By Peter Coffee
November 1, 2004
Jamming devices such as TV-B-Gone and Cell-Block-R pose new challenges of detection and defense, and manufacturers must reckon with them.
October's advent of wireless weapons suggests a new and scary meaning of the phrase "disruptive technology." The month began with a worldwide wave of cell phone blockers appearing in churches, theaters and university examination rooms. Things then took a turn for the absurd with the Oct. 19 shipment of a $15 key-chain-fob device that will turn off almost any type of TV set within its range.
It's not going to stop here. The same kind of happy innocence that informed the early design of the Internet is also built into most of our wireless products, and it's made them—so far—inexpensive and easy to use. One has to wonder if we'll someday look back at the early '00s as a brief Gilded Age of cable-free convenience—before our wireless systems all had to be armored in cumbersome defensive measures, both concrete and abstract.
The threats to system function are diverse. Cornfield Electronics' TV-B-Gone is a digital shotgun, spewing out remote control power-switching codes from the same database that's built into any off-the-shelf universal remote control. Within a minute of activation, it will usually hit the infrared pulse code (or codes) to turn off any nearby TV unit. If you happen to have other devices in the area that use one of those codes, either by choice or by accident, then welcome to the world of collateral damage.
Cell phone blockers, such as the Cell-Block-R from Cell Block Technologies, take a different approach that sets—in effect—a protocol pitfall. To any nearby cell phone, the blocker device appears to be the best available network access point. The cell phone locks on to the blocker and disappears into its black hole. There's no escalating war of power levels or risk of damage to communications devices, pacemakers or other electronic equipment—just a bit of electronic aikido that turns the device's normal function into the means of its own defeat.
To read about plans for in-flight cell phone service, click here.
Vendors of these devices, both the TV-B-Gone and the Cell-Block-R and its competitors, stoutly maintain that they aren't "jamming" signals—a good position to take if they don't want to go up against the Communications Act of 1934, which pretty much defines the regulation of radio emissions in the United States. Subchapter III, Part I, Section 333 of the act concisely states, "No person shall willfully or maliciously interfere with or cause interference to any radio communications of any station licensed or authorized by or under this Act or operated by the United States Government."
These devices escape the Section 333 prohibition in two ways. They don't "interfere"; they merely communicate under what one might call false pretenses. And they cause no nuisance to any licensed radio installation: Cell phones and TV receivers are appliances, and their designers are obligated to take the world as they find it in terms of surrounding signals. That world, like any ecosystem, initially had no enemies that targeted these emergent species, but, over time, nature always seems to evolve new predators for new prey.
I haven't yet mentioned the previous generation of (mostly legendary) electronic weapons, such as EMP (electromagnetic pulse) bombs or HERF (high-energy radio frequency) guns. Like any good urban legend, most stories of terrorist EMP attacks and hobbyist HERF hacks mix just enough technical fact with requisite vagueness as to crucial details.
There are two fundamental reasons, moreover, to doubt that EMP or HERF technologies will ever play key roles in the terrorist arsenal. Conventional bombs and guns are cheaper to build or buy, and much more terrifying. Which gets more TV play: blood and body parts and smoking holes in the ground, or dead computers that merely look as if they've been turned off?
EMP and HERF are electronic Godzillas, able to stomp on an entire building but also easily detected. The TV-B-Gone and Cell-Block-R are termites in the woodwork that can cause a lot more damage before their presence is known. No future wireless device can be responsibly designed and deployed without active, extensive consideration of the means and motivations for taking it down—and active defense, despite the resulting cost and complexity.
Innocence was fun while it lasted.