Long Term Evolution (LTE) is a mobile network technology that is being deployed by mobile operators on both the GSM and the CDMA technology paths. It is designed to be backward compatible with GSM and HSPA.
LTE incorporates MIMO (Multiple Input Multiple Output) technology, Orthogonal Frequency Division Multiple Access (OFDMA) air interface in the downlink and Single Carrier FDMA in the uplink. This combination provides high levels of spectral efficiency and network performance, coupled with high network capacity and low latency. LTE will support spectrum channel bandwidths from 1.4 MHz to 20 MHz; i.e., it is scalable.
Some of the improvements LTE brings over currently used wireless mobile radio technologies are a better spectral efficiency, lower costs, high transfer speeds, improved services, etc. LTE will provide 300 Mbps downlink speed and uplink speeds upto 75 Mbps.
Evolution from GSM to LTE
Ericsson helped deployed LTE network for AT&T
The main problem LTE is facing is that many countries are using different frequency bands making interoperability an issue. Some of countries with their frequency bands are:
Band 1[2100 MHz]- Japan, Philippines, South Korea
Band 3[1800 MHz]- Australia, Belgium, Finland, Germany, Hong Kong, Hungary, Italy, Singapore, Solvenia, Solvakia, South Korea, United Arab Emirates, UK
Band 4[1700 MHz]- AT&T in United States
Band 7[2600 MHz]- Austria, Brazil, Canada, Finland, Germany, Hong Kong, Russia, Singapore, Sweden, Switzerland
Band 17[700 MHz]- AT&T and Verizon in United States, Canada