Which arrangement allows higher throughput by combining different 802.11 technologies in the same area?

• A. Using a single 802.11b AP.
• B. Setting all APs to the same channel.
• C. Using only wired backhaul.
• D. Co-locating FHSS and DSSS APs in the same area.

Answer: (D)

Different wireless technologies can operate in the same area to boost total capacity. FHSS and DSSS use the same 2.4 GHz spectrum but employ different spreading and channel access methods, so they can run in parallel without fighting over the exact same signaling. By co-locating APs that use these distinct PHYs, you give devices access to the technology they support and keep transmissions from clashing, which increases the overall throughput you can achieve in that space.

In practice, this means legacy devices on FHSS can coexist with newer devices on DSSS, with careful channel planning to keep their transmissions from interfering. The other options don’t provide a throughput boost: a single 802.11b AP is limited to its low maximum rate; putting all APs on the same channel increases collisions and reduces efficiency; and relying only on wired backhaul doesn’t improve the wireless access capacity.