Android : load map of google map api more quickly

Two question :

1) My application load the map (I use google maps api) but I have seen that google maps load map more much quickly also when you zoom into a zone. My application i开发者_Python百科s very slow because it must charge the data with 3G.....How can I do such as google map ?

2) When You start google maps it display a progressdialog that show off when it finish to charge the map, how can I do it? how can I know when the map is charged ??

Thanks