As far as I know:
(1) Latency (τ) = transmission delay + propagation delay + queuing delay + processing delay
(2) Round-trip time (RTT) is two times the latency (assuming the same latency both ways)
However, while I was reading about slot time, I found the standard 802.3 says:
The slot time shall be larger than the sum of the Physical Layer round-trip propagation time and the Media Access Layer maximum jam.
Is this round-trip propagation time the same as RTT? If so, why add "propagation"? RTT includes other times beside propagation, that would be misleading.