Ko ta yaya al'umma masu wayewa suka tsawatar da talabijin saboda mummunan tasirinsa a kan sani, duk da haka, siginar talabijin yana nan a kusan dukkanin wuraren zama (da yawancin wuraren da ba mazauna ba). A cikin manyan biranen, wannan kusan ko da yaushe gidan talabijin na USB ne, ko da duk wanda ke kusa da su ya saba kiransa "antenna". Kuma idan tsarin liyafar talabijin ta ƙasa ta kasance a bayyane (ko da yake yana iya bambanta da eriyar da aka saba da ita akan windowsill, tabbas zan yi magana game da wannan daga baya), tsarin talabijin na USB na iya zama kamar ba zato ba tsammani rikitarwa a cikin aiki da gine-gine. Ina gabatar da jerin kasidu game da wannan. Ina so in gabatar da waɗanda ke sha'awar ka'idodin aiki na cibiyoyin sadarwa na CATV, da kuma aikin su da bincike.

• Kashi na 1: Babban tsarin cibiyar sadarwa na CATV
• Sashe na 2: Haɗin sigina da siffa
• Sashe na 3: Abubuwan Siginar Analog
• Sashe na 4: Bangaren Siginar Dijital
• Sashe na 5: Cibiyar Rarraba Coaxial
• Sashe na 6: Amplifiers Siginar RF
• Sashe na 7: Masu karɓar gani
• Sashe na 8: Cibiyar sadarwa ta Kashin baya na gani
• Kashi na 9: Gaba
• Sashe na 10: Matsalar hanyar sadarwa ta CATV

Ba na yin kamar na rubuta cikakken littafin rubutu ba, amma zan yi ƙoƙari in tsaya a cikin tsarin kimiyya kuma ba zan cika kasidu da dabaru da kwatancen fasaha ba. Wannan shine ainihin dalilin da ya sa na bar kalmomin "masu hankali" a cikin rubutu ba tare da bayani ba; ta hanyar yin amfani da su za ku iya zurfafa kamar yadda kuke buƙata. Bayan haka, an kwatanta duk abin da aka kwatanta da kyau, amma zan gaya muku yadda duk abin ya haɗa da tsarin talabijin na USB. A kashi na farko, zan yi bayanin tsarin hanyar sadarwa a zahiri, sannan kuma in yi nazari dalla-dalla kan ka'idojin aiki da tsarin gaba daya.

Gidan talabijin na USB yana da tsarin bishiya. Babban tashar ne ke haifar da siginar, wanda ke tattara sigina daga tushe daban-daban, ya samar da su zuwa guda ɗaya (bisa ga tsarin mitar da aka ba da shi) sannan a aika su zuwa babban hanyar rarrabawa ta hanyar da ake buƙata. A yau, cibiyar sadarwar kashin baya, ba shakka, na gani ne kuma siginar yana shiga cikin kebul na coaxial kawai a cikin ginin ƙarshe.

Babban tashar

Tushen sigina na kan kai na iya zama ko dai eriya ta tauraron dan adam (wanda za a iya samun dozin) ko rafukan dijital da tashoshi na TV ko wasu ma'aikatan sadarwa ke aikawa kai tsaye. Don karɓa da tara sigina daga tushe daban-daban, ana amfani da dikodi/modulators masu yawa na tashoshi masu yawa, waɗanda ke da katako mai ɗaukar hoto tare da katunan faɗaɗa daban-daban waɗanda ke ba da haɗin kai zuwa musaya daban-daban, gami da ƙaddamarwa, daidaitawa da samar da siginar da ake so. .

Anan, alal misali, muna ganin nau'ikan nau'ikan 6 don karɓar siginar watsa shirye-shiryen tauraron dan adam da na'urori biyu na DVB-C.

Kuma wannan chassis yana aiki ne don lalata siginar. Kuna iya ganin nau'ikan CAM, waɗanda aka saka a cikin TV don karɓar tashoshi masu rufewa.

