A Category 3 hurricane nearing the East Coast has wireless operators up and down the seaboard bracing for an onslaught from the second storm of this year's Atlantic hurricane season.

Hurricane Irene is expected to gain power as it nears the coast and has maximum sustained winds near 110 mph.

A storm surge of as much as six to 11 feet above ground level is expected to rock the North Carolina Coast when Irene makes landfall on Saturday, with water rising four to eight feet over southern portions of Chesapeake Bay and three to six feet along the New Jersey shore as the storm makes its way up the coast.

The hurricane poses a major threat to wireless networks, which are vulnerable to high winds, rain, power outages and flooding. Verizon Wireless, AT&T, Sprint, T-Mobile USA and Cricket Communications all report that they are taking steps to protect their networks.

The companies are moving in portable generators, batteries and fuel to maintain the flow of power to their networks. Response teams are being readied to conduct repairs in the wake of the hurricane, and cell sites on wheels are being moved to neighboring areas unaffected by the storm to quickly restore wireless service.

"Wireless communication is critical before, during and after hurricanes and other weather-related emergencies," said Nancy Clark, Northeast president for Verizon Wireless. "Preparation is key to staying safe. We have years of experience of planning for and maintaining service during severe weather and are very proud of how our employees and network have performed in meeting these challenges."

Wireless networks are often inundated with calls during emergencies. An earthquake that struck Virginia and sent tremors throughout the East Coast earlier this week left wireless infrastructure unscathed, but a high volume of calls in the wake of the temblor jammed networks and left customers without service.

Hurricane Katrina knocked down more than a thousand cell sites when it devastated the Gulf Coast in 2005, according to damage estimates from the FCC.

Operators recommend customers limit non-emergency calls during the hurricane to conserve battery power and free up capacity for disaster relief agencies. Customers are also advised to send text messages instead of making calls.

Hurricane Irene is predicted to be the largest storm to hit parts of the East Coast in more than 70 years, according to the American Red Cross. It is the second major storm of the 2011 Atlantic hurricane season after Tropical Storm Arlene struck Veracruz, Mexico, in late June.