B GIAO THNG VN TI TRNG I HC HNG HI KHOA: IN IN T TU BIN B MN: IN T VIN THNG

BI GING KHAI THC THNG TIN VT HNG HI GMDSSTN HC PHN : KHAI THC THNG TIN VT HNG HI - GMDSS -

M HC PHN TRNH O TO

: V TUYN IN : I HC CHNH QUY

DNG CHO SV NGNH: IN T VIN THNG

HI PHNG - 2008

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CHNG 1. GII THIU CHUNG V H THNG THNG TIN GMDSS1.1 LCH S RA I CA H THNG THNG TIN GMDSS.Nm 1979 t chc hng hi quc t IMO t chc hi ngh v vn tm kim v cu nn trn bin , vi mc ch l lp ra v thng nht mt k hoch ton cu cho cng tc tm kim v cu nn trn bin p ng yu cu cp thit v vn an ton trn bin. Hi ngh cng yu cu t chc hng hi quc t IMO

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thit lp mt h thng an ton v cu nn ton cu, vi nhng quy nh bt buc v cc thit b thng tin lin lc gip cho cng vic tm kim v cu nn trn bin t hiu qu cao nht. n nm 1988 th h thng thng tin an ton v cu nn hng hi ton cu c thng qua, gi tt l GMDSS (Global maritime distress and safety system). c trng ca h thng GMDSS l h thng mang tnh ton cu v tnh t hp. c im chnh ca h thng GMDSS nh sau:

Phn chia vng thng tin tho c ly hot ng ca tu, t xc nh cc loi thit b s c lpt trn tu cng vi tn s v phng thc thng tin thch hp

Khng s dng cc tn s cp cu 500Khz bng VT bo v tn s 2182 Khz bng VT thoi bo ng v gi cp cu m dng k thut gi chn s DSC vi nhng tn s thch hp ginh ring cho bo ng v gi cp cu.

Nhng thng tin c ly xa s c m bo thng qua thit b thng tin v tinh v cc thit bhot ng trn di sng ngn HF.

vic trc canh cp cu v thu nhn cc thng bo an ton hng hi v d bo thi tit bngphng thc t ng

S dng k thut gi chn s DSC, in ch trc tip bng hp NBDP v v tuyn in thoi trongthng tin lin lc, b khng dng VT bo nn khng nht thit phi s dng cc s quan chuyn nghip.

1.2 CU TRC CA H THNG GMDSS.Cu trc ca h thng thng tin GMDSS gm c hai h thng thng tin chnh l: H thng thng tin v tinh v h thng thng tin mt t.

2.1.1.

H thng thng tin v tinh

H thng thng tin v tinh l mt c trng quan trng trong h thng GMDSS. H thng thng tin v tinh trong h thng GMDSS gm c: Thng tin qua h thng v tinh INMARSAT v thng tin qua h thng v tinh COSPAS-SARSAT. H thng INMARSAT vi cc v tinh a tnh hot ng trn di tn 1.5 Mhz v 1.6 Mhz(bng L), cung cp cho cc tu c lp t trm i tu v tinh mt phng tin bo ng v gi cp cu c kh nng thng tin hai chiu bng phng thc telex v v tuyn in thoi. Ngoi ra cc v tinh INMARSAT cn c s dng nh phng tin chnh thng bo cc thng tin an ton hng hi MSI cho cc vng khng c ph sng bi dch v NAVTEX. Cc v tinh trong h thng bao gm bn v tinh a tnh hot ng cao 36.000 Km, bao ph 4 vng i dng t 70 v bc n 70 v nam. AOR-E, AOR-W, IOR V POR.

1.2.1.1.Cc thit b thng tin trong h thng INMARSAT.

INMARSAT A: l h thng thng tin INMARSAT u tin c a vo hot ng thng mi tnm 1982, cung cp cc dch v thoi, telex, fax, email v cc dch v truyn s liu. . . Cc th h mi ca INMARSAT hin nay nh gn hn v d s dng hn so vi cc th h trc. Hnh 1.2a. Cc v tinh a tnh INMARSAT

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INMARSAT B: l thit b thng tin di ng v tinh hin i s dng cng ngh s, k tc s pht trinca INMARSAT A. INMARSAT B cung cp cc dch v thng tin ging nh cc dch v ca INMARSAT A.

INMARSAT C: l thit b thng tin di ng v tinh ra i nm 1993 cung cp cc dch v truyn sliu v telex hai chiu vi tc 600bit/s. INMARSAT C n gin, gi thnh r vi anten v hng, nh, nh, ton b thit b c th xch tay hoc gn vo bt c tu thuyn no.

INMARSAT M: l s pht trin tip theo ca INMARSAT B nhng c kch thc nh nh v githnh r hn. Cc dch v thng tin trong INMARSAT M ch c thoi, fax v truyn d liu

INMARSAT E: l EPIRB v tinh hot ng trn bng L qua h thng INMARSAT, c dng nhmt phng tin bo ng cu ng cu nn cho cc tu hot ng nm trong vng bao ph ca v tinh INMARSAT.

