Ericsson, SingTel and Qualcomm claim first FDD/TDD carrier aggregation

Ericsson, SingTel and Qualcomm Technologies have announced the successful demonstration of frequency division duplex (FDD) and time division duplex (TDD) carrier aggregation of the LTE Advanced network. The aggregated approach allows for more efficient use of spectrum, and increased network speeds.

Infrastructure vendor Ericsson claims that the demonstration, run on commercial hardware and software for SingTel, achieved data speeds of up to 260 Mbps. Tan Yeow Lian, SingTel’s Managing Director for Networks, believes that the aggregated approach will lead the way in ensuring customer experience satisfaction on LTE Advanced networks.

“We are already using dual-layers of LTE FDD with LTE-Advanced Carrier Aggregation, and we know the performance of our mobile network is critical to ensuring that our customers have a great experience on their smartphones and tablets,” he said. “Therefore, we will continue to explore the future option of bundling even TDD spectrum into the LTE carrier aggregation to expand network capacity, allowing our customers to enjoy consistent high data speed download even at high traffic areas”

Utilising Qualcomm’s Snapdragon 810 processor, alongside Ericsson’s LTE software which is designed to support macro and small-cell network performance, the demonstration took place on 3rd of October, and aggregated 20MHz of LTE FDD spectrum.

FDD and TDD work in different ways by aggregating in-bound and out-bound spectrum use. FDD typically utilises two separate communication channels and safe-guards each band to avoid conflict between the transmitting and receiving chips inside the handset. TDD, meanwhile, uses a single spectrum frequency, and time-lapses in-bound and out-bound frequencies. A combination of the two allows for more efficient uplink coverage with FDD and downlink capacity with TDD.

“We demonstrated that the combination of low to mid band FDD with high band TDD can provide significant network performance gains,” said Per Narvinger, Head of Product Area LTE at Ericsson. “This compliments the FDD/TDD interoperability work which we have already commercialized in countries where TDD spectrum is granted.”

Ericsson also conducted trials of the carrier aggregation approach over the summer, and commercial devices which support FDD/TDD carrier aggregation are expected to be more widely available in 2015.