N10-009 Question 175
Single answerAntennas: Omnidirectional vs. directionalA network technician is asked to extend Wi-Fi from the main office to a detached warehouse located 250 meters away across a parking lot. The warehouse only needs connectivity in that single direction, and the company wants to reduce signal leakage into neighboring businesses. Which antenna choice is the BEST fit for this requirement?
- A
Install an omnidirectional antenna on the office access point so the signal radiates evenly in all directions
- B
Install a directional antenna aimed at the warehouse to focus RF energy along the path between the two buildings
- C
Replace the access point with a higher-speed Wi-Fi standard so antenna type is no longer a factor
- D
Add a second SSID on the existing access point so warehouse clients can connect without changing antenna coverage
Show answer and explanation
Correct answer: B
Explanation
Directional antennas are typically used when wireless coverage is needed in a specific direction, especially for point-to-point or building-to-building connectivity. Omnidirectional antennas are generally preferred when clients are distributed around the access point and broad area coverage is desired. In real deployments, technicians also consider line of sight, transmit power, local regulations, mounting alignment, Fresnel zone clearance, and weatherproofing for outdoor links. CompTIA Network+ objectives commonly expect candidates to distinguish between omnidirectional antennas for general surrounding coverage and directional antennas for focused transmission with reduced signal dispersion. Vendor wireless design guides and general RF best practices consistently recommend directional antennas for targeted links where improved reach and reduced interference or leakage are desired.
- A. Incorrect.
This is incorrect. An omnidirectional antenna radiates signal in a 360-degree pattern horizontally, which is useful for serving clients around an access point in many directions, such as in an office floor or open workspace. In this scenario, however, the requirement is to reach a warehouse in one specific direction while minimizing RF leakage to surrounding areas. Using an omnidirectional antenna would waste energy by broadcasting into areas that do not need coverage and could increase unwanted signal exposure to neighboring businesses.
- B. Correct.
This is correct. A directional antenna concentrates RF energy in a narrower beam, making it well suited for point-to-point or focused building-to-building links. Because the warehouse is located in a single known direction, a directional antenna can improve effective range and signal strength along that path while reducing coverage in other directions. That aligns directly with the business goal of connecting the warehouse and limiting signal leakage beyond the intended area.
- C. Incorrect.
This is incorrect. Upgrading to a faster Wi-Fi standard does not eliminate the importance of antenna selection. Throughput standards such as 802.11ac or 802.11ax affect data capabilities, but coverage pattern and RF propagation are still determined in part by antenna design, placement, power, and environmental conditions. A higher-speed standard alone would not address the need to focus the signal toward the warehouse or reduce leakage to neighboring properties.
- D. Incorrect.
This is incorrect. Creating another SSID changes logical network presentation, not the physical RF pattern. Clients in the warehouse would still depend on the existing antenna's coverage characteristics. This option reflects a common misconception that SSID configuration can solve a wireless coverage or antenna-directionality problem. It cannot improve focused range to a separate building.