Molo Habr.
Kwiminyaka yakutshanje, ukungeniswa komgangatho werediyo wedijithali iDAB + kuxoxwe ngayo eRashiya, eUkraine naseBelarus. Kwaye ukuba eRashiya inkqubo ayikaqhubeki, ngoko e-Ukraine naseBelarus kubonakala ngathi sele betshintshele ekuvavanyeni ukusasazwa.
Isebenza njani, ziziphi iingenelo kunye nokubi, kwaye iyimfuneko kwaphela? Iinkcukacha phantsi kokusikwa.
Te knoloji
Umbono wonomathotholo wedijithali waqala ukuvela ngasekupheleni kweminyaka engama-80, xa kwacaca ukuba akusekho “ndawo” yaneleyo kwiqela le-FM eliqhelekileyo kuye wonke umntu-kwizixeko ezikhulu imbonakalo yasimahla kuluhlu lwe-88-108 MHz. uphelelwe ngamandla. Kulo mba, i-DAB yathathwa njengenye indlela elungileyo - ngumgangatho wedijithali apho, ngenxa yekhowudi esebenzayo ngakumbi, izikhululo ezininzi zinokufakwa. Inguqulelo yokuqala yeDAB isebenzise iMP2 codec, inguqulelo yesibini (DAB +) isebenzise iHE-AAC entsha. Umgangatho ngokwawo umdala ngokwemigangatho yangoku-isikhululo sokuqala seDAB esasungulwa ngo-1995, kunye nesikhululo seDAB+ ngo-2007. Ngaphezu koko, "ubudala" bomgangatho kule meko bungaphezulu kwe-plus kune-minus - ngoku akukho ngxaki yokuthenga umamkeli werediyo kuyo yonke incasa kunye nohlahlo lwabiwo-mali.
Kukho umahluko phakathi kweDAB kunye neFM eqhelekileyo. Kwaye inqaku alikho nokuba enye "yidijithali" kwaye enye "yi-analog". Umgaqo wokudluliselwa komxholo ngokwawo uhlukile. Kwi-FM, isikhululo ngasinye sisasaza ngokuzimeleyo, kwaye kwi-DAB +, zonke izikhululo zidityanisiwe zibe "multiplex", nganye yazo inokuba nezikhululo ezili-16. Iitshaneli zamaza ohlukeneyo ziyabonelelwa ukuze amazwe awohlukeneyo akwazi ukukhetha lawo asimahla kwezinye iinkonzo.
Ukusuka kwindawo yokujonga ishishini, lo mahluko ubangela inani leengxabano phakathi kwabasasazi malunga nendlela yokusasaza kwi-multiplex. Ngaphambili, abasasazo ngokwabo bafumana ilayisenisi ye-frequency, bathenga i-antenna kunye ne-transmitter, ngoku ilayisenisi iya kukhutshwa kumqhubi we-multiplex, kwaye uya kuqesha iziteshi kwizikhululo zerediyo. Kunzima ukutsho ukuba kungcono okanye kubi, kwabanye kulungele ukuba nayo yonke into yabo, kwabanye kulungele ukurenta.
Ngendlela, kulo mba, i-DAB inobunzima obukhulu kunye nenkalipho kumphulaphuli - ixabiso lerenti ye-multiplex ixhomekeke kwi-bitrate. Kwaye ukuba ukhetha phakathi kwe-192 kunye ne-64kbps ... Ndicinga ukuba wonke umntu uyayiqonda into eya kunyulwa. Ukuba kwi-FM kunzima kakhulu ukusasaza ngomgangatho ophantsi, ke kwi-DAB oku kuyakhuthazwa nakwezoqoqosho (kucacile ukuba oku akusiyo impazamo yabaphuhlisi bomgangatho, kodwa kunjalo). Amaxabiso aseRashiya, ngokuqinisekileyo, awaziwa, kodwa amaxabiso esiNgesi, njengomzekelo, anokufumaneka .
Ukusuka kumbono wezobugcisa, i-DAB + i-multiplex yisignali ye-broadband kunye nobubanzi be-spectrum malunga ne-1.5 MHz, ebonakala ngokucacileyo usebenzisa i-RTL-SDR receiver.
