The U.S. Federal Communications Commission has moved to set up a system that would send text alerts to people on their mobile phones in case of natural disasters and other emergencies.

With an order released Wednesday, the FCC adopted technical requirements for transmission of the alerts, which would require the cooperation of mobile operators. However, at least one large hurdle remains before the system is launched: No government agency has yet been named to collect and transmit the alerts to mobile operators.

The Commercial Mobile Alert System (CMAS) would be designed to reach U.S. residents regardless whether they have access to a TV, radio or electricity. More than 250 million people in the country have mobile phones today, FCC commissioners noted.

The system would send out three types of alerts: Imminent Threat Alerts, with information on emergencies that may pose an imminent threat to peoples' lives or well-being, Child Abduction Emergency/AMBER Alerts concerning missing children and Presidential Alerts, which would preempt any other pending alerts. The alerts initially would be text only, though with vibration and audio signals for people with disabilities. They eventually might include audio and video content.

Any subscriber to a mobile service with roaming agreements could get the alerts wherever they were, as long as their handset supports the system, according to an FCC statement.

"We are enabling wireless providers that choose to participate in this system to begin designing their networks to deliver wireless alerts," FCC Chairman Kevin Martin said in a prepared statement. "It would have been better, of course, if we had a Federal entity in place now to take on the role of alert aggregator and gateway." Martin said he hopes Wednesday's order starts a dialog that helps get an agency assigned to this role quickly.

Participating carriers will be required to comply with the rules adopted in the order within 10 months after it's announced that an agency has been chosen to handle the system, the FCC said in a news release.

The FCC adopted the order in compliance with the Warning, Alert and Response Network (WARN) Act, which Congress passed in 2006. Its standards are based on the recommendations of the Commercial Mobile Service Alert Advisory Committee.

The Federal Emergency Management Agency (FEMA) was intimately involved in developing the idea of a single agency to collect and send alerts to carriers, but then objected to playing that role, Commissioner Michael Copps said in a written statement. FEMA said it would be unable to step in for statutory and other reasons, Copps said.