MC LCLI NI U3

CHNG I: TNG QUAN H THNG VSAT5Tnh nng5Nguyn l hot ng5

CHNG II: CC THNG S K THUT CA H THNG72.1. B ghp knh CX-200072.2. Antenna72.3. B nng tn (UP Converter)82.4. B h tn (Down Converter)92.5. B chuyn mch bo v LNA112.6. Modem UMOD 10PAK12

CHNG III: CU HNH V KHAI THC H THNG153.1. B ghp knh CX2000153.2. Cu hnh modem UMOD 10 PAK16

CHNG IV: BO DNG H THNG214.1. Nhim v ca nhn vin trc214.2. Cc thit b, dng c sa cha v vt t cn thit224.3. Cc bc tin hnh kim tra trc khi bo dng234.4. Lch trnh kim tra bo dng nh k234.4.1. Bo dng tun234.4.2. Bo dng thng244.4.3. Bo dng 6 thng244.4.4. Bo dng nm25

CHNG V: CCH KHC PHC CC S C THNG GP275.1. Cc n hin th trn h thng275.1.1. B ghp knh CX2000275.1.2. Khi nng tn (Up Converter)295.1.3. Khi h tn (Down Converter)305.1.4. Khi chuyn mch bo v LNA305.1.5. Khi NTU315.1.6. Khi MODEM UMOD 10 PAK325.2. Cch khc phc cc s c thng gp345.2.1. B ghp knh CX2000345.2.2. Modem UMOD 910035

KT LUN...............................................................................................38

TI LIU THAM KHO.......................................................................39

LI NI U

Cng vi s pht trin ca khoa hc k thut, s linh hot ca con ngi cng i hi mc cao hn v c bit l v tr a l ca Vit Nam ta hn 1/3 l i ni, do mng thng tin hu tuyn khng p ng ht cc nhu cu c trong thng mi v qun s. Cc h thng thng tin v tinh trm mt t VSAT ra i p ng nhu cu truyn d liu ca con ngi, cng nh p ng c dch v gi r trong thng mi. Vn ti nguyn tn s rt hn hp, nn vic cp pht knh tn s i hi phi c ti u khng lm nh hng n cc h thng khc, ng thi gim nhiu trong h thng. Mc khc, do h thng thng tin v tinh VSAT s dng trong mi trng truyn v tuyn c suy hao ng truyn ln, c bit l suy hao do ma, giao thoa (Interference) v cc loi nhiu khc (nh nhiu nhn to, nhiu cng nghip...) lm nh hng rt ln n cht lng ca h thng.

ti Tng quan v h thng thng tin v tinh VSAT vi mc ch gip mi ngi hiu c tng quan v h thng VSAT v qu trnh cu hnh h thng cng nh qu trnh bo dng v khc phc li pht sinh trong thc t.Ni dung chi tit bao gm:CHNG I: Tng quan v h thng VSAT.CHNG II: Cc thng s k thut ca h thng.CHNG III: Cu hnh v khai thc h thng.CHNG IV: Bo dng h thng.CHNG V: Cch khc phc cc s c thng gp.

Trong qu trnh hon thnh ti ny, mc d nhn c s gip tn tnh ca cc thy c trong khoa in T -Vin Thng v c bit l thy gio, TS. Nguyn c Thy nhng do cn hn ch v thi gian v kin thc nn khng th trnh khi nhng thiu st. Em rt mong c s gp chn thnh ca cc thy c.

H Ni, ngy 4 thng 7 nm 2013

CHNG ITNG QUAN H THNG VSAT

1.1.Tnh nngCung cp ng truyn s liu, thoi gia trung tm Hip ng iu hnh bay vi cc cng ty QLB Min Bc, cng ty QLB Min Trung, cng ty QLB Min Nam qua h thng v tinh mt t VSAT.

1.2.Nguyn l hot ng

S u ni

u pht: Cc tn hiu thoi hoc s liu t cc my u cui, tng i, my ch c a ti b ghp knh CX-2000 thc hin s ho v truyn ti UMOD 9100 thng qua h thng ghp knh quang Gia Lm - u ng. Ti UMOD hay cn gi l b iu ch cc tn hiu sau khi ghp knh s c iu ch theo phng thc iu ch QPSK. Tn hiu sau iu ch c chuyn qua b UPCONVERTER (B nng tn) chuyn i tn hiu ln cao tn. Tn hiu cao tn c a qua b khuych i cng sut HPA ri bc x ra khng gian ln v tinh thng qua anten parabol.

u thu: Sng in t thu c t v tinh c a ti b khuych i tp m thp LNA. Sau b khuych i tp m thp tn hiu s c a ti b h tn DOWN CONVERTER bin i thnh tn hiu trung tn. Tn hiu trung tn c a ti UMOD gii iu ch tch tn hiu cn thu ra khi sng mang. Sau b UMOD 9100 tn hiu c a ti b CX-2000 thng qua h thng ghp knh quang Gia Lm - u ng. Ti b CX-2000 tn hiu s c tch knh thnh cc tn hiu ring r a ti cc u cui s.