My thu gi nhm tng cng EGC: l my thu chuyn dng thu cc thng tin an ton v cu nnhng hi trong h thng v tinh INMARSAT. N c thit k kh nng t ng trc canh lin tc trong mng SAFETYNET, pht trn h thng thng tin v tinh INMARSAT. My thu EGC c tch hp trong cc trm i tu INMARSAT A/B, INMARSAT C hoc c thit k c lp vi anten thu ring nh, gn. 1.2.1.2.Thit b thng tin trong h thng COSPAS SARSAT. H thng COP l mt h thng v tinh tr gip tm kim v cu nn, c thit lp xc nh v tr ca thit b EPIRB trn tn s 121.5 Mhz hoc 406 Mhz. H thng cop c s dng phc v cho tt c cc t chc trn th gii c trch nhim tm kim v cu nn trn bin, trn khng v trn t lin. Hin nay c 3 loi beacon v tinh: ELP (emergency locator transmitter) dng trong nghnh hng khng, EPIRB (emergency position indicating radio beacon) dng trong nghnh hng hi v PLB (personal locator beacon) dng trn t lin. Cc beacon pht tn hiu v cc thit b thu ca v tinh trong h thng cop thu nhn v x l tn hiu ph hp. cc tn hiu c chuyn tip ti mt trm thu trn mt t LUT (local user terminal) s x l cc tn hiu xc nh v tr ca beacon. Sau , mt bo ng cp cu c cc s liu v v tr, s nhn dng v cc thng tin khc nhau cng c gi ti mt trung tm phi hp iu khin MCC (Mission control centre) v trung tm phi hp cu nn RCC (recue co-ordination centre) quc gia, cng nh ti cc MCC khc hoc ti mt t chc tm kim v cu nn thch hp phi hp hnh ng. H thng cop ng dng hiu ng DOPPLER xc nh v tr ca beacon cc tn s sng mang 121.5 Mhz v 406.025 Mhz. H thng cop thc hin 2 dng bao ph mt t cho vic pht hin v xc nh v tr ca beacon. l dng tc thi v dng bao ph ton cu. C hai loi 121.5 Mhz v 406.025 Mhz u hot ng dng tc thi, trong khi ch c loi 406.025 Mhz mi c thm dng bao ph ton cu.

1.2.1.1.Cc trm v tinh mt t Cc trm v tinh mt t bao gm:

Cc trm i tu SESs (ship earth stations) bao gm cc trm INMARSAT-A/B, INMARSAT Choc M c chc nng gi v bo ng cp cu chiu t tu n b v chc nng thng tin thng thng trong vng bao ph ca cc v tinh INMARSAT.

Cc trm i mt t LESs (land earth stations), trong mi vng bao ph ca v tinh INMARSATc th c nhiu trm LES, cc trm LES ny c ni mng vi thu bao qua ng bu in quc gia v

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quc t thu nhn cc bc in thng thng , c pht t tu thng qua v tinh m cc trm LES nm trong vng bao ph ca cc v tinh v chuyn cc bc in ny ti cc thu bao v ngc li. ng thi cc trm LES ny cng c ni vi cc trung tm phi hp tm kim v cu nn RCC, trong trng hp c cc cuc gi cp cu t tu thng qua cc knh u tin ca v tinh, trm LES s nhn v chuyn tip cc bc in ti trung tm phi hp tm kim cu nn thch hp

2.1.2. H thng thng tin mt t.Trong h thng thng tin mt t gm cc thit b chnh sau y: 1.2.1.1.Thit b gi chn s DSC. Cc thit b DSC c th l cc thit b c lp hoc c kt hp vi cc thit b thoi trn cc bng tn HF/MF, VHF. Thnh phn c bn ca mt bc in DSC gm: nhn dng ca trm ch, t nhn dng trm pht v ni dung bc in bao gm nhng thng tin ngn gn, c bn nht ch ra mc ch cuc gi. 1.2.1.1.Thit b thng thoi. Cc thit b thng tin thoi trong h thng GMDSS lm vic trn cc di sng MF/HF v VHF cc ch J3E, H3E (cho tn s cp cu 2182 Khz) v G3E. Cc thit b thng thoi ny cng c dng gi cp cu khn cp v an ton. 1.2.1.1.B pht p radar tm kim v cu nn SART. SART l phng tin chnh trong h thng GMDSS xc nh v tr tu b nn hoc xung cu sinh ca cc tu b nn . Theo cng c ca SOLAS/88 sa i, tt c cc tu chy trn bin u phi trang b SART. Cc thit b SART lm vic di tn 9 Ghz (bng X) v s to ra mt chui tn hiu phn x khi c s kch hot ca bt k mt tn hiu ca radar hng hi hoc hng khng hot ng bng X no. 1.2.1.1.EPIRB VHF DSC. i vi tu hot ng trong vng bin A1, c th s dng EPIRB gi chn s DSC trn knh 70 VHF, pht i tn hiu bo ng khi b kch hot theo chu k c qui nh gm 5 tn hiu cp cu lin tc pht i trong giy th 230+10N (N l s ca nhm tn hiu pht i). EPIRB DSC cho php hin th lun tnh cht b nn ging nh EPIRB pht i. Ngoi ra EPIRB ny cn c b phn x radar hot ng trn tn s 9 Ghz. 1.2.1.1.NAVTEX quc t. Navtex quc t l mt dch v truyn ch trc tip trn tn s 518 Khz , s dng k thut truyn ch trc tip bng hp NBDP v ch pht FEC, truyn nhng thng tin an ton hng hi MSI bng ting Anh vi phm vi bao ph sng cch b khong 400 hi l. Dch v ca navtex bao gm d bo v kh tng v thi tit, cc loi thng bo hng hi, cc thng tin v khn cp v an ton,... s truyn ti tt c cc tu nm trong vng ph sng ca Navtex. 1.2.1.1.Thit b NBDP. Cc thit b NBDP l mt b phn cu thnh trong h thng GMDSS, h tr trong thng tin cp cu khn cp v an ton. Cc thit b NBDP hot ng trn cc di sng MF v HF, cc ch ARQ,dng trao i thng tin gia 2 i v ch FEC dng pht cc thng tin c tnh cht thng bo ti nhiu i. Trn mi di sng VT hng hi u c thit k mt tn s dnh ring cho cp cu khn cp v an ton bng thit b NBDP.

