CompTIA Network+ (N10-009)Network TroubleshootingMedium
A network administrator is setting up a new point-to-point wireless link between two buildings. After configuring the access points, they observe very low signal strength and poor throughput, despite having clear line-of-sight and the devices being within the specified range. A site survey confirms no major interference. What is a likely cause of this issue?
- AOutdated wireless security protocol (e.g., WEP).
- BInsufficient transmit power on one of the access points.
- CIncorrect channel width (e.g., 20 MHz vs 40 MHz).
- DMismatched antenna polarization.
Show answer & explanationAnswer & explanation
Correct answer: D. Mismatched antenna polarization.
Antenna polarization mismatch occurs when the transmitting antenna is oriented differently (e.g., vertical vs. horizontal) than the receiving antenna. This can lead to a significant drop in signal strength and poor link quality, even with clear line-of-sight.
Why the other options are wrong
- A. An outdated security protocol would affect connectivity or security, not directly cause low signal strength or poor throughput inherently due to signal issues.
- B. Insufficient transmit power would lead to low signal, but the problem implies all basic configurations (like power) were checked or are assumed adequate given the 'specified range'. Polarization is a specific point-to-point issue.
- C. Incorrect channel width would affect throughput but not typically cause very low signal strength with clear line of sight.
Antenna Polarization
The orientation of the electric field of an electromagnetic wave, usually defined as vertical, horizontal, or circular.
- For optimal signal reception, transmitting and receiving antennas should have matching polarization.
- Mismatch can lead to significant signal loss (up to 20-30 dB).
- Important for point-to-point and point-to-multipoint wireless links.
Memory trick: Antennas must align to shine.