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.”

Traynor said most current cellular networks send messages individually, meaning a system like Virginia Tech’s would require thousands of texts to go out one by one. As cellular broadcast technology improves, Traynor said, emergency messages will be able to go out to subscribers at the same time.

If local networks are bogged down by thousands of messages that eclipse network capacity, emergency cell-phone calls from students or professors could be blocked, cutting people off from police and fire departments, Traynor said.

“The messages go out one at a time, and there’s nothing that the companies can do to improve that,” Traynor said. “These campus text systems can actually cause more problems than they solve.”

Karla Lemmon, a program manager for New Jersey-based Honeywell International, which makes alert systems for K-12 schools and colleges, said mass text-message blasts will bog down a cell tower, but broadcasting messages from a host of servers makes text delivery more reliable.

More than 2,600 schools nationwide use Honeywell’s Instant Alert system to send automated phone calls and text messages, and about 230 college campuses have adopted the product’s higher-ed model, Lemmon said.

Industry experts said the technology is still being perfected in tests nationwide. Lemmon acknowledged that she conducted a text-message test last summer in which one message didn’t reach her for three weeks.

“It’s not necessarily always the fault of the provider,” she said. “Delays in text-message systems can happen at any time, on any day.”

Last year, researchers at Purdue University tested the school’s emergency text-alert system and found that 4 percent of nearly 10,000 text messages failed to transmit. That means about 400 students and faculty members wouldn’t have received an emergency message via cell phone.

Purdue officials said the test would help researchers better understand how text messages are interrupted.

Scott Ksander, Purdue’s executive director of information technology networks and security, said the university tested the system again this fall and found that about half of the 17,000 messages sent out were delayed. The test text-massage blast was processed in about six minutes, and more than 50,000 eMail alerts were transmitted in 12 minutes, he said. While the eMail messages reached their destination within that 12-minute period, some text messages took up to an hour to deliver.

Ksander said the university would conduct another test during the spring semester, and officials expect better results. Purdue IT employees tracked the delays in real time, he said, and fixed the “congestion management problem” that surfaced.

“It’s important to keep testing,” he said, adding that some Purdue students or faculty that signed up for text alerts don’t have phones with text capabilities. “That’s probably the biggest lesson learned.”

Virginia Tech officials did not discount the possibility of finding a new provider of emergency text-message alerts to replace 3n if the company cannot show that the system will work next time.

“We want to make sure they fix it, so whatever went wrong doesn’t ever happen again,” said Mark Owczarski, a Virginia Tech spokesman, adding that the university is in its second year of a three-year, $200,000 contract with 3n. “And that drives whether or not we’ll stay with 3n. We’re really disappointed with what happened. … It’ll probably behoove Virginia Tech to keep our options open.”

Colleges and universities should use a variety of warning systems, Traynor said, including alerts via television, campus radio, eMail, and the use of sirens that can be heard across the campus.

“They need to have a diverse approach,” he said.

Even service providers agree. With more colleges and universities adopting emergency-alert systems, Lemmon said, campus decision makers should supplement emergency texting with a bevy of other alerts.

“Text-only systems are not the way to go,” she said. “You are going to have problems with a single-mode system. … You can’t rely on one means of communication. There are too many things in the system that can go wrong.”

Virginia Tech officials said the campus’s other emergency systems did function properly during the recent false alarm–campus-wide eMails, electronic message boards in lecture halls, and the university home page kept student updated.

Owczarski said Virginia Tech officials are working with 3n technicians to determine what caused the alert-system failure. The university wants to ensure that students and faculty members know the campus has a reliable way to broadcast alerts in the coming years, he said.

“I would say Virginia Tech still feels the emotional repercussions of last year’s tragedy,” Owczarski said. “I would say we’re no more vulnerable than anyone else in society, but we have a heightened sensitivity to it because of what has happened in the past.”

Links:

Study on text message limitations

Virginia Tech statement