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CHNG 2. CNG C QUC T V THNG TIN VT TRONG H THNG GMDSS.2.1. NH NGHA CC VNG BIN HOT NG CA TU.Cn c vo c im ca cc thit b trong h thng GMDSS v pht huy c tnh hiu qu ca h thng, t chc hng hi quc t IMO chia cc vng bin v i dng thnh 4 vng nh sau:

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2.1.3. Vng bin A1.L vng nm trong tm hot ng ca t nht mt trm i b VHF c dch v gi chn s DSC. Thng thng mi mt trm VHF c vng ph sng vi bn knh t 25-30 hi l.

2.1.4. Vng bin A2.L vng bin, tr vng A1, nm trong tm hot ng ca t nht mt trm i b c dch v gi chn s DSC. Thng thng mi trm MF c vng ph sng vi bn knh t 150-200 hi l.

2.1.5. Vng bin A3.L vng bin , tr vng A1 v A2, nm trong vng bao ph ca cc v tinh a tnh INMARSAT ca t chc v tinh hng hi quc t. Vng bao ph ca v tinh hng hi t 70 v bc n 70 v nam.

2.1.6. Vng bin A4. L vng bin cn li, tr vng A1, A2, A3. V c bn l cc vng gn a cc. 2.2. QUI NH V CC TRANG THIT B THNG TIN TRN TU TRONG H THNG GMDSS. 2.2.1. Cc trang thit b thng tin VT trong h thng GMDSS trang b cho tu bin. 2.2.1.1.Qui nh chung cho tt c cc tu hot ng trn bin(khng ph thuc vo vng bin m tu hot ng)Mi tu hot ng trn bin bt buc phi c trang b cc thit b sau y trong h thng GMDSS m khng ph thuc vo vng bin m tu hot ng:

My thu pht VHF:+ C kh nng thu pht v trc canh lin tc bng DSC trn knh 70. + C cc tn s ca knh thoi 156.8 Mhz (knh 16), 156.650 Mhz (knh thit b thu pht VHF thoi)

Thit b phn x radar (radar transponder) hot ng trn tn s 9 Ghz phc v cho tm kim vcu nn.

Thit b thu nhn v x l thng tin an ton hng hi(MSI) My thu Navtex, nu tu hot ngtrong vng bin c cc dch v Navtex quc t. Nu tu hot ng cc vng bin khng c cc dch v Navtex quc t th phi c trang b mt my thu gi nhm tng cng (EGC).

Phao nh v v tuyn qua v tinh: C kh nng pht bo ng cp cu qua v tinh qu o cchot ng trn tn s 406 Mhz, hoc nu tu ch hot ng vng bao ph ca v tinh INMARSAT th EPIRB v tinh phi c kh nng pht bo ng cp cu qua v tinh a tnh INMARSAT hot ng bng L.

Cc tu khch phi c trang b cc thit b cho thng tin hin trng: VHF two ay phcv cho mc ch tm kim v cu nn trn tn s 121.5 Mhz v 123.1 Mhz

2.2.1.2.Trang thit b v tuyn in cho tu chy vng bin A1. Tt c cc tu khi hot ng trong vng bin A1, ngoi cc trang thit b qui nh chung c nu mc 2.2.1.1, cn phi bt buc trang b mt trong cc thit b v tuyn in sau y, c kh nng bo ng cp cu chiu t tu n b.

VHF DSC EPIRB, hoc EPIRB v tinh hot ng trn tn s 406 Mhz, hoc thit b thu pht MF gi chn s DSC hoc, 7

Thit b thu pht HF gi chn s DSC hoc, Mt trm INMARSAT, hoc EPIRB INMARSAT hot ng trn bng L2.2.1.3.Trang thit b v tuyn in cho tu chy vng bin A1 v A2. Tt c cc tu khi hot ng ngoi vng bin A1 nhng trong vng bin A2, ngoi cc trang thit b qui nh chung nh mc 2.2.1.1, s phi trang b thm:

Thit b MF, c th thu pht tn hiu cp cu bng DSC trn tn s 2187.5 Khz v trn tn s2182 Khz bng thng tin v tuyn in thoi.

My thu trc canh DSC c kh nng duy tr lin tc vic trc canh trn tn s 2187.5 Khz Mt thit b pht tn hiu cp cu chiu t tu ti b (ngoi thit b MF), c th l EPIRB 406Mhz, hoc thit b HF/DSC, hoc mt trm INMARSAT, hoc EPIRB v tinh INMARSAT bng L.

