Write notes on evolution from UMTS to LTE.

Evolution from UMTS to LTE:

LTE evolved from an earlier 3GPP system known as the Universal Mobile Telecommunication System (UMTS), which in turn evolved from the Global System for Mobile Communications. Even related specifications were formally known as the evolved UMTS terrestrial radio access (E-UTRA) and evolved UMTS terrestrial radio access network (E-UTRAN). First version of LTE was documented in Release 8 of the 3GPP specifications.

There was no global standard for wireless broadband until the advent of LTE. The goal with LTE was to merge a fragmented market and offer a more efficient network for network operators.

LTE was first proposed in 2004 by Japan's NTT Docomo, with studies on the standard officially commenced in 2005. In May 2007, the LTE/SAE Trial Initiative (LSTI) alliance was founded as a global collaboration between vendors and operators with the goal of verifying and promoting the new standard in order to ensure the global introduction of the technology as quickly as possible.The LTE standard was finalized in December 2008, and the first publicly available LTE service was launched by TeliaSonera in Oslo and Stockholm on December 14, 2009, as a data connection with a USB modem

LTE services were launched by major North American carriers as well, with the Samsung SCH-r900 being the world's first LTE Mobile phone starting on September 21, 2010, and Samsung Galaxy Indulge being the world's first LTE smartphone starting on February 10, 2011

Main Reasons behind evolution from UMTS to LTE:-

• There was a need to ensure the continuity of competitiveness of the 3G system for the future.

• Users growing demands for higher data rates and quality of service.

• There was a need for Packet Switch optimised system.

• Continued demand for cost reduction (CAPEX and OPEX).

• Low complexity.

• For avoiding unnecessary fragmentation of technologies for paired and unpaired band operation.

LTE offers higher peak data transfer rates than 3G, which is up to 100 Mbps downstream and 30 Mbps upstream. It provides reduced latency, scalable bandwidth capacity and backward-compatibility with the existing Global System for Mobile communication (GSM) and Universal Mobile Telecommunications Service (UMTS) technology. The subsequent development of LTE-Advanced (LTE-A) yielded peak throughput on the order of 300 Mbps.