T-Mobile, one of the country's three largest cellphone service providers, said it had a "voice and text wireless issue" that began around noon EDT Monday. The company said at 1 a.m. Tuesday that all problems had been resolved.
The company blamed an internet traffic issue that caused problems with its network for the outage.
AT&T and Verizon both said their networks were operating normally. But calls between their customers and T-Mobile customers could have run into trouble because of T-Mobile's issues, creating the impression of a widespread communications failure.