I am using 4G network for long-distance flight. Looking to add a new GCS failsafe logic. For example, RTL is started after the gcs connection is lost for 60 seconds and the RC connection is also disconnected. (The purpose of determining whether RC is disconnected is to prevent return home caused by GCS disconnection at close range).
The current FS_GCS_ENABL method does not seem to determine whether the RC signal is lost. And FS_LONG_ACTN is also common with RC.
The idea is to use the 4G network in guided mode flight to prevent the aircraft from flying to a place without network and continuing to circle there until it runs out of power. Generally, if there is no successful reconnection within 1 minute, it is a common method to judge that there is no network in the area.