Definition of Optical Carrier (OC-x) Levels in the Network Encyclopedia.
What is Optical Carrier (OC-x) Levels?
OC-x stands for Optical Carrier Levels, is a set of signaling rates designed for transmission over Synchronous Optical Network (SONET) networks. Optical carrier (OC-x) levels also apply to Asynchronous Transfer Mode (ATM) networks. The term “optical carrier” indicates that SONET runs over fiber-optic cabling. The following table shows some of the common OC-x transmission rates.
OC-x Transmission Rates
OC-1 is roughly equivalent to T3 in the T-carrier system. It is a standard SONET Synchronous Transport Signal (STS) transmission rate of 51.85 Mbps. This data transmission rate is known as STS-1. Higher data transmission rates (OC-3, OC-12, and so on) are multiplexed STS-1 transmissions. In other words, OC-3 is three times faster than OC-1 (STS-1).