| While WDM technology brings huge transmission capacity
potential to a single fiber, the capacity requirement of a single traffic request might be far less
than the capacity of a single wavelength running on a fiber. Traffic grooming tries to address this
capacity mismatch problem by packing low-rate traffic requests into high-rate wavelength channels
(lightpaths) in a cost-effective way that either resources requirement is minimized when traffic
requests are given or network throughput is maximized when the amount of network resources is given.
Because SONET is the most widely deployed optical network architecture, traffic grooming in SONET/WDM
ring networks has been a research focus for several years. With the development of optical switching
cross-connects, IP/WDM seems to be a promising architecture to meet the tremendous traffic increase of
Internet. Since Internet has a mesh topology, traffic grooming in mesh networks also evokes great
interest currently. This presentation gives an introduction to the traffic grooming problem in
SONET/WDM ring networks and WDM mesh networks, including issues such as concepts and benefits of
efficient traffic grooming, key technologies enabling grooming, mathematical formulation of the traffic
grooming problem, computational complexity of traffic grooming problem, grooming heuristics and traffic
models. |