U.S. Cellular (NYSE:USM) finally launched the nationwide LTE roaming service it hinted at months ago, but it isn't saying which carrier is has partnered with.

CEO Ken Meyers said on an earnings call in July that the operator had inked its first LTE roaming deal, but he declined to mention the carrier partner. He predicted that customers would be able to access LTE while roaming within the next 60 to 90 days, but U.S. Cellular didn't begin to commercially offer nationwide LTE roaming until Dec. 1, a spokesperson confirmed.

The spokesperson declined to name the carrier partner as well. The operator is likely a tier-one, though, which would give U.S. Cellular's customers access to a much broader and more robust network.

Meyers has said U.S. Cellular plans to participate in the upcoming 600 MHz incentive auction and hopes to secure spectrum in markets where it doesn't already have low-band spectrum and also where it needs additional capacity. U.S. Cellular ended the third quarter with 4.72 million subscribers.

U.S. Cellular isn't the only major U.S. wireless operator moving toward LTE roaming. T-Mobile in August joined the Competitive Carriers Association's LTE data roaming hub, giving small and rural carriers another partner to work with as they seek to expand their network coverage. And in March, Sprint said roughly half of its rural LTE roaming partners have launched LTE service.

For more:

- see this updated U.S. Cellular coverage map

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