Quantifying spectrum, cost, and energy efficiency in fixed-grid and flex-grid networks [Invited]

E. Palkopoulou, M. Angelou, D. Klonidis, K. Christodoulopoulos, A. Klekamp, F. Buchali, E. Varvarigos, I. Tomkos

Research output: Contribution to journalArticleResearchpeer-review

70 Citations (Scopus)


Single and multi-carrier networks offering channel rates up to 400 Gb/s are evaluated under realistic reach parameters. It is found that efficient spectrum utilization and fine bit-rate granularity are essential to achieve cost and energy efficiency. Additionally, the break-even cost of flexible orthogonal frequency division multiplexing transponders is examined under different settings. The break-even cost of a flexible transponder corresponds to the cost value for which the total cost of the network is equal to that of the related single-line-rate network. The impact of the traffic load, the additional cost required for flex-grid optical cross connects, the cost of spectrum, as well as the cost of fixed-grid transponders is examined.

Original languageEnglish
Article number6360168
JournalJournal of Optical Communications and Networking
Issue number11
Publication statusPublished - 2012
Externally publishedYes


  • Cost analysis
  • Energy efficiency
  • Flexible optical networking
  • Optical OFDM

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