Real-world: Operator migration case studies

T-Mobile USA and Reliance Jio

T-Mobile USA pioneered the layer-cake strategy: low-band n71 (600 MHz) for nationwide coverage, C-band n41 (2.5 GHz, acquired from Sprint) for urban capacity, and mmWave n258 for dense hotspots. They launched SA early (2020) and lead in mid-band 5G coverage. The Sprint spectrum acquisition was transformative — 2.5 GHz provides excellent balance of coverage and capacity. Reliance Jio in India took a unique greenfield approach: built a 4G-only network (no 2G/3G legacy) and is deploying 5G SA-only from the start, making it the fastest large-scale 5G rollout globally with nationwide coverage…