Initially, the choice between FDD and TDD is driven by spectrum availability, but now an increasing number of operators deploy both TDD and FDD to leverage all their spectrum assets. Within globally assigned IMT bands for mobile services, significant resources are suitable for LTE TDD.
The advanced technological performance of LTE came with in-built flexibility to operate in either paired (FDD, or Frequency Division Duplexing, mode) or unpaired (TDD, or Time Division Duplexing mode) spectrum and various channel bandwidths – all with a single technology. There is major commonality of the LTE specifications for the FDD and TDD modes. The vast majority of the LTE standard is identical for both modes, and this contributes to the huge global success of LTE.
There are a growing number of LTE TDD operator commitments, deployments and trials worldwide, a rapidly establishing system maturity and expanding eco-system. Several operators have deployed both the FDD and TDD modes in their networks. LTE TDD also provides a future-proof evolutionary path for TD-SCDMA, another 3GPP standard, as seen with huge success in China.
LTE TDD is a globally accepted technology and has been selected by many WiMAX™ operators as the ideal path to grow their business.