Thit b thu pht cho mc ch thng tin thng thng bng VT thoi, hoc truyn ch trc tipbng hp NBDP hot ng di tn s t 1605 Khz 4000 Khz hoc di tn s t 4000 Khz 27500 Khz, hoc mt trm INMARSAT. 2.2.1.4.Trang thit b v tuyn in cho tu chy vng bin A1, A2 v A3. Tt c cc tu khi hot ng ngoi vng bin A1, A2 nhng trong vng bin A3, ngoi cc trang thit b qui nh chung nh mc 2.2.1.1, s phi trang b theo mt trong hai cch la chn sau: A/ la chn 1:

Trm INMARSAT c kh nng:+ Pht v thu nhng thng tin cp cu v an ton bng truyn ch trc tip bng hp. + Nhn nhng cuc gi u tin cp cu + Duy tr vic trc canh i vi nhng bo ng cp cu chiu t b ti tu. + Pht v thu nhng thng tin thng thng bng VT thoi hoc truyn ch trc tip bng hp.

Mt thit b MF c kh nng thu pht cp cu v an ton trn tn s 2187.5 Khz bng DSC v tns 2182 Khz bng VT thoi.

Mt my thu trc canh c kh nng duy tr vic trc canh lin tc bng DSC trn tn s 2187.5Khz

Mt thit b pht tn hiu cp cu chiu t tu - b. Ngoi cc thit b k trn c th l EPIRBtrn tn s 406Mhz, hoc thit b HF/DSC, hoc mt trm INMARSAT d phng, hoc EPIRB v tinh INMARSAT. B/ la chn 2:

Mt thit b thu pht MF/HF cho mc ch thng tin cp cu v an ton trn tt c cc tn s cpcu v an ton trong di tn t 1605 Khz 4000 Khz v 4000Khz -27500Khz bng cc phng thc thng tin DSC, thoi v truyn ch trc tip bng hp.

Mt thit b c kh nng duy tr vic trc canh bng DSC trn tn s 2187.5 Khz v 8414.5 Khzv t nht mt trong nhng tn s cp cu v an ton DSC sau: 4207.5 Khz, 6312 Khz, 12577 Khz hoc 16804.5Khz.

Thit b thu pht tn hiu cp cu chiu t tu - b. 8

Thit b thu pht MF/HF c di tn 1605 Khz 4000 Khz v 4000Khz 27500 Khz, phc v chocc dch v thng tin thng thng bng phng thc thng tin thoi hoc truyn ch trc tip bng hp. 2.2.1.5.Trang thit b v tuyn in cho tu chy vng bin A1, A2, A3 v A4. Tt c cc tu khi hot ng ngoi vng bin A1, A2 nhng trong vng bin A3, ngoi cc trang thit b qui nh chung nh mc 2.2.1.1, s phi trang b thm cc thit b sau:

Thit b thu pht MF/HF s dng cho mc ch an ton v cu nn, c cc phng thc thng tingi chn s DSC, thoi v truyn ch trc tip bng hp, lm vic trong di tn 1605 Khz 4000 Khz v 4000Khz 27500 Khz.

My thu trc canh DSC trn tn s 2187.5 Khz, 8414.5 Khz v t nht mt trong cc tn s sau:4207.5 Khz, 6312Khz, 12577Khz v 16804.5Khz.

Thit b EPIRB-406Mhz, thu pht tn hiu cp cu chiu tu-b. Thit b thu pht thng tin thng thng, c dch v thng tin VT thoi v truyn ch trc tipbng hp.

2.2.2. Thi hn p dngCng c quc t v an ton sinh mng trn bin SOLAS/74 sa i 1988 c hiu lc k t ngy 1/2/1992. V h thng thng tin GMDSS c p dng tng phn trong thi gian chuyn tip, t 1/2/1992 n 1/2/1999.

2.3.

QUI NH V NGUN CUNG CP CHO CC THIT B VT TRN TU.Ngun in chnh, ngun in s c v ngun in d tr ca tu c b tr theo s hnh 2.1 Main source AC-DC Auto Switch Radio Equipments

Emergency Source

Charger Battery

Charger Battery

Hnh 2.1. S b tr ngun cung cp cho cc thit b Thng tin VT.

2.3.1. Ngun in chnh ca tu:Gm t nht hai my pht in phi c kh nng cung cp in nng cho tt c cc thit b in v VT trn tu.

2.3.2. Ngun in s c:Trong trng hp ngun in chnh ca tu b mt th ngun in s c phi cung cp in nng cho cc thit b VT trong thi gian t nht 18gi i vi tu hng v 36 gi i vi tu khch.

2.3.3. Ngun in d trNgun in d tr y l c qui hoc pin. Trong trng hp c ngun in chnh v ngun in s c ca tu b mt th c quy hoc pin s l ngun in d tr cung cp in nng cho cc thit b VT thc hin cc thng tin cu nn v an ton hng hi.

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2.4.

QUI NH V TRC CANH.

t c mc ch l an ton sinh mng trn bin, ng thi vi vic qui nh v cc trang thit b trn tu, T chc Lin minh vin thng Quc t a ra nhng qui nh v trc canh nh sau:

2.4.1. i vi i duyn hi.i vi cc i duyn hi m nhn trch nhim trc canh trong h thng GMDS, s phi duy tr vic trc canh t ng bng DSC trn cc tn s cp cu v an ton trong di tn lm vic ca i duyn hi. Vic trc canh ny phi theo mt chu k nht nh trong gi nghip v ca mnh. Tn s v gi trc canh ca mi mt i c ch r trong danh b cc i duyn hi.

