The goal is to cover 90 to 95 percent of the 26-square-mile county. The network would not cover the Pentagon, Arlington National Cemetery or Fort Myer, where the county does not have jurisdiction.

EarthLink would spend an estimated $5 million to build, own and operate the network, said Jerry Grasso, the company's director of corporate communications.

EarthLink would provide an estimated 33 free public wireless-Internet access sites throughout the county, including parks, community centers and libraries. The company would also provide free Internet access for as many as 30 nonprofit organizations in the county and an estimated 60 free mobile accounts for county workers to use while they are in the field.

In exchange, EarthLink would gain access to a county full of potential subscribers. Nonsubscribers would also be able to access several free Web sites, including government and public school sites.

Arlington joins Alexandria in going wireless. Under a deal approved in December, Atlanta-based EarthLink will build a citywide, 16-square-mile wireless network with free connections available in more than two dozen public locations. EarthLink will spend $4 million to build the system and will provide an additional $9 million for wireless access for student computers and municipal uses in exchange for the right to build the network on city property.

The Arlington contract is expected to go before the County Board at its Saturday meeting. Officials do not expect much opposition.

"I have yet to hear somebody tell me they don't want wireless," said Rob Billingsley, information technology procurement manager for the county's Department of Technology Services. "It seems every time we present it, people seem to respond very positively to the idea of wireless in Arlington."

If approved, EarthLink will begin surveying the area by May 1. The process of surveying and acquiring permits to mount the antennas should take two to three months. The company will then begin hanging and mounting the antennas, which could take four to eight months. The 1,100 to 1,200 antennas will be mounted on telephone poles and rooftops. No more than a dozen should be mounted on rooftops, officials said.

"For the most part, it is as simple as hanging antennas on poles," Billingsley said. "There might be some construction involved. It's a very low-impact type of network. We don't really expect any digging up of streets or sidewalks or the kind of things you would see with other kinds of cable TV installations or telephone installations."

The earliest the network could be up and running is November, but an exact completion date is difficult to determine because of the unpredictable nature of wireless technology. The latest the county expects the network to be available is May 1, 2008.

Billingsley said the network will increase the productivity of some county workers, although how the 60 free mobile accounts will be allocated has not been finalized. EarthLink is also providing $40,000 a year to the county to help enhance public and governmental use of the network.

"I think we've worked out a really good deal that doesn't create any out-of-pocket costs for the county," Carlee said.