Archived — Fiber Optic Technology

>> Who is Telcordia? Together with the Regional Bell Operating Companies (RBOCs), Bellcore published specifications for many products used by Telecom Service Providers. Examples of the more widely mentioned of these specifications are GR-20-CORE, “Generic Requirements for Optical Fiber and Optical Fiber Cable”, for outside plant cables and GR-409-CORE, “Generic Requirements for Premises Fiber Optic Cable”, for intrabuilding cable. In 1997, Bellcore was purchased by SAIC (Science Applications International Corporation) and renamed Telcordia. Telcordia continues to maintain various product specifications.   >> What is Telcordia GR-326-CORE? Telcordia GR-326-CORE, “Generic Requirements for Single-mode Optical Connectors and Jumper Assemblies,” is a specification

>> The Purpose of ANSI/TIA/EIA-942 TIA/EIA 942 is the telecommunications infrastructure standard for data centers. The list below shows its purpose: 1. The purpose of this standard is to provide requirements and guidelines for the design and installation of a data center or computer room. 2. It is intended for designers who need a comprehensive understanding of the data center design including the facility planning, the cabling system, and the network design. 3. It facilitates the planning for data centers to occur earlier in the building development process (architectural, facilities, and IT). Data centers support a wide range of transmission

>> Why NRZ Isn’t Always the Best Modulation Format Most optical systems use NRZ modulation format. While NRZ modulation is suitable for long haul systems in which the dispersion of the single mode fiber is compensated for by another fiber with negative dispersion, it is not the best choice for uncompensated single mode fibers. Duobinary modulation turns out to be a much better choice in this case, since it is more resilient to dispersion and is also reasonably simple to implement. We will explain the basics of duobinary modulation and present the lab test result which shows that duobinary modulation

All amplifiers degrade the signal-to-noise ratio (SNR) of the amplified signal because of spontaneous emission that adds to the signal during its amplification. The SNR degradation is quantified through a parameter Fn, called the amplifier-noise figure in analogy with the electronic amplifiers, and is defined as (Equation 1.12) where SNR refers to the electrical power generated when the signal is converted to electrical current by using a photodetector. In general, Fn would depend on several detector parameters which govern the shot noise and thermal noise associated with the detector. One can obtain a simple expression for Fn by considering an

>> What is Radio Over Fiber (RoF)? Radio over Fiber (RoF) refers to an analog transmission over fiber technology whereby light is amplitude modulated by a radio signal and transmitted over an optical fiber link to facilitate wireless access. Although radio transmission over fiber is used for multiple purposes, such as in cable television (CATV) networks and in satellite base stations, the term RoF is usually applied when this is done for wireless access. In RoF systems, wireless signals are transported in optical form between a central station and a set of base stations before being radiated through the air.