Help using new inter-grid communications

Can someone explain how the new inter-grid communication system works? The old method of using the "IMyRadioAntenna.TransmitMessage" doesn't seem to work anymore and I can't find any information about the new system. I've been searching through the forums, Malware's API index, and google for any information. The most information I've found was on Malware's API index, but that still left me confused of how to actually use it.

For reference, when I tried running a script that used the...

Help using new inter-grid communications