37 distinct OC-48 ITU 100 GHz dense wavelength division multiplexing (DWDM) cards provide the ONS 15454 DWDM channel plan. Each OC-48 DWDM card provides one Telcordia-compliant, GR-253 SONET OC-48 port. The port operates at 2.48Gbps over a single-mode fiber span. The card carries VT, concatenated, and non-concatenated payloads at STS-1, STS-3c, STS-6c, STS-12c or STS-48c signal levels.Each OC-48 ELR DWDM card uses extended long reach optics operating individually within the ITU-T 100 GHz grid. The OC-48 DWDM cards are intended to be used in applications with long unregenerated spans of up to 200 km (with mid-span amplification). These transmission distances are achieved through the use of inexpensive optical amplifiers (flat gain amplifiers) such as Cisco ONS 15216 erbium-doped fiber amplifiers (EDFAs).