T-Mobile Picks Its Next Cell Sites Off a Grid of 165-Metre Hexagons

Ask T-Mobile US where to put the next cell site and the answer starts with a grid of millions of hexagons, each roughly 165 metres wide. Inside each cell the operator trains models on dropped calls, data and voice experience, churn profiles, acquisition and retention rates and competitive pressure, then ranks candidate builds by the customer and revenue impact they would carry. John Saw, its president of technology and chief technology officer, laid out the system at the AI Investor Day run by Deutsche Telekom, the German group that holds the majority of T-Mobile US, and put it among the largest AI programmes the carrier has run. “Customer-driven coverage is one of the biggest AI lifts in the history of our company,” he said.

Lake Tahoe is the example he returns to. Few people live there year round, yet the model saw heavy visitor traffic arriving from San Francisco, Oakland and Sacramento, and T-Mobile spent on capacity that a plain population map would never have justified.

Storms test the other half of it. Winter storm Fern cut power to more than a million people across 30 states in January 2026; T-Mobile’s self-organising network pushed out some 30,000 antenna adjustments and trimmed power at sites to stretch backup batteries by over 250,000 minutes. By Saw’s account, 68 per cent of affected customers were back within an hour and 98 per cent within eight hours.

Independent measurement has tracked the same 5G lead. Opensignal’s January 2026 US report gave T-Mobile 5G download speed of 249 Mbps, ahead of AT&T on 184.3 Mbps and Verizon on 176.6 Mbps, and put its 5G availability at 91.2 per cent of the time. 5G coverage experience scored 8.3 out of 10.

A second tool, Dynamic CX, handled the 2026 World Cup, making more than 11,000 automated adjustments across 12 host cities as crowds shifted.