• Suitable bi-directional amplifiers are commercially available;
• The outside antenna should have high gain;
• Sector antennas used on cell phone towers are ideal as outside antennas;
• Smartphone apps that provide signal strength and base station ID are useful;
• With the arrival of “Long Term Evolution” (LTE), covering both voice and data frequencies becomes important.
• Android does not provide information on what frequency band the phone is operating on (unlike say Blackberry);
• Some providers (e.g. Verizon Wireless), do not encode base station geo-location in the signal (unlike say U.S. Cellular);
• Some Android systems radio layers (RIL) (e.g. Samsung Galaxy Nexus) do not decode information on base station geo-location properly (others, such as Motorola Droid do);
• Some Android systems (e.g. Samsung Galaxy Nexus) do not provide detailed signal stength information (all values, such as dBm, are quantized to the same 5 levels) — while others, such as Motorola Droid, do provide fine detail;
• Some antenna gains may be overstated in manufacturer's listing (common exception: sector antennas);
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The FCC licenses the spectrum, yet does