A warehouse with floor-to-ceiling metal racks has clients whose signal flutters sharply even when they stand near an access point with a clear view of it. Which propagation effect are the racks adding?
Select an answer to reveal the explanation.
Short Explanation
Metal racks are mirrors for radio. Your client hears the direct wave and a stack of reflections, and those copies add and cancel so the signal flutters even at close range. Open air beside the access point is not what is canceling it.
Full Explanation
Reflection bounces the wave off a conductive surface. In a metal warehouse the client receives the direct path plus delayed copies, which is multipath. Those copies reinforce or cancel as the client moves a few inches, so the signal flutters even with a clear view of the access point. The racks are the reflectors. Free-space spreading lowers power smoothly as distance grows. It does not by itself create a sharp flutter in place, and it does not require metal. A country code is a configuration on the controller. Racks do not change it, and a country code does not produce location-sized fading. Absorption removes energy as a wave passes through a material. Open air next to the access point is not an absorber that cancels only the near clients, and the symptom tracks the metal, not the air. Exam caveat: 802.11n and later can use multipath with MIMO, but deep cancels still hurt a one-stream handheld. Do not assume the racks are harmless because the access point has multiple antennas. Operational check: watch the client RSSI while moving a few feet among the racks and confirm the flutter tracks position, then test the same client in an open aisle.