Kungakhathaliseki ukuthi umphakathi okhanyisiwe uyithethisa kanjani ithelevishini ngomthelela wayo omubi ekwazini, nokho, isignali kamabonakude ikhona cishe kuzo zonke izindawo zokuhlala (kanye neziningi okungezona ezokuhlala). Emadolobheni amakhulu, lena cishe njalo ithelevishini yekhebula, noma ngabe wonke umuntu oseduze nayo ejwayele ukuyibiza ngokuthi “i-antenna”. Futhi uma isistimu yokwamukela ithelevishini yasemhlabeni isobala (nakuba ingase ihluke ku-antenna evamile enezimpondo efasiteleni, nakanjani ngizokhuluma ngalokhu kamuva), khona-ke uhlelo lwethelevishini lwamakhebula lungase lubonakale luyinkimbinkimbi ngokungalindelekile ekusebenzeni kwalo kanye nezakhiwo. Ngethula uchungechunge lwezihloko mayelana nalokhu. Ngifuna ukwethula labo abanentshisekelo ezimisweni zokusebenza kwamanethiwekhi e-CATV, kanye nokusebenza kwawo kanye nokuxilonga.
- Ingxenye 1: I-General CATV network Architecture
- Ingxenye 2: Ukwakheka kwesignali kanye nokuma
- Ingxenye 3: Ingxenye Yesiginali ye-Analogi
- Ingxenye 4: Ingxenye Yesiginali Yedijithali
- Ingxenye 5: Inethiwekhi yokusabalalisa i-coaxial
- Ingxenye 6: Izikhulisi Zesiginali ye-RF
- Ingxenye 7: Abamukeli be-Optical
- Ingxenye 8: Inethiwekhi ye-Optical backbone
- Ingxenye 9: Isihloko
- Ingxenye 10: Ukuxazulula inkinga inethiwekhi ye-CATV
Angenzi sengathi ngibhala incwadi ebanzi, kodwa ngizozama ukuhlala ngaphakathi kohlaka lwesayensi futhi ngingagcwalisi izindatshana ngamafomula nezincazelo zobuchwepheshe. Yingakho ngishiye amagama “ahlakaniphile” embhalweni ngaphandle kwencazelo; ngokuwahlola ungajula ngokudinga kwakho. Phela, konke kuchazwe kahle ngabanye, kodwa ngizokutshela nje ukuthi konke kuhlanganisa kanjani ohlelweni lwethelevishini lwekhebula. Engxenyeni yokuqala, ngizochaza ngokucacile ukwakheka kwenethiwekhi, futhi kamuva ngizohlaziya ngokuningiliziwe izimiso zokusebenza kwalo lonke uhlelo.
Inethiwekhi yethelevishini yekhebula inesakhiwo somuthi. Isignali ikhiqizwa yisiteshi esikhulu, esiqoqa amasignali emithonjeni ehlukene, siyenze ibe eyodwa (ngokohlelo olunikeziwe lwemvamisa) futhi siyithumele kunethiwekhi yokusabalalisa enkulu ngendlela edingekayo. Namuhla, inethiwekhi yomgogodla, yebo, i-optical futhi isignali ingena kukhebula le-coaxial kuphela ngaphakathi kwesakhiwo sokugcina.
Isiteshi esikhulu
Imithombo yesignali yesihloko kungaba izinti zesathelayithi (okungaba khona ishumi nambili) noma ukusakazwa kwedijithali okuthunyelwa ngokuqondile ngamashaneli e-TV noma abanye opharetha bezingcingo. Ukwamukela nokuhlanganisa amasiginali avela emithonjeni ehlukene, kusetshenziswa amadekhoda/amamoduli anezinkonzo eziningi eziteshini eziningi, okuyi-rack-mount chassis enamakhadi okunweba ahlukahlukene ahlinzeka ngoxhumano lwezindawo ezihlukene, kanye nokuqopha, ukulungisa kanye nokukhiqiza isignali oyifunayo. .
Lapha, ngokwesibonelo, sibona amamojula ayi-6 okuthola isignali yokusakaza ngesathelayithi kanye namamojula amabili okukhiphayo e-DVB-C.
Futhi le chassis ibambe iqhaza ekwehliseni isignali. Ungabona amamojula e-CAM, afanayo ashuthekwa kuma-TV ukuze uthole iziteshi ezivaliwe.
