This automatic tracking ability is the one that has many privacy advocates concerned the technology may be abused by others, including law enforcement officials.
EPIC's Sobel says while the FCC mandated the E911 program, federal legislators haven't put into place how that information may be used or who would have access to it.
"The Justice Department and FBI do routinely get information from cell-phone service providers," says Sobel. But, "There are lingering question on what the legal standard is to be used to get location information from cell-phone providers. There is nothing in federal law that addresses that issue."
But such issues are unlikely to be addressed soon, since the cell-phone location systems have yet to be implemented on a broad scale.
One of the difficulties in implementing phase two technologies, for example, is the additional equipment wireless carriers and PSAPs must add to the telecommunication infrastructure, with over 137 million wireless subscribers nationwide.
"We're talking about replacing millions of wireless handsets," says Larsen. "It's not going to be a flash-over process."
Still, some areas of the United States, such as St. Clair County, Ill., have been able to implement phase two E911 technology.
Norm Forschee, county coordinator, says it took about two years to work with all six major wireless service providers to upgrade their systems. But he added the upgrade, fully operational across the county last December, has already proven its worth.
Of the more than 156,000 emergency calls handled by the county's 10 PSAPs last year, more than 76,000 were made from cell phones. Forschee says about half of those cell phone calls were successfully located using the phase two technology still under development.
"The time savings to the dispatchers in knowing where the calls [originate] compared to questioning [the caller] is tremendous," concluded Forschee.