802.11b Range at Top Speed — Maximum distance while sustaining 11Mbps In typical indoor conditions, what is the approximate maximum distance at which an 802.11b client can still hold its maximum PHY data rate of 11Mbps?

Introduction / Context:
As distance increases and signal quality drops, Wi-Fi devices fall back to lower data rates. 802.11b (DSSS/CCK at 2.4GHz) requires a good SNR to hold 11Mbps. Understanding the approximate range for the top rate helps with legacy design considerations and interpreting client behavior in mixed environments.

Given Data / Assumptions:

• Indoor environment with typical walls and interference.
• Standard omnidirectional antennas and transmit power.
• Client and AP are stationary; rate adaptation is active.

Concept / Approach:
802.11b's maximum 11Mbps is more tolerant than OFDM's highest rates but still needs adequate SNR. Many deployments observe that 11Mbps can be sustained to roughly 90–100 feet indoors before stepping down to 5.5, 2, or 1Mbps. These are approximate values; building materials, interference sources (microwaves, Bluetooth), and device radios significantly influence actual performance.

Step-by-Step Solution:
Identify target rate: 11Mbps (802.11b max).Relate rate vs. SNR vs. distance: farther distance → lower SNR → lower rate.Use common planning heuristics indicating ~90–100 feet at 11Mbps indoors.Choose the closest matching range.

Verification / Alternative check:
Historical vendor datasheets and independent site surveys show client speed tests at roughly 90–100 feet sustaining 11Mbps under good conditions; beyond this, fallbacks are typical.

Why Other Options Are Wrong:

• 65–75 feet: Too conservative; 11Mbps often holds further than that.
• 150 feet / over 200 feet: Unrealistic for sustaining the maximum 11Mbps indoors.
• 30 feet: Far below practical expectations in typical layouts.

Common Pitfalls:
Confusing PHY rate with throughput; even at 11Mbps, user throughput will be far lower. Real-world range varies, so these numbers guide expectations rather than guarantee performance.

Final Answer:
About 90-100 feet