Abstract: To test a cell in a cellular telecommunication network, a test mobile station is placed in the network near the cell and a server is connected to fixed communication devices of the network via a switched telephone network. The cell is confirmed to be operating correctly if a first call requested by the server to the test mobile station is set up and then cleared down by the test mobile station after first parameters transmitted by the server are received in the test mobile station, and thereafter if a second call requested by the test mobile station to the server via the cell under test is set up and then cleared down by the test mobile station after second parameters emitted by the test mobile station are received in the server. If this is not the case, the server reports incidents during the first or second call.