PROCEDURE AND SYSTEM FOR ENSURING EMERGENCY COMMUNICATION IN A WIRELESS LOCAL LOOP ENVIRONMENT

摘要

The invention relates to a procedure for ensuring emergency calls in a wireless local loop environnement which is based on technology employed in a mobile telephone system and which comprises a telephone exchange (1), an access node (2) connected to the telephone exchange, a terminal device (3) and a base station (4) connected to the telephone exchange via the access node and serving to transmit call signals between the access node and the terminal device, in which the home network (5) of the terminal device is defined by the base station and the associated access node and in which base stations (7) of other networks are disposed in the environment of the local loop, so that the terminal device receives information signals from the surrounding base stations and, based on said information signals, determines the base station it is communicating with, and the emergency call is set up via any base station compatible with the terminal device. To ensure successful set-up of an emergency call when connection between the terminal device (3) and the telephone exchange (1) of its home network (5) is lost, a dial tone is generated by means of the terminal device, an emergency number dialled via the terminal device is identified and the emergency call function of the mobile telephone system is used for the set-up of the emergency call.