IEC TR 61282-1:2000 pdf download

IEC TR 61282-1:2000 pdf download.Fibre optic communication system design guides – Part 1:Single-mode digital and analogue systems.
4 General considerations for BFOS design
This clause presents the information needed for the design of the BFOS. Blank detail specifications (BOSs) summarize this information. These BOSs consist of device parameters under standard and extended operating conditions, which the system designer should provide.
4.1 Environmental conditions
Environmental conditions are specified for the individual elements of the BFOS. Environmental conditions may include ranges and durations of temperature, humidity, vibration and other parameters. They may apply to testing environments or operating environments. Individual BFOS elements may see different environmental conditions due to differences in their physical location in the OFOS.
4.2 Worst-case values
The value of a parameter may vary with one or more of the following factors: environmental conditions, wavelength variations, ageing and manufacturing variations. The worst-case value of a parameter is determined by the combined variations of all the above during the lifetime. For ranges of temperature, humidity and wavelength, the worst-case value need not occur at the extremes of the range or at end-of-life
4.3 General system attributes
The general description of the overall System Consists of the following:
terminal device identification
The identification should uniquely characterize the type of product and provide a traceable indicator for determining the product specifications, features, issue or revision, and manufacturer.
a) For digital transmission systems:
line bit rate
the unencoded rate fbit/s) at the boundary between the fibre optic cable plant and the terminal device
transport bit rate
the internal bit rate (bills) that is acted upon by the line coding algorithm to result in the line bit rate
line code
a sequence of symbols that the binary data is converted into for purposes of transmission. Examples include Manchester, return-to-zero, block codes, digital scrambling, etc. Line codes are used to recover timing, and in some cases they may be used to detect line errors and to convey additional information
b) For analogue transmission systems:
line bandwidth
the optical interlace bandwidth (Hz) at the boundary between the fibre optic cable plant and the equipment
transport bandwidth
the electrical modulated signal bandwidth (Hz), internal to the terminal device, that when acted upon by the modulationdemodulation scheme (for example. AM-VSB, FM-FDM. PFM, etc.) results in the line bandwidth.
4.4 Transmitter description
4.4.1 General
Transmitter description
The unit containing the transmitter should have a label providing the following information:
— manufacturer;
— equipment identification,
— system design application, for example, digital, analogue;
— operating wavelength;
— output power level;
— source type:
— temperature controller:
— optical isolator incorporated;
— IEC 60825 laser classification;
— manufacturer’s product change designation, for example, issue, revision.
Optical source type
The optical source type Is characterized by Identifying as a minimum:
— type of laser;
— material composition of source: for example, lnGaAsP;
— generic device structure: for example, DFB.
Transmitter connector
The transmitter connector is the optical connector provided at the output of the transmitter. The Iransmitter connector description, as a minimum, includes:
— type (for example, ST. SC, etc.).
Transmitter pigtail
The identification of the transmitter pigtail shall include the following informahon (if Included):
General fibre type:
— class of fibre;
— mode field diameter.
4.4.2 Transmitter parameters
The system parameters should be specified as follows:
nominal central wavelength (A1 nom)
the nominal value of the transmitter central wavelength for me apphcatlon unoer COnSiceralion.
The supplier should specify the following:
measurement method for central wavelength (As)
the procedure for determining the central wavelength is chosen from those in IEC 61280-1-3
transmitter central wavelength range (A, mm’ A1 max)
the minimum and maximum wavelength limits, respectively, of the total allowed range of transmitter central wavelengths caused by the combined worst-case variations due to manufacturing. environmental conditions, ageing, and any other significant factors, as described in 4.2
transmitter output power (PT)
the worst-case minimum value of the optical power (dBm) coupled into the cable plant (on the line side of the transmitter unit connector), as measured utilizing the procedure contained in IEC 61280-1-1. The worst-case minimum value combines manufacturing variations with environmental conditions and ageing, as described in 4.2