Barbour also serves as the 911 director for Johnston County, N.C., southeast of Raleigh, the first county in the state to adopt Phase II. "Our operators no longer had to go through the pain of having to listen to the tragedy going on when they couldn't find the location of the call."
Internet phone service has also changed the landscape for 911 centers. Voice Over Internet Protocol sends voice signals over a broadband signal, and as a result, 911 service isn't the same as landlines.
According to the Vonage, one of the largest providers of VoIP service, customers must fill out a form stating the street address where the service will be used. When a customer makes a 911 call, the center covering the address provided to Vonage will be notified.
There are some issues with the service, however. If the call center in question isn't able to receive the caller's phone number and address, the operator won't be able to determine the call's origin.
If a local call center can't be reached, the call will go to a national emergency center run by Vonage. The center requires the caller to be able to speak to the operator to provide information about the situation and the caller's location, which isn't always possible during an emergency.
"The average consumer generally has no idea what the limitations [of VoIP] are in terms of 911 service," said Patrick Halley, NENA's government affairs director.
And consumers might not always have 911 service at the front of their minds when making the decision to switch to a different type of service, forgoing a traditional landline. "They think, 911 is for other people, I'm not ever going to need it, but when they need it, they'll want the system to work," he said.
Close to 10 percent of U.S. callers rely on wireless as their primary phone -- that's expected to rise to 23 to 37 percent by 2009, according to a NENA report. The number of VoIP users, currently around 8 million, is projected to jump to more than 27 million in the next two years.
Congress has in the last decade passed two pieces of legislation meant to deal with the advancing technology. In 1999, legislation mandated 911 as the official emergency phone number and required the FCC to work with states to push advanced service.
Five years later, Congress authorized the creation of a coordination office within the federal government and a funding system allowing $250 million per year for programs and grants. That system has yet to receive funds, though Sen. Ted Stevens, R-Alaska, introduced a bill that aims to appropriate $43.5 million.
Currently, a bill introduced by Sen. Bill Nelson, D-Fla., seeks to bring VoIP service into the fold and further examine the infrastructure needs of the emergency response system. NENA supports the bill.
"We just want Congress to help us live up to the public's expectation that when they call that three-digit number, they get someone on the other end," said Halley.