n257 (28 GHz)

n257 is a 5G FR2 mmWave band. It operates from 26.5 to 29.5 GHz, a frequency previously used for millimeter-wave point-to-point services. The band was designed to harmonise with the spectrum plans of Japan, North America, and South Korea, but is available for use globally. This band is capable of significantly expanding the capacity and speed of 5G networks due to its large bandwidth. Like all mmWave bands, n257 is a capacity layer designed for short range transmission with high data rates.

Standardising a single 28 GHz band would not be practical as to cover the entire 24.25 to 29.50 GHz range would require RF devices to handle a 5.25 GHz wide bandwidth. As such three bands were defined to cover the three geographical groups:

• n257: Covering 26.5 to 29.5 GHz for Japan, North America, and South Korea
• n258: Covering 24.25 to 27.5 GHz for Europe and China
• n261: Covering a narrower 27.5 to 28.35 GHz for operation alongside n260 (39 GHz) in the United States