Hamwe nogutezimbere imiyoboro yitumanaho igana umurongo mugari no kugenda, sisitemu ya optique ya fibre optique itumanaho (ROF) ihuza itumanaho rya fibre optique hamwe n’itumanaho ridafite insinga, bigatanga umukino wuzuye kubyiza byumuyoboro mugari no kurwanya kwivanga kumurongo wa fibre optique, ndetse no gutumanaho bidafite umugozi. .Ibintu byoroshye kandi byoroshye byujuje ibyifuzo byabantu mugari.Ikoranabuhanga rya mbere rya ROF ryari ryibanze cyane cyane mugutanga serivise zoherejwe na terefone nyinshi, nka milimetero ya optique fibre.Hamwe niterambere no gukura kwikoranabuhanga rya ROF, abantu batangiye kwiga imiyoboro ya Hybrid insinga nogukwirakwiza insinga, ni ukuvuga sisitemu ya optique fibre itumanaho (ROF) itanga serivisi zinsinga kandi zidafite umugozi icyarimwe.Hamwe niterambere ryihuse ryitumanaho rya radio, ibura ryumutungo wa spekure ryarushijeho kugaragara.Nigute ushobora kunoza imikoreshereze yumurongo mugihe cyumutungo muke utagikoreshwa kugirango ugabanye itandukaniro riri hagati yo gutanga no gukenera ibikoresho bya spekiteri byabaye ikibazo gikemurwa murwego rwitumanaho.Radiyo yo kumenya (CR) nubuhanga bwo kugabana ibintu byubwenge.Irashobora kunoza neza imikoreshereze yumutungo wa spécran binyuze muri "ikoreshwa rya kabiri" ryemewe ryemewe, kandi ryabaye ahantu h’ubushakashatsi mubijyanye n'itumanaho.Muri 802.11 umuyoboro w’akarere utagira umugozi [1], umuyoboro w’akarere ka 802.16 [2] na 3G itumanaho rya terefone igendanwa [3] batangiye kwiga ikoreshwa rya tekinoroji ya radiyo yubwenge kugirango bongere ubushobozi bwa sisitemu, batangira kwiga kubishyira mu bikorwa Ikoranabuhanga rya ROF kugirango rigere ku kuvanga ibimenyetso bitandukanye byubucuruzi [4].Imiyoboro ya radiyo ishingiye kuri optique fibre itumanaho itumanaho itanga insinga kandi zidafite insinga niterambere ryiterambere ryitumanaho.Sisitemu yo gukwirakwiza imiyoboro ya ROF ishingiye ku buhanga bwa radiyo ikorana buhanga ihura n’ibibazo byinshi bishya, nk'ibishushanyo mbonera by'imiterere y'urusobekerane, igishushanyo mbonera cya porotokoro, ibisekuruza by'insinga zidafite insinga kandi zidafite insinga zishingiye kuri serivisi nyinshi, gucunga imiyoboro, no kumenya ibimenyetso byahinduwe.
1 Ikoranabuhanga rya radio
Radiyo yo kumenya ni inzira nziza yo gukemura ikibazo cyo kubura ibiyobya bwenge no kudakoreshwa neza.Radiyo yo kumenya ni sisitemu yo gutumanaho idafite ubwenge.Yumva imikoreshereze yimiterere yibidukikije kandi igahindura ibipimo byayo mu buryo bworoshye binyuze mu kwiga kugirango igere ku mikoreshereze inoze.Ibikoresho bya Spectrum hamwe n'itumanaho ryizewe.Ikoreshwa rya radio yubwenge nubuhanga bwingenzi kugirango tumenye ibintu bituruka kumurongo wagenwe kugeza kugabanwa imbaraga.Muri sisitemu yo kumenya amaradiyo, kugirango urinde umukoresha wemerewe (cyangwa kuba umukoresha mukuru) kutivanga kumukoresha wumucakara (cyangwa umukoresha CR), umurimo wo kumva ibintu ni ukumenya niba umukoresha wemewe abaho.Abakoresha radio bamenyekana barashobora gukoresha by'agateganyo umurongo wa radiyo mugihe hagenzuwe ko umurongo wumurongo ukoreshwa numukoresha wemerewe udakoreshwa.Iyo hagenzuwe ko umurongo wumurongo wumukoresha wemewe urimo gukoreshwa, umukoresha CR arekura umuyoboro kubakoresha babiherewe uburenganzira, bityo ukemeza ko umukoresha CR atabangamira umukoresha wemerewe.Kubwibyo, umuyoboro wogukoresha itumanaho udafite imiyoboro ifite ibintu byingenzi bikurikira: (1) Umukoresha wibanze afite icyifuzo cyambere cyo kugera kumuyoboro.Ku ruhande rumwe, iyo umukoresha wemerewe adafite umuyoboro, umukoresha wa kabiri afite amahirwe yo kugera kumuyoboro udafite akamaro;mugihe umukoresha wibanze yongeye kugaragara, umukoresha wa kabiri agomba kuva kumuyoboro mukoresha mugihe hanyuma agasubiza umuyoboro kumukoresha wibanze.Ku rundi ruhande, iyo umukoresha mukuru afite umuyoboro, umukoresha arashobora kugera kumuyoboro bitagize ingaruka kumiterere ya serivise yumukoresha.