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  1. 1. TEST REPORT Fibre Optic Distribution System • loss-less distribution system for satellite signals • each outlets gets the original satellite signal • distributes both bands and both polarizations in one cable • easy to build system due to smart connectors • cable length not critical to performance The Global Invacom System54 TELE-satellite International — The World‘s Largest Digital TV Trade Magazine — 09-10/2012 — — 09-10/2012 — TELE-satellite International — 全球发行量最大的数字电视杂志 55
  2. 2. TEST REPORT Fibre Optic Distribution SystemThe Battle Is Over andFiber Has Won The carrier-to-noise ratio and low noise LNB to ensure Thanks to their innovative balInvacom’s FibreMDU Uni-is one of the major concerns high carrier-to-noise ratio at solution based on fiber optic versal Optical LNB. We firstwhen designing large sys- the input of the distribution cables and optical splitters, reported about this innova-tems to distribute satellite system. However, this may building even very exten- tive LNB in TELE-satellitetv signals. When you have not work well enough for re- sive networks becomes easy 04-05/2008 and in a follow-to deal with long coaxial ally large systems. and manageable. up story in TELE-satellitecables and/or many signal What then? Until recently, In order to switch from 08-09/2009. But this time,splitters, your signal qual- you had no choice but to in- coax cable to fiber optic we had the opportunity toity degrades significantly. stall additional large dishes cable, the very first thing test something else. It wasTo keep it good enough for and LNBs and build several needed is the conversion of the FibreIRS LNBm whole-the most peripheral users, separate distribution sys- the electromagnetic waves band LNB with integratedyou have to minimize the tems. Of course, this is not coming from a satellite (or frequency stacker.number of signal splitter be- a welcome solution. It adds from a DTT transmitter) to The FibreIRS LNBm istween the LNB and the very complexity, cost and the an- modulated light that can be installed in place of an or-last receiver and keep the tenna farm on the roof does then distributed over fiber dinary LNB but it does nottotal cable length as short not make (normal) people optic cables. TELE-satellite output signal in the familiaras possible. You also need happy. But now GlobalInva- readers remember that we 0.95 – 2.15 GHz frequencyto install quite a large dish com comes to our rescue. already introduced Glo- range. And it does not re-■ The FibreIRS LNBm mounted on a 90cm dish 09-10/2012 Global Invacom System Finally a system to build really large distribution nets without having to care at all about attenuation TELE-satellite International — The World‘s Largest Digital TV Trade Magazine — 09-10/2012 —
  3. 3. tenuated before reaching DC power via the thick coax everything comes down Then, we decided to test the FibreIRS ODU32. cable from the ODU 32. through the fiber optic ca- the whole system. First, we Except for the satellite But the picture is not com- bles to FibreMDU. measured a classical system signal, the FibreIRS ODU32 plete yet. Two optical chan- We started our tests with with a very good low noise accepts also a signal from nels have to be distributed measuring the optical split- LNB installed on a 90 cm DTT/DAB/FM antennas. among a number of end us- ters. Spli2-OFpro specifica- offset dish to have a refer- Preferably, the latter one ers. To do that, you can use tion promises not more than ence for the optical system. should come not directly optical splitters like Spit2- 4 dB attenuation of the sig- Our reference system had from terrestrial antennas OFpro or Split4-OF – 2 way nal (from the input to any of about 20 meters of coax- but through a DTT proces- or 4 way optical splitters its two outputs). We meas- ial cable. The problem was sor of Global Invacom de- offered by GlobalInvacom. ured that the actual attenu- which satellite we should scribed in the previous issue At the very end of such sys- ation was only 3.5 dB. The use? A very strong one in of TELE-satellite (Pages 16- tem, a device called FibreM- same story repeated for our location - like ASTRA 21 in TELE-satellite 06-07- DU should be connected. Split4-OFpro. Its actual per- 19.2° East or HOTBIRD 13° 08/2012). In this way, we The FibreMDU converts the formance was better than East or rather a weaker one ■ Checking the optical signal can achieve the best possi- optical signal back to the its specifications (6 dB vs. like TURKSAT 42° East. We at one of the fibre optic to coax converters ble performance. FibreIRS RF domain. It has four out- 7 dB). This is the way good decided to make it hard for ODU32 has two optical out- puts. So, up to four regular manufacturers specify their GlobalInvacom and chose puts as well as a connector satellite receivers can be products. Once they prom- TURKSAT. Some of its tran- for 20V DC power supply. connected to it and each of ise something, they deliver sponders are actually below GlobalInvacom provides a them will be able to receive it! It is not a universal rule the reception threshold of suitable plug type power any channel from the satel- these days unfortunately. most contemporary receiv- supply unit. You do not need lite the dish is directed to. We are happy to say that ers. Fortunately, our satel- a separate power supply No matter which sub band you can trust GlobalInva- lite analyzer – SPAROS