TD-LTE White Paper

Executive Summary Spectrum, the single most important resource for telecommunication voice and mobile broadband service, is finite and limited. As subscribers demand faster and increased capacity anytime, anywhere, operators face the challenge of maximizing all available spectrum assets – FDD or TDD. In previous 3GPP standards, mobile operators have deployed Frequency Division Duplex (FDD) technology and the expectation was the same for LTE. However, in designing LTE, 3GPP committed to the first truly global technology standard by ensuring it supported not only FDD, but also Time Division Duplex (TDD) spectrum. To open the LTE ecosystem to FDD and TDD operation, the 3GPP standard has identified fifteen paired FDD and eight unpaired TDD spectrum bands. This allows an operator to introduce LTE in previously unattractive TDD spectrum bands, as well as in previously unavailable spectrum bands. A key advantage of the LTE ecosystem is the vast economy of scale gained through combining LTE FDD and TDD (TD-LTE) in a standardized way. The 3GPP standard allows both devices and implementations to be simpler, a major factor in reducing cost for deploying a mobile broadband technology. Since other TDD based technologies, including TD-SDMA and WiMAX, also have a migration path to LTE, combining FDD and TDD makes the scale and economy of the LTE ecosystem especially robust and attractive. This paper addresses TD-LTE's physical layer, performance, applicable spectrum, differences from FDD and its global momentum, while answering questions operators, regulators, license holders and investors may have about the technology. Clearly no single technology will solve the growing mobile broadband demand. Operators will need to use all the spectrum they can secure. In TD-LTE, operators have a very intriguing alternative, with global momentum, that matches its FDD counterpart. Today most operators are running their networks and spectrum at full capacity, trying to meet the ever increasing mobile data demand. Monthly data consumption in 2010 is already topping 5GB per month. Since penetration of smartphone devices – a key driver for data growth – is still below 20% worldwide, operators expect the growth to continue. To address this growing mobile broadband demand, the 3GPP standards body released the next technological step, Long Term Evolution (LTE). LTE is designed to substantially improve end-user throughputs, increase sector capacity and reduce user plane latency. It is a simple and flat network architecture that delivers a significantly improved user experience with full mobility, resulting in low operating costs for …