why lte operator are choosing TDD-LTE instead of FDD-LTE?

Question

Why operators in Asia are preferring LTE TDD mode? what are the reasons behind this? Is there any impact on throughput while choosing TDD mode?

Comments

TDD is better than FDD for smaller cell which makes sense in Asia where population density is higher than many developed countries in the West.

Answer 1

What is being said is True. FDD provide larger coverage than TDD. For the same coverage area FDD gives double the data rate of TDDThere are also differences in relation to spectrum. Unpaired band is handy for TDD while there is associated cost of frequency bandwidth loss in FDD. The bottom line of choosing which duplex scheme is what the operator strategy,environment and customers look like. TDD has specific potential in utilizing channel reciprocity for channel estimation.

Answer 2

FDD LTE deployments require the use of paired frequency spectrums (i.e separate UL and DL frequency bands). This means that the operator has to segregate his acquired quota of spectrum into UL and DL.
It is often the case that in this segregation, there are some fragments which lie unused leading to inefficient utilization of an already scarce resource.

TDD LTE allows operators to make use of these unpaired and unutilized frequency bands.
Even for a green field operator, its cheaper to acquire unpaired spectrums required for TDD LTE deployments.

Answer 3

some frequency allocations are unpaired so TDD is more practical. There are other benefits such as the flexible DL/UL ratio can be set to match your traffic demand giving you overall better efficiency and channel reciprocity can be expoited in beamforming algorithms. If there are legacy systems in the spectrum ( such as 802.16e WiMAX ) TD-LTE can be frame aligned to give smooth migration without interference issues.

Having said that, in my view the discussion of TDD vs FDD is the wrong one. Most operators will end up deploying both and expoit the advantages of each. FDD in lower bands for coverage; TDD in higher bands where there is more spectrum for capacity. The growing converged device ecosystem and infrastructure mechanisms such as HO and load balancing make it a viable and, could be argued essential, proposition.