Compare the 2.4 GHz and 5 GHz bands in terms of range, data rate, and interference.

• A. 2.4 GHz provides higher data rates but shorter range.
• B. 2.4 GHz has fewer interference sources.
• C. 2.4 GHz offers longer range and better penetration but more interference and fewer channels; 5 GHz offers higher data rates with more channels but shorter range and less penetration.
• D. 5 GHz provides longer range and better penetration.

Answer: (C)

The question tests how the two common Wi‑Fi frequency bands differ in range, data rate, and interference. The 2.4 GHz band propagates farther and penetrates walls better because its longer wavelength travels more easily through obstacles. That makes it feel like it covers a larger area and reaches devices farther from the router. But this advantage comes with more interference: many devices share this band (microwave ovens, Bluetooth, cordless phones, and other networks), and there are only a few non-overlapping channels, so congestion and cross‑talk are common.

The 5 GHz band, on the other hand, supports higher data rates because it has more available spectrum and can use wider channels, which translates to faster speeds—especially near the access point. However, higher frequency signals attenuate more quickly, so the practical range is shorter and penetration through walls and obstacles is weaker. Because it’s less crowded and offers more channels, 5 GHz generally experiences less interference in busy environments.

So the described trade‑off is that 2.4 GHz offers longer range and better penetration but more interference and fewer channels, while 5 GHz offers higher data rates with more channels but shorter range and less penetration.