CHNG IICC THNG S K THUT CA H THNG

2.1.B ghp knh CX-2000Truyn ti a c 8 lung T1/E1 hoc 4 lung T3/E3 ATM.Truyn ti a c 62 knh thoi Analog.Truyn ti a c 360 knh thoi s/Fax.C ti a 160 cng ni tip tc cao.Cu trc phn cng ca CX2000 gm: Bn modul CPU (trn mi module c 8 khe cm) Hai ngun cung cp cho mi CPU (mt chnh mt d phng) Hai chuyn mch Ethernet. Hai khi qut lm mt. Hai module u vo ngun c cm cu ch. Hin nay ti TT HHB b ghp knh CX2000 ch s dng 3 module CPU vi: CPU 1 : Gia Lm Ni Bi. CPU 3 : Gia Lm Tn Sn. CPU 4 : Gia Lm - Nng.

2.2.Antennang knh Antenna: 4.5 m.Loi Anten: Prime Focus.Tn s hot ng (GHz).Tn s thu: 3.7 - 4.2 GHz.Tn s pht: 5.925 - 6.425 GHz.Khuych i Antenna.Thu: 43.9 dBi.Pht: 46.6 dBi.Phn cc: Tuyn tnh.H s sng ng (VSWR)Thu (Pht): 1.30 (1.25).Trng lng: 1089 kg.Kch c: 5.2m x 4.5 m x 5.3 m.Nhit hot ng: - 400C - 520C.Chu c sc gi: 200 km/h.

2.3.B nng tn (UP Converter)Tn sNhiu pha

Khong tn s:UT - 45055.845 6.425 GHz10 Hz- 59 dB

o ccDual, No Inversion100 Hz- 69 dB

Bc nhy125 Khz1 KHz- 79 dB

Cc knh nh trc32 tn s10 KHz- 89 dB

n nh (Time) 1 x 10-9/ Ngy100 KHz- 99 dB

n nh (Temp) 1 x 10-8/ Ngy1 Mz- 109 dB

u vo IFiu khin xa

Khong u vo52 88 hoc104 176 MHZ.Comm Port RS 485 hoc RS 232 C

Mc u vo-35 dBmCh th (mt my)

Suy hao23 dB minimumBt NgunLED xanh

in tr75 OhmTruyn tn hiuLED vng

u ra RFiu khin xaLED vng

Mc u ra+ 10 dBmFaulLED

in tr50 OhmOn lineLED vng

Suy hao phn hi20 dB MinimumStored FaultLED

Kch cim kim tra

Rng48.26 cmRFSMA, - 20 dBc

Cao4.44 cmIFBNC, - 20 dBc

Su55.88 cmNgun

Trng lng25 Poundin p100 125 VAC hoc 200 250 VAC

Tn s47 63 Hz

I/O Module

IOM 11RF: Loi N, 50 Ohm

IF: BNC, 75 Ohm

IOM 12RF: Loi N, 50 Ohm.IF: BNC, 75 Ohm

TSM XX1: N

2.4.B h tn (Down Converter)Tn sNhiu pha

Khong tn s:DT - 45033.625 4.200 GHz10 Hz- 59 dB

o ccDual, No Inversion100 Hz- 69 dB

Bc nhy125 Khz1 KHz- 79 dB

Cc knh nh trc32 tn s10 KHz- 89 dB

n nh (Time) 1 x 10-9/ Ngy100 KHz- 99 dB

n nh (Temp) 1 x 10-8/ Ngy1 Mz- 109 dB

u vo RFiu khin xa

Comm Port RS 485 hoc RS 232 C

Mc u vo-45 dBmCh th (mt my)

Bt NgunLED xanh

Tr khng50 OhmThu tn hiuLED vng

FaultLED

u ra IFiu khin xaLED vng

Mc u ra+ 20 dBm @ 1dB Comp+ 12 dBm @ 20 dB Attn.On lineLED vng

in tr50 Ohm hoc 75 OhmStored FaultLED

Suy hao phn hi23 dB Minimum

Khong tn s52 - 88 hoc 104 - 176 MHz.im kim tra

RFSMA, - 20 dBc

Kch cIFBNC, - 20 dBc

Rng48.26 cmNgun

Cao4.44 cmin p100 125 VAC hoc 200 250 VAC

Su55.88 cmTn s47 63 Hz

Trng lng25 poundI/O Module

IOM 11RF: Loi N, 50 Ohm

IF: BNC, 75 Ohm

IOM 12RF: Loi N, 50 Ohm.IF: BNC, 50 Ohm

TSM XX1: N

2.5.B chuyn mch bo v LNACng sut u vo:in p: 90 132 VAC hoc 175 264 VAC. Tn s: 47 63 Hz. Cng sut: 25 W (140 W Maximum).iu kin mi trng: iu kin hot ng:Nhit : 00C 500C. m: 5% - 95%.Chuyn mc:Thi gian chuyn mch: 70 ms Max.H s sng ng (VSWR): 1.25:1 Max.H thng chuyn mch RF:H s sng ng (Input/Ouput): 1.25:1/ 1.50:1.Cng sut RF: 1W.

