Consider what obstructions are between you and the access point, including distance, material, and other nearby electronic signals. Distance is often a key factor in determining how far away you may be able to pick up a WiFi signal. The greater the distance between the access point and your device, the weaker the signal that reaches your device will be. This means that obstructions such as walls or trees will weaken a WiFi signal while buildings or open spaces may let it reach further. If there are two transmitters in proximity to each other which broadcast on different channels you'll only be able to pick up one signal because otherwise they would interfere with each other.