I should say that the system was two satellites sending radio signals back-and-forth to each other.
It consisted of telegraph operators sending signals back and forth.
Researchers say we have two brains: one in the head and one in the gut, which work in tandem, sending signals back and forth.
If the events in question are at some distance from one another, judgments of simultaneity can be made only by sending light signals back and forth.
He began to explain how the robot operated: a coated fibre-optic wire connected the ship to the R.O.V., sending signals back and forth.
The two function cheek-by-jowl, constantly sending signals back and forth through a bundle of 200 million to 300 million nerve fibers to help balance learning, analysis and communication throughout the brain.
But instead of running wires to the guest house or installing a separate base station there with its own Internet connection, Mr. Walter established a wireless link between the two buildings using two special antennas to beam signals back and forth.
These low earth orbit systems will be able to bounce signals back and forth much faster than older systems.
A recent Forbes.com special report on communicating highlighted the different ways people and other animals send signals back and forth to best get along in the world.
FLORHAM PARK, N.J. — The coming and going of each player's car on Jets Drive signaled the back-and-forth uncertainty about the short-term meaning over the end — probably a temporary one — of the N.F.L. lockout.
