LTE Vulnerable to Jamming

Wireless carriers are well along on their transition to LTE technology. The FCC has stated it has determined “LTE is the technology that will best provide a baseline for required interoperability and operability for public safety broadband communications.” An article Wednesday by David Talbot in the MIT Technology Review cautions One Simple Trick Could Disable a City's 4G Phone Network. The Government's National Telecommunications and Information Administration sought comments from experts on the feasibility of using LTE for emergency responder communications and one of the comments was from Dr. Jeffrey H. Reed, director of Wireless@ Virginia Tech.

Dr. Reed filed comments outlining the vulnerabilities in LTE. In the comments, he writes, “If LTE technology is to be used for the air interface of the public safety network, then we should consider the types of jamming attacks that could occur five or 10 years from now. It is very possible for radio jamming to accompany a terrorist attack, for the purpose of preventing communications and increasing destruction.”

He cautioned jamming could also be used to “create mayhem among public safety personnel.” The preliminary research described by Dr. Reed and research assistant Marc Lichtman showed the extent to which LTE is vulnerable to jamming.

As every technical aspect of the LTE target signal is known, someone who knows communications engineering could use a laptop computer and a software-defined radio to target specific LTE control or synchronization signals.

In Talbot's article, Lichtman says, “There are multiple weak spots--about eight different attacks are possible. The LTE signal is very complex, made up of many subsystems, and in each case, if you take out one sub-system, you take out the entire base station.”

He used this analogy to describe what would happen: “Imagine blocking all traffic lights so nobody can see if they are red and green, and see what happens to the traffic. Cars hit each other and nobody gets through.”

Qualcomm, one of the companies that developed LTE and Ericsson, the Swedish telecom that supplied much of the world's LTE infrastructure, did not respond to Talbot's request for comments.

Doug Lung is one of America's foremost authorities on broadcast RF technology. He has been with NBC since 1985 and is currently vice president of broadcast technology for NBC/Telemundo stations.