2.6.Modem UMOD 10PAKKch thc:Trng lng 45 Kg.Cao: 40 cm.Rng: 43.9 cm.Su: 48.3 cm.in p u vo: 100 240 VAC (47 Hz 63 Hz).Tn s hot ng: Khong tn s: 52-88 Mhz hoc 104 - 176 Mhz (c t nh mt tu chn).Bc nhy: 100 Hz. Loi iu ch: BPSK, QPSK. Tc : Khong tc : 9,6 Kbps 8,448 Mbps (BPSK 9,6 Kbps 2,048 Mbps). Bc nhy: 1 bps. Symbol rate: 9.6 Kbps 10 Mbps.M sa li trc (FEC): Loi: Concatenated FEC, Reed-Solomon, Sequential, Viterbi.Tc : 1/2, 3/4, 7/8,1 (Khng m ho).Giao tip d liu:DIM: RS-232, RS-449, V.35.GIM: G.703 Scrambling: CCITT V.35 v IESS- 309 (IBS). n nh: 2ppm; 1 ppm/nm.Gim st v iu khin M&C: Cu hnh, Loop vng, cnh bo (Local hoc Remote).Chuyn d phng: Chuyn d phng tu chn h tr cho tt c cc chassis c trong cu hnh 1-PAK chassis v 1:1.u vo Station Clock: 1 Mhz --> 10 Mhz ( 10ppm, 100Hz/bc).

Thng s iu ch:Cng sut pht:Cng sut pht: -5 dBm n -30 dBm. phn gii: 0.1 dB. chnh xc: + 0.25 dB.Tr khng ra: 50 hoc 75 tu chn.Suy hao u ra: 20 dB. n nh tn s ra: 2ppm ; 1 ppm/nm.Dng ph: C th lp trnh (IDS, IBS, Custom).Mo v hi:> 50 dBc.Nhiu pht: - 100 dBm/Hz ti mc pht ra 0 dBm.- 130 dBm/Hz ti mc pht ra - 30 dBm.

Thng s gii iu ch:Cng sut vo:Tr khng vo: 50 hoc 75 tu chn.Suy hao u vo: 20 dB.Tm sng mang chp nhn c: - 30 n 55 dBm.Phm vi d:Sng mang: 30 Khz.Clock: 100 ppm.

CHNG IIICU HNH V KHAI THC H THNG

3.1.B ghp knh CX2000 cu hnh, qun l gim st b ghp knh Memotec CX2000, s dng phn mm CXAccess v1.1 ci trn my tnh gim st h thng VSAT. Chy chng trnh CXAccess t shortcut chng trnh trn desktop. T menu Tree, chn cng kt ni COM. thit lp tc cng COM: nhn tab Device > Modify.

Sau khi chy xong qu trnh boot h thng, nhp vo password ca CX2000 trn mn hnh xut hin du nhc nh hnh di y:Password:

1-CX:

T y ta bt u cu hnh h thng

3.2.Cu hnh modem UMOD 10 PAKS dng phn mm M&C cu hnh thit b. nh cu hnh Umod: Double - Click vo biu tng UMOD M&C trn desktop m chng trnh. Khi ca s UMOD M&C m, bn s thy vi biu tng. Double - click vo biu tng Manager lc hp hi thoi Select UMOD Address xut hin. Nhp a ch UMOD mong mun, sau kch vo nt OK.

Khi ca s Manager m, chn Edit Online Profile t Configuration Menu.

Ca s UMOD Configuration s xut hin hin th cu hnh Profile 0. T ca s ny ta c th xem v sa i cc ni dung ca cu hnh giao tip v tinh hin hnh trn UMOD.

t cu hnh chung:1. Nhn vo nt Tx Modem Mode (Pull - Down Menu). Lnh ny cho php chn hot ng khng to khung, IDR hoc IBS/SMS. Chn ch mong mun.2. Nhn nt Rx Modem Mode. Lnh ny lm vic ging nh lnh Tx Modem Mode bc 1.

