You can setup limited number of celluar network base stations. Obstacles are muffle signal, and you must choose stations optimal positions to cover maximum area.
It better, if you covers 100% of area, but if you're lazy, you can continue game with 97% covered, and return to level next time :)
There are 40 levels, first 5 is introductory, to understand game mechanics, last 3 is most harder. Good luck!