GES initiates a DATA-2 ACARS transmission (uplink), but receives no acknowledgement from the SATCOM. Therefore, the SATCOM Link was lost at sometime between 1707:48 and 1803:41 (UTC).
Ground earth station. A satellite ground station sends or receives data from orbiting satellites. (Source: ATSB)
Aircraft Communication and Reporting System
Satellite Communications
Coordinated Universal Time