The very first GPS lock for a device in a new area takes a while because it has to download the satellite positions first. After that (if you haven't moved too far away in the meantime) subsequent GPS fixes should be much faster.
(Quoting Wikipedia: »in order to obtain an accurate satellite location from this transmitted message the receiver must demodulate the message from each satellite it includes in its solution for 18 to 30 seconds. In order to collect all the transmitted almanacs the receiver must demodulate the message for 732 to 750 seconds or 12 1/2 minutes.«)
(Quoting Wikipedia: »in order to obtain an accurate satellite location from this transmitted message the receiver must demodulate the message from each satellite it includes in its solution for 18 to 30 seconds. In order to collect all the transmitted almanacs the receiver must demodulate the message for 732 to 750 seconds or 12 1/2 minutes.«)