March 1, 2012 – As IP traffic continues to increase and the router interface rate extends beyond 100 Gb/s, future optical networks—ones that would achieve speeds of 1 terabit-per-second (Tb/s)—will be required to support the growth of data services with different capacities and patterns on the same optical platform.

To address this issue, researchers at NTT Network Innovation Laboratories in Japan created and demonstrated a “spectrally efficient, scalable elastic optical transport network architecture”. The team will report on their findings at the Optical Fiber Communication Conference and Exhibition/National Fiber Optic Engineers Conference (OFC/NFOEC) taking place next week in Los Angeles.

Conventional optical networks allocate fixed bandwidth to every optical path, regardless of the actual traffic volume and path length on the basis of the “worst-case design policy”. In contrast, the NTT researchers’ spectrum-sliced elastic optical path network, known as ‘SLICE’, is flexible and relies on adaptive spectrum allocation to an optical path based on the traffic volume and path length. It essentially enables allocation of only the necessary minimum bandwidth corresponding to individual requests—providing significant savings of network resources.

The bit rate per distance adaptive feature leads to spectral savings and increased network capacity. Elastic optical path networks make it possible to offload IP traffic to an elastic optical layer by using multi-flow optical transponders combined with elastic optical networking technology. This reduces the number of router interfaces, while keeping simplifying router-to-wavelength cross-connect interconnections.

The technologies and functionality of elastic optical path networks will become a viable way to achieve efficient, cost-effective IP optical networks, say the NTT researchers.