Sakamakon aikin wannan kayan aiki shine siginar fitarwa wanda ke dauke da dukkanin tashoshi da za mu ba wa masu biyan kuɗi, wanda aka tsara ta mita daidai da tsarin da aka ba da shi. A cikin hanyar sadarwar mu, wannan shine kewayon daga 49 zuwa 855 MHz, yana ƙunshe da tashoshi na analog da dijital a cikin tsarin DVB-C, DVB-T da DVB-T2:

Nuna bakan sigina.

Ana ciyar da siginar da aka samar a cikin na'urar watsawa na gani, wanda shine ainihin mai sauya watsa labarai kuma yana tura tashoshi zuwa matsakaicin gani a madaidaicin talabijin na gargajiya na 1550 nm.

Mai watsa gani.

Cibiyar rarraba gangar jikin

Ana haɓaka siginar gani da aka karɓa daga saman kai ta amfani da na'urar erbium amplifier (EDFA), wanda ya saba da kowane ƙwararriyar sadarwa.

Biyu dubun dBm na matakin siginar da aka ɗauka daga fitowar amplifier tuni za a iya raba su kuma aika zuwa wurare daban-daban. Ana gudanar da rabo ta hanyar masu rarrabawa, don dacewa, an sanya su a cikin gidaje na rack-mount cross-connects.

Mai rarraba gani a cikin haɗin haɗin kai mai raka'a ɗaya.

Siginar da aka raba ta kai ga abubuwa inda, idan ya cancanta, ana iya haɓaka ta ta amfani da amplifiers iri ɗaya, ko raba tsakanin wasu kayan aiki.

Wannan shine yadda kumburin wurin zama zai yi kama. Ya haɗa da amplifier na gani, mai rarraba sigina a cikin gidaje na rackmount, da rarraba rarrabawar gani, daga abin da ake rarraba fibers zuwa masu karɓa na gani.

Cibiyar rarraba masu biyan kuɗi

Masu karɓar gani, kamar mai watsawa, matsakaita ne masu canzawa: suna canja wurin siginar gani da aka karɓa zuwa kebul na coaxial. OPs sun zo a cikin nau'i daban-daban kuma daga masana'antun daban-daban, amma aikin su yawanci iri ɗaya ne: matakin saka idanu da daidaitawar sigina na asali, wanda zan tattauna dalla-dalla a cikin labarai masu zuwa.

Ana amfani da masu karɓar gani a cibiyar sadarwar mu.

Dangane da tsarin gine-ginen gidaje (yawan benaye, yawan gine-gine da ƙofofin gaba, da dai sauransu), ana iya samun mai karɓa na gani a farkon kowane riser, ko watakila daya daga cikin da dama (wani lokaci ma tsakanin gine-ginen babu wani abu. na gani, amma coaxial na USB dage farawa), a cikin wannan A wannan yanayin, da makawa attenuation a kan masu rarraba da manyan hanyoyi ana biya ta amplifiers. Kamar wannan, misali:

CATV amplifier siginar Teleste CXE180RF

An gina hanyar sadarwar rarraba masu biyan kuɗi akan nau'ikan kebul na coaxial daban-daban da masu rarrabawa daban-daban, waɗanda zaku iya gani a cikin ƙaramin kwamiti na yanzu akan matakalanku.

An haɗa igiyoyi masu shiga cikin ɗakin zuwa abubuwan da aka fitar na masu raba masu biyan kuɗi.

Hakika, a mafi yawan lokuta, akwai da dama talabijin a kowane Apartment kuma an haɗa su ta hanyar ƙarin splitters, wanda kuma gabatar da attenuation. Sabili da haka, a wasu lokuta (lokacin da akwai talabijin da yawa a cikin babban ɗakin), ya zama dole don shigar da ƙarin siginar siginar a cikin ɗakin, wanda don waɗannan dalilai sun fi ƙanƙanta da rauni fiye da manyan.

source: www.habr.com