I am working on a project where I need to wirelessly communicate two arduino boards. One arduino will be used as a beacon to relay info for others. The one relaying information will have to be burried in ground say 6 inches beneath surface level. The distance between two boards cane be around 10 feet. I learned arduino Wireless SD Shield is a way to establish wireless communication but it also says that communication is going to be in line of sight. But in my matter, there is no line of site. The setup has to be one point to many points as the beacon will send information to many points.
How I do that? Can someone give link to some latest tutorial for such setup.