Callers using Internet-based phone service may find they are unable to connect when they need to most, trying to reach 911, according to Deschutes County 911 Director Laura Wolfe.

Voice over Internet Protocol (VoIP) technology uses a broadband Internet connection to transmit phone calls, according to the Federal Communications Commission’s Web site.

Special VoIP phones exist, but callers can also use an adapter to connect a regular phone to a cable or DSL modem. People do not need to be VoIP subscribers to receive calls.

And VoIP subscribers pay nearly one-third less than standard subscribers for a plan including unlimited local and long-distance calls, according to CNET News, an online technology news source.

Some VoIP providers, however, do not automatically include 911 service, according to a news release from the Deschutes County 911 Service District.

More worrisome, Wolfe said, is the inability to locate a VoIP caller unless he or she can tell the dispatcher his or her location.

When someone calls 911 using a traditional phone line, the address associated with the number is automatically displayed at the emergency center.

While a similar objection can be leveled at cell phones, cell phone providers are working to satisfy an FCC regulation requiring cell phones to include technology that enables dispatchers to locate callers.

Triangulation with cell towers and technology using the Global Positioning System allow dispatchers to find cell phone users.

Wolfe said she expects Deschutes County 911 to be able to implement the system to locate cell phone callers within a year.

No such technology to locate VoIP callers exists.

”We’re still trying to get the wireless industry covered,” Wolfe said.

VoIP users also cannot make calls during power outages, because the technology requires an active Internet connection to work, according to the FCC’s Web site.

”I’m not in a position to say don’t get (VoIP service),” Wolfe said. ”I’m just saying be aware. I’m not trying to discourage anybody.”