Which statement is true concerning Bluetooth technology?

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 uses frequency-hopping spread spectrum in the 2.4 GHz ISM band, jumping across many 1-MHz channels as it transmits. Wi‑Fi in the same band uses fixed, wider channels (about 20 MHz). When Bluetooth hops onto the spectrum that a Wi‑Fi channel is using, it creates brief bursts of interference across that channel. Because Bluetooth spreads its activity across the band over time, a Wi‑Fi receiver experiences interference that can look like noise across the 2.4 GHz spectrum. So, while both can operate at the same time, Bluetooth transmissions tend to appear as all-band interference to IEEE 802.11 networks in this band. The other statements don’t hold: they can overlap and cause interference, they’re not immune to interference, and they aren’t guaranteed to operate without affecting each other.

Bluetooth uses frequency-hopping spread spectrum in the 2.4 GHz ISM band, jumping across many 1-MHz channels as it transmits. Wi‑Fi in the same band uses fixed, wider channels (about 20 MHz). When Bluetooth hops onto the spectrum that a Wi‑Fi channel is using, it creates brief bursts of interference across that channel. Because Bluetooth spreads its activity across the band over time, a Wi‑Fi receiver experiences interference that can look like noise across the 2.4 GHz spectrum. So, while both can operate at the same time, Bluetooth transmissions tend to appear as all-band interference to IEEE 802.11 networks in this band. The other statements don’t hold: they can overlap and cause interference, they’re not immune to interference, and they aren’t guaranteed to operate without affecting each other.