2.4.2. Cc i v tinh mt t.Cc i v tinh mt t m nhn trch nhim trc canh trong h thng GMDSS s phi duy tr vic trc canh t ng i vi cc cuc gi chuyn tip bo ng cp cu c pht bi cc v tinh

2.4.3. Cc i tu.Tt c cc tu trong khi hnh trnh trn bin phi duy tr vic trc canh t ng bng DSC trn cc tn s gi cp cu v an ton thch hp trong cc bng tn m i tu ang khai thc. Cc i tu c trang b cc thit b VT trong h thng GMDSS theo quy nh, cng phi duy tr vic trc canh trn cc tn s thch hp t ng nhn cc thng bo kh tng, thng bo hng hi v cc thng tin khn cp khc.

2.4.4. Cc i tu mt t.Cc i tu v tinh mt t phi c kh nng duy tr vic trc canh i vi cc cuc gi chuyn tip bo ng cp cu chiu t b ti tu, tr khi nhng thng tin thc hin trn knh lm vic. a/ Mi tu khi hnh trnh trn bin phi duy tr vic trc canh lin tc trn:

VHF/DSC knh 70, nu tu lp t thit b radio VHF/DSC, c kh nng trc canh lin tc bngDSC trn knh 70.

Tn s cp cu v an ton DSC 2187.5Khz nu tu c lp t thit b radio c kh nng duy trvic trc canh lin tc bng DSC trn tn s 2187.5Khz kt hp vi thit b radio MF.

Tn s cp cu v an ton DSC: 2187.5Khz, 8417.5Khz v trn t nht mt trong cc tn s cpcu v an ton DSC sau: 4207.5Khz, 6312Khz, 12577Khz hoc 16804.5Khz, tu theo thi gian v v tr thch hp ca tu, nu tu c lp t cc thit b VT c kh nng duy tr vic trc canh lin tc bng DSC trn cc tn s k trn v c kt hp vi mt thit b VT MF/HF. Vic trc canh ni trn cng c th c thay th bng mt my thu trc canh qut t ng.

i vi cc bo ng chuyn tip cp cu bng v tinh chiu t b -tu, nu tu c trang btrm i tu mt t INMARSAT. B/ Mi mt tu trong khi hnh trnh trn bin s phi duy tr vic trc canh VT i vi cc thng bo an ton hng hi trn cc tn s thch hp, m cc thng bo ny c pht ti cc vng bin m tu ang hnh trnh. C/ Cho n ngy 1/2/1999 hoc n mt ngy no khc c th c n nh bi U ban v an ton hng hi, tt c cc tu khi hnh trnh trn bin vn s phi duy tr vic canh nghe lin tc trn knh 16VHF v trn tn s VT thoi 2182Khz.

2.5. H HIU V S NHN DNG CA CC I LM NGHIP V THNG TIN LU NG HNG HI. 2.5.1. Qui nh chung. 10

Tt c mi pht x trong nghip v thng tin VT hng hi u phi c nhn dng bng tn hiu nhn dng. Tn hiu nhn dng phi tun th v ph hp vi cc khuyn ngh ca U ban t vn VT quc t (CCIR). Tn hiu nhn dng c th l mt trong cc dng sau: + Ting ni: S dng trong thoi iu bin; + M Morse quc t: S dng trong morse A1A; + M in bo ph hp vi cc thit b truyn ch trc tip bng hp + Cc dng khc do CCIR khuyn ngh

2.5.2. H hiu(C/S) v s nhn dng (ID) ca cc thit b thng tin mt t.H hiu ca cc i tu, cc i duyn hi v cc i lm nghip v lu ng hng hi c cu to t 26 ch Latin v 10 ch s t nhin t 0 n 9. S nhn dng (ID) ca cc i lm nghip v thng tin lu ng hng hi c cu to t 10 ch s t nhin t 0 n 9. Trong nghip thng tin lu ng hng hi c 4 loi s nhn dng nh sau:

s nhn dng i tu s nhn dng ca nhm tu s nhn dng ca cc i duyn hi s nhn dng ca nhm i duyn hi s nhn dng ca cc i pht Navtex.Mi mt quc gia c Tng th k ca t chc lin minh vin thng quc t n nh mt s nhn dng hng hi MID (Maritime Identification Digits). Mi mt quc gia c n nh mt MID duy nht, tr khi s MID c s dng qu 80% th tng th k lin minh vin thng quc t s n nh mt MID b sung. H hiu v s nhn dng ca cc i phi c cu trc sao cho khng c nhm ln vi cc tn hiu cp cu, khn cp v an ton hoc cc tn hiu c bn cht tng t. A/ H hiu ca i duyn hi. H hiu ca i duyn hi bao gm 3 k t chnh ch tn i l cc ch ci hoc hn hp ch ci v ch s, trong :

cho mi mt quc gia.

Hai k t u l dy h hiu do T chc t vn VT quc t (CCIR) n nh ring

K t th ba l mt trong cc ch ci Rp t A n Z nm trong dy k t ca quc gia doCCIR n nh cho quc gia. Ngoi 3 k t chnh k trn, h hiu ca cc i duyn hi cn c th c thm phn k t ph gm 2 ch s t 0 n 9 nhng ch s ngay sau ch ci khng c dng ch s 0. B/ H hiu ca i tu. H hiu ca i tu gm 4 k t chnh l mt nhm ch ci hoc hn hp ch ci v s, trong :

Hai k t u tin l dy h hiu quc t do T chc t vn VT quc t CCIR n nh cho miquc gia:

Hai k t tip theo nm trong dy h hiu quc gia do quc gia n nh ring cho mi tu, haik t ny l cc ch ci, khng dng cc ch s.

