802.11g Range at Top Speed — Maximum distance while sustaining the maximum data rate In typical indoor conditions, what is the approximate maximum distance at which an 802.11g client can still hold the maximum PHY data rate (54Mbps)?

Introduction / Context:
PHY data rates in Wi-Fi depend strongly on received signal strength and signal-to-noise ratio (SNR). As distance and obstacles increase, modulation and coding schemes step down. Knowing the ballpark distance at which the top 802.11g rate (54Mbps) can be maintained helps with practical access point placement.

Given Data / Assumptions:

• Indoor office/home environment with walls and typical interference at 2.4GHz.
• Omnidirectional antennas with standard transmit power.
• Client is stationary; rate adaptation is enabled.

Concept / Approach:
802.11g uses OFDM at 2.4GHz. Highest rate 54Mbps typically requires high SNR (for example, 20–25 dB+ depending on implementation). Practical deployments show that the top rate is sustained over short to moderate distances. As the client moves farther, the rate adapts down (48, 36, 24, 18, 12, 9, 6Mbps). Therefore, the common rule of thumb is roughly 65–75 feet for many indoor environments to keep 54Mbps, although layouts and RF noise can change this significantly.

Step-by-Step Solution:
Identify the target rate: 54Mbps (highest for 802.11g).Recall required SNR: relatively high, so shorter distance.Apply indoor attenuation expectations at 2.4GHz.Choose the distance range most consistent with sustaining the highest MCS: about 65–75 feet.

Verification / Alternative check:
Vendor site surveys and heatmaps often show primary cell radii of ~50–75 feet at top rates for 2.4GHz in typical structures. Beyond that, modulation fallback occurs quickly.

Why Other Options Are Wrong:

• 90–100 feet and above: At these distances, most clients drop to lower rates (24Mbps or below).
• 150 feet or 200+ feet: Usually far beyond the range to keep 54Mbps indoors.
• 30 feet: Possible, but too conservative; many designs sustain 54Mbps beyond 30 feet.

Common Pitfalls:
Equating PHY rate with throughput; even at 54Mbps, user throughput is much lower. Also, different buildings and devices vary widely; this is an approximate planning value, not a guarantee.

Final Answer:
About 65-75 feet