The N-GREEN project targets the current ICT challenges: the ever-growing global data traffic and unsustainable increase of energy consumption. The main bottleneck is the switching, extremely power-hungry in current electronic switch/routers. N-GREEN proposes a new type of switching/routing node by introducing a new high-capacity design including new optical technologies to reduce by several orders of magnitude the energy consumption per bit switched.
The project targets modelling and proof of concept of this novel node, focusing on:

• A backplane, highly integrated yet modular, based on fast optical switches of small connectivity but addressing large switching capacities, thanks to the WDM technique. This technique is compatible with the conventional packet switching technique, while addressing a switching capacity beyond 100 Tb/s (160 Tbit/s for a 16×16 optical switch).
• A network architecture exploiting WDM packets thanks to a new generation of optical add/drop multiplexers (WSADM: WDM slotted add/drop multiplexer). These packets having a fixed duration close to 1 μs are transported in a transparent way, to better exploit the switching matrix of the node; their headers will be transported over one dedicated wavelength at a lower bit rate, to reduce the physical constraints of the electronic processing and scheduler.
• New interfaces improving the interconnection of data storage and processing units. These interfaces support new functionalities such as dynamical bandwidth allocation and secured interconnection.

These innovations allow limiting the amount of data to be electronically handled, while introducing a limited number of optical components thanks to WDM slots, thus reducing energy consumption per transmitted bit.