(2) Itumanaho rya CR itumanaho rifite imirimo yo kwiyumvisha, kuyobora no guhindura.Ubwa mbere, itumanaho rya CR rishobora gutahura imirongo yumurongo hamwe numuyoboro wibidukikije mubikorwa byakazi, kandi bikagena kugabana no kugabura umutungo wa spekure ukurikije amategeko amwe ukurikije ibisubizo byagaragaye;kurundi ruhande, itumanaho rya CR rifite ubushobozi bwo guhindura ibipimo byakazi kumurongo, nko guhindura ibipimo byoherejwe nkinshuro zitwara abantu nuburyo bwo guhindura ibintu bishobora guhuza nimpinduka mubidukikije.Mumuyoboro woguhuza imiyoboro itumanaho, sensing sensing ni tekinoroji yingenzi.Ibisanzwe bikoreshwa muburyo bwo kumva algorithms zirimo imbaraga zo kumenya ingufu, guhuza filteri ihuye, hamwe nuburyo bwo kwerekana ibimenyetso bya cyclostationary.Ubu buryo bufite ibyiza byabwo nibibi.Imikorere yiyi algorithm biterwa namakuru yabanje kuboneka.Ibiriho byerekana sensiborithm ni: guhuza filtri, gushakisha ingufu hamwe nuburyo bwo kumenya ibintu.Akayunguruzo gahuye gashobora gukoreshwa gusa mugihe ikimenyetso nyamukuru kizwi.Ikimenyetso cyingufu zirashobora gukoreshwa mubihe ibimenyetso nyamukuru bitazwi, ariko imikorere yabyo igenda yangirika mugihe hakoreshejwe igihe gito cyo kumva.Kuberako igitekerezo nyamukuru cyibintu byerekana ni ugukoresha cyclostationarite yikimenyetso kugirango tumenye binyuze mumikorere ifitanye isano.Urusaku ni ikimenyetso cyagutse kandi ntaho gihuriye, mugihe ibimenyetso byahinduwe bifitanye isano na cyclostationary.Kubwibyo, imikorere yibikorwa irashobora gutandukanya imbaraga zurusaku nimbaraga za signal yahinduwe.Mubidukikije bifite urusaku rutazwi, imikorere yikimenyetso kiranga icyiza kuruta icyuma gipima ingufu.Imikorere yibiranga disiketi munsi yikimenyetso gito-cy-urusaku ntarengwa, ifite kubara cyane, kandi bisaba igihe kirekire cyo kwitegereza.Ibi bigabanya amakuru yinjira muri sisitemu ya CR.Hamwe niterambere ryikoranabuhanga ryitumanaho ryitumanaho, ibikoresho bya sprifike bigenda birushaho kuba bibi.Kubera ko ikoranabuhanga rya CR rishobora kugabanya iki kibazo, tekinoroji ya CR yitaye ku miyoboro y’itumanaho ridafite insinga, kandi amahame menshi y’itumanaho ridafite insinga yatangije ikoranabuhanga rya radiyo.Nka IEEE 802.11, IEEE 802.22 na IEEE 802.16h.Mu masezerano ya 802.16h, hari ibintu byingenzi byo gutoranya ibintu byoroheje kugirango byorohereze WiMAX gukoresha imirongo ya radiyo na tereviziyo, kandi ishingiro ryayo ni tekinoroji yo kumva.Muri IEEE 802.11h mpuzamahanga mpuzamahanga kumurongo waho utagira umugozi, hashyizweho ibitekerezo bibiri byingenzi: guhitamo imbaraga za sprifike (DFS) no kohereza amashanyarazi (TPC), kandi radio yubwenge yakoreshejwe kumiyoboro yabantu idafite umugozi.Muburyo bwa 802.11y, tekinoroji ya orthogonal frequency multiplexing (OFDM) ikoreshwa mugutanga uburyo butandukanye bwumurongo mugari, ushobora kugera kumurongo wihuse.Sisitemu ya WLAN (idafite aho ihuriye numuyoboro) irashobora kwifashisha ibiranga OFDM kugirango wirinde kwirinda muguhindura umurongo no kohereza ibipimo byingufu.Wivange nabandi bakoresha bakora muriyi bande ya frequency.Kuberako optique ya fibre optique ifite ibyiza byo guhuza itumanaho rya fibre optique hamwe nibiranga ibintu byoroshye guhuza itumanaho, byakoreshejwe cyane.Mu myaka yashize, ihererekanyabubasha rya radiyo yerekana ibimenyetso bya WLAN muri fibre optique yakwegereye abantu.Umwanditsi w'ibitabo [5-6] yasabye ko sisitemu ya ROF Ibimenyetso bya radiyo ya Cognitive itangwa munsi yubwubatsi, kandi ubushakashatsi bwikigereranyo bwerekana ko imikorere y'urusobe rwateye imbere.
2 ROF ishingiye kuri Hybrid optique fibre idafite imiyoboro ya sisitemu yububiko
Kugirango uhuze ibikenerwa na serivise zitandukanye zo kohereza amashusho, fibre igaragara-murugo (FFTH) izahinduka ikoranabuhanga ryogukwirakwiza umurongo mugari, kandi umuyoboro wa optique (PON) wabaye intumbero yibitekerezo bimaze kuza hanze.Kubera ko ibikoresho bikoreshwa murusobe rwa PON ari ibikoresho byoroshye, ntibikeneye gutanga amashanyarazi, birashobora gukingirwa ingaruka ziterwa na electromagnetic yivanga n’umurabyo, bishobora kugera ku itumanaho rya serivisi mu mucyo, kandi bifite sisitemu yo hejuru yizewe.Imiyoboro ya PON ikubiyemo cyane cyane kugabana umwanya kugwiza imiyoboro ya optique (TDM-PON) hamwe no kugabana umurongo wikurikiranya kugwiza imiyoboro ya optique (WDM-PON).Ugereranije na TDM-PON, WDM-PON ifite ibiranga abakoresha umurongo mugari n'umutekano mwinshi, bigahinduka umuyoboro mwiza wa optique mugihe kizaza.Igishushanyo 1 kirerekana igishushanyo mbonera cya sisitemu ya WDM-PON.