nh cu hnh b iu ch pht:Nhn Tx IF Freq (Hz) Text Box chn (s 7.000.000 mc nh s sng). Lnh ny iu khin tn s b tng hp IF n b iu ch truyn. Phm vi thay i tn s l:a. 70.000.000 Hz 18.000.000 Hz.b. 140.000.000 Hz 36.000.000 Hz.H thng ca chng ta s dng tn s trung tn 70.000 KHz nh vo tn s pht mong mun.1. Nhn vo nt Tx Modulation Type. Lnh ny cho php chn BPSK hoc QPSK. Chn loi iu ch mong mun. H thng ca chng ta dng iu ch l QPSK2. Nhn vo nt Tx Filter Type. Lnh ny iu khin hnh dng ph ca tn hiu IF c iu ch. Chn loi b lc mong mun.H thng ca chng ta dng HNSA.3. Nhn nt Tx Spectral Inversion. Lnh ny cho php kch hot hoc khng kch hot c im o ngc ph trn b iu ch. Chn ON hoc OFF. H thng ca chng ta t OFF4. Nhn nt Tx FEC Encoding. Chn mt trong cc ch m ho sau: BYBASS. VITERBI CONCAT (Viterbi v Reed Solmn kt ni vi nhau). SEQUENTIAL.H thng ca chng ta dng m ho VITERBI5. Nhn nt Tx FEC Rate. Lnh ny iu khin tc FEC ca b m ho knh. Chn tc mong mun.H thng dng FEC 3/4.6. Nhn nt Tx Diff Encoding. Lnh ny kch hot hoc khng kch hot vic m ho vi phn. H thng t ON7. Nhn nt Tx Scrambling. Lnh ny t loi i tn s: V.35, IESS hoc khng (off). Chn loi mong mun. H thng t V.35.8. Nhn nt Tx Data Rate (bps) text box chn n. Lnh ny iu khin tc d liu c a ti b iu ch truyn. Phm vi tc d liu t 9600 8.448.000 bps. H thng t tc 128 Kbps9. Nhn nt Tx Clock Source. Lnh ny t ngun Clock pht . Chn mt trong cc ch sau INTERNAL, STATION, RECOVER, Tx DTE. H thng t Clock l INTERNAL.10. Nhn nt Tx Power (dBm) text box chn n. Vo cc yu cu v cng sut (c th thay i mi 0.1 dB) iu khin cng sut IF u ra. Ga tr cng sut c hin th. Ph thuc vo mi hng kt ni, thng t cng sut l - 18dBm.11. Nhn nt Tx Carrier Enable. Lnh ny kch hot sng mang. Vic t ti OFF lm cho UMOD ch truyn (pht) tn hiu sng mang. Sng mang pht phi c t ti ON truyn d liu trn ng truyn khng gian. H thng t l ON.

nh cu hnh b gii iu ch thu:Nhn Rx IF Freq (Hz) Text Box chn n. Lnh ny iu khin tn s b tng hp IF nhn c ti b gii iu ch. Phm vi thay i tn s l:c. 70.000.000 Hz 18.000.000 Hz.d. 140.000.000 Hz 36.000.000 Hz.H thng dng tn s IF l : 70.000.000 Hznh vo tn s pht mong mun.Nhn vo nt Rx Modulation Type. Lnh ny cho php chn BPSK hoc QPSK. Chn loi iu ch mong mun. H thng dng loi iu ch QPSK.1. Nhn vo nt Rx Filter Type. Lnh ny iu khin hnh dng ph ca tn hiu IF c iu ch. Chn loi b lc mong mun. H thng dng b lc l HNSA.2. Nhn nt Rx Spectral Inversion. Lnh ny iu khin c im o ngc ph trn b gii iu ch. Chn ON hoc OFF. H thng t o ngc ph l ON.3. Nhn nt Rx FEC Decoding. Chn mt trong cc ch m ho sau: BYBASS. VITERBI. CONCAT (Viterbi v Reed Solmn kt ni vi nhau). SEQUENTIAL.H thng dng m ho l VITERBI.4. Nhn nt Rx FEC Rate. Chn tc mong mun. H thng dng tc FEC l 3/4".5. Nhn nt Rx Diff Encoding. Lnh ny gii m vi phn iu khin loi iu ch ca b gii m knh. H thng t ch l ON.6. Nhn nt Rx Scrambling. Lnh ny t loi i tn s: V.35, IESS hoc khng (off). Chn loi mong mun. H thng dng cng l V.35.7. Nhn nt Rx Data Rate (bps) text box chn n. Lnh ny iu khin tc d liu c a ti b iu ch thu. Phm vi tc d liu t 9600 8.448.000 bps. H thng s dng ng truyn vi tc l 128 Kbps.8. Nhn nt Rx Clock Source. Lnh ny t ngun Clock thu . Chn mt trong cc ch sau INTERNAL, STATION, RECOVER, Tx DTE. H thng dng Clock l RECOVER.

CHNG IVBO DNG H THNG

4.1.Nhim v ca nhn vin trcKhi lm vic vi bt c mt thit b no cc b phn khc nhau u c nhim v ring ca mnh cc nhn vin khai thc thit b cn phi thc hin y cc nhim v sau: Lm ch h thng thit b c giao qun l. Thc hin tt cc ni quy v v sinh an ton lao ng ni ring v cc ni quy, quy nh ca c quan ni chung. Kim tra thng xuyn cc thng s ca thit b ng h trn mt my (Cc n hin th LED bo tnh trng thit b), cng nh tip mt cc u dy, conector lin quan khc. Khi pht hin thit b c s c cn nhanh chng chuyn i thit b d phng ng thi phi hp cng nhn vin k thut kim tra, khc phc s c. Trong ca trc phi thng xuyn theo di tnh trng hot ng ca thit b. Trc ng v tr, lun lng nghe nhng phn nh v tnh trng thit b m bo thit b lun trng thi lm vic tt nht. V sinh my mc, bo dng nh k thit b. Ghi chp s sch nh (s giao ca, s ghi chp k thut...). Thc hin bo co thng xuyn vi t trng cng nh cc cp lnh o phng v tnh trng thit b ca i. Trc khi bn giao ca trc phi kim tra li ton b cc thit b mnh qun l. Bo co ngi ph trch v cn b ban v tnh hnh ca trc nhng s c xy ra cng nh cch khc phc nhng s c , bo co v ngi nhn ca tip theo. Ghi chp s sch ca trc y . Khi bn giao ca trc phi phi hp vi ngi nhn ca kim tra li tt c cc thng s ca thit b cng nh dng c sa cha, thit b d phng. H thng v tinh VSAT l h thng ng truyn lin lc chnh gia TT H - HB vi Cty BHB Min bc, Cty BHB Min Trung, Cty BHB Min nam. Do cn thit c s ghi chp y vo nht bin, l lch thit b v cc s c trong ca trc d khc phc c ri hay cha khc phc c cng nn ghi y lm c s cho cc s c tng t ln sau. K s giao ca v bn giao ca.

