Which statement is true concerning Bluetooth technology?

• A. Bluetooth transmissions appear as all-band noise to IEEE 802.11 networks operating in the 2.4 GHz ISM band.
• B. Bluetooth transmissions never overlap with 2.4 GHz networks
• C. They both operate simultaneously without any interference
• D. They are immune to interference

Answer: (A)

Bluetooth operates in the same 2.4 GHz ISM band and uses frequency-hopping spread spectrum, jumping across many 1 MHz channels hundreds of times per second. Because it doesn’t stay on one frequency, its energy winds up appearing on different parts of the band over time. To a Wi‑Fi device working on a specific 20 MHz channel, Bluetooth activity will look like interference that comes and goes as the Bluetooth device hops, effectively acting like noise across the band rather than a single steady signal. That’s why Bluetooth transmissions can disrupt IEEE 802.11 networks in the 2.4 GHz band. The other statements don’t fit, because devices can and do overlap in the same band, interference can and does occur, and neither technology is immune to it.