An arrangement for connecting mobile client devices to the Internet, or other IP based networks, uses WPAN and WLAN infrastructures or certain cellular systems like GPRS. This is achieved substantially seamlessly by providing a routing mechanism (IP-IP Tunnel) that allows mobile client devices to connect to an application server using communications standards depending on the available infrastructure, e.g. GPRS, IEEESO802.llb or Bluetooth wireless standards. The mobile client device and the server are arranged to communicate at a network layer through an Internet Protocol tunneling technique, such that an Internet Protocol address of the mobile client remains the same during a handover from a first communications standard to a second communications standard.