PORTLAND, Ore. (AP) _ For the second time in two weeks, a ``ping'' is helping search and rescue teams do their work in remote parts of Oregon.
A ping _ a signal sent from a cell phone to a provider tower, or vice versa _ from a family cell phone was critical in narrowing the search for a family in the mountains of southern Oregon last week, officials have said. The father died of hypothermia, but his wife and their two children were rescued.
This week, rescue workers are again working with cell phone signals on Mount Hood, where three climbers have been missing since the weekend.
A phone must be on and in a coverage area to register a ping, either by sending or receiving a signal. Once a ping is registered, a cell phone provider can narrow the location of a handset based on the location of the receiving cell towers.
``The ping is essentially the handset's way of saying: 'I'm here and I'm ready to be used,''' said T-Mobile spokesman Peter Dobrow. The company is helping in the Mount Hood search; it provides cell phone service to one of the missing climbers.
Mount Hood has limited cell phone coverage. But climber Kelly James, was able to call his family from a snow cave Sunday to say the group was in trouble.
Using that information and pings sent every five or 10 minutes by T-Mobile to the phone over two days, the company was able to determine a roughly quarter-mile area where the handset might be located.
Normally, a provider uses the three closest towers to pinpoint a triangle where a person might be. But James' phone was at the periphery of a coverage area and registered to only one tower.
Based on the coverage area of the tower that the ping hit, T-Mobile was able to narrow the climber's location to just below the 11,239-foot summit, on the northeast side.
On Tuesday, the cell phone didn't respond to the pings, meaning the battery died or the phone has been moved or turned off.
Edge Wireless LLC helped in the search in southern Oregon.
People heading into the remote outdoors shouldn't count on their cell phone saving them in a tough situation, though. The chance of a signal making it through rugged terrain or areas with little coverage is slim.
``I think it is pretty remarkable and encouraging that we were able to get this information in such hard conditions,'' Dobrow said.