WASHINGTON -- Reports that wireless networks became clogged Thursday morning during the horrific bomb attacks in London came as no surprise to people in the United States.
After all, Americans went through the same frustrations on Sept. 11, 2001, when millions of citizens couldn't get through to friends and relatives on mobile networks.
As Londoners discovered on Thursday, an emergency puts enormous strain on wireless infrastructure.
"(Mobile) phones were erratic for a few hours," said London resident Stuart Williams, an IT manager. "Thankfully, normal phones were fine, and the internet, of course, was fine."
The question for governments and wireless companies around the world is: What can be done about keeping these networks up and running during an emergency?
"In a disaster scenario when people are bombing stuff, everybody's whipping out their cell phones at the same time," said John Muleta, co-chair of the communications practice at Washington, D.C.-based law firm Venable LLP and former chief of the Federal Communications Commission's Wireless Telecommunications Bureau. "You can't really build wireless networks for peak usage."
In other situations, Muleta said the bottleneck actually occurs where the wireless node connects to the public switched telephone network, not within the wireless network itself.
Other problems people face in getting through during an emergency are by design.
Authorities can prioritize use of the network for emergency personnel. This does not stop service, but degrades it for general use, said John Green, wireless industry partner at East Brunswick, New Jersey-based BusinessEdge Solutions.
Muleta agreed that such an approach makes sense in crisis situations, noting that "as important as it is for you to tell your mother that you're OK, it's more important for the mayor to get through."
Next-generation wireless networks may be better able to handle heavy traffic that comes during emergency situations.
"As the technology moves on, the ability of a single cell to cope with more simultaneous transactions will increase over time," said Green, adding that new technologies such as Wi-Max will help considerably.
In the meantime, people have been using various workarounds to get through, including text messaging when voice traffic gets tied up.
"Anything that's IP-based has much more survivability," Muleta said.
In fact, world leaders meeting at an emergency summit in Jakarta, Indonesia, on Thursday discussed development of an emergency text-messaging system to help warn people about tsunamis and other potential disasters.
In the United States -- where emergency wireless service has been a hot topic since Sept. 11, 2001 -- some wireless carriers have been working with the FCC to provide more reliable emergency communications.
In July 2004, Nextel worked out an arrangement (.pdf) with the FCC to swap some of its spectrum to relieve interference in the 800-MHz band used by first responders.
"The public-safety sector has been asking for that swap for a long time," said Janee Briesemeister, a policy analyst at Consumers Union.
In addition, in August 2004, the agency adopted new rules (.doc) requiring wireless and satellite providers to report network disruptions to the FCC for the first time. The reporting rules had previously only covered wire-line providers.
Meanwhile, the Network Reliability and Interoperability Council has developed a set of best practices addressing network fortification and service restoration.
The private sector has also stepped in with technologies designed to improve wireless communications during emergencies -- especially for emergency workers.
Startup PacketHop, for example, has deployed an extended Wi-Fi network around the Golden Gate National Recreation Area near San Francisco. The system allows "access points on the fly" when first responders arrive on the scene, said Michael Rolnick, a senior partner at ComVentures, the venture capital firm funding PacketHop.
"It continuously reconfigures the network as more emergency personnel arrive on the scene by leveraging the equipment they bring with them," he said.
Cranbury, New Jersey-based Broadbeam, meanwhile, provides software enabling entities such as the London Ambulance Service to access secure data over Wi-Fi and other wireless networks -- all while compensating automatically for wireless coverage gaps, high latency and congestion.
"Compensating for wireless limitations and switching among wireless networks ensures emergency personnel access to critical information leveraging different networks' coverage, performance and cost," said Broadbeam CEO Janet Boudris.
Of course, another way to help unclog networks is to free up more spectrum.
Briesemeister said wireless networks will get much needed capacity when broadcasters complete the digital TV, or DTV, transition and are required to give back their old analog spectrum. A portion of that spectrum will go to public-safety agencies.
It's unclear when that spectrum will be returned, but lawmakers in Congress are increasingly jelling around a Dec. 31, 2008, deadline for the digital TV transition. At some point after that, the spectrum would be reallocated.
But as next-generation networks enable emergency workers to exchange information more freely, the need for security also intensifies -- especially during a terrorist attack such as the one in London on Thursday.
"As networks become more extended, they are more vulnerable to both internal and external security threats," said Terry Brown, president and CEO of Petaluma, California-based Caymas, a company specializing in network security. "In an emergency, network vulnerabilities could allow terrorists access to detailed information about targets as well as first-responder data."
At the same time, during a crisis, authorities may have little choice but to depend on wireless technologies to stay in touch and coordinate their response.
"London makes it clear that in these kinds of situations, wireless communication is really the communications vehicle of choice," said Green.
