Standby channel changeover system for communications - checks validity of changeover request and availability of standby channel

摘要

The reserve channel changeover system which is used in communications systems, switches in two or more reserve channels when a number of main channels become unusable owing to noise. For any main channel requesting changeover the availability of a reserve channel is first checked and the validity of the changeover request is examined by comparing with all the other channels. If a changeover is possible -- ie if a reserve channel is available and if the request is valid -- the defective main channel is switched over to a reserve by following a specified sequence of control processes, so that interruptions in data transmission are kept to a minimum.