The two main cellular-phone companies used by Black Hills residents have different timelines for shutting off their analog systems in South Dakota.

Verizon Wireless is launching a computer program that spokeswoman Karen Smith said will shut down the signal in South Dakota by the end of February. The program was scheduled to shut the signal down throughout the country beginning Wednesday, Feb. 20.

Scott Morris, Alltel's vice president of corporate communications, said Alltel plans to shut down analog in the state June 30. He said South Dakota is the second of three phases to shut down the signal nationwide.

"For Alltel customers in South Dakota, there's no need to panic," he said Monday. "Their service won't be affected tonight, but we certainly encourage them to upgrade to a digital phone when it's convenient for them (before June 30)."

The Federal Communications Commission has given cellular providers nationwide the option of shutting down their analog signals after Feb. 19 and keeping only a digital signal.

The vast majority of cell-phone users have phones capable of receiving a digital signal, but there are still a few who have analog-only phones.

Smith said Verizon has been warning customers about the upcoming change for the past year. The company has gone so far as mailing those customers new digital phones, she said.

"It should not be a surprise to our customers," she said.

Any customer who was still on an analog-only calling plan had their account suspended Monday, Smith said.

As per Federal Communications Commisson regulations, the companies must not shut down analog systems unless a sufficient digital signal will replace the older signal.

Smith said Verizon has been working to shore up the digital signal to meet those requirements.

"We've met the FCC requirements, and we've overlapped our analog coverage with our digital signal in South Dakota," she said. "Our coverage area has met those requirements."

Morris said that waiting until June 30 to shut down analog in South Dakota will give Alltel time to notify customers with analog-only phones of the change. It will also allow the company to make sure a sufficient digital signal exists in place of the analog signal.

Morris said Alltel will be offering special promotional deals to help customers switch to the digital network.

Analog-only cell phones are typically five years old or older.

Both Morris and Smith said that fewer than one percent of customers still have analog-only phones.

Phones that are capable of text or instant messaging and Internet browsing or have an MP3 player can be identified as digital phones.

Smith said switching to an all-digital network has many advantages, including clearer reception, call security and better battery life.

She said citizens who used the more powerful bag phones - which work only on the analog network - to get a better signal will be able to buy a digital version of that phone. But she said that type of phone may run into some interference.

People with questions about the switch can call the Public Utilities Commission at 605-773-3201 or contact either cellular company.

The commission plans to monitor the switch to make sure it does not cause major problems for consumers.

Contact Ryan Woodard at 394-8412 or ryan.woodard@rapidcityjournal.com