I dont think you can catch and redirect a signal. However you may be able to amplify an existing signal. I am unaware of the device that they use to complete this, but some business do do this up in Fort McMurray (especially inside large concrete warehouses). To be honest the device is hit or miss
It's a cell repeater. Wilson (the same company that makes heavy duty truck antennas) makes it. It's normally meant to bring a signal inside a structure that has terrible indoor reception despite adequate signal. I have no idea how it could be mounted and powered for your needs but if you're in a farm, chances are you can figure something out to get it going. Oh, did I mention they aren't cheap.