I need clarification on the differences between EoSDH and Ethernet using "wave" technology. What does "wave" bring to the table? I understand EoSDH but not sure where "wave" fits into the picture. Actually EoSDH is transported using fiber as well so in it fact uses "wave " technology, does it not? I think maybe the issue is a single light wave vs. multiple light waves as in WDM, DWDM, and CWDM. Please clarify.