11

Ngoi 4 k t chnh h hiu ca tu cn c th c thm phn ph l cc ch s t 1 n 9. C/ Nhn dng ca i pht thoi Nhn dng ca i pht thoi c qui nh dng tn a danh ni t i pht km theo ch Radio nhn dng i pht thoi. V d: HAIPHONG Radio i vi cc i tu di ng, dng tn ca i di ng nhn dng cc i pht thoi . D/ Nhn dng ca i Radio Telex. Nhn dng ca i Radio Telex. c cu to t cc s t nhin t 0 n 9, gm 4 ch s i vi i b v 5 ch s i vi i tu. V d: S gi chn ca i Radio telex Singapore l 4620 Ngoi s gi chn k trn, cc i Radio telex cn c s Answerback code dng t xng trong cc cuc thng tin radio telex. E/ Nhn dng ca i pht DSC. S nhn dng ca cc i c nghip v lu ng hng hi (MMSI) gm 9 ch s t nhin t 0 ti 9, c cu to nh sau:

i vi i b: 00MIDXXXXTrong : 00: ch i duyn hi MID: s nhn dng hng hi quc gia XXXX: 4 ch s t nhin ch s nhn dng ca i duyn hi. V d: i HaiPhng radio c s nhn dng MMSI l 005741997 Trong : 00: ch i duyn hi 574: s nhn dng hng hi ca Vit Nam 1997: s nhn dng ca i duyn hi Hi Phng.

i vi i tu: MIDXXXXXXTrong : MID l s nhn dng hng hi quc gia XXXXXX: 6 ch s t nhin ch s nhn dng ca i tu. V d: Tu Brazil Victoria c s nhn dng l 636005973, trong 636 l s nhn dng hng hi quc gia ca Liberia, 005973 l s nhn dng ring ca tu Brazil Victoria.

i vi nhm tu: 0MIDXXXXXTrong :Nhm ch s 0 u tin ch nhm tu MID: l s nhn dng hng hi quc gia XXXXX: l 5 ch s t nhin t 0 n 9 ch s nhn dng ca nhm tu. F/ Nhn dng ca i pht Navtex. Trong h thng Navtex quc t, cc vng bin trn th gii c chia thnh 16 vng c nh s t I n XVI. S trm pht cc dch v Navtex quc t trong mt vng khng qu 24 trm, s nhn dng ca mi mt trm trong mt vng l mt ch ci theo th t t A n Z. Ch ci th 2 tip sau ch loi bc in v 2 ch s tip theo ch s bc in Navtex . V d: Mt bn in Navtex c dng nh sau: ZCZC X1X2X3X4

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............. (ni dung bc in) NNNN. Trong : ZCZC: m bt u bc in NBDP X1: s nhn dng ca i pht k hiu t A n Z. X2: bng mt ch ci ch loi bc in k hiu t A n Z. X3X4: l 2 ch s t nhin ch s bc in.

2.5.3. S nhn dng ca cc thit b thng tin v tinh.S nhn dng ca cc thit b thng tin v tinh cng phi tun th theo cc qui nh ca U ban t vn VT quc t (CCIR). A/ S nhn dng ca cc i tu v tinh mt t (SES). S nhn dng ca cc i tu v tinh mt t (INMARSAT) ging nh mt s thu bao dng gi t mt i v tinh mt t hoc t mt thu bao khc thng qua mt trm v tinh mt t. Chc nng ca n ging nh mt s in thoi hoc mt s fax. Cu trc s nhn dng ca cc i tu v tinh mt t nh sau: + vi INMARSAT A: Gm mt nhm 7 ch s octal c dng TMIDXXX. Trong : T=1 ch trm INMARSAT A MID l 3 ch s nhn dng quc gia do T chc INMARSAT quc t n nh. XXX l 3 ch s c n nh ring cho mi trm + vi INMARSAT B: Gm mt nhm 9 ch s Decimal c dng TMIDXXXYZ. Trong : T=3 ch trm INMARSAT B MID l 3 ch s nhn dng quc gia do T chc INMARSAT quc t n nh. XXX l 3 ch s gia 000 v 999 nhn dng mt i tu v tinh, XY l 2 ch s gia 10 v 99 dng nhn dng mt i tu v tinh MES trn tu (Y khng c dng ch s 0) + vi INMARSAT C: Gm 9 ch s decimal c dng TMIDXXXYZ. Trong : T=4 ch trm INMARSAT C MID l 3 ch s nhn dng quc gia do T chc INMARSAT quc t n nh. XXX l 3 ch s gia 000 v 999 nhn dng mt i tu v tinh, YZ l 2 ch s gia 10 v 99 dng nhn dng i MES trn tu. + vi INMARSAT M: Gm 9 ch s decimal c dng TMIDXXXYZ. Trong : T=6 ch trm INMARSAT M MID l 3 ch s nhn dng quc gia do T chc INMARSAT quc t n nh. XXX l 3 ch s gia 000 v 999 nhn dng mt i tu v tinh, YZ l 2 ch s gia 10 v 99 dng nhn dng i MES trn tu. + vi INMARSAT mini M: Gm 9 ch s decimal c dng TMIDXXXYZ. Trong : T= 7 ch trm INMARSAT mini M.

