The tools center around computers, antennas and routers.
For the radio waves that wireless networks operate on, line-of-sight is a principle concern. Line-of-sight is not the same as visual line-of-sight. In visual line of sight, a direct line exists between two points; it is easy to think this way between two antennas in a point-to-point design. However, radio line of sight is not a straight line between the antennas; it is more of an ellipse. As the distance increases, other factors must be considered including the Earth’s curvature, not to mention physical, biological and electromagnetic.
Here are common antennas used for wireless networks. The first picture demonstrates an omni-directional antenna that transmits a signal in 360 degrees. The second picture is of a directional antenna that pushes a stronger signal than an omni-directional antenna, but in only one direction.
Ubiquiti’s Picostation routers are popular in community wireless networks like the one pictured below.
This picture from SFLan (San Francisco Local Area Network) shows both types of antennas at play.