A method and a system for establishing a communication session between a first communication device in a main communication network and a second communication device in a local communication network comprising a wireless network, the second communication device being located in the vicinity of a mobile device, the first communication device contacting an external phone number, wherein the external phone number is assigned to a unique identifier of the mobile device. The method comprises (i) the mobile device sending the unique identifier detectable on the wireless network; (ii) providing the unique identifier of the mobile device) and a local communication identifier to a service provider adapter; (iii) determining the location of the mobile device, associating the mobile device to the second communication device in dependence of its location.