13

MID l 3 ch s nhn dng quc gia do T chc INMARSAT quc t n nh. XXX l 3 ch s gia 000 v 999 nhn dng mt i tu v tinh, YZ l 2 ch s gia 10 v 99 dng nhn dng i MES trn tu. B/ S nhn dng ca cc trm v tinh mt t (SES). S nhn dng ca cc trm v tinh mt t l mt nhm gm 3 ch s, trong :

Ch s th nht ch tn v tinh:Ch s 0 ch v tinh AOR-W Ch s 1 ch v tinh AOR-W Ch s 2 ch v tinh POR Ch s 3 ch v tinh IOR.

Hai ch s tip theo ch s nhn dng ca ring mi trm trong mt vng v tinh. 2.6. QUI TRNH V BO DNG V CHNG CH KHAI THC VIN TRN TU TRONG H THNG GMDSS. 2.6.1. Qui trnh v bo dng cc thit b thng tin VT trn tu.Vn bo dng cc thit b thng tin VT trn tu c qui nh r trong iu 15 chng 4 nh sau:

Cc thit b phi c thit k theo dng Modul c th d dng thay th v khng c iuchnh hoc chun li.

Vi cc tu p dng h thng GMDSS cc thit b phi c cu trc v lp t sao cho r rng,thun tin cho vic thanh tra,kim tra v bo dng trn tu

Nhng chc nng thng tin ca cc thit b c lp t trn tu phi c tho mn v duy trkh nng lm vic ca cc thit b.

2.6.2. Cc phng php m bo tnh sn sng ca thit b thng tin VT.Theo qui nh trong iu 15 chng 4 ca SOLAS sa i 1988, c ba phng php m bo tnh sn sng ca cc thit b thng tin, nh sau:

1. Trang thit b kp cc thit b 2. Bo dng b v 3. Bo dng trn tu 2.6.3. Qui dnh v chng ch khai thc vin trn tu trong h thng GMDSS.2.6.3.1.Qui nh chung. Trong trng hp khng c mt khai thc vin chnh thc, cc nhim v ca khai thc vin ch gii hn trong mt s ni dung sau:

Gi cp cu, chuyn bc in cp cu, khn cp v an ton. Pht cc bc in lin quan trc tip ti an ton sinh mng trn bin Cc bc in khn lin quan n s di chuyn ca tu. i vi cc i tu hoc cc i di ng mt t p dng h thng GMDSS c 4 loi chng ch khai thc vin nh sau:

The first - class radio electronic certificate 14

The second - class radio electronic certificate The general operators certificate The restricted operators certificateMi mt khai thc vin trc khi c cp nhng chng ch trn y, phi c mt trnh nht nh v l thuyt v thc t khai thc i vi h thng thng tin GMDSS theo qui nh. 2.6.3.2.iu kin cp cc chng ch khai thc vin VT. The first-class radio electronic certificate Nhng ngi c cp chng ch The first-class radio electronic certificate phi c kin thc chuyn nghip nh sau: 1. C kin thc nguyn l v ngun in nng v kin thc l thuyt v VT v in t p ng nhng yu cu 2, 3, 4 di y. 2. C kin thc l thuyt v cc thit b thng tin VT trong h thng GMDSS, bao gm cc thit b thu v pht NBDP, radio telephone, thit b DSC, EPIRBs, MES, h thng anten hng hi, thit b VT cho phao b, cng vi tt c cc thit b d phng bao gm ngun cung cp, cng nh nhng kin thc chung v nguyn l ca cc thit b VT hng hi vi nhng qui tc ring bit bo dng cc thit b . 3. C kin thc thc t v khai thc v bo dng nhng thit b k trn. 4. C kin thc thc t cn thit xc nh v sa cha c hiu qu cc thit b k trn khi cc thit b h hng trn bin 5. C kh nng pht v thu chnh xc bng thoi v telex 6. C kin thc chi tit v nhng qui tc p dng trong thng tin VT, nhng ti liu lin quan n cc ph trong thng tin VT v nm nhng iu khon ca Hi ngh quc t v an ton sinh mng trn bin lin quan n thng tin VT. 7. C kh nng ni v vit thnh tho mt trong nhng ngn ng ca t chc Lin minh vin thng quc t The second-class radio electronic certificate

2.7. GIY PHP V VIC KIM TRA GIM NH TRN TU. 2.7.1. Giy php VT i tuNi dung ca giy php VT i tu bao gm:

Tn tu H hiu, s nhn dng (ID) hay cc s hiu nhn bit khc Tn ch tu Cc loi thit b pht Cng sut pht x Ch pht x Di tn s lm vic Cc tn s n nh khc 2.7.2. Kim tra, gim nh VT trn tu.Theo qui nh th tt c cc thit b thng tin VT trn tu u phi c gim nh, kim tra nh k bi cc c quan c thm quyn m bo rng cc i tu tho mn v ph hp vi cc cng c, cc

15

qui nh hin hnh. Ch tu v nhng ngi c trch nhim trn tu phi c trch nhim to mi iu kin vic kim tra, gim nh ny c tin hnh thun li. Khi cc c quan c thm quyn ca nc s ti tin hnh vic thanh tra, kim tra i tu, thuyn trng hoc ngi c trch nhim trn tu phi trnh bo nhng chng ch VT c lin quan n i tu cng nh nhng chng ch ca s quan VT.

2.8.

CHC TRCH CA S QUAN VT TRN TU.

