NeTS: Medium: Collaborative Research: Digital SubCarrier Multiplexing (DSCM) Networks: from the Core to the Access
Project Award Date: 08-15-2014
Green networking is more important than ever now that Internet traffic is undergoing another significant steep growth driven by video applications and cloud computing developments. With packet switching being the Internet mantra, data content routed over the IP network requires per-packet store-and-forward
along the path. In an IP router, 50-60% of its energy is used by the forwarding engine. With real-circuit switching, on the other end, once the connection is established, any data content can be routed over the network without requiring per-packet store-and-forward, and therefore it can potentially be more resource
and energy efficient. For example, all-optical Wavelength Division Multiplexed (WDM) networks enable data transmission over established optical circuits, thus both packet header processing and O-E-O (optical-electronic-optical) conversion are not required along such circuits. WDM networks are well suited for large capacity circuits (10Gbps and above) and find good applications in the core network where they yield tangible energy savings. A second example is Optical Transport Network (OTN), a SONET/SDH-like electronic Time Division Multiplexed (TDM) solution that is capable of establishing circuits with sub-wavelength bandwidth through time interleaving, which is suitable for metro networks but not flexible enough for access/campus networks.