The UHVDC power transmission project from Yunnan to Guangdong is embedded into ac system, so the Yunnan power grid at the sending end will face with challenges.
The latter two are simply the "inverse" of the first two, the only difference being whether the end point in question is on the receiving or sending end of the initial message.
The receiving and sending end of the data collection network shall be equipment with dedicated computers and telecommunications equipment and managed by dedicated personnel.
In communications, to interrupt the sending end and take control of the circuit at the receiving end.