Meteor M1 satellite
Kunobva: vladtime.ru
Nhanganyaya
Kushanda kwehunyanzvi hwemuchadenga hakugoneki pasina kutaurirana neredhiyo, uye muchinyorwa chino ndichaedza kutsanangura pfungwa huru dzakaumba hwaro hwezviyero zvakagadziridzwa neInternational Advisory Committee yeSpace Data Systems (CCSDS. Ichi chipfupiso chichashandiswa pazasi) .
Iyi posvo inozonyanya kutarisisa pane data link layer, asi mafundo ekutanga emamwe mazinga achaunzwa zvakare. Ichi chinyorwa hachirevi kuti itsananguro yakakwana uye yakazara yezviyero. Unogona kuiona pa CCSDS. Zvisinei, ivo vakaoma zvikuru kunzwisisa, uye takapedza nguva yakawanda tichiedza kuvanzwisisa, saka pano ndinoda kupa ruzivo rwekutanga, kuva narwo izvo zvichava nyore zvikuru kunzwisisa zvimwe zvose. Saka, ngatitange.
Noble Mission yeCCSDS
Zvichida mumwe munhu ane mubvunzo: sei munhu wese achifanira kutevedzera zviyero kana iwe uchikwanisa kugadzira yako wega redhiyo protocol stack (kana yako wega chiyero, ine blackjack uye zvitsva maficha), nekudaro uchiwedzera kuchengetedzeka kwehurongwa?
Sezvinoratidzwa nemaitiro, zvinobatsira zvakanyanya kuomerera kune CCSDS zviyero nekuda kwehuwandu hunotevera hwezvikonzero:
- Dare rinoona nezvekushambadza zviyero rinosanganisira vamiriri kubva kune ese makuru makuru ezvemuchadenga munyika, achiunza ruzivo rwakakosha rwakawanikwa mumakore mazhinji ekugadzira nekushanda kwemamishini akasiyana. Zvingave zvisina musoro kufuratira chiitiko ichi uye kutsika pareki yavo zvakare.
- Aya zviyero zvinotsigirwa nemidziyo yepasi station yatove pamusika.
- Paunenge uchigadzirisa chero matambudziko, unogona kugara uchitsvaga rubatsiro kubva kune vamwe vaunoshanda navo kubva kune mamwe masangano kuti vakwanise kuita musangano wekutaurirana nemudziyo kubva pachiteshi chavo chepasi. Sezvauri kuona, zviyero chinhu chinobatsira zvakanyanya, saka ngatitarisei iwo akakosha mapoinzi.
akitekicha
Miyero iyi seti yemagwaro anoratidza iyo yakajairika OSI (Open System Interconnection) modhi, kunze kwekuti padanho rekubatanidza data kuwirirana kunogumira pakukamurwa kuita telemetry (downlink - space - Earth) uye telecommands (uplink).
Ngatitarisei mamwe mazinga mune zvakadzama, kutanga nemuviri uye nekukwira kumusoro. Kuti zvive nekujekesa kukuru, tichatarisa mavakirwo edivi rekugamuchira. Iyo inotumira iyo mufananidzo wayo wegirazi.
Physical layer
Panhanho iyi, iyo modulated redhiyo chiratidzo inoshandurwa kuita karukova. Izvo zviyero pano zvinonyanya kuraira mune zvisikwa, sezvo padanho iri zvakaoma kubvisa kubva kune chaiyo kuitiswa kwehardware. Pano, basa rinokosha reCCSDS nderekutsanangura zvinogamuchirwa modulations (BPSK, QPSK, 8-QAM, nezvimwewo) uye kupa mamwe mazano pamusoro pekushandiswa kwemaitiro ekuenzanisa zviratidzo, Doppler muripo, nezvimwewo.
