Population: 525,796
Worst Carrier: T-Mobile
Best Carrier: Sprint
Signal strength is typically measured in decibels – but the same decibel reading will produce different amounts of bars on different phones. You and your friend might stand side by side, your iPhone showing four bars while his Android shows five—and in truth you’re both getting the same amount of juice. The average reading in Tucson, according to OpenSignalsMaps, would likely be around the three-to-four bar threshold.