in the radio parameters of wireless :
hysteresis reflects a “lag” to go from one cell to another.
offset is a “distance” between a cell and its neighbours.
but basically, in GSM, those two words define the same thing: a difference of rxlev… and the word “hysteresis” is actually closer to what the parameters are doing.
to conclude : laws of vocabulary don’t apply to parameters names… the only thing that matters is their definitions 🙂