Transmission method of time advance information to a mobile moving in a cellular radio telephone network, mobile, controller and information exchange system using this method.

摘要

The method of the invention is applied to a cellular radiotelephone network comprising a mobile, at least two transmitter/receiver stations and a controller of these stations. Information exchanges between the mobile and the stations are of the time-distribution multiple-access type. The controller, via one of the stations, called first station, with which the mobile is communicating, sends an instruction to the mobile, indicating to it that it should interrupt its communication with the first station in order to send a sequence of synchronisation signals to a second station allowing the second station to calculate time advance information, the transmission of this instruction being carried out when the mobile passes from a first cell, corresponding to the geographic coverage of the first station, to a second cell, corresponding to the geographical coverage of the second station. The time advance information calculated is supplied to the mobile. This method is characterised in that the instruction supplied to the mobile is also an indication that the mobile should continue to communicate with the first station immediately after sending this first sequence of synchronisation signals to the second station, and the time advance information calculated is transmitted from the second station to the controller and from the controller to the mobile, via the first station.