Board Thread:Warhammer 40k General Discussion/@comment-24265847-20141215012629/@comment-8881468-20141221002417

you have ship to ship vox, which is in system, which is pretty much several hundred thousand kilometers, surface to ship is no problem depending on the power of the vox unit (normally nothing man portable reaches orbit)and even astartes usually use relay stations from f.e. a thunderhawk to communicate. as far as I remember