DETROIT — AT&T Inc. announced an upgrade to its wireless network on 25 cell towers across a dozen Michigan counties. The improvements include adding greater capacity or bandwidth and speeds in 21 communities, including Idlewild, Kalkaska, Cass City, Beaverton, and Charlevoix.

These upgrades are like adding more lanes to a highway carrying traffic from a customer’s device to the cell tower, resulting in faster speeds.

The improvements also were made in the following areas: Boyne Falls, Hersey, Kingston, Marion, Northport, Pigeon, Reese, South Boardman and Sebewaing. Tustin, Unionville and Vassar round out the list of towns getting faster speeds.

The following communities had upgrades made on two locations: Caro, National City/Sand Lake, Reese and Traverse City.

“We are increasing network speeds and capacity, as we continue to expand the availability of our network using the latest technology,” said David C. Lewis, president of AT&T Michigan.

Additional information about AT&T products and services is available at about.att.com.