Cable Polarity

Method A, B, & C

An optical link needs a pair of optical fibers to transmit signals. The optical module comprises a transmitting end (Tx) and a receiving end (Rx). Proper interconnection between the two ends is needed, which is called polarity. Polarity indicates the direction of optical signal movement in the fiber, and it is essential for matched transmitting and receiving ends. TIA 568 standard defines three methods for correct polarity, referred to as Method A, Method B, and Method C. Three types of MTP fibers, namely Type A, Type B, and Type C, are used to match the three different connectivity methods in compliance with these guidelines.