SAT unit for the LNBm. It gets or polarity. That’s because com. HD of SPAUN is an extreme- quire a receiver for switch- converter which is desig- ing between lower or higher nated as FibreIRS ODU32. sub-band of Ku Band and Because here we deal with horizontal or vertical po- very high frequencies, we larization. No, it outputs two can not use regular coax sub-bands of Ku-Band and cable to connect these two both polarities stacked one devices. Global Invacom ■ TELE-satellite Test Editor Jacek Pawlowski testing over another in the range provides a special 2 meters a setup with rolls of fibre optic cable imitating a large 0.95 – 5.45 GHz. Such RF long thick and stiff coaxial distribution system. signal is then fed to the cable. Thanks to that, even■ TELE-satellite has introduced GlobalInvacom‘s fibreoptic LNB first in 2008 and then again in 2009. Global Invacom RF-to-light a 5.45 GHz signal is not at-58 TELE-satellite International — The World‘s Largest Digital TV Trade Magazine — 09-10/2012 — — 09-10/2012 — TELE-satellite International — 全球发行量最大的数字电视杂志 59
  4. 4. ly sensitive instrument - ca- were significantly stronger everything was connected. fiber optic cables, splitterspable of processing even in the optical system. MER All optical and RF connec- and converters, we couldsuch weak signals. We mean was at par with the classi- tors of the devices had pro- deliver exactly the samesignals with a MER of 5.5 dB cal system. This means that tective covers so that no signal as presented on ourand less. It corresponds to a signal quality did not de- dirt could access it during graphs to not fewer but 64C/N below 8 dB. Such tran- graded despite 300 meters transportation or the in- satellite receivers. And allsponders are hardly receiv- of cable and two splitters! stallation process. Building this from a single dish andable by regular receivers. You can see our results on such optical system was like single FibreIRS LNBm. If we The optical system we the attached graphs. playing with LEGO blocks. It used even more splittersbuilt had FibreIRS LNBm in- After the first round of was nothing but joy. or Spit4-OFpros in place ofstalled on the same 90 cm measurements, we changed If we connected more Spit2-OFpros, the numberdish, FibreIRS ODU32, 100 the output of Spit2-OFpro of end users would be muchmeters of fiber optic cable, splitter and did the second greater. The only thing oneSpit2-OFpro, another 100 run for the optical system. can expect then is some-meters of fiber optic cable, And finally, we changed the what lower output powerSpit4-OFpro, another 100 output of Spit4-OFpro split-meters of fiber optics ca- ter and repeated the meas-ble and FibreMDU to which urements. As you can see,we connected the satellite there was practically no dif-signal analyzer. As you can ference in performance whatcalculate, the system had in proves that all outputs oftotal 300 meters of fiber op- the splitters produced verytic cable and two splitters in similar signal. (graph.1, 2)series. All the GlobalInvacom The results were really components we tested wereastonishing! The optical perfectly finished off and wesystem was able to deliver had absolutely no problemalmost all transponders we in making the connections.had with a classical system Just click, click, click andexcept for the two weakesttransponders (12577HH and12618HH). As we said be-fore, those two transpond-ers were below the recep-tion threshold of a regularreceiver anyway. So, in fact,we did not lose anything. Allthe remaining transponders60 TELE-satellite International — The World‘s Largest Digital TV Trade Magazine — 09-10/2012 —
  5. 5. 62 TELE-satellite International — The World‘s Largest Digital TV Trade Magazine — 09-10/2012 — — 09-10/2012 — TELE-satellite International — 全球发行量最大的数字电视杂志 63
  6. 6. but this is not a problem as about signal attenuation or TECHNICALthe 80-90 dBµV we achieved carrier to noise ratio. Using DATAin our test setup was a very optical components, practi- Manufacturer Global Invacom Ltd., Great Britainstrong signal. Normally, you cally everybody can build Web www.gloablinvacom.comhave 60-70 dBµV or so. a large distribution system E-mail So, we can do nothing without tedious gain mar- Phone +44-1621-743440but heartily recommend the gin calculations or interfer- Fax +44-1621-743676optical system of GlobalIn- ence concerns. No more FibreIRS LNBmvacom for large distribution problems. The battle is over Function Wholeband LN with integrated frequency stackersystems. You can forget thanks to fibre optics. Input frequency range 10.7 – 12.75 GHz Output frequency range 0.95 – 5.45 GHz Expert Opinion Noise figure typ. 0.7 dB FibreIRS ODU32 High signal gain Very good carrier-to-noise ratio Function RF to fiber optic converter Solid design and workmanship Satellite input frequency range 0.95 – 5.45 GHz+ Actual performance better than parameter specification DAB/DTT input frequency range 217-230 MHz and 470-854 MHz No. of optical outputs 2 All components available from the same manu- Power supply 20 V DC, < 0.5A incl. wholeband LNB facturer Jacek Pawlowski TELE-satellite Spli2-OFpro & Spli4-OFpro Test Center FibreIRS LNBm is larger and heavier than a Poland Function 2 way and 4 way optical splitters– classical LNB – select a dish with a robust LNB CR typ. 50% and 25 % respectively holder Insertion loss typ. 4 dB and 7 dB respectively64 TELE-satellite International — The World‘s Largest Digital TV Trade Magazine — 09-10/2012 —