Using an antenna indoors
If you've read the guides on our website you'll be aware that weak service in many suburban and built up areas tends to be caused by nearby buildings, trees, and your building itself. What this means is that to see a significant improvement to your connection an antenna really needs to be placed outside or on the roof where the impact of your building and other nearby obstructions is minimised.
Of course if you're like many (perhaps you're renting) and don't have any choice in the matter, or you're picking up some service inside but just need to boost it up a bit, an indoor antenna can work quite well. The key to success with a indoor antenna is location, location, location.
As radio waves cannot penetrate well through thick walls or metal, signal often flows into the building through open doors and windows. It reaches around corners and into rooms by reflecting off just about every surface, creating an extreme multipath environment. Because inbound radio waves will be approaching from just about every possible angle the best performing antenna for this situation is a 0dBi antenna (i.e. one that can receive from every spherical direction) such as the one that's already in your modem. This means that in order to use an indoor antenna successfully you need to locate it in the source of the signal - i.e. in the window or doorway.
It's also worth mentioning that these antennas must be connected into your mobile phone or modem with a patch lead. If your device doesn't support an external antenna the best choice is a Smart Repeater unit.