP performance targets (TelecomsEurope, October 13, 2008)

LTE or WiMAX? Regional carriers, MVNOs mull next-gen plans (RCR WirelessNews, September 22, 2008)

EDGE, HSPA, LTE: The Mobile Broadband Advantage (3G Americas white paper, Sept 2007)

Long-Term Evolution: The vision beyond 3G Nortel Networks' white paper on LTE, the next-generation technology beyond 3G. (August 2007; PDF - 343 K)

LTE Questions and Answers