Synchronization uye encoding level
Pakare, iyo sublayer ye data link layer, asi inowanzo patsanurwa kuita yakaparadzana layer nekuda kwekukosha kwayo mukati meCCSDS zviyero. Iyi nhanho inoshandura karukova kuita anodaidzwa kuti mafuremu (telemetry kana telecommands), yatichataura nezvayo gare gare. Kusiyana nechiratidzo chekuenzanisa pane yemuviri layer, iyo inokutendera iwe kuti uwane iyo chaiyo bit rwizi, furemu kuwiriranisa kunoitwa pano. Funga nezve nzira iyo data inotora padanho iri (kubva pasi kusvika kumusoro):
Zvisinei, izvi zvisati zvaitika, zvakakodzera kutaura mazwi mashomanana pamusoro pekodhi. Maitiro aya anodiwa kuti uwane uye/kana kugadzirisa zvikanganiso zvidiki zvinongoitika kana uchitumira data pamusoro peredhiyo chiteshi. Pano isu hatizotarise maitiro ekudhirodha, asi tinongowana ruzivo rwunodiwa kuti unzwisise imwe pfungwa yezinga.
Macode anogona kuvharika kana kuenderera. Izvo zviyero hazvimanikidze kushandiswa kweimwe mhando ye encoding, asi inofanirwa kuve iripo saizvozvo. Continuous codes zvinosanganisira convolutional codes. Ivo vanoshandiswa encode inoenderera bit stream. Izvi zvakasiyana nemakodhi evhavha, uko data rakakamurwa kuita macodeblocks uye rinogona kungogadziriswa mukati mezvivharo zvakakwana. Iyo kodhi kodhi inomiririra data rakafambiswa uye iyo yakasungirirwa isina ruzivo rwakakosha kuti uone kurongeka kweiyo data yakagamuchirwa uye kugadzirisa zvikanganiso zvinogona kuitika. Makodhi makodhi anosanganisira anozivikanwa Reed-Solomon makodhi.
Kana convolutional encoding ikashandiswa, bitstream inopinda mudhikodha kubva pakutanga. Mhedzisiro yebasa rayo (zvese izvi, zvechokwadi, zvinoitika nguva dzose) ndeye CADU (chiteshi chekuwana data unit) data blocks. Ichi chimiro chinodiwa kuti furemu synchronization. Pakupera kweCADU yega yega pane yakanamatira synch maker (ASM). Aya ndiwo 4 bytes anozivikanwa mberi, iyo iyo synchronizer inowana kutanga uye kupera kweCADU. Iyi ndiyo nzira iyo furemu synchronization inowanikwa.
Iyo inotevera yekusarudzika nhanho yekuwiriranisa uye encoding layer inosanganiswa nezvakasiyana zvemuviri layer. Izvi zvinonzi derandomization. Icho chokwadi ndechekuti kuti uwane kuwiriranisa kwechiratidzo, kugara uchichinja pakati pezviratidzo kunodiwa. Saka, kana tikatumira, toti, kilobyte yedata rine yese, kuwiriranisa kucharasika. Naizvozvo, panguva yekufambisa, data rekuisa rinosanganiswa ne periodic pseudo-random sequence kuitira kuti density ye zero uye imwe ive yakafanana.
Tevere, iyo block kodhi inogadziriswa, uye chinosara ndicho chigadzirwa chekupedzisira chekuyananisa uye encoding level - furemu.
Data Link Layer
Kune rimwe divi, iyo yekubatanidza layer processor inogamuchira mafuremu, uye kune rimwe divi inoburitsa mapaketi. Sezvo hukuru hwemapaketi husina kuganhurirwa zviri pamutemo, nekuda kwekutapurirana kwavo kwakavimbika zvinodikanwa kuaputsa kuita zvimiro zvidiki - mafuremu. Pano tichatarisa zvikamu zviviri: zvakasiyana zve telemetry (TM) uye telecommands (TC).
Telemetry
Zvichitaurwa zviri nyore, iyi ndiyo data iyo chiteshi chepasi chinogashira kubva muchadenga. Ruzivo rwese rwunofambiswa rwakakamurwa kuita zvidimbu zvidiki zvehurefu hwakatarwa - mafuremu ane data rakafambiswa uye masevhisi minda. Ngatitarisei zvakanyanya pane chimiro chefuremu:
Uye ngatitange kufunga kwedu nemusoro mukuru weiyo telemetry furemu. Uyezve, ini ndichazvibvumira kuti ndingo shandura zviyero mune dzimwe nzvimbo, ndichipa imwe tsananguro munzira.
