DIGITAL CELLULAR SWITCHING SYSTEM WITH MEANS FOR SECURING UNINTERRUPTED DATA TRANSPARENCY DURING HANDOFFS

摘要

In a cellular communications system, the quality of a signal over a first two-way connection from a destination to a mobile terminal is compared with a threshold. When the signal quality becomes lower than the threshold, a second two-way connection is established and a switching request signal and an information-bearing signal are sent from the mobile terminal through both connections to a switching exchange. In response to the request signal, one directional path of the first connection is cleared by the exchange to prevent a version of the signal passing through the first connection from reaching the destination and a first switching complete signal is sent through the other path of the first connection to the mobile terminal to allow it to clear the first connection and return a second switching complete signal. The other path of the first connection is then cleared by the exchange in response to the second switching complete signal.