Homing in on a plan for cellular 911

Cellular companies need to provide more accurate information to police and firefighters who are trying to locate people calling 911 from mobile phones, according to the FCC. But exactly how to measure compliance and achieve this goal is still up for debate.

Last week, the FCC said it would seek public comment from the industry and public safety organizations on several issues that it believes could improve the accuracy of what's known as enhanced 911 service, or E911.

One proposal, supported by the FCC, would require cell phone operators to measure the accuracy of their location technology in smaller geographic areas. The commission is also looking at requiring mobile operators to use a hybrid solution that combines both GPS (Global Positioning System) satellite receivers in handsets and network-based location technologies to help pinpoint the location of callers.

The FCC said all accuracy requirements would also apply to voice over Internet Protocol services, such as Vonage, that allow people to move their service to new locations.

The new proposals, which if passed could cost the cell phone industry a lot of money in network upgrades, have stirred debate among cell phone companies and organizations representing public safety entities. While all agree that improving the accuracy of e911 is important, they disagree about how to measure its effectiveness and how to actually improve it.

"We understand and support the chairman and commission's efforts to improve location accuracy; we share that goal," said Joe Farren, a spokesman for the CTIA, an industry group representing the cell phone industry. "As part of that effort, we look forward to educating the commission on the state of technology, its limitations, and what can and cannot be accomplished now, and how to move forward in the future."

Emergency dispatchers can easily trace people who call 911 from a regular telephone. But that's not so easy with cell phones. People calling 911 from a cell phone could be anywhere. And relying on a caller to provide location information to a dispatcher is unreliable and puts callers at grave risk.

The FCC estimates that of the 200 million calls made to 911 each year, a third of them are from callers using a mobile phone. In many communities, more than half of 911 calls are placed from cell phones. Many people have come to depend on their cell phones, which they almost always have with them, in times of emergency. In fact, roughly 29 percent of people who bought a cell phone in the past year said they did so for emergencies, according to a Consumer Reports survey.

"With so many people using cell phones as their primary telephone, it's important to make this issue a priority," said Patrick Healy, a spokesman for the National Emergency Number Association, or NENA, a group that promotes 911 research, planning, training and education.

More than a decade ago, the FCC mandated that wireless operators would have to provide E911 capabilities to at least 95 percent of their subscribers. At the end of last year, about 70 percent of the nation's 6,140 call centers had implemented the final phase for E911, according to NENA. These call centers cover about 80 percent of the U.S. population. But the Rural Cellular Association claims that only about 25 percent of rural emergency call centers have implemented location services for E911.

While some regions of the country are still working on E911 capabilities, some industry experts say the accuracy of these services is still a problem. At last week's meeting, FCC commissioners expressed concern that emergency responders may not be able to find callers due to poor location information.

"A call to 911 is among the most important calls that any of us will ever make," said Commissioner Michael Copps. "Just consider the example of first responders focusing an exhaustive search for an injured caller on the ground next to 300 meters of highway--only to learn, too late, that the victim was actually 1,000 meters down the road."

The FCC already requires carriers to test their location systems and be able to pinpoint callers within certain distances. But carriers have been allowed to test their equipment and average the results over their entire national service areas or within a particular state, which means that good results in one region could skew the average, producing misleading data.

"Multistate or statewide averaging can mask the reliability of 911 outside of large urban areas," said FCC Chairman Kevin Martin. "For example, meeting location accuracy standards on average in the entire state of New York by providing enhanced 911 capability in Manhattan does not help first responders in Buffalo."

The FCC supports a proposal from the Association of Public Safety Communications Officials International (APCO) that specifies accuracy should be tested at the public safety answering point, or PSAP, level instead of on a statewide or regional basis. In a recent report, APCO reported that if accuracy were measured from the PSAP level, about 71 percent of tests made in seven sample regions would have failed to meet the FCC's standard for accuracy.

The cell phone industry opposes these new requirements. In a letter filed with the FCC, Verizon Wireless, T-Mobile USA, Dobson Communications and the Rural Cellular Association (RCA) said that changing the requirement would be "unwise" and "unlawful." They also fear that establishing stricter requirements would be too expensive, especially for carriers operating in rural areas.

"Rural carriers are doing everything they can to improve accuracy of E911," said Clay Dover, executive director for the RCA. "But in some of these areas you only have one cell tower, and you can't mandate companies build out a network for E911 compliance if it's cost-prohibitive."

Indeed, location accuracy can be especially problematic for carriers using GSM (Global System for Mobile Communications) technology. These carriers, which include AT&T and T-mobile, use a network-based technology that uses signals from multiple cell phone towers to determine a caller's location. But in some sparsely populated regions where there is only one cell phone tower, it's impossible to triangulate signals to get an accurate location. And putting up additional towers is too expensive.

Carriers that use CDMA (Code Division Multiple Access) technology have their own challenges. These carriers, which include Verizon Wireless and Sprint Nextel, have embedded GPS receiver chips in handsets to track devices by satellite. This solution works well in a rural or suburban area where there is a direct line of sight between the satellite and the device, but it isn't as effective in cities where tall buildings can block satellite signals.

Both the network-based technology and the handset solutions can have trouble locating people inside large buildings, because some signals can't penetrate walls.

Due to these technology limitations, the FCC has applied two different sets of standards for accuracy compliance. Carriers using GPS-enabled handsets must be able to locate callers within 150 meters 95 percent of the time and within 50 meters about 67 percent of the time. Mobile operators using a network-based solution only need to locate individuals within 300 meters 95 percent of the time and within 150 meters 67 percent of time.

In an effort to address these issues, the FCC also has proposed looking at new technologies to improve accuracy. For example, it is currently seeking public comments on whether it should mandate the use of hybrid solutions that would combine network-based triangulation technology with handset-based satellite technology.

Verizon Wireless said it is already using a hybrid solution to help improve E911 accuracy as well as to provide location and navigation services to its subscribers. The way it works is that the system first uses a GPS receiver to get the location of the handset. If the signal isn't strong enough, the system then uses data from cell sites combined with satellite information to get a location. And if that doesn't work, it can use cell site data, which is similar to triangulation used on GSM networks, said Debra Lewis, a spokeswoman for Verizon.

Regardless of which rules, if any, the commission eventually adopts, Wanda McCarley, president of APCO, said it is important that the cell phone industry and public safety groups move forward to improve location accuracy, because it's what the public expects.

"Carriers have limitations in terms of the technology that is available to them," she said. "We understand that. But I think it's clear that in some areas of the country people are not getting the services they expect. We need to deal with that and fix it."