300-360 Question #233: Real Exam Question with Answer & Explanation

The correct answer is D: Clients are restricted to 802.11b data rates.. 802.11b uses DSSS (Direct Sequence Spread Spectrum) modulation and supports a maximum data rate of 11 Mbps. When an AP detects 802.11b clients in its BSS, it must activate protection mechanisms (such as CTS-to-self or RTS/CTS) to prevent collisions between 802.11b and 802.11g/n d

Question

A wireless network is being designed to support 802.11a/b/g/n clients. Which problem occurs when 802.11b clients are heard by APs?

Options

AAPs enable RTS/CTS.
BAPs disable RTS/CTS.
CClients are restricted to 802.11g data rates.
DClients are restricted to 802.11b data rates.

Explanation

802.11b uses DSSS (Direct Sequence Spread Spectrum) modulation and supports a maximum data rate of 11 Mbps. When an AP detects 802.11b clients in its BSS, it must activate protection mechanisms (such as CTS-to-self or RTS/CTS) to prevent collisions between 802.11b and 802.11g/n devices, which use OFDM. Because the protection overhead and the need to transmit at rates all clients can decode forces the BSS to accommodate the lowest common denominator, the effective throughput for all clients in the cell drops to 802.11b data rates (maximum 11 Mbps). This is sometimes called the '802.11b tax' and is why many enterprise WLANs disable 802.11b data rates entirely.

Community Discussion

No community discussion yet for this question.

Full 300-360 Practice