Simplex and Duplex Fiber Optic Patch Cable Overview

It is generally known that fiber optic patch cable can be classified by transmission medium (single mode or multimode), by connector construction (FC, LC etc) and by fiber cable structure (simplex or duplex). This paper will introduce simplex fiber patch cable and duplex fiber patch cable. In order to have a better understanding of simplex and duplex fiber optic patch cable, the definition of simplex and duplex will be explained in the first part.

Definition of Simplex

Simplex communication is a communication channel that sends information in one direction only (see Figure 1). For instance, in TV and radio broadcasting, information flows only from the transmitter site to multiple receivers.

simplex transmission
Figure 1
Definition of Duplex

Duplex communication system is a point-to-point system composed of two connected parties or devices that can communicate with each other in both directions. It has two clearly defined paths and each path could carry information in only one direction (A to B over one path, and B to A over the other). Duplex communication system can be classified into half-duplex and full duplex. In a half-duplex system, there are still two clearly defined paths/channels, and each party can communicate with the other but not simultaneously (see Figure 2). Typically, once a party begins receiving a signal, it must wait for the transmitter to stop transmitting, before replying. A walkie-talkie is a half-duplex communication system. In a full duplex system, both parties can communicate with each other simultaneously (see Figure 3), such as a telephone.

half duplex transmission
Figure 2
full duplex transmission
Figure 3
Simplex Fiber Optic Patch Cable

Simplex fiber optic patch cable consists of a single strand of glass fiber, and is used for applications that only require one-way data transfer. It is commonly used where only one single transmit and receive line is desired. Simplex fiber optic patch cable is available in single mode and multimode. For instance, a single mode simplex fiber patch cable (see Figure 4) is a great option for data travelling in one direction over long distance.

LC-LC simplex single mode fiber patch cable
Figure 4
Duplex Fiber Optic Patch Cable

Duplex fiber optic patch cable consists of two strand fibers of glass structured in a zipcord arrangement where each fiber strand has independent coatings that are linked together by a thin layer of coating material. Duplex fiber patch cable is most used where separate transmit and receive signals are required, that is, one strand transmits in one direction while the other strand transmits in the opposite direction. It is available in single mode and multimode. Multimode duplex fiber optic patch cable or single mode duplex fiber optic patch cable is usually used for applications that require simultaneous and bi-directional data transfer. For example, 10 gigabit multimode duplex cables can support 10 Gb/s bandwidth in both directions within a short distance. LC to LC duplex single mode fiber patch cable (see Figure 5) can make simultaneous data transfer with LC-LC connectors over long distance.

LC-LC duplex single mode fiber patch cable
Figure 5

After reading the above statements, do you have a brief understanding of simplex fiber patch cable and duplex fiber patch cable? When choosing one over the other, the key factor is that the equipment requires one-way or bi-directional data transfer. Fiberstore has large numbers of simplex and duplex fiber optic patch cables, such as single mode simplex fiber patch cable, LC to LC duplex single mode patch cable, 10 gigabit multimode duplex cables, LC ST duplex patch cord and so on. I believe you can find a suitable fiber optic patch cable for your devices in Fiberstore.