Optical Carrier levels (OCx)
The Synchronous Optical Network (SONET) includes a set of signal rate
multiples for transmitting digital signals on optical
fiber. The base rate (OC-1) is 51.84 Mbps.
OC-2 runs at twice the base rate, OC-3 at three times the base rate, and
so forth. Planned rates include OC-1, OC-3 (155.52 Mbps),
OC-12 (622.08 Mbps), and OC-48 (2.488 Gbps). Asynchronous
transfer mode (ATM) makes use of some of the Optical Carrier levels.
You can compare these data rates with data rates of other technologies
on the data rates page.