4.2.Cc thit b, dng c sa cha v vt t cn thit Trong qu trnh khai thc, bo dng, kim tra nh k h thng tu theo yu cu c th ta cn c cc thit b o lng nh sau:1. ng h vn nng. 2. My o cng sut. 3. My phn tch ph (0 Hz n 26.5 GHz).4. Audio test set.5. My o li bit (BER): EDT-135 E1 and Data Tester.6. B Tuc-n-vit, km, m hn nhanh, c l chng loi.7. Thic, nha thng, bng dnh in, cao su non... 8. Ti liu v thit b, cng cc s khi h thng thit b.9. Cc s chi tit mch ca thit b.10. S u ni cp tn hiu. Ngoi ra cn cn cc vt t l nh cp tn hiu, cp ngun . . .4.3.Cc bc tin hnh kim tra trc khi bo dng1. Kim tra cc n LED hin th trn mt my, xem mc tn hiu Eb/No v cc thng s bng phn mm M&C UMOD, kim tra sng mang bng my phn tch ph. 2. Kim tra vic cp ngun cung cp. Hin ti ngun cung cp cho ton b thit b l ngun AC. in p: 90 - 132 VAC hoc 175 - 264 VAC.Tn s: 47 - 63 Hz.Do phi ch xem in p u vo l trong khong no.3. Kim tra cc dy tn hiu vo ra thit b DB35 chn (Ni cc V35 ca Megaplex-2100 v UMOD) .4. Kim tra cc ng tn hiu vo ra cc Krone v cc ng tn hiu u ni h thng.5. Kim tra cng sut my.6. Kim tra anten, phi, LNA.7. Kim tra dy tip mt, chng st.8. Kim tra cc SW, cc Jumper iu chnh.9. Kim tra cc chc nng khc ca thit b nh rle chuyn i MAIN/STANDBY... (i vi thit b LNA Switch Protection).

4.4.Lch trnh kim tra bo dng nh kCng tc bo dng kim tra nh k thit b gm c:4.4.1. Bo dng tunThc hin bo dng thng xuyn mi tun mt ln bao gm cc cng vic sau: V sinh cng nghip thit b. Kim tra cc u dy. Kim tra tip mt. Kim tra ngun. Kim tra cc thng s k thut ca thit b... Cc cng vic ny c thc hin theo ng lch trnh bo dng tun sau khi bo dng tun song ngi thc hin bo dng phi c trch nhim ghi li ton b cc cng vic v kt qu bo dng tun vo bng kt qu bo dng.

4.4.2.Bo dng thngCng vic ny c thc hin mi thng mt ln vo u hoc cui thng tu theo ch o ca ngi c thm quyn. Cng vic bao gm: Ton b cc cng vic ca bo dng tun. Kim tra ton b cc mc trn mt my. Cc thng s c bn ca thit b. Kim tra anten, phid v cc u ni. Kim tra tip mt, chng st thit b. Kim tra cc ng tn hiu vo, ra ... Sau khi thc hin bo dng song ngi thc hin bo dng phi c trch nhim so snh vi kt qu kim tra trc khi thc hin ng thi ghi li ton b cc cng vic v kt qu bo dng thng vo bng kt qu bo dng.

4.4.3.Bo dng 6 thngCng vic ny c thc hin su thng mt ln, y l ln bo dng ln trong nm cho nn trc khi thc hin bo dng phi kim tra li ton b cc thng s trn mt my v ghi vo bng kim tra thit b trc khi bo dng lm c s so snh sau ln bo dng ln ny sau mi tt thit b cn bo dng. Cng vic phi lm ca ln bo dng ny bao gm ton b cc cng vic ca bo dng tun, thng v thm cc cng vic sau Kim tra o li v cn chnh cng sut ca thit b. Kim tra o li pht x ca anten. Bc li cc u ni gia anten v thit b. Kim tra ngun cung cp. Kim tra cn chnh li ton b cc thng s ca thit b. Kim tra li ton b cc loi dy ni nu cn th thay th. Kim tra o li tip mt, chng st thit b. Kim tra cc tm khi ca thit b.V nhiu cng vic khc c lin quan n thit b...Sau khi bo dng song ton b thit b ri a thit b v v tr lp t lp t li ton b cc u dy, anten, tip mt ngun cung cp... Sau bt ngun kim tra li cc thng s v n LED hin th trn mt my ng thi so snh vi kt qu kim tra trc khi bo dng xem st iu chnh li v ng vi mc danh nh sau cho thit b vo lm vic th xem c vn g khng nu tt ri th yu cu ghi li kt qu bo dng vo bng kt qu lm bin bn bn giao v bo co vi cc b phn lin quan v cng vic lm.

