Could Text Messages Overwhelm Cellular Voice?

In the wake of the London bombings and Hurricane Katrina, survivors were able to send and receive text messages using their cell phones, even though all voice channels were at peak capacity. But according to a paper by researchers at Penn State, one day text messages could be used to choke off cellular voice service.

Even a moderate amount of SMS (Short Message Service) traffic targeted to a specific area on a single provider's network could prevent mobile subscribers from receiving or making calls, according to the study of GSM network vulnerabilities, which will be published at the upcoming 12th ACM Conference on Computer and Communications Security. The authors claim that 165 messages per second in the Manhattan area would be enough to bring a carrier's voice network to its knees.

SMS messages traverse the same control channel as the one used to set up voice calls, and if that channel is saturated with text message deliveries, it could make it impossible to initiate or receive calls. Cingular, Sprint PCS and Verizon Wireless all say they have mechanisms to identify and mitigate such risks.

Enterprises can avoid using SMS for intracompany communication by considering alternatives, such as cellular data services that can deliver rich text e-mail and attachments to handheld devices like the BlackBerry. These all offer a better experience than SMS' 160-character plain text.