The deadly Northridge earthquake ripped through the Southland while most people were fast asleep in January 1994, flatting highways, bursting gas lines and squashing buildings.
Relentlessly upbeat ads from wireless operators may have led U.S. consumers to believe the country’s cellphone networks can handle anything. But Tuesday’s East Coast earthquake, which originated in Virginia in the early afternoon and was felt along the Eastern seaboard, revealed the truth: cell networks still get congested when millions of people try to make calls at the same time.
In the hours following the quake, which rated a 5.8 on the Richter Scale, many people in crowded areas like New York City encountered busy signals when they dialed numbers.
The problem appeared to afflict all the major U.S. wireless networks: AT&T, Sprint, T-Mobile and Verizon Wireless. None of the companies reported infrastructure problems, as the quake inflicted little physical damage.
With nothing to fix, the carriers urged customers to be patient and communicate via text message or even email. Even text messages were balky on Tuesday afternoon, though, leaving some people frustrated with their cell service in general.
The experience pointed up the fact that large, sudden bursts of traffic will clog up networks despite the rollout of advanced cellular technology. One reason is that many of the carriers’ recent upgrades focused on the data side of their networks. These “4G” upgrades were largely implemented to better support mobile web browsing and relatively new services like streaming high-definition video to phones.
The other reason is that service on wireless networks is greatly affected by the number of users in a given area. As CTIA, the country’s main wireless industry association, notes on its website, “The more people wanting to use their wireless devices, the more capacity is needed to provide service.” That’s why carriers need to install more antennae and other infrastructure to cover crowded areas like cities. It's also why operators have mobile cell sites known as cell-on-wheels or COWs that they deploy for major events like sports tournaments and conventions.
So, counterintuitive as it may seem, in surprise events like earthquakes when carriers aren’t able to prepare for the surge of traffic, don't rely solely on your cellphone for communication.