How to make a network /tower coverage map in in mapbox

I am new to mapping and currently I am trying to make a map showing coverage of a network provider here in my country. The map I am trying to achieve should look similiar to that at http://www.imore.com/best-us-iphone-carrier-2014. I already have the lat and long coordinates of the tower locations in csv format and have so far managed to plot the markers in tile mill(ideally want to show coverage as opposed to markers) . I have also downloaded mapbox studio and OSGEo4W for windows under the assumption that I might have to convert the data into another format. Please guide I cant seem to find any comprehensive tuts for this all I see for mapbox is openstreets , terrain , markers , shapefiles etc I am not sure how I should proceed as I am a newbie . In addition , I have also attached an image of what I am trying to achieve