4.4.4. Bo dng nmCng tc bo dng nm c thc hin mi nm mt ln (yu cu ging nh bo dng 6 thng). Cng tc bo dng nm cng yu cu phi kim tra ton b thit b sau mi tt my cng vic gm ton b cc cng vic ca bo dng su thng v thm nhng vic cn thit m bo an ton cho thit b lm vic n nh nh: Thay th nhng tm, khi khng m bo cht lng. Kim tra thay th cc linh kin cm thy c nguy c gy ra s c hng hc. V cc cng vic khc c lin quan n thit b.Sau khi thc hin song yu cu lp thit b vo bt ln kim tra ton b cc thng s ca thit b v so snh vi kt qu kim tra trc khi thc hin cng vic nu tt ri th yu cu ghi li kt qu bo dng vo bng kt qu lm bin bn bn giao v bo co vi cc b phn lin quan v cng vic lm.

CHNG VCCH KHC PHC CC S C THNG GP

Da vo cc n hin th trn h thng, nhn vin k thut c th xc nh tnh trng k thut h thng ng thi khc phc cc s c hng hc thng gp.

5.1.Cc n hin th trn h thng5.1.1.B ghp knh CX2000Ch th mt trc ca b ghp knh.Tng cng c 14 n LED xanh/ trn chassis.2 n LED cho hot ng chuyn mch (chnh v d phng) ch th trng thi kt ni tng h backplane module CPU cho (cross-CPU module backplane interconnection status).Mi CPU c: 1 n LED trng thi Module ch th c hay khng c CPU cm trong Chassis v trng thi hot ng. 2 LED trng thi chuyn mch. Ri - Khng truyn d liu. Nhp nhy - Truyn d liu. 2 n LEDs cung cp ngun. Mt ch th khi ngun cung cp chnh c s dng. Mt ch th khi s dng ngun d phng. n ngha l cnh bo - Ngun cung cp thc hin khng ng chc nng hoc khng cung cp ngun.

LED

MuTrng thi nCh th

SngModule ang hot ng bnh thng.

Trng thi ModulesXanhTtHin nay khng c Module cm vo v tr ny.

Nhp nhyLi phn cng hoc phn mm xy ra.

XanhSngTt c in p u ra nui CPU cp in p ng.

Ngun(Chnh)SngMt trong cc in p u ra nui CPU cp in p khng ng. Hoc cha cp in AC vo thit b.

---TtKhng c Card ngun cm vo .

XanhSngTt c in p d phng u ra nui CPU cp in p ng.

NgunD phngSngMt trong cc in p d phng u ra nui CPU cp in p khng ng. Hoc cha cp in AC vo thit b.

---TtKhng c Card ngun d phng cm vo .

Chuyn mchchnhXanhSngBt k khi no lung d liu chy qua chuyn mch chnh th n LED sng. n sng ch th rng c mt lung d liu mnh chy qua. Mt khc nu n nhp nhy khi cm lung d liu xy ra.

TtKhng c lung d liu no chy qua chuyn mch chnh.

Chuyn mchd phngXanhSngBt k khi no lun d liu chy qua chuyn mch d phng th n LED sng. n sng ch th rng c mt lung d liu mnh chy qua. Mt khc nu n nhp nhy khi cm lung d liu xy ra.

Tt

Khng c lung d liu no chy qua chuyn mch chnh.

5.1.2. Khi nng tn (Up Converter)TnLoiChc nng

POWER ONn xanhSng - Thit b c cung cp ngun.Tt - Thit b cha c cung cp ngun

TRANSMITn vngSngUp Converter ang thc hin chc nng truyn tn hiu.

ONLINEn vngSngCh th rng b Converter ang hot ng chnh (cn b kia hot ng ch d phng) ch Online ang truyn s liu.

REMOTEn vngTtSng - Ch th rng b Converter ang hot ng ch iu khin t xa khi cc lnh v s liu c truyn thng qua cng RS-485 (RS-232C).Tt - Trng thi bnh thng.

FAULTn TtSng - Thit b Up Converter b li.Tt - Thit b hot ng bnh thng.

STORED FAULTn

TtSng - ch th rng cc li c logged li v lu tr vo my mi khi thit b xy ra s c.Tt - Thit b hot ng bnh thng.

5.1.3. Khi h tn (Down Converter)TnLoiChc nng

POWER ONn xanhSng - Thit b c cung cp ngun.Tt - Thit b cha c cung cp ngun

RECEIVEn vngSngDown Converter ang thc hin chc nng nhn tn hiu.

ONLINEn vngSngCh th rng b Converter ang hot ng chnh (cn b kia hot ng ch d phng) ch Online ang nhn s liu.

