A logistics bridge had a stable outdoor link. A new structure now rises into the space around the visual line of sight, and the link fades even though both antennas still point at each other. What did the structure enter?
Select an answer to reveal the explanation.
Short Explanation
The antennas still look at each other, and the link still got worse. A radio path needs a clear volume around that line, not just a peek down the middle. Your new structure is sitting in that volume.
Full Explanation
The first Fresnel zone is the volume around the visual line of sight that a link needs mostly clear. A structure that intrudes into it adds loss even when the antennas still point at each other and a person can see from one end to the other. That is what happened to the bridge. A guest VLAN does not weaken a radio because a building went up. DHCP does not detune antennas. A certificate store does not fade a bridge when line of sight is touched. Those are network and security objects. The fade started when the structure entered the radio path. Visual line of sight is the straight line. The Fresnel zone is the volume around that line, and the new structure sits in that volume. Exam caveat: trees, trucks, and wet scaffolding count too. A survey on an empty Sunday can miss a weekday obstruction in the same zone. Read the live result after the change, not only the object you edited. Operational check: compare the received signal with the structure in place and, if you can, with the path cleared, and keep later construction out of that volume.