All wireless carriers will have to meet new location-accuracy rules at the county or PSAP level when delivering emergency calls from their customers within eight years, FCC commissioners decided today during their monthly open meeting.

“The order we adopt today makes location-accuracy requirements more stringent for wireless service providers,” FCC Chairman Julius Genachowski said. “This will give first responders a better chance at locating callers much faster.”

Under the new rules, handset-based carriers that rely on GPS must ensure that 67% of Phase II calls must be accurate to within 50 meters, and 90% of Phase II calls must be accurate to within 150 meters in all counties or public-safety answering point (PSAP) service areas at the end of the eight-year period. Network-based carriers must ensure that 67% of Phase II calls are accurate to within 100 meters in all counties or PSAP service areas, and 90% of Phase II calls are accurate to within 300 meters in 85% of counties or PSAP service areas.

Previous FCC rules included similar accuracy measurements, but wireless carriers were able to include results from larger regional areas in meeting benchmarks. Public-safety officials complained that location information from 911 callers in some rural areas was so inaccurate that it provided little benefit to first responders, which sparked the push for the proceeding.

As expected, the new rules mirror the location-accuracy guidelines that three of the nationwide wireless carriers — AT&T, Verizon and Sprint — previously agreed to as part of merger agreements. In addition, some exceptions proposed by T-Mobile also were included in the order.

“Basically, if there’s heavy forestation, up to 15% of the counties can be excluded from meeting the benchmark,” FCC spokesman Rob Kenny said.

In addition to the eight-year final goals, the new FCC order calls for wireless carriers to meet location-accuracy benchmarks at interim periods, as well.