"Summer ascent" and "Winter ascent" there are russian operators on the slopes like "Megafon", "Beeline", "MTS" (not so good). You can freely call anyone and tell about your victory! Only in the col and the very top there is no connection (above 5300), and it will not be easy to find suitable words there. In the first part of the tour, in the mountain gorges, waterfalls, glaciers and passes, communication will only disappear occasionally. There will also be a connection in the Terskol village , where we will spend the night on the main part of the trip.... With mobile internet there are no problems... let's say if you have a laptop running through modem - then the Internet will cost the same as your home.