By plane [edit]. The largest gateway for air travel is Frankfurt Main airport in central Germany, which offers connections to all continents and to most airports in Europe. Zurich, Munich, Vienna and Warsaw airports are a lot smaller but provide good connections to selected regional and intl. destinations.
To connect via Bluetooth, first turn on your phone or tablet's Bluetooth. When you use a new Bluetooth accessory, pair it with your phone or tablet. After pairing, devices can connect with each other automatically. Important: On a tablet that people share, each person can change the overall Bluetooth settings.
you can discover and connect to other devices when each device supports Wi-Fi P2P, then communicate over a speedy connection across distances much longer than a Bluetooth connection. but knowing that is not enough for me. because of my aim I need numbers! I mean a range of distances in which Wi-Fi P2P works.