"Long Term Evolution"

LTE , short form of  ''Long-Term Evolution'', is considered by many, to 
be the natural successor to current-generation 3G technologies, in part because it updates UMTS networks to provide significantly faster data rates for both uploading and downloading. The specification calls for downlink peak rates of at least 100Mb/s and an uplink of 50Mb/s, but going by real world tests its transfer speeds will more likely range from 
5-12Mb/s for downloads and 2-5Mb/s for uploads.




LTE is being developed by a group of telecommunications associations known as the 3rd Generation Partnership Project, or 3GPP, as an eight release of what has been evolving since 1992 from the GSM family of standards.

There are two fundamental aspects of LTE. The first is that the technology finally leaves behind the circuit switched network of its GSM roots and moves to an all-IP flat networking architecture. This is a significant shift which in very simple terms means that LTE will treat everything it transmits, even voice, as data. The other big change relates to the use of MIMO (Multiple Input & Multiple Output)  technology, or multiple antennas at both the transmitter and receiver end to improve communication performance. This setup can either be used to increase the throughput data rates or to reduce interference.

Many big-name global operators and mobile communications companies are backing LTE in the race for 4G mobile broadband, including Vodafone, Orange, T-Mobile, LG Electronics, Ericsson, Nokia, Siemens, NTT DoMoCo, and others. In the U.S., Verizon Wireless has said it is going commercial with its LTE network in the fourth quarter, with 25 to 30 markets up and ready at launch. AT&T and T-Mobile claim they will begin to deploy LTE in 2011, but in the meantime both networks have moved to HSPA 7.2 and the latter plans to roll out HSPA+ beginning this year. Theoretically these can support speeds of up to 7.2 and 21 Mbps, respectively, but in real world scenarios they are only marginally faster than most 3G data services.

The reason behind LTE’s strong industry support lies in the relative ease of upgrading from current 3G networks worldwide over to LTE mobile broadband, compared to the significant infrastructure build out that WiMAX has taken thus far. Fewer cell sites have to be built and penetration into buildings is better at the 700 MHz spectrum LTE uses. However, WiMAX deployments are already up and running while LTE's formal debut is still a few months out.


Source - 3GPP