Questions abound as emergency alert flops

The failure of Virginia Tech’s text-messaging alert system has raised questions about the effectiveness of such systems to warn faculty members and students of an emergency — an important consideration as schools nationwide continue to invest in these technologies.

One researcher who specializes in mass-communications systems warns that the use of text messaging to alert students of danger could bog down cellular networks and block phone calls from students or faculty members trying to contact local authorities, but industry experts and many higher-education officials insist there are ways to reliably send thousands of warning messages without interference.

On Nov. 13, Virginia Tech’s VT Alert System–designed to send text and voice messages to cell phones and handheld computers–did not work when the sound of gunfire was heard near a campus dormitory. The loud sounds were caused by a nail gun being fired into a garbage bin. When university officials sent out text alerts to students and faculty at 1:40 p.m., only a portion of the messages were received.

The campus community did not receive second and third emergency alerts sent by text and voice message later in the afternoon, Virginia Tech officials said. The campus’s service provider, California-based 3n, said in a statement that the alert system was restored at 4:25 p.m. and the company was working “to understand the root cause and to correct it.”

It was the first time the school’s new emergency-alert system was used since a student killed 32 people and injured 20 in a horrific shooting spree 19 months ago.

Patrick Traynor, an assistant professor in the School of Computer Sciences at Georgia Tech and author of a study examining the limitations of text-messaging services, said text-alert systems that use current cellular networks to transmit thousands of messages simultaneously will often overwhelm the network and cause a partial or complete failure.

“I have no surprise at all on this,” said Traynor, who has studied cellular networks for six years. “If you load thousands of messages at once, the network just doesn’t have that capacity. All networks are limited in this way. … They’re not designed for massive throughput.”