In a communication system comprising - at least one mobile telephone (1) having Bluetooth capability and software- implementing possibilities, - at least one Bluetooth access point (6) providing an internet connection, - at least one internet-connected VOIP server (8) providing call connections in the form of PSTN, GSM, VOIP, etc., there is provided a software-implemented client (11,12,13,18) functioning as a call centre and controlling outgoing and incoming communications to be directed via the Bluetooth connection (5) between the mobile telephone (1) and the Bluetooth access point (6) and via the internet (7) to and from the VOIP server (8) controlling the call connections. This provides the possibility of making calls at a reduced price or even free.