Iyo Master Channel ID ndima inofanirwa kunge iine iyo furemu vhezheni nhamba uye mudziyo wechiratidzo.
Imwe neimwe spacecraft, zvinoenderana neCCDSS miyero, inofanirwa kuve neyayo yakasarudzika identifier, iyo, ine furemu, munhu anogona kuona kuti ndeipi mudziyo. Zviri pamutemo, zvinodikanwa kuendesa chikumbiro chekunyoresa chishandiso, uye zita racho, pamwe nechiziviso chayo, zvichaburitswa munzvimbo dzakavhurika. Nekudaro, vagadziri veRussia vanowanzo furatira maitiro aya, vachipa chiziviso chinopokana kune mudziyo. Iyo furemu vhezheni nhamba inobatsira kuona kuti ndeipi vhezheni yezviyero inoshandiswa kuitira kunyatsoverenga furemu. Pano isu tichatarisa chete yakanyanya kuchengetedza mwero neshanduro "0".
Iyo Virtual Channel ID munda inofanira kunge iine VCID yechiteshi kwakabva pakiti. Iko hakuna zvirambidzo pasarudzo yeVCID; kunyanya, chaiwo chiteshi haafanirwe kuverengerwa sequentially.
Kazhinji kazhinji pane kudiwa kwekuwandisa data inotumirwa. Nekuda kweichi chinangwa, pane nzira yemachaneti chaiwo. Semuyenzaniso, iyo Meteor-M2 setiraiti inotamisa mufananidzo weruvara munzvimbo inooneka, ichikamura kuita matatu matema uye machena - rumwe ruvara runofambiswa mune yarwo chaiyo chiteshi mupaketi yakaparadzana, kunyangwe paine kumwe kutsauka kubva kumazinga ari mukati. maumbirwo emapuranga ayo.
Iyo Operational Control mureza ndima ichave chiratidzo chekuvapo kana kusavapo kweiyo Operational Control ndima mune telemetry furemu. Aya mabhayiti mana pakupera kwefuremu anoshanda kuti ape mhinduro kana achidzora kuendeswa kwenharembozha. Tichazotaura nezvavo zvishoma gare gare.
Iwo makuru uye chaiwo chiteshi dhizaini minda inowedzerwa neimwe nguva imwe neimwe furemu inotumirwa. Shumira sechiratidzo chekuti hapana kana furemu imwe yakarasika.
Iyo telemetry furemu data chimiro ndeye mamwe maviri mabyte emureza uye data, yatichatarisa mashoma.
Iyo Sekondari Header mureza ndima inofanirwa kunge iri chiratidzo chekuvapo kana kusavapo kweSekondari Header mune telemetry furemu.
Kana uchida, iwe unogona kuwedzera imwe musoro kune yega yega furemu uye woisa chero data ipapo pakufunga kwako.
Yekutanga Musoro Inonongedzera ndima, kana mureza wekuwiriranisa waiswa ku "1", uchange uine bhinari inomiririra yenzvimbo yekutanga octet yePaketi yekutanga muData Field yetelemetry furemu. Nzvimbo yacho inoverengwa kubva ku0 mukukwira kurongeka kubva pakutanga kwedata data. Kana pasina kutanga kwepakiti mumunda we data ye telemetry furemu, ipapo chinongedzo kumunda wekutanga wemusoro unofanirwa kuve nehukoshi mukumiririra kwebhinari "11111111111" (izvi zvinogona kuitika kana imwe refu packet yakapararira pamusoro peinopfuura furemu imwe. )
Kana iyo data data iine packet isina chinhu (Idle Data), ipapo chinongedzo kumusoro wekutanga chinofanira kuve neukoshi mukumiririra kwebhinari "11111111110". Uchishandisa iyi ndima, mugamuchiri anofanira kuwiriranisa rukova. Iyi ndima inovimbisa kuti kuwiriranisa kunodzoserwa kunyangwe mafuremu akadonhedzwa.
