Optical Carrier

What Does Optical Carrier Mean?

An optical carrier is the standard unit of measure for the rate of transmission bandwidth for data being carried by Synchronous Optical Networking (SONET) fiber-optic networks.


Optical carrier transmission rate signifies the speed of a fiber-optic network and is abbreviated as OCx, where x is a variable representing a multiplier whose base rate is 51.84 Mbps. Therefore, an OC-1-rated fiber network would have a transmission rate of 51.84 Mbps, while an OC-3-rated network would have a speed of 155.52 Mbps.

Techopedia Explains Optical Carrier

Optical carriers are standardized sets of specifications for transmission bandwidths for SONET fiber networks. The following is a list of all the OC levels available and their corresponding speeds:

    1. OC-1 (STM-0): 51.84 Mbps
    2. OC-3 (STM-1 or STS-3): 155.52 Mbps
    3. OC-9 (STM-3): 466.56 Mbps
    4. OC-12 (STM-4): 622.08 Mbps
    5. OC-18 (STM-6): 933.12 Mbps
    6. OC-24 (STM-8): 1244.16 Mbps
    7. OC-36 (STM-12): 1866.24 Mbps
    8. OC-48 (STM-16): 2488.32 Mbps
    9. OC-192 (STM-64): 9953.28 Mbps
    10. OC-768 (STM-256): 40 Gbps
    11. OC-3072 (STM-1024): 160 Gbps

The Synchronous Transport Module (STM) is equivalent to the OC defined in the Synchronous Digital Hierarchy (SDH). The STM refers to how the data is being framed or arranged for transport.


Related Terms

Latest Internet Terms

Related Reading

Margaret Rouse

Margaret Rouse is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical, business audience. Over the past twenty years her explanations have appeared on TechTarget websites and she's been cited as an authority in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine and Discovery Magazine.Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages. If you have a suggestion for a new definition or how to improve a technical explanation, please email Margaret or contact her…