REMOTEn vngTtSng - Ch th rng b Converter ang hot ng ch iu khin t xa khi cc lnh v s liu c truyn thng qua cng RS-485 (RS-232C).Tt - Trng thi bnh thng.

FAULTn TtSng - Thit b Down Converter b li.Tt - Thit b hot ng bnh thng.

STORED FAULTn TtSng - ch th rng cc li c logged li v lu tr vo my mi khi thit b xy ra s c.Tt - Thit b hot ng bnh thng.

5.1.4. Khi chuyn mch bo v LNATnLoiChc nng

No.1 Failn LNA 1 b li

No.2 Failn LNA 2 b li

P.S.1n xanhNgun cung cp 1 hot ng bnh thng

P.S.2n xanhNgun cung cp 2 hot ng bnh thng

P.S.1 Failn Ngun cung cp 1 b li hoc khng Online

P.S.2.Failn Ngun cung cp 2 b li hoc khng Online

AUTOn xanhThit b c thit lp ch t ng chuyn mch gia LNA 1 v LNA2

MANUALn vngThit b c thit lp ch chuyn mch bng tay gia LNA 1 v LNA2

LAMP TESTNt bmNhn vo nt ny hin th tt c n panel mt my nhm mc ch kim tra hot ng ca cc n ch th

5.1.5. Khi NTUTnLoiChc nng

PWRn xanhSng - C ngun cp cho NTU.

RTSn vngSng - DTE kch hot lnh yu cu truyn.

TDn vngSng - Sn sng truyn tn hiu.Nhp nhy - ang truyn s liu.

RDn vngSng - Sn sng nhn tn hiu.Nhp nhy - ang nhn s liu.

DCDn vngSng : 2 Modem c ng b (bt tay nhau) v chuyn mch SW6 c thit lp l ON. - 2 Modem c ng b (bt tay nhau), chuyn mch SW6 thit lp l OFF v RTS ti u Modem xa l ON.

LOSn Sng - Mt ng b gia hai Modem.

TESTn vngSng - NTU ang Loopback hoc ang nhn nt PATT.

ERRn vngNhp nhy hoc sng n, nu nh c li xy ra

DIGNhn ntNhn nt ny kch hot NTU ti ch loop lung s liu thu vi b pht ca n.

ANANhn ntLoopback ti ch kch hot NTU loop u ra ca mch pht quay tr li u thu ca n.

REMNhn ntNhn nt REM kch hot NTU u xa loop lung s liu thu vi u pht ca n.

PATTNhn ntChuyn mch PATT kch NTU truyn v nhn mt mu tn hiu kim tra.

RESETNhn ntReset li NTU.

5.1.6. Khi MODEM UMOD 10 PAKBng ch th n LED ca Card UMODM LEDMode t chn on, kim traMode hot ng

0B nh truy nhp ngu nhin

1Kim tra CPU

2Kim tra b nh thi trong

3Kim tra DMA

4Kim tra b pht/thu bt ng b QUART.

5Kim tra SCC

6Kim tra SCC DMA

7B iu khin ngt chng trnh ni.

8Kim tra NVRAM

AMode tm kim sng mang thu

Bang thc hin BERT

=ang thc hin Loopback (LB, TLB, BLB)

CXc nh m b nh FLASH

DChn on chc nng

ECho php ci t phn mm

PNgun cung cp b liP1 = Ngun cung cp 1P2 = Ngun cung cp 2

FCnh bo Fatal

LSng mang thu c Lock

UMode ri (bao gm: Khng c sng mang pht, khng c cnh bo Fata, khng d tm sng mang)

rD phng (Nu c card d phng)

roOffline (Nu c card d phng)

-UMOD ch hot ng ch pht

Ch : Trong qu trnh vn hnh thit b UMOD cn lu v hiu cc ch th n k hiu sau:A: Ch th rng thit b ang d tm sng mang.L: Ch th rng thit b Lock sng mang.U: ch th rng thit b ang ch ri v sn sng lm vic.r: Ch th rng Card ny ang chy ch d phng cho ton b h thng.

Bng ch th n LED ca khi qutTnLoiChc nng

Qutn xanhC hai ngun cung cp ang hot ng

n Mt ngun cung cp b li. Khng c ngun cung cp s khng ch ra li.

5.2.Cch khc phc cc s c thng gp5.2.1. B ghp knh CX20001. Ton b h thng khng hot ng.Cc n cnh bo bo mt ngun hoc ng vo/ra d liu khng c nhy.Khc phc:Kim tra ngun vo CPU (c 2 ngun chnh v d phng). Kim tra trng thi CPU.

2. CPU khng remote c bng my tnh gim stKhc phc:Kim tra u dy console c cm vo CPU VSAT v cng COM ca my tnh gim st cha. Nu cm m khng remote c th reset li my tnh gim st, nu vn khng c th reset CPU.

3. Cc ng trung k bo bn (gim st thng qua my tnh gim st tng i)Khc phc: Dng cu lnh reset nhm trung k ti my tnh gim st tng i hoc rt ra cm li jack trung k E/M hng .

