Let’s break down some common questions regarding MTP polarity methods.
Optical fiber networks require two fibers to make a complete circuit. The matching of the transmit Tx signal to the receive Rx equipment is referred to as polarity, and a transmit and receive side on optical transceivers usually use a duplex fiber connector to maintain the polarity. On most cabling systems, maintaining polarity just requires that the A side of one connector pair matches the B side of the other connector pair, with fiber connectors such as ST, LC, SC, and MTRJ.
MTP/MPO high density network design requires its own set of rules regarding maintaining polarity throughout the link. These three polarity methods are commonly referred to as Method A, Method B, and Method C, and we will discuss the difference further here.