Inkcazo eneenkcukacha ngakumbi kwiPDF inokufunyanwa .
Imigangatho ekhuphisanayo
Ngokubanzi, akukho baninzi kubo. I-DAB + isetyenziswa eYurophu, umgangatho udumile e-USA , eIndiya balinga ngomgangatho , kodwa kunzima ukuchaza ukuba baphela njani.
Ikhadi liphelelwe lixesha (i-DRM nayo yavavanywa eRashiya, kodwa yashiywa), kodwa umbono jikelele unokuqondwa:
(umthombo )
Ngokungafaniyo ne-DAB, abaqulunqi bomgangatho we-HD Radio bathatha indlela eyahlukileyo - isignali yedijithali ibekwe ngokuthe ngqo ecaleni kwesignali ye-analogue, ivumela abasasazo ukuba basebenzise i-eriyali kunye neemasti zabo.
Nangona kunjalo, oku akusombululi ingxaki eyaqala yonke into - ingxaki yokunqongophala kweendawo zokubeka simahla kwi-spectrum. Kwaye ngokufanelekileyo ngokwejografi (kwaye mhlawumbi nezopolitiko), kumazwe angaphambili e-CIS, ukwamkelwa komgangatho waseYurophu kubonakala kunengqiqo ngaphezu kokusetyenziswa komgangatho waseMelika - kusekho ukhetho olukhulu lwempahla yaseYurophu kwaye kulula ukuthenga abamkeli. Bekusakhankanywa ngo-2011 , kodwa yonke into yafa (kwaye siyambulela uThixo, kuba umgangatho wayo wedijithali, ongahambelaniyo nantoni na, yeyona nto imbi kakhulu enokuyilelwa abaphulaphuli bakanomathotholo).
Ukuvavanywa
Ekugqibeleni masiqhubele phambili kwinxalenye ephathekayo, okt. ukuya kuvavanyo. I-DAB ayikasebenzi eRussia okwangoku, ke siya kusebenzisa ushicilelo lwe-SDR olusuka kwi-multiplex yesiDatshi. Abo basuka kwamanye amazwe nabo banokujoyina kwaye bandithumelele iirekhodi kwifomathi ye-IQ, ndiya kuziqhuba kwaye ndenze itafile yesishwankathelo.
Ungamamela njani iDAB? Ngokuba umgangatho wedijithali, unokuyichaza usebenzisa ikhompyutha kunye nomamkeli we-rtl-sdr. Kukho iinkqubo ezimbini - и , bobabini banokusebenza kunye ne-rtl-sdr.
kubonakala ngathi umsebenzi wekhosi yomfundi, kwaye umbhali ngokucacileyo akazange akhathazeke ngokuyila - iifonti azihambelani nokulawula, iifestile azilingani. Kodwa eyona nto ibalulekileyo kuthi kukuba ikuvumela ukuba ufunde kwaye ubhale iifayile ze-IQ.
Isekwi-beta, kodwa isebenza ngcono kwaye icacisa ngcono. Kukwakhona ukukhupha ulwazi oluninzi olongezelelweyo lokulungisa iimpazamo:
Kodwa welle.io ayikayazi indlela yokusebenza ngeefayile ze-iq, ke siya kusebenzisa iQt-dab.
Ukuvavanya, ndilayishe iifayile ze-3 kwi-cloud.mail.ru, nganye iqulethe ukurekhoda kwexesha elide le-DAB multiplex, ubungakanani befayile bu malunga ne-500 MB (obu bubukhulu beerekhodi ze-IQ ze-SDR kunye ne-2.4 MHz bandwidth). Ungavula iifayile kwi-Qt-dab, ikhonkco lokukhuphela elinikwe ngasentla.
Ifayile-1: DAB-8A.sdr — . I-Multiplex 8A isebenza ngokuphindaphindiweyo kwe-195.136 MHz kwaye iqulethe izikhululo ze-16. I-bitrate yazo zonke izitishi yi-64Kbps.
Ifayile-2: DAB-11A.sdr — . I-Multiplex 11A kwi-frequency ye-216.928 MHz. Iqulethe izikhululo ezi-6, ezine-bitrate ye-48, 48, 48, 48, 64 kunye ne-48KBps ngokulandelelanayo.
