Definitions for "Edge of coverage"
Limit of defined service area, typically 3 dB down from beam center, but may be more. Reception is still possible beyond this line.
Limit of a satellite's defined service area. A satellite's beam may be shaped for specific coverage or the service area may be geographically limited by the need to have a minimum elevation angle to the satellite.
Limit of a satellite's defined service area. In many cases, the EOC is defined as being 3 dB down from the signal level at beam center. However, reception may still be possible beyond the -3dB point.