Binary transitions, power consumption

I'm studying the ethernet devices and the transmission system over cable wire and i'm interested especially on the power consumpiot due to the binary transitions from 0 to 1 and viceversa in the transistors. It is possible to estimate how many WATTS (i thinks nW) are necessary to the device to switch from 0 to 1 or viceversa?
it is due to the charge and discharge of the cable parasitic capacitance?
thank you in advance

Some of the power goes into charging and discharging the cable capacitance; some goes into the driver output transistors as they source/sink the transition current; some goes into the termination resistors at the receiver.

thank you!
do you think it is possible to estimate how much energy is consumed during a transition?

1. Spice modelling. Difficult to model because the model is only as good as the estimate of cable capacitance, accuracy of models of drivers, receivers.

2. Actual measurements on typical system. More accurate, but what is a "typical" system?