A method of selecting a cellular network for a mobile device, the method comprising: determining a battery level of the mobile device; if the battery level is above a low-battery threshold level: determining a current location using a Global Navigation Satellite System (GNSS) receiver in a mobile device, the determining step comprising obtaining, using the GNSS receiver, a partial position fix providing a coarse approximation for the current location based on a rapid-fix technique using Doppler frequency shift measurements, ephemeris data already stored in a memory of the mobile device, and a received time tag within a received GNSS signal; and prioritizing cellular network frequency bands based on the current location to define a band priority; if the battery level is at or below the low-battery threshold level, the battery level thereby corresponding to a low-battery condition: requesting user input corresponding to a current location, comprising displaying an interface for selecting a country or continent corresponding to the current location from at least one of: a plurality of countries and a plurality of continents; receiving the user input; and prioritizing cellular network frequency bands based on the user input to define a band priority; and selecting the cellular network based on the band priority. determining a battery level of the mobile device; if the battery level is above a low-battery threshold level: determining a current location using a Global Navigation Satellite System (GNSS) receiver in a mobile device, the determining step comprising obtaining, using the GNSS receiver, a partial position fix providing a coarse approximation for the current location based on a rapid-fix technique using Doppler frequency shift measurements, ephemeris data already stored in a memory of the mobile device, and a received time tag within a received GNSS signal; and prioritizing cellular network frequency bands based on the current location to define a band priority; determining a current location using a Global Navigation Satellite System (GNSS) receiver in a mobile device, the determining step comprising obtaining, using the GNSS receiver, a partial position fix providing a coarse approximation for the current location based on a rapid-fix technique using Doppler frequency shift measurements, ephemeris data already stored in a memory of the mobile device, and a received time tag within a received GNSS signal; and prioritizing cellular network frequency bands based on the current location to define a band priority; if the battery level is at or below the low-battery threshold level, the battery level thereby corresponding to a low-battery condition: requesting user input corresponding to a current location, comprising displaying an interface for selecting a country or continent corresponding to the current location from at least one of: a plurality of countries and a plurality of continents; receiving the user input; and prioritizing cellular network frequency bands based on the user input to define a band priority; and requesting user input corresponding to a current location, comprising displaying an interface for selecting a country or continent corresponding to the current location from at least one of: a plurality of countries and a plurality of continents; receiving the user input; and prioritizing cellular network frequency bands based on the user input to define a band priority; and selecting the cellular network based on the band priority.