Contention resolution between TE’s for the D channel
The E bit echoed from the NT is a 0 bit if atleast one of the TE’s transmitted a 0 bit and is a 1 bit if and only if all the TE’s transmitted a 1 bit
TE’s continue transmitting only if the echoed back bit is same as the bit that it had transmitted
Behavior of NT is similar to that of an AND gate