Umphumela wokusebenza kwalesi sisetshenziswa isignali yokuphumayo equkethe wonke amashaneli esizowanikeza ababhalisile, ahlelwe ngamafrikhwensi ngokuvumelana nohlelo olunikeziwe lwefrikhwensi. Kunethiwekhi yethu, leli ibanga elisuka ku-49 kuye ku-855 MHz, eliqukethe womabili amashaneli e-analog nedijithali kumafomethi e-DVB-C, DVB-T kanye ne-DVB-T2:
Bonisa i-spectrum yesignali.
Isignali ekhiqiziwe ifakwa kusidlulisi se-optical, okuyi-converter yemidiya futhi edlulisela iziteshi zethu endaweni yokubona kubude begagasi bethelevishini bendabuko obungu-1550 nm.
I-Optical Transmitter.
Inethiwekhi yokusabalalisa isiqu
Isignali yokubona etholwe kusihloko ikhuliswa kusetshenziswa i-optical erbium amplifier (EDFA), ejwayeleke kunoma yimuphi uchwepheshe wezokuxhumana.
Amashumi ambalwa we-dBm weleveli yesiginali ethathwe kokuphumayo kweamplifier angakwazi ukuhlukaniswa futhi athunyelwe ezindaweni ezihlukene. Ukuhlukaniswa kwenziwa ngabahlukanisi abangenzi lutho, ukuze kube lula, babekwe ezindlini ze-rack-mount cross-connects.
Isihlukanisi se-Optical ngaphakathi kweyunithi eyodwa ye-optical cross-connect.
Isignali ehlukanisiwe ifinyelela ezintweni lapho, uma kunesidingo, ingakhuliswa kusetshenziswa ama-amplifiers afanayo, noma ihlukaniswe phakathi kwezinye izinto zokusebenza.
Yile ndlela i-node yendawo yokuhlala engase ibukeke ngayo. Kuhlanganisa i-amplifier optical, isihlukanisi sesignali endlini ye-rackmount, kanye nokusabalalisa kokusabalalisa optical, lapho imicu isakazwa khona kubamukeli be-optical.
Inethiwekhi yokusabalalisa yababhalisile
Abamukeli be-Optical, njenge-transmitter, bangabaguquli abaphakathi: badlulisela isignali ye-optical eyamukelwe kukhebula le-coaxial. Ama-OP afika ngezinhlobo ezahlukene futhi avela kubakhiqizi abahlukene, kodwa ukusebenza kwawo kuvame ukufana: ukuqapha izinga kanye nokulungiswa kwesignali okuyisisekelo, engizoxoxa ngakho ngokuningiliziwe ezihlokweni ezilandelayo.
Izamukeli ezibonakalayo ezisetshenziswa kunethiwekhi yethu.
Ngokuya ngokwakhiwa kwezindlu (inombolo yaphansi, inani lezakhiwo neminyango yangaphambili, njll.), isamukeli se-optical singatholakala ekuqaleni kwesikhuphukeli ngasinye, noma mhlawumbe esisodwa kwezimbalwa (ngezinye izikhathi ngisho naphakathi kwezakhiwo akukho optical, kodwa ikhebula le-coaxial elibekwe), kulokhu, ukuncishiswa okungenakugwemeka kumahlukanisi kanye nemigwaqo emikhulu kunxeshezelwa ngama-amplifiers. Njengalokhu, isibonelo:
Isikhulisi sesignali se-CATV i-Teleste CXE180RF
Inethiwekhi yokusabalalisa yababhalisile yakhelwe ezinhlotsheni ezahlukene zekhebula eliqinile kanye nezihlukanisi ezihlukahlukene, ongazibona kuphaneli yamanje ephansi ezitebhisini zakho.
Amakhebuli angena efulethini axhunywe kokuphumayo kwama-splitter ababhalisi.
Yiqiniso, ezimweni eziningi, kukhona amathelevishini amaningana efulethini ngalinye futhi axhunywe ngokusebenzisa izihlukanisi ezengeziwe, ezibuye zethule ukuthunjwa. Ngakho-ke, kwezinye izimo (uma kukhona amathelevishini amaningi efulethini elikhulu), kuyadingeka ukufaka ama-amplifiers engeziwe efulethini, okuyizinto ezincane futhi ezibuthakathaka kuneziyinhloko ngalezi zinhloso.
Source: www.habr.com