Ndiko kuti, packet inogona, toti, kutanga pakati pechina yefuremu uye kupera pakutanga kwemakumi maviri. Munda uyu unoshandiswa kutsvaga matangiro awo. Mapaketi anewo musoro unotsanangura hurefu hwayo, saka kana chinongedzo kumusoro wekutanga chawanikwa, chinongedzo-layer processor chinofanira kuiverenga, nekudaro ichiona kuti pakiti ichaguma kupi.
Kana nzvimbo yekudzora kukanganisa iripo, inofanirwa kunge iri mune yega telemetry furemu yeimwe nzira yemuviri mukati memishoni.
Iyi ndima inoverengerwa uchishandisa nzira yeCRC. Iyo nzira inofanirwa kutora n-16 bits ye telemetry furemu uye isa mhedzisiro yekuverenga mukupedzisira 16 bits.
Zvikwata zveTV
Iyo TV yekuraira furemu ine akati wandei akakosha misiyano. Pakati pavo:
- Yakasiyana musoro chimiro
- Dynamic urefu. Izvi zvinoreva kuti kureba kwefuremu hakuna kugadzikwa zvakasimba, sezvinoitwa mu telemetry, asi inogona kusiyana zvichienderana nemapaketi anotapurirwa.
- Packet delivery guarantee mechanism. Ndiko kuti, spacecraft inofanira, mushure mekuigamuchira, kusimbisa kurongeka kwekugamuchira furemu, kana kukumbira kutumirwa kubva kune furemu yaigona kunge yakagamuchirwa nekukanganisa kusingagadziriswe.
Minda mizhinji yatove kujaira kwatiri kubva kune telemetry furemu musoro. Vane chinangwa chimwe chete, saka pano tichatarisa chete minda mitsva.
Imwe diki yebypass mureza inofanirwa kushandiswa kudzora furemu yekutarisa kune inogamuchira. Hukoshi hwe "0" pamureza uyu hucharatidza kuti furemu iyi ndeye Type A furemu uye inofanira kuongororwa maererano neFARM. Kukosha kwe "1" pamureza uyu kunofanira kuratidza kumugamuchiri kuti furemu iyi ndeye Type B furemu uye inofanira kudarika kutarisa kweFARM.
Mureza uyu unozivisa mugamuchiri kana oshandisa furemu yekubvuma nzira inonzi FARM - Frame Acceptance and Reporting Mechanism.
Iyo control command mureza inofanirwa kushandiswa kunzwisisa kana iyo data data inotakura murairo kana data. Kana mureza uri "0", ipapo nzvimbo yedata inofanira kunge iine data. Kana mureza uri "1", ipapo nzvimbo yedata inofanira kunge iine ruzivo rwekutonga kweFARM.
FARM muchina une finite state une maparameter anogona kugadzirwa.
RSVD. SPARE β reserved bits.
Zvinoita sekuti CCSDS ine zvirongwa kwavari mune ramangwana, uye zvekudzokera kumashure kweshanduro dzeprotocol vakachengeta mabhiti aya atove mushanduro dzazvino dzechiyero.
Hurefu hweforemu hurefu hunofanirwa kuve nenhamba in bit inomiririra yakaenzana nehurefu hwefuremu mu octets kubvisa imwe.
