How does spread spectrum technology reduce the probability of signal jamming?

• A. By increasing transmit power.
• B. By spreading the signal over a wide frequency spectrum.
• C. By using shorter frames.
• D. By reducing data rate.

Answer: (B)

Spread spectrum works by distributing the transmitted energy over a much wider bandwidth than the original data rate. Because the energy is spread, the power per hertz is much lower, so a narrowband jammer has a harder time overwhelming the signal. At the receiver, a correlating despreader uses the spreading code to reclaim the original data, concentrating the energy back and providing a processing gain that improves resilience to interference. To jam effectively, an attacker would need to jam a wide portion of the spread band or emit much higher power, which is more difficult than jamming a narrow slice. This combination of spreading and the ability to recover the signal through despreading reduces the likelihood and impact of jamming.