Ericsson, SingTel and Qualcomm have successfully demonstrated FDD / TDD Carrier Aggregation using commercial track hardware and software. The demonstration achieved 260 Mbps downlink speeds.

SingTel is already using dual-layers of LTE FDD with LTE-Advanced Carrier Aggregation and is continuing to explore the future option of bundling even TDD spectrum into the LTE carrier aggregation to expand network capacity. 

The technical demonstration took place at the SingTel office in Singapore on October 3, 2014, utilizing a Qualcomm® Snapdragon(TM) 810 processor, and Ericsson LTE software designed to support the company's multi-standard RBS6000 family of base stations for macro and small-cell networks. In the demonstration, Ericsson aggregated 20 MHz of LTE FDD spectrum with 20 MHz of LTE TDD spectrum, supporting peak data rates up to 260 Mbps.

FDD / TDD Carrier Aggregation enables operators to complement their FDD networks with a cost-efficient deployment of TDD. For operators using TDD bands, the TDD uplink coverage can be a constraint. By combining TDD and FDD spectrum through Carrier Aggregation, low band FDD can deliver good uplink coverage while the TDD band can be leveraged for higher downlink capacity. LTE FDD / TDD Carrier Aggregation enables spectrum from both LTE FDD and LTE TDD to be combined to deliver higher peak data speeds and improve app coverage across the network. It increases the effective TDD coverage area by up to 70%, reducing the cost of providing TDD coverage. It also ensures efficient utilization of spectrum, increasing both the combined FDD / TDD coverage area and capacity of the network.

Commercial devices supporting FDD / TDD Carrier Aggregation are expected in 2015.