Iyo furemu data munda inofanirwa kutevedzera musoro usina nzvimbo uye ine nhamba yakazara yeoctets, iyo inogona kunge inodarika 1019 octets pakureba. Iyi ndima inofanirwa kunge iine kana furemu data block kana control command ruzivo. Iyo furemu data block inofanira kunge ine:
- nhamba yakakwana ye data data octets
- segment header inoteverwa nenhamba yenhamba yedata data octets
Kana musoro uripo, saka data block inofanira kunge iine Packet, seti yePaketi, kana chikamu chePaketi. Iyo data block isina musoro haigone kuve nezvikamu zvePaketi, asi inogona kuve neyakavanzika fomati data block. Izvi zvinotevera kubva pane izvi kuti musoro unodiwa kana iyo yakatumirwa data block isingakwane mune imwe furemu. A block of data ine musoro inonzi segment
Iyo-two-bit mireza ndima inofanira kunge iine:
- "01" - kana chikamu chekutanga che data chiri mu data block
- "00" - kana chikamu chepakati che data chiri mu data block
- "10" - kana chikamu chekupedzisira che data chiri muvharo re data
- "11" - kana pasina kupatsanurwa uye imwe kana mamwe mapaketi anokodzera zvakakwana muvharo re data.
Iyo MAP ID ndima inofanirwa kunge iine zero kana MAP nzira dzisina kushandiswa.
Dzimwe nguva 6 mabhiti akagoverwa kune chaiwo machani haana kukwana. Uye kana zvichidikanwa kuwanda data pahuwandu hukuru hwechiteshi, mamwe 6 mabhiti kubva kuchikamu chemusoro anoshandiswa.
purazi
Ngatitarisei zvakanyanya pamaitiro ekushanda kwevashandi vekudzora hurongwa. Iyi sisitimu inongopa chete kushanda nemafuremu emafoni nekuda kwekukosha kwawo (telemetry inogona kugara ichikumbirwa zvakare, uye spacecraft inofanirwa kunzwa chiteshi chepasi zvakajeka uye nguva dzose ichiteerera mirairo yayo). Saka, ngatitii isu tafunga kuvheneka satellite yedu, uye kutumira bhinari faira regumi kilobytes muhukuru kwairi. Padanho rekubatanidza, iyo faira yakakamurwa kuita gumi mafuremu (10, 10, ..., 0), ayo anotumirwa kumusoro rimwe nerimwe. Kana kutapurirana kwapera, satellite inofanirwa kusimbisa kurongeka kwepaketi yekugamuchira, kana kushuma pane furemu iyo kukanganisa kwakaitika. Ruzivo urwu rwunotumirwa kundima yekutonga yekushanda mune iri pedyo telemetry furemu (Kana kuti spacecraft inogona kutanga kutapurirana kwefuremu isina basa kana isina chekutaura). Kubva pane yakagamuchirwa telemetry, isu tinogona kuve nechokwadi chekuti zvese zvakanaka, kana isu tinoenderera mberi nekutumira meseji. Ngatifungei kuti setiraiti haina kunzwa furemu #1. Izvi zvinoreva kuti tinomutumira mafuremu 9, 7, 7. Kana pasina mhinduro, pakiti yose inotumirwa zvakare (uye zvakadaro kakawanda kusvikira taona kuti kuedza hakuna maturo).
Pazasi pane chimiro chebasa rekutonga rine tsananguro yemamwe minda. Iyo data iri mundima iyi inonzi CLCW - Kukurukurirana Link Kudzora Izwi.
Sezvo iwe uchigona kufungidzira zviri nyore kubva pamufananidzo chinangwa cheminda mikuru, uye mamwe ari kufinha kutarisa, ndiri kuvanza tsananguro yakadzama pasi pemuparadzi.
Tsanangudzo yeminda yeCLCWKudzora Rudzi rweMazwi:
Kune rudzi urwu, izwi rekutonga rinofanira kunge riine 0
Dzora Shoko Shanduro (CLCW Version Number):
Kune iyi mhando, izwi rekutonga rinofanira kuenzana ne "00" mune inomiririra bit.
Status Field:
Kushandiswa kwendima iyi kunotemerwa mishoni yega yega. Inogona kushandiswa kuvandudza kwenzvimbo neakasiyana masangano emuchadenga.
Virtual Channel Identification:
Inofanirwa kunge iine chiziviso cheiyo chaiyo chiteshi inobatanidzwa izwi rekutonga iri.
