Fixed Wireless works by direct Line of Sight between the Subscriber Module (antenna installed on the home) and Access Point (remote antenna installed on a tower or pole).   The below images are graphical representations of the signal between an Access Point and Subscriber Module, one image shows a clear line of sight and the other shows a signal being obstructed.  Obstructions can be trees, barns, shops, or anything that blocks the line of sight between the antennas.  To receive optimal internet speeds all obstructions, need to be cleared.