WASHINGTON-The telecom industry is still scratching its head about what potential impact a directive regarding the U.S. global positioning system signed by President Bush Dec. 8 could have on its networks.
The directive allows the president to deny access to GPS in times of emergency or for national-security reasons, and sets up planning procedures in case this occurs.
“The secretary of Homeland Security shall in coordination with the secretary of Defense and in cooperation with the secretaries of Transportation and Commerce ensure mechanisms are in place to identify, understand and disseminate timely information regarding threats associated with the potential hostile use of space-based positioning, navigation and timing services within the United States; and ensure procedures are developed, implemented and routinely exercised to request assistance from the defense secretary should it become necessary to deny the hostile use of space-based position, navigation and timing services within the United States,” according to a federal fact sheet.
While the directive is classified, the White House Office of Science and Technology Policy issued a fact sheet Dec. 15 that has been rippling through the industry.
“We and others in the industry are having discussions with the Defense Department, DHS and the White House to ensure that telecommunication interests are protected and services are available during any national emergency,” said James Fisher, spokesman for Sprint Corp.
The impact could be enormous because a variety of important telecom functions use GPS. The most obvious use is for location technology, but the timing of CDMA networks and landline switching also use GPS technology.
So does that mean the entire telecom network would go dark in a national emergency? Not so fast, said the government.
First, this is nothing new.
“There is a long history of GPS, and this authority has been around for a long time,” said Edmond Thomas, chief of the FCC’s Office of Engineering & Technology.
The Federal Communications Commission sat in on meetings to develop the new policy, said Thomas. Because the policy was developed at the executive level, the FCC-as an independent agency-could not participate, although it regulates commercial entities that use GPS technology.
Second, the chances the GPS system would be turned off are quite remote.
“Make no mistake. The president is not going to wake up one day and decide to turn off the GPS system,” said Thomas. “Nobody is going to go around in a helter-skelter way turning off the GPS system.”
A national security expert backed up Thomas’ assessment.
“What is new is that they have come out and said this,” said James Lewis, senior fellow at the Center for Strategic and International Studies. The denial of access to GPS “would only occur in a situation where it would make a difference.”
“This is a classic tempest in a teapot that is really ill founded,” said a senior Bush administration official. “The last thing the U.S. would want to do is anything that would cause anyone to have anything but the perfect confidence in GPS 24-7-365.”
The administration believes the confusion arises from a plan to develop a replacement for the “selective availability” component of GPS. The Clinton administration turned off selective availability in 2000, thus greatly improving GPS timing and navigation. The Bush administration is working on a new plan that would allow it to deny access to GPS under specific-tailored circumstances.
Lewis believes the plan would be to use a combination of jamming and encryption to deny access to GPS in an area about the size of most counties in the United States during military operations or when a specific threat is determined.
“Some of this comes out of our efforts to make sure that others won’t jam us,” said Lewis. “On the military side, the incident could last days, but on the domestic side, the most would probably be about 12 hours.”
If Lewis is correct about the domestic implications, the impact on CDMA networks would appear to not be devastating and could be completely nil if advance warning was given.
CDMA networks use GPS to synchronize the soft handoffs so that while users are mobile, the signal seamlessly moves between base stations. This would continue for the first four hours of denial and then a gradual degradation would occur, said a CDMA expert.
Location technologies would be impacted, but Phase I of wireless enhanced 911 would still work because it is determined by the cell site.
Other timing should work, but gradually degrade based on how long the denial lasts.
