Introduction - Allied Telesis AT-FS201 Installation Manual

Chapter 1: Overview

Introduction

The fiber optic port on the bridging converter offers an important
advantage over fiber optic ports commonly found on Fast Ethernet
equipment. It can simultaneously transmit and receive Ethernet data for
full-duplex operation over a single fiber strand. In comparison, a
conventional fiber optic port requires two fiber strands for full-duplex
operation.
In a conventional fiber optic installation, each fiber optic strand carries
only one data stream at a time and in only one direction, as shown in
Figure 1.
Fiber Strand
Data Stream
λ1
Figure 1. Data Stream on a Single Fiber Strand
The data stream is transmitted at a specific wavelength, typically 850
nanometers (nm), 1310 nm, or 1550 nm. These wavelengths are known
for their low attenuation.
Full-duplex operation in a conventional fiber installation involves two
separate fiber strands, one for transmitting data and another for receiving
data, as shown in Figure 2. Both data streams are transmitted at the
same wavelength, but since each is on a separate strand, the signals
remain separate.
λ1
λ1
Figure 2. Full-duplex Operation on a Conventional Fiber Optic Installation
The fiber optic port on the bridging converter combines two data streams
onto one fiber optic strand. This allows you to use more of the bandwidth
inherent in fiber cable and so significantly increase the efficiency of your
existing fiber optic backbone network.
2