2.13.3
Receiver Dynamic Range
The dynamic range of receivers shall be large enough to accommodate both
the worst-case, minimum receiver flux density and the maximum possible,
receiver flux density. The receiver dynamic range shall be at least 15 dB.
Where required, optical attenuators shall be used to force the FO link
power to fall within the receiver dynamic range.
2.14
OPTICAL FIBERS
**************************************************************************
NOTE: FO systems use one or two fibers for each
full duplex FO link. In the two-fiber links data
flows only in one direction in each fiber. DWM and
CWM systems often use one fiber for each full duplex
FO link in which differing wavelenghts travel in
opposite directions on one fiber. In some cases,
such as sending sync and receiving video from long
distances, bi-directional transmission on one fiber
is desired. Shorter wavelenghts generally have
greater attenuation; loss budgets should be based on
the wavelength with the greater attenuation.
**************************************************************************
2.14.1
General
Optical fibers shall be coated with a suitable material to preserve the
intrinsic strength of the glass. The outside diameter of the glass-cladded
fiber shall be nominally 125 microns, and shall be concentric with the
fiber core. Optical fibers shall meet EIA ANSI/EIA/TIA-455-46A, and EIA
ANSI/TIA/EIA-455-177A.
2.14.2
50 Micron Multimode Fibers
Conductors shall be multimode, graded index, solid glass waveguides with a
nominal core diameter of 50 microns. The fiber shall have transmission
windows centered at 850 and 1300 nanometer wavelengths. The numerical
aperture for each fiber shall be a minimum of 0.20. The attenuation at 850
nanometers shall be 3.5 dB/Km or less. The attenuation at 1300 nanometers
shall be 1.5 dB/Km or less. The minimum bandwidth shall be 500 MHz-Km at
both transmission windows. The fibers shall be certified to meet EIA
ANSI/EIA/TIA-455-30B and EIA ANSI/EIA/TIA-455-58B.
2.14.3
62.5 Micron Multimode Fibers
Conductors shall be multimode, graded index, solid glass waveguides with a
nominal core diameter of 62.5 microns. The fiber shall have transmission
windows centered at 850 and 1300 nanometer wavelengths. The numerical
aperture for each fiber shall be a minimum of 0.275. The attenuation at
850 nanometers shall be 3.5 dB/Km or less. The attenuation at 1300
nanometers shall be 1.5 dB/Km or less. The minimum bandwidth shall be 160
MHz-Km at 850 nanometers and 500 MHz-Km at 1300 nanometers. FO cable shall
be certified to meet EIA ANSI/EIA/TIA-455-30B and EIA ANSI/EIA/TIA-455-58B.
2.14.4
8.3 Micron Single-Mode Fibers
**************************************************************************
NOTE: Single-mode FO DTS offer larger bandwidth,
and lesser attenuation, usually at greater system
SECTION 16768A
Page 25
Previous Page