Mureza wekuwana chiteshi:
Mureza unofanirwa kupa ruzivo nezve kugadzirira kweiyo anogamuchira yemuviri layer. Kana iyo yemuviri dhizaini yeanogamuchira isati yagadzirira kugamuchira mafuremu, ipapo munda unofanirwa kunge uine "1", neimwe nzira "0".
Kukoniwa kwemureza
Mureza unogona kuratidza kuti chimiro chemuviri chiri kushanda pamwero wechiratidzo chisina kunaka uye huwandu hwemafuremu arambwa hwakanyanya. Kushandiswa kwendima iyi ndeyekusarudza; kana ikashandiswa, inofanira kunge iine "0" kana kuwiriranisa kuripo, uye "1" kana isiri.
Kuvharisa mureza
Ichi chidimbu chichava neFARM kukiya mamiriro kune yega yega chiteshi. Kukosha kwe "1" mundima iyi kunofanira kuratidza kuti FARM yakaremara uye mafuremu anoraswa pachikamu chega chega, kana zvisina kudaro "0".
Mirira mureza
Ichi chidimbu chichashandiswa kuratidza kuti anogamuchira haakwanise kugadzirisa data pane yakataurwa chaiyo chiteshi. Kukosha kwe "1" kunoratidza kuti mafuremu ese anoraswa pane iyi chiteshi, kana zvisina kudaro "0".
Forward Flag:
Mureza uyu uchange uine "1" kana furemu imwe kana akawanda emhando A akaraswa kana kuti maburi awanikwa, saka kutumira patsva kunodiwa. Mureza we "0" unoratidza kuti pakanga pasina mafuremu akadonha kana kusvetuka.
Kukosha kwemhinduro:
Frame number isina kutambirwa. Inotemerwa nekaunda mune telecommand furemu musoro
network layer
Ngatimbobatai padanho iri zvishoma. Pane sarudzo mbiri pano: ingave shandisa space packet protocol, kana encapsulate chero imwe protocol muCCDSS packet.
Kutarisisa kwenzvimbo yepakiti protocol inyaya yechinyorwa chakasiyana. Yakagadzirirwa kubvumira anonzi maapplication kuchinjanisa zvisina musono data. Imwe neimwe application ine kero yayo uye basa rekutanga rekuchinjanisa data nemamwe maapplication. Kune zvakare masevhisi anofambisa traffic, control delivery, nezvimwe.
Ne encapsulation zvese zviri nyore uye zvakajeka. Izvo zviyero zvinoita kuti zvikwanise kuvharidzira chero maprotocol mumapaketi eCCSDS nekuwedzera imwe musoro.
Iko musoro une zvirevo zvakasiyana zvichienderana nehurefu hweprotocol iri kuvharirwa:
Pano munda mukuru ndehurefu hwehurefu. Inogona kusiyana kubva ku0 kusvika ku4 bytes. Zvakare mumusoro uyu unofanirwa kuratidza mhando yeakavharidzirwa protocol uchishandisa tafura .
IP encapsulation inoshandisa imwe add-on kuona rudzi rwepakiti.
Iwe unofanirwa kuwedzera imwezve musoro, imwe octet kureba:
Iko PID imwe protocol identifier yakatorwa
mhedziso
Pakutanga kuona, zvingaite sekuti misoro yeCCSDS yakawandisa uye mamwe minda anogona kuraswa. Zvechokwadi, kushanda kweiyo inoguma chiteshi (kusvika kune network level) inenge 40%. Zvisinei, nokukurumidza kana pachidiwa kushandisa mitemo iyi, zvinova pachena kuti munda mumwe nomumwe, musoro wega wega une basa rayo rinokosha, kuregeredza izvo zvinotungamirira kuhuwandu hwekusanzwisisika.
Kana iyo habrasociety ikaratidza kufarira mumusoro uyu, ini ndichafara kuburitsa nhevedzano yezvinyorwa zvakapihwa kune dzidziso uye tsika yekutaurirana kwemuchadenga. Ndinokutendai nekuteerera kwenyu!
Sources
PS
Usarove zvakanyanya kana ukawana zvisizvo. Vaudze uye ivo vachagadziriswa :)
Source: www.habr.com