Nokia and AT&T completed trials of voice calls in C-Band spectrum, moving the pair closer to a goal of launching 5G service in the band this year.

The companies employed a device running Qualcomm’s Snapdragon X55 5G modem-RF in a pair of trials conducted at AT&T’s headquarters in Texas and the city of Detroit, Michigan.

Nokia’s AirScale baseband and 5G massive MIMO 64T64R C-Band radio were used, with the calls conducted in the n77 spectrum band (3700MHz to 3980MHz).

AT&T awarded Nokia a five-year contract to deploy C-Band equipment in March. The operator aims to cover 200 million people by the end of 2023.

Tony Seyfried, tech vendor manager at the operator, explained the trial calls will speed deployment of C-Band. The spectrum “will help enable our 5G network to reach its full potential,” he added.

AT&T acquired 80 MHz of C-Band spectrum during a record-setting government auction this year. The operator expects some of the spectrum to be cleared and available later this year.