Starfleet Jedi

I'm talking about the clone pilot who was following Plo Koon in his ARC-170 starfighter.

He receives a holo transmission from Sidious, who commands him to execute Order 66.

Sidious didn't send any form of preemptive call before establishing connection swith various clone commanders.

How did the order got off from Coruscant, to Cato Neimodia, into the pilot's fighter?

Midichlorians :D

I'm wondering if the novelisation has detailed descriptions of how Palpatine transmitted his orders, who or what relayed them, who received them, over what distance, how long it took, how many were concerned first, before all the clones joined the Jedicide bandwagon...