PD IEC TR 61282-2:2003

What is PD IEC TR 61282-2- Gigabit ethernet model about? 

PD IEC TR 61282-2 is an international standard that discusses multimode and single-mode Gbit/s applications for fibre optic communication system. 

PD IEC TR 61282-2 describes a model developed as a tool to assist the physical layer committee of the gigabit ethernet (IEEE 802.3z) standard to understand potential trade-offs between the various link penalties associated with laser-based backbone links.  

PD IEC TR 61282-2 presents the theoretical model. Experimental verification is also presented for links operating at valid gigabit ethernet wavelengths of 780 nm, 850 nm and 1,300 nm. 

PD IEC TR 61282-2 is organized as follows: 

• In Clause 2, a simple theoretical prediction of laser-driven links is presented 
• Clause 3 contains the description of the experimental measurements and the experimental verification of the theoretical predictions 
• Finally, Clause 4 contains some example calculations and a discussion of the results and use of the model 

Who is PD IEC TR 61282-2- Gigabit ethernet model for?  

PD IEC TR 61282-2 on gigabit ethernet model is relevant to: 

• Manufacturers of gigabit ethernet  
• Manufacturers of multimode optical fibre and single-mode fibre 
• Electrical engineers and electronics engineers 
• Enterprise networks 
• Electricians 
• Telecom industries 
• Optical fibre technicians 
• Optical fibre installers 
• System designers 
• Testing authorities  

Why should you use PD IEC TR 61282-2- Gigabit ethernet model? 

Gigabit ethernet utilizes an 8B10B code that adds a 25 % overhead to the bit rate resulting in a baud rate of 1,25 Gb/s. The finite modal bandwidth of multimode fibre, particularly 62 MMF at a short wavelength, makes meeting the desired bandwidth distance product for gigabit ethernet a serious technical challenge.  

A model was developed as a tool to assist the physical layer committee of the gigabit ethernet (IEEE 802.3z) standard to understand potential trade-offs between the various link penalties associated with laser-based backbone links. An objective for the model was for it to be uncomplicated and able to be implemented in a simple form so that many users could work with it. Another objective of the model is to be applicable to both multimode fibre and single-mode fibre links. The purpose of PD IEC TR 61282-2 is to document the model as used by gigabit ethernet and to identify how it was used to develop the standard specifications. 

PD IEC TR 61282-2 presents the theoretical model. Experimental verification is also presented for links operating at valid gigabit ethernet wavelengths of 780 nm, 850 nm, and 1,300 nm. The model described in PD IEC TR 61282-2 is an extension of previously reported models for LED-based links [1,2]1). The model specifies power penalties which are calculated to account for the effects of inter-symbol interference (ISI), mode partition noise (MPN), extinction ratio (ER), and relative intensity noise (RIN). In addition, a power penalty allocation is made for model noise and the power losses due to fibre attenuation, connectors, and splices are included. The model in accordance with PD IEC TR 61282-2 is applicable to single-mode and multimode fibre-based links that incorporate multimode, Fabry Perot, or vertical-cavity surface emitting laser (VCSEL) lasers. Operation at wavelengths in the 1,300 nm transmission window on multimode fibre includes effects of fibre attenuation, ISI (due to the chromatic and the modal bandwidth of the fibre) and MPN. 

However, the model described in PD IEC TR 61282-2 has several limitations as follows: 

• The model ignores chirp. Therefore, it should not be used to predict dispersion penalties of links incorporating single-mode fibre and directly modulated single-frequency lasers since such links are often chirped with limited 
• Optical amplifiers and nonlinear effects, especially significant for dense-WDM (DWDM) systems, and polarization-mode dispersion (PMD), both important for long cable lengths between regenerators, are not treated 
• Interferometric and reflection-induced power penalties are not included 
• The model assumes the link components have been designed such that baseline wander is negligible 
• The model simply adds power penalties or losses in dB. However, for the noise-like terms (MN, MPN, RIN) the variances should have been added and an overall power penalty calculated. However, the error introduced can be shown to be small and within the measurement errors 
• For operation on multimode fibre, if single-frequency lasers and a non-restricted launch into the fibre is used, the modal noise power penalty allocation may not be correct 

PD IEC TR 61282-2 uses bandwidth and rise time specifications. The model includes expressions that convert the RMS impulse width of the laser, fibre, and optical receiver to rise times fall times and bandwidths. These calculated rise times, fall times and bandwidths are used to determine the fibre and composite channel exit response and the ISI penalty of the optical communications link.  

PD IEC TR 61282-2 assists with all the necessary details for the multimode and single-mode Gbit/s applications. PD IEC TR 61282-2 is a design guide for fibre optic communication systems that can help you to expand your business globally. 

Overall, PD IEC TR 61282-2 is useful as it provides guidance on gigabit ethernet model which can be beneficial for your business.