When the city of Augusta rolls out its downtown Wi-Fi service in September, it will join a small but growing number of cities also hoping to create a municipal wireless Internet network.

Service in some of those cities, such as Philadelphia and San Francisco, has failed. Others, such as Corpus Christi, Texas, and Minneapolis, appear to be succeeding.

The impact of Augusta's $850,000 investment in Wi-Fi service remains to be seen, but officials and industry analysts say the city appears to be following the pay-for-service model considered to be the most viable.

Under the city's plan, residents in a four-square-mile area of downtown can pay to subscribe to the wireless broadband network, which will be built and run by a third-party service provider.

Gary Hewett, the project manager and assistant director of the Augusta Information Technology department, said the city will be accepting bids to run the service during the next two months.

The operator will install the 144 wireless transmitters throughout the service zone and handle all administration, such as billing and marketing. Prices for the service have not been determined.

The city is launching the project with a $562,500 state grant and $281,250 in local funds.

As part of the program, the city will continue to offer free Wi-Fi service on the Augusta Common and will provide free service to the Peabody Apartments, Allen Homes and Ervin Towers public housing developments.

"It's mostly to bridge the digital divide and promote educational achievement," said Tameka Allen, the director of the Augusta Information Technology department.

Craig Settles, a consultant and wireless industry analyst in California, said Augusta's program resembles the "viable business model" being used in cities such as Providence, R.I., and Santa Monica, Calif. Many large and mid-sized cities that planned to offer free Wi-Fi underestimated the costs, and the programs were canceled.

"In the second half of '07, reality struck. ... A number of high profile projects were stalled or put on the shelf," Mr. Settles said.

Portland, Ore., is considered to be the only large city with a free-access municipal Wi-Fi program.

Minneapolis is said to have the most successful, large-scale municipal wireless project, Mr. Settles said. That city's service provider, USI Wireless, needs 10,000 subscribers to make a profit. Mr. Settles said it already has 8,000 signed up.

Augusta officials say its Wi-Fi service would be expanded if enough residents subscribe. The success of the program will depend on whether the service "has been deployed to consumers and is paying for itself."

"We hope to have the entire city of Augusta covered at some point," Mr. Hewett said. "I do believe the time will come when a person would not consider moving into a community that did not have wireless. It's evolving into a necessity."

Barry White, the president and CEO of the Augusta Convention and Visitors Bureau, thinks that providing Wi-Fi service could bring economic rewards to Augusta. He would like to see the city find a way to offer the service for free.

"If we can offer the service for free to visitors who are in town for a convention, event or meeting, we think that would be a competitive advantage for us," Mr. White said.

The wireless transmitters measure about 9 inches by 12 inches and will be mounted on light and power poles.