mmWave refers to higher frequency radio bands ranging from 24GHz to 40GHz, and Sub-6GHz refers to mid and low-frequency bands under 6GHz . Low-frequency bands are under 1GHz, while mid-bands range from 3.4GHz to 6GHz and are not considered “mmWave.” mmWave 5G networks are ultra-fast, but they’re also ultra-short range.10 May 2021