The autor is Artemii Lebedev, one of the leading web-designers in Russia. He recently went on a trip to DPRK. You can read full story in Russian here :http://tema.ru/travel/choson-1/ I'll translate his comments briefly. On your arrival at the airport you need to leave your cellphone, no roaming service is avaliable but if you select an operator manually you get PRK 03 although I never saw a single person with a cell-phone. Laptops are allowed it seems that north koreans are not aware of cards that can make your laptop to work like a cellphone.