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Difficulty: MediumTroubleshooting Wireless Connectivity and Signal Issues

A network technician is investigating reports of intermittent dropouts and low data rates for mobile workstations in a newly renovated wing of a medical facility. The access point status indicates normal operational health, but a site measurement near the reinforced concrete walls shows a received signal strength indicator (RSSI) of -84 dBm compared to -52 dBm in the central hallway. Which of the following is the most likely cause of the degraded wireless performance?

  1. Signal attenuation caused by physical absorption from building construction materialsAnswer
  2. B
    Co-channel interference caused by selecting overlapping 2.4 GHz channels on neighboring access points
  3. C
    A DHCP scope exhaustion causing mobile workstations to self-assign APIPA addresses
  4. D
    A duplex mismatch between the access point ethernet port and the distribution switch

Answer

Signal attenuation caused by physical absorption from building construction materials is the primary cause of the low RSSI readings.
The correct answer correctly identifies physical attenuation. High-density materials like reinforced concrete absorb wireless radio frequency signals, drastically reducing received signal strength (RSSI) for devices operating behind or near those barriers.

Step-by-Step Solution

1
Analyze the reported symptom and site survey metrics
Identified a severe drop in RSSI from -52 dBm (acceptable/good signal) to -84 dBm (poor/unusable signal) specifically near reinforced concrete walls.
RSSI measures signal power at the receiver; a major drop across a physical boundary points to environmental interference.
2
Evaluate RF propagation characteristics against physical barriers
Dense obstacles such as concrete, brick, and rebar cause high signal attenuation (absorption of radio frequency energy).
Physical obstacles weaken RF wave amplitude as they pass through, dropping RSSI significantly.
3
Differentiate from logical or channel configuration issues
Eliminated DHCP, duplex mismatch, and channel overlap as causes because none of these directly decrease measured RF power level (RSSI).
Only physical distance, transmission power, or physical obstacles cause RSSI reductions.

Key Concept

Wireless Signal Attenuation and Environmental Obstacles
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Topics

Troubleshooting Wireless Connectivity and Signal Issues

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