​Leti has been using the 3.5 GHz frequency with a bandwidth of 40 MHz to test a 5G network on the MINATEC campus since January 2017. The frequency could be the first to be released for 5G network rollout.

To run the multiservice transmission tests, a base station was installed at a high point on the campus and three mobile terminals are used to emulate smartphones. The researchers working on the project started by tackling how to enhance the signal waveform and decode it at the receiver. “We tested a post-OFDM multicarrier waveform to make sure it was compatible with the three types of service 5G networks will provide: very-high-speed internet, optimized transmission for IoT, and high-reliability low-latency communications,” said a Leti researcher.

The researchers are also currently testing innovative multiple-access control systems to demonstrate that information can be transmitted and received by multiple users simultaneously. Finally, some of the more advanced features of tomorrow’s 5G networks will also be tested, such as in-band full-duplex, which can double capacity by allowing data to be transmitted and received at the same time on the same frequency band.