Summary Questions with answers in optical network

Chapter 15

15.1 Briefly discuss the evolution of optical networks. Indicate the
significant features of the optical network generations.
***********************Answer***********************




Generations of optical fiber network:
1- First Generation:
Point-to-point optical fiber network: Synchronous digital hierarchy (SDH) and
Synchronous optical network (SONET)
2- Second Generation:
Wavelength Routing Network: static in the sense that the allocated resources carrying the
traffic cannot be reassigned automatically once the transmission has failed to reach a
destination→Not reconfigurable.
3- Third Generations:
Fast and Reconfigurable network.

, There are three types of optical switching
Optical Circuit Switching Optical Packet Switching Optical Burst Switching
(OCS) (OPS) (OBS)
a path is set up between the source the message is broken into a message is transmitted in data
and destination before the small units or packets and bursts on an established path
transmission can take place and each packet is sent on an while separate bursts of
then after successful transmission established path. information are sent containing
of the entire message the path is the control data.
removed.
Slow switching speed Fast switching speed Moderate switching speed