First Commercial Hybrid Massive MIMO System for Sub-6Hz Bands. - Reza Monir Vaghefi; Glenston Miranda; Rakesh Srirambhatla; Giovanni Marzin; Chris Ng; Farid Fayazbakhsh; Sanjeev Tarigopula; Ramesh Chembil Palat; Mihai Banu (5G World Forum, 2018)