  We discuss the possibility of receiving a radio signal from extra-Galactic
intelligence, around the time when we observe a binary neutron star merger in
their galaxy. High-precision measurements of the binary parameters allow them
to send the signal ~ $10^4$ years before they themselves observe the merger
signal. Using the SKA, we might receive ~ $10^4$ bits of data, transmitted from
40 Mpc distance with the output power of ~ 1 TW. We also discuss related topics
for GW170817 and mention potential roles of future gravitational wave detectors
in relation to this transmission scheme.
