25-09-2010, 10:57 AM
LIGHT TREE-final.pptx (Size: 1.63 MB / Downloads: 313)
INTRODUCTION
Today, there is a general consensus that, in the near future, wide area networks (WAN)(such as, a nation wide backbone network) will be based on Wavelength Division Multiplexed (WDM) optical networks.
Depending on the underlying physical topology networks can be classified into three generations:
First Generation: these networks do not employ fiber optic technology; instead they employ copper-based or microwave technology. E.g. Ethernet.
Second Generation: these networks use optical fibers for data transmission but switching is performed in electronic domain. E.g. FDDI.
Third Generation: in these networks both data transmission and switching is performed in optical domain. E.g. WDM.
Depending on the underlying physical topology networks can be classified into three generations:
First Generation: these networks do not employ fiber optic technology; instead they employ copper-based or microwave technology. E.g. Ethernet.
Second Generation: these networks use optical fibers for data transmission but switching is performed in electronic domain. E.g. FDDI.
Third Generation: in these networks both data transmission and switching is performed in optical domain. E.g. WDM.