Ericsson, SingTel and Qualcomm last week demoed FDD-TDD carrier aggregation (CA) with a peak downlink speed of 260Mb/s using commercially available hardware and software.

The demonstration on SingTel’s network, which aggregated 20MHz of FDD spectrum with 20MHz of TDD spectrum, used Qualcomm’s Snapdragon 810 processor and Ericsson’s LTE software, which is designed to support its multi-standard RBS6000 family of base stations for macro and small cell networks. The companies claimed the demo using commercial hardware and software is an industry first.

Tay Yeow Lian, SingTel’s managing director for networks, said SingTel is already using dual layers of FDD with LTE-Advanced CA and is exploring the option of bundling TDD spectrum into its LTE carrier aggregation to expand the network capacity.

A month ago China Telecom and Nokia Networks demoed FDD-TDD CA with a peak download speed of 260Mb/s using a commercial user chipset from Marvell.

FDD-TDD CA enables operators to complement their FDD networks with a cost-efficient deployment of TDD. By combining TDD and FDD spectrum, low-band FDD can deliver stable uplink coverage while the TDD band can be leveraged for higher downlink capacity.

Ericsson said FDD-TDD CA increases the effective TDD coverage area by up to 70 per cent, thereby reducing the cost of providing TDD coverage. It also ensures more efficient use of spectrum, increasing both the combined FDD-TDD coverage area and capacity of the network.

Per Narvinger, Ericsson’s head of LTE, said the demo shows the combination of low- to mid-band FDD with high-band TDD can significantly improve network performance. “This complements the FDD-TDD interoperability work we have already commercialised in countries where TDD spectrum is granted,” he commented.