Title :
On the value of optical-layer reconfigurability in IP-over-WDM lightwave networks
Author :
Chaudhuri, Sid ; Goldstein, Evan
Author_Institution :
Tellium Inc., Oceanport, NJ, USA
Abstract :
As packet traffic threatens to rapidly dominate core lightwave networks, while IP-router architectures take aim at multi-Tb/s capacities, a fundamental architectural question is beginning to take shape. Will the simple expedient of directly connecting IP routers to wavelength-division-multiplexing (WDM) optical-transport systems offer decisive economies in emerging core-transport networks, or is there yet a role for an added layer of reconfigurable wavelength-level circuits interposed among router ports? By examining regular network topologies with uniform and random traffic, we show that by adding a reconfiguring optical layer one reaps large economies, so long as router ports remain marginally more costly than optical-layer crossconnect ports. These economies are essentially invariant with nodal degree over the range of interest in lightwave networks. They grow rapidly with network node count. The results offer a compelling case for incorporating optical-layer crossconnects in large datacentric core-transport networks, and suggest that the resulting economies will rise rapidly as the network itself grows.
Keywords :
Internet; access protocols; optical fibre subscriber loops; optical interconnections; reconfigurable architectures; telecommunication network routing; telecommunication traffic; wavelength division multiplexing; IP-over-WDM lightwave networks; IP-router architectures; WDM; core lightwave networks; core-transport networks; datacentric core-transport networks; multi-Tb/s capacities; nodal degree; optical-layer crossconnect ports; optical-layer crossconnects; optical-layer reconfigurability; optical-transport systems; packet traffic; random traffic; reconfigurable wavelength-level circuits; regular network topologies; router ports; uniform traffic; wavelength-division-multiplexing; Circuits; Costs; Intelligent networks; Joining processes; Multiprotocol label switching; Network topology; Optical fiber networks; Shape; Telecommunication traffic; Wavelength division multiplexing;
Journal_Title :
Photonics Technology Letters, IEEE