Wanda Wrinkle started noticing changes in her cell phone coverage in early September, with more dropped calls and “terrible” reception at her Omaha home.

Ken Mixan, also of Omaha, had similar problems with his Verizon Wireless service. His phone has dropped more calls in the last couple of months than Mixan said he could remember.

Wrinkle and Mixan are among a number of Verizon customers in Omaha and Lincoln who have reported similar problems since late July.

The service disruptions stem from Verizon’s purchase of Alltel Communications and the integration of Verizon and Alltel equipment.

Although the $28 billion Verizon-Alltel deal closed in September 2009, service changes weren’t noticed until recently. That’s when Verizon began selectively turning off some of its older towers, which were providing service that overlapped with new towers it acquired from Alltel, said Ron Goldschmidt, Verizon’s director of system performance for the great Plains region.

Goldschmidt said the company decided to use Alltel’s existing cell towers as its service base, augmenting them with certain Verizon sites.

Goldschmidt declined to say how many towers each company had, but integrating them increased the total number of Verizon towers in Omaha and Lincoln by about 40 percent.

But because some of the Verizon sites were shut down, Goldschmidt said, “a small percentage” of customers have experienced poor reception and more dropped calls.

He declined to say how many people have been affected or how many customers Verizon now has. Before the merger, which created the nation’s largest wireless carrier, Alltel was the biggest carrier in Nebraska, providing service to more than half of all cell phones in the state.

Gene Hand, director of the telecommunications department at Nebraska’s Public Service Commission, said he doesn’t know the exact number of Verizon subscribers in the state but said it is significantly more than AT&T or Sprint, the second- and third-largest providers nationally.

Verizon has about 33 percent of the market share nationally, said Dave Novosel, an analyst who covers cellular companies for the credit research firm Gimme Credit. Nationally, Verizon has about 92 million customers, according to the company.

Karen Smith, the Verizon spokeswoman, said in a statement that the company is working to improve its network of transmission towers.

“we believe overall the integration is a net gain for Omaha and Lincoln,” Smith said.

Hand said that from mid-August through the end of September the PSC received seven complaints from Verizon customers, all in Omaha. for the first five months of the year, by comparison, the office received eight complaints from Verizon customers throughout the state, he said.

While Hand acknowledged that the transition hasn’t been completely smooth, he said, “there will be give and take in this.”

“It doesn’t mean that all service was degraded in some way. Most people should see an improvement,” Hand said.

In acquiring Alltel, Verizon was required by the U.S. Justice Department to sell $2.35 billion worth of towers and equipment to AT&T in 10 counties where the merged company wouldn’t have competition. so as Alltel customers were absorbed by Verizon, some older Verizon subscribers were transferred to AT&T if they didn’t opt out and go with a different carrier.

The Verizon-Alltel deal and resulting network reconfiguration are similar to a 2005 situation, when Alltel acquired Western Wireless, the parent company of Cellular one.

Hand said Alltel’s integration with Western Wireless had some service problems similar to those created by the Alltel-Verizon merger.