Spectrum sharing helps maintain the wireless network and keep it in a good state by shifting the excess users to the shared spectrum. Couple this with the fact that the US government is quite eager to provide 4G facilities near border areas, and you’ve got yourself a partnership with neighboring countries.
To achieve this goal, The Federal Communications Commission made a deal with Mexico and Canada for sharing certain wireless band spectrums. The FCC has not disclosed many details regarding the deal. However, the deal with the Canadian industry involves the sharing of commercial spectrum in 700 megahertz and 800 MHz bands.