Jamming Cellphones with Text Messages

Steve writes "Some Penn State professors and students have published a way to jam cellular voice service with simple text messages. From the article: 'Because text messages are transmitted on the same signal that is used to set up voice calls, just 165 messages a second is enough to disrupt all cellphones in Manhattan.' Cellular providers, of course, fired back, one stating that it 'constantly and aggressively monitors potential threats to the integrity and security of its network.'"

Comments

One problem.

[Musteval]

165 messages a second would cost you about ten thousand dollars a minute, at the prices the cell companies charge.

Text is low priority raffic

[EmbeddedJanitor]

AFAIK, text is typically low priority traffic, but that can depend on configuration, network type etc. Network control is highest, voice next, followed by data and text.

The reason for this prioritisation is that delaying isochronous (eg. voice) data makes it unusable, but backing up text is OK. If you try jamming with text all you'll end up with is a load of backed up text.

VERY TYPICAL OF GSM

[KayEyeDoubleDee]

Several years ago I was involved in solving a similiar problem in the GSM/MAP/SS7 backbone network of a major European cellular provider/broker. In that case, there was an problem because the SMS messaging is carried in the MAP "signalling" layer, which resulted in the waste of the vast majority of the bandwidth that was meant to be used to handle subscriber management, roaming, authentication, etc. The network (which provided roaming between 100+ sizable European, Asian, and North African carriers) was being saturated with internet-generated SMS text messaging. Essentially, we were only able to block the traffic, having little control over its generation and/or entry into the network.

Clearly the people that designed the air interface made the same poor architectural decision.