Ifayile-3: DAB-11C.sdr — . I-Multiplex 11C kwi-frequency ye-220.352 MHz nayo iqulethe izikhululo ze-16. I-bitrate yazo zonke izitishi ngokulandelelana kwazo: 80, 80, 80, 80, 56, 96, 80, 64, 56, 48, 64, 64, 64, 96, 80 kunye ne-64Kbps.
Njengoko ubona, akukho ngxaki ngenani lezikhululo, kodwa ingxaki enkulu yi-bitrate ephantsi. Ngokubhekiselele kumxholo ngokwawo, incasa iyahluka kwaye andizukuxoxa ngayo; abo banqwenelayo banokukhuphela iifayile kwaye baziphulaphule ngokwabo. Ayizizo zonke ii-multiplexes ezidweliswe kumangeno, kodwa ndiyathemba ukuba umbono jikelele ucacile.
ezifunyanisiweyo
Ukuba sithetha ngamathemba osasazo lukanomathotholo lwedijithali, maye, lusizi kakhulu. Inzuzo ephambili ye-DAB kukusetyenziswa ngokufanelekileyo kwe-spectrum, evumela ukuba izikhululo ezininzi zibekwe emoyeni. Kule nkalo, i-DAB + yenza ingqiqo kuphela kwezo zixeko apho kungekho ndawo yamahhala kwi-FM. KwiRashiya, oku mhlawumbi kuphela eMoscow naseSt. Petersburg; kuzo zonke ezinye izixeko azikho iingxaki ezinjalo.
Ngokuphathelele umgangatho wesandi, ngokobuchwepheshe, iDAB+ inokubonelela nge-bitrate ukuya kuthi ga kwi-192Kbps, eya kunika phantse isandi seHiFi. Ngokwesiqhelo, njengoko sibona ngasentla, abasasazo bonga imali kwaye abaweli nebar ye-100Kbit / s. Kwii-multiplexes ezintathu, kwakukho enye kuphela (!) isikhululo sosasazo kwi-96Kbps (kwaye andinako ukubiza umculo wokusasaza ngo-48kbps nantoni na ngaphandle kokunyelisa - abasasazi abanjalo kufuneka bahluthwe imvume yabo;). Ke, yeha, sinokuthi nge-99% ngokuzithemba ukuba xa utshintshela kwi-FM ukuya kwi-DAB, umgangatho wesandi uya kuba kubi kakhulu kunokuba kwakunjalo. Ewe, mhlawumbi kwamanye amazwe imeko ingcono, kodwa umzekelo, nalu uphononongo lwesiNgesi kwiYouTube enesihloko esicacileyo. . Ngokobuchwephesha, iDAB ilungile kwaye akukho zikhalazo ngayo, kodwa ngokwezoqoqosho, “imali yoyisa ububi.”
Ukubuyela eRussia, ngaba kufanelekile ukukhathazwa kwaye uqalise ukusasaza kwiDAB? Ngokombono wodumo lwamazwe ngamazwe, mhlawumbi ewe, ukuze ungabonakali njengelizwe lesithathu elibuyela ngasemva emehlweni abamelwane balo, kwaye njengebhonasi, ukuze iimoto kunye noonomathotholo abathengwe eYurophu banokufumana ngokupheleleyo zonke izikhululo. Kodwa ngokombono wabaphulaphuli kunye nomgangatho wesandi, kunokwenzeka ukuba, abasebenzisi abayi kufumana naziphi na izibonelelo nokuba kumgangatho wesandi okanye kumgangatho womxholo.
Ukuba sicinga ngamathemba exesha elide, ngoko mhlawumbi kwixesha elizayo umamkeli werediyo uya kuba sisixhobo esinekhadi elihlanganisiweyo le-e-sim kunye nokubhaliselwa kumculo weYandex Spotify okanye Apple Music xa kuthengwa. Ikamva ngokucacileyo leleenkonzo zokusasaza kunye nomxholo owenziwe ngumntu. Kuya kwenzeka njani oku, siza kubona, ixesha liya kuxela.
umthombo: www.habr.com