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TELE-audiovision International — The World‘s Leading Digital TV Industry Publication

— 03-04/2015


Improving Optical Signals

The GlobalInvacom Fi-

breIRS family of products

are specially designed for

top quality satellite and ter-

restrial TV distribution sys-

tems. “Fibre” is the key word

here. The basic idea of this

distribution system is a con-

version of the electrical sig-

nals coming off the satellite

to fiber optic signals right at

the LNB output or better yet

even inside a dedicated opti-

cal LNB, a system GlobalIn-

vacom pioneered. The result

is that the signals distributed

off the LNB use fibre optic

cables rather than the usual

coax cables. Thanks to the

very low signal attenuation

of fibre optic cables, long

distances (even in the range

of kilometers) do not pose

any problem.

More important than end-

lessly long cable runs in most

cases is the possiblity of lots

of signal splitting. If you split

an optical signal into n ports

you will get 1/n signal power

at each output. To be very

precise, slightly less than 1/n

due to some additional cou-

pling loss. So, you can not

split an optic signal endlessly

but nevertheless it is possible

to split it up to 32 times in

GlobalInvacom’s system and

keep the original signal qual-

ity at each split as good as at

the LNB’s output. But that’s

not all! If, at every fibre line

end, you use a quad optical-

to-electrical converter, you

The Ideal Amplifier

known FibreIRS ODU this

system hugely expands the

number of possible outlets

fed by one single fibre optic


How does it work? Let’s

assume that our system

consists of GlobalInvacom’s

optical LNB (GI Fibre MDU)

connected to a 1:32 optical

splitter (GI Split32pro). This

gives us 32 optical outputs

to which we could connect



verters producing signals

“understandable” by satel-

lite receivers. If we use the

GlobalInvacom’s converters

(GI FibreIRS GTU) this gives

us four independent electri-

cal outputs just like from a

regular Quad LNB.

GI FibreIRS O2E Converter

Amazing: better signal at the output

than what goes in

But now instead of con-

necting the FibreIRS GTU

converter we can connect

the new converter - the GI

FibreIRS O2E. This is also

an optical-to-electrical con-

verter but its output is not

the same as that of the GI

FibreIRS GTU. The GI Fi-

breIRS O2E generates a

stacked signal containing

all sub bands of the original

satellite Ku-Band of both po-

larizations. So, its bandwidth

is not just about 1 GHz but

about 4 GHz. Its output is in

fact the same as the output

of another GlobalInvacom

product: the wholeband uni-

versal LNB FibreIRS LNBm.

So, now at the end of one

of the 32 fibre optic lines we

have an electrical wholeband

will get 32x4=128 outputs of

perfect signal from a single

LNB. That is the real poten-

tial of fibre optic installations.

While 128 outputs fed

by one single LNB already

seems to be quite a lot, what

do you do if you need even

more top quality outputs? Of

course, you can always mul-

tiply such systems starting

by installing more satellite

dishes. But there is a more

practical and elegant way.

GlobalInvacom came up

with the new FibreIRS O2E.

Together with the already