Toner Cable Lightlinks (TM) L-Band Fiber Optic System - Manual

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Linear Fiber Optic LightLinks™
215-675-2053 800-523-5947 215-675-7543 [email protected] http://www.tonercable.com
969 Horsham Road
Horsham, Pennsylvania 19044 USA
Linear Fiber Optic LightLinks™
Providing direct broadcast satellite service to cus-
tomers in medium and large-size multiple-dwelling
unit (MDU) properties without compromising the
satellite link budget can be extremely difficult using
coaxial cables. The insertion loss of type RG-6 coax-
ial cable is approximately 9 dB per 100 foot length at
1450 MHz and 11 dB at 2050 MHz, resulting in
severe distance limitations. This effectively pre-
cludes using a single cable to carry both satellite
polarizations simultaneously, making it difficult to
connect more than one satellite receiver (IRD) in an
individual apartment or condominium unit.
Fortunately, linear fiber optics can be employed as
a cost-effective way of providing DBS distribution
with negligible signal losses at distances of thou-
sands of feet.
In conventional, all-coaxial distribution systems, the
high coaxial insertion loss and the loss in passive
components such as splitters and directional taps
can be offset using in-line amplifiers, but only up to a
point. Cascading several of these devices along the
same path can degrade the signal quality and
reduce the rain fade margin by introducing exces-
sive noise and intermodulation distortion. The size of
the distribution network is therefore limited, and the
LightLinks™ Family of DBS distribution products
system must be carefully designed and implemented
to ensure that signal losses are accounted for along
every single path.
Multiswitches can be used to combine both polariza-
tions onto a single drop cable, because the IRD typi-
cally selects either one or the other by setting the dc
voltage on the center conductor of the drop cable.
But multiswitches are expensive, and require that
each IRD uses one multiswitch output and its own
drop cable, even if other IRDs are in the same unit.
Using Linear Fiber Optic Lightlinks™ for Direct Broadcast
Satellite Reception in Multiple Dwelling Units
Figure 1: Linear Fiber Optic LightLinks™ MDU Distribution System