4. Kim tra trung k CO (cp thu bao thoi ko di)Ly my in thoi, cm vo khe cm cn kim tra trn CX (da vo s cp tn hiu ca CX2000 theo tng hng CPU), nghe xem c m tone mi quay s khng.Nu khng c tone c ngha l khng c cp trung k CO. Gi in bo bn kia kim tra li.

5. Mt tn hiu radarTn hiu radar truyn ng b.Cu lnh kim tra: bopoprsap:450 txfrm,rxfrm (hoc 430,440)Nu thy tham s txfrm, rxfrm ln u th l tt.Thay i tham s: bopadminsap.Ch n tham s txframe, rxframe v tc .

5.2.2.Modem UMOD 9100Cc li v gim st v iu khinHin tngCch gii quyt

LED trc mt mt b tt; Qut lm mt khng hot ng.Kim tra ngun cung cp cho UMOD.

UMOD khng th nhn tn hiu tr li t thit b u cui ASCII.Kim tra cp RS-232 c ni t M&C Port vi UMOD.Kim tra tc baud phi l 2400, parity thit lp l None, v bits per character thit lp l 8.

Cc li lin quan n tuyn phtHin tngCch gii quyt

Khng c tn hiu iu chKim tra sng mang iu ch ang ch hot ng v kt ni vi u ni BNC.

Cc li lin quan n phn thuHin tngCch gii quyt

Tc li bit cao Thc t cho thy rng, vic xc nh cc nguyn nhn gy ra li rt kh xc nh. C th l: u cui s liu. Cp ni. UMOD. Nhiu trn ng ngun vo. Can nhiu in t trng pht ra t thit b bn cnh. phn tch v x l vn ny, thc hin theo sau: u tin, kim tra cc mc nu trn xem liu mt trong cc li trn c gy ra. Nu cc thng s thit lp Modem, cc u ni, cc mc RFl ng, th nn kim tra u cui s liu.Nu u cui s liu khng gy ra li, th s dng phn tch ph kim tra u vo Modem t cp. Kim tra RF tm dng nhiu hoc cc xung gai nhn. Bt k trng hp no cng gy ra cc vn v li bt cao.

UMOD khng thu c sng mang- Kim tra tt c cc cp ni.- Kim tra u ra b iu ch ti Modem u ra l cho php.- Kim tra cu hnh b iu ch v gii iu ch l tng thch.- Kim tra rng t s tn hiu trn nhiu t yu cu hot ng.

UMOD thu c sng mang, nhng kt qu ca s liu b sai. Kim tra cu hnh b iu ch v gii iu ch tng thch khng (c bit loi iu ch, tc mu, loi m).

UMOD cht c sng mang nhng khng n nh v kt qu s liu l sai. Mc Eb/No c th qu thp.

UMOD thnh thong mt ng b gii m.- Ma hoc vn v mt ngun tn hiu s gy ra cc li gii m trc khi gy ra cc li d tm sng mang hoc nh thi bit. - Nu mc Eb/No l bnh thng, hu ht nguyn nhn ca li ny l nhiu phase cao hoc can nhiu ca b Upconverter hoc Downconverter.

KT LUN

Ngy nay, tuy cc h thng thng tin v tinh VSAT khng cn l mt vn mi nhng n vn ng mt vai tr quan trng trong mng vin thng hng khng. Do u th v kh nng ph sng cng tnh linh hot v tnh di ng, nn h thng v tuyn thng tin v tinh VSAT cho php cc nh khai thc pht trin mng vin thng mt cch nhanh chng cc vng c a hnh phc tp v c s h tng vin thng cha cao. Qua ti ny, em nm bt c cc vn c bn ca h thng VSAT, qu trnh cu hnh h thng cng nh qu trnh bo dng v khc phc li pht sinh trong thc t. C th thy vn vn dng l thuyt vo trong thc t c th hon thnh cng vic lun l mt vic rt kh khn i vi nhng sinh vin sp tt nghip. T l thuyt n thc t vn dng vo my mc lun c 1 khong cch rt ln. Vi 1 thit b my mc khi c xut xng th nhng hng dn trn giy ca nh sn xut ch c th ng 80% m thi, 20% cn li l do kinh nghim lm vic lu nm mi c th tm ra v sa nhng li pht sinh c. Do , khi tip xc vi trang thit b my mc chng ta cn phi khim tn v hc hi kinh nghim t nhng ngi i trc. Chc tt c thnh vin lp D09VT3 thnh cng trong cng vic v cuc sng.

TI LIU THAM KHO

[1] Thng tin v tinh Tng cc bu in. NXB khoa hc v k thut.[2] Ks ng Anh Tun, Thng tin v tinh. Trung tm nghin cu ng dng khoa hc truyn hnh 2/2002.[3] V nh Thnh, H thng vin thng. Trng i hc bch khoa Tp H Ch Minh 1996.[4] TS Nguyn Kim Sch, Thu truyn hnh trc tip t v tinh. NXB Khoa hc K thut 1991.[5] KS Ng Anh Ba, Truyn hnh v tinh, Hi v tuyn in t Vit Nam, chuyn K thut truyn hnh 1994.39