If you are using Cel-Fi in a location where it is difficult to get a high signal value on the Coverage Unit (for example a small apartment or a very open commercial space), here are quick tricks that can help you achieve a higher signal value on the Coverage Unit (and therefore stronger coverage).
First of all, if the area to be covered is large and open, put the Coverage Unit up higher and where its signal can travel unimpeded for the longest distance before it has to go through walls etc. But if the area is small, such as an apartment, then it's usually best to put the Coverage Unit as far as possible from the Network(Window) Unit.
Second, try to increase the Coverage Unit signal value by creating more isolation near the Network(Window) Unit. This allows for more power out of the Coverage Unit, who's output power is controlled in real time to prevent it from feeding back into the Network(Window) Unit. To do this place the Network(Window) Unit on the other side of signal blocking objects and/or more walls. Note that the blocking objects can be anywhere in between the units, but the closer to the Network(Window) Unit the better and you should see the signal value on the Coverage Unit go up.