LTE is estimated to be commercially available in end of 2009/ beginning of 2010. Qualcomm pushes for UMB (Ultra Mobile Broadband), Intel for WiMax and Ericsson for LTE. Some believe vendors are pressing operators for new technologies like LTE just to earn more money. But many of today's end-users have high demand on quality and latency when using mobile applications. LTE offers 100 Mbps in downlink and 50 Mbps in downlink. End user Latency is bellow 10 ms. These are very good figures for applications like online interactive gaming and VoIP.
LTE Physical Layer:
Transmission bandwidth: It can vary between 1.4 to 20 MHz with sub-carrier spacing of 15 KHz.
Duplexing Techniques: To support transmission on paired and unpaired spectrum, FDD (Frequency Division Duplex) and TDD (Time Division Duplex) are supported.
Multiple Access Schemes: MSC for LTE in Downlink is OFDMA (Orhogonal Frequency Multiple Access) and for Uplink is SC_FDMA (Single Carrier Frequency Division Multi Carrier).
Modulation and Coding: Like HSPA, LTE uses AMC (Adaptive Modulation and Coding). Examples are QPSK, 16QAM, 64QAM, Zadoff-chu.
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