The problem is that the metal roof prevents microwaves from being transmitted from the cell phone towers as well as from the cell phones. There is no infallible way to avoid the annoyance of dropped calls, there are technological fixes available that allow for improvement in the reception and transmission of cell phone signals. An electronics store should be able to sell you a cell phone signal booster and an external antenna. This is the most effective method of treating the problem. You will have to connect power booster to the RF port of the cell phone. The cables should come with the power booster. The power booster will be plugged into an electrical outlet inside the building. Now, connect your power booster to the external antenna. The store where you bought the booster should carry the cable you need. Now, test it out by making a call. The signal should be at least ten times stronger than before, possibly even stronger. zBoost YX-510 Cell Phone Signal Booster Dual-Band Unit for Home or Office is one such product that helps in enhancing the signal. Features include: Extends cellular coverage for single or multiple users in homes or offices--provides up to 2500 square feet of coverage Dual-band device works with 800/1900 MHz frequencies from all major carriers--AT&T, Sprint, T-Mobile, Verizon, Alltel, Cricket, and more (not compatible with Nextel) Omni-directional signal antenna receives signals from multiple cell towers Antenna can be installed outdoors above the roofline or indoors in the attic or near a window Extends phone battery life--uses less power when signal is stronger. You can fulfil all your cellular phone needs with the Wireless Extenders YX510-PCS/CEL zBoost zP Wireless Booster, which works with both cellular frequencies (800 and 1900 MHz) and can extend cellular coverage up to 2500 square feet. This unit can handle signals from all the major U.S. cellular carriers. The package includes: amplifier base unit, power supply, base unit antenna, low-loss SATV coaxial cable (RG6), signal antenna and mounting hardware. The omni-directional signal antenna receives signals from multiple cell towers. Using a revolutionary, patent pending technology that protects the carrier network, the YX510 improves indoor cell phone coverage by capturing and repeating the outside signal, bringing it into the building and enhancing it. This process creates a "Cell Zone" in your home or office.