TD-LTE and FDD-LTE networks.

[tyberry]

Hi All,

Can some one explain why we have two type of networks for LTE: with TD and FDD?

Whats the difference? Any why would operators select one over the other, I'm assuming its related to the spectrum that they have at their disposal?

[rabatcasa]

Hi Tyberry
Yes the main difference is the spectrum type and where it is available :
FDD used paired spectrum while TDD use unpaired
TDD requires a time synched networks to avoid UL/DL intereference between differents Cells
TDD offers more flexibility to devide between uplink and downlink :the operator can choose the timeslots configurations that will assign timeslots for UL and DL
Some more facts:
3GPP Standard:
› 95% of standard common for FDD&TDD
› Small differences even at physical layer
› Notable differences resides in
1› UL/DL frame structure
2› Position of synch signals
3› HARQ processes

Regards
Casa