S quan VT trn tu chu s ch o trc tip ca thuyn trng hoc ngi c trch nhim trn tu. Ngi c thm quyn s yu cu s quan VT phi tun th theo cc qui nh, th l thng tin VT quc t. S quan VT s l ngi trc tip chu trch nhim thc hin cc chc nng thng tin trn tu.

CHNG 3. NGHIP V THNG TIN CP CU, KHN CP V AN TON3.1. CC TRNG HP CP CU, KHN CP V AN TON.Ch p dng i vi cc i lm nghip v thng tin lu ng hng hi hoc hng khng.

3.1.1. Cc trng hp cp cu.Mt i tu hoc mt i tu mt t l cc i lu ng c gi l ang trong tnh trng cp cu khi i tu hoc i tu mt t ; hoc mt hoc nhiu ngi trn cc tu ang hoc s gp nguy him cn s tr gip ngay lp tc.

16

Cc cuc gi cp cu c bt u bng tn hiu bo ng cp cu Cc bc in cp cu c bt u bng tn hiu bo ng cp cu MAY DAY

3.1.2. Cc trng hp khn cp.Mt i tu hoc mt i tu mt t l cc i lu ng c gi l ang trong tnh trng khn cp khi i tu hoc i tu mt t ; hoc mt hoc nhiu ngi trn cc tu ang hoc s gp nguy him cn s tr gip. Cc cuc gi khn cp c bt u bng tn hiu bo ng khn cp Cc bc in khn cp c bt u bng tn hiu khn cp PAN PAN

3.1.3. Cc trng hp gi an ton.Cc cuc gi an ton c thc hin bi cc i lu ng, cc i duyn hi hoc cc i b lm nghip v lu ng hng hi pht i cc thng bo hoc cc bn tin m cc i nhn thy rng chng cn thit cho vn an ton hng hnh ca cc i lu ng khc. Cc bc in an ton c bt u bng tn hiu an ton SECURITY

3.2.

QUI NH CHUNG V CP CU KHN CP V AN TON. Nhng thng tin cp cu s c u tin tuyt i trn tt c cc loi thng tin khc. Tt c cc

3.2.1. Nhng qui nh chung.i khi nghe c mt cuc gi cp cu hoc thng tin cp cu hoc nhng thng tin lin quan n cp cu, phi ngay lp tc ngng mi pht x gy can nhiu hoc c th gy can nhiu ti cuc gi hoc cc thng tin cp cu v pht in cp cu.

Cc cuc gi cp cu v in cp cu ch c pht i khi c lnh ca thuyn trng hoc ngic trch nhim trn tu.

Cc i dch v di ng mt t trong khu vc dn c tha tht hoc hot ng trong khu vchn ch, cho mc ch cp cu v an ton s dng cc tn s c qui nh trong h thng GMDSS.

Nhng th tc v cp cu, khn cp v an ton c trnh by trong chng ny l bt buc ivi trm dch v di ng mt t dng cc tn s c qui nh trong h thng GMDSS cho mc ch thng tin cp cu, khn cp v an ton.

Khng c bt k mt iu khon no ngn cm cc i di ng hoc cc i v tinh di ng mtt trong khi b nn, dng bt c phng tin g bo v tr, gy s ch v t c mc ch cu tr.

Khng c bt k mt iu khon no ngn cm cc i tu, i my bay, cc i duyn hi hoccc i v tinh mt t dng bt k mt phng tin no tin hnh vic tm kim cu tr mt i di ng hoc mt i di ng mt t khc ang trong tnh trng b nn.

Cc trm i tu v tinh mt t c th c ch nh thc hin cc mc ch thng tin cpcu v an ton vi mt i khc trn cc bng tn dng cho nghip v di ng v tinh hng hi trong nhng hon cnh c bit mc d cc phng php lm vic quy nh trong cc iu khon ca T chc lin minh vin thng quc t.

Khi pht in cp cu, khn cp hoc an ton bng VT thoi phi pht m chm ri, r rng.Trong trng hp kh khn v ngn ng, c nghip v v bng phin m quc t.

Cc trng hp cp cu, khn cp v an ton c th c pht trn cc bng tn MH/HF v VHFca cc thit b DSC, thoi SSB, NBDP hoc cc thit b thng tin v tinh trn cc knh(tn s) chung quc t vi mc u tin cao nht.

17

Cc i lm nghip v di ng hng hi c th thng tin vi cc i my bay cho mc ch anton nhng phi s dng tn s thch hp cho nghip v ny v phi tun theo cc th tc qui nh.

Cc i my bay khi thng tin vi cc i lu ng hng hi cho mc ch cp cu v an ton,phi tun theo cc qui nh ca quc gia hoc quc t v cc qui nh trong h thng GMDSS. Cc i phi c kh nng thu, pht ch J3E v H3E trn cc tn s 2182 Khz v 4125Khz; c kh nng thu, pht ch G3E trn cc tn s 156.8Mhz (knh 16) v 156.3Mhz (knh 6).

3.2.2. Cc tn s trong thng tin cp cu khn cp v an ton.3.2.2.1.Cc tn s cho cp cu, khn cp v an ton bng DSC.

Di tn MF/HF: Cc tn s 2187.5Khz, 4207.5Khz, 8414.5Khz, 12577Khz v 16804.5Khz cqui nh ch ginh ring cho vic gi cp cu v an ton bng DSC ca cc i lm nghip v di ng hng hi. Cc tn s ny khng c php dng cho cc mc ch khc.

Di tn VHF: Tn s 156.525 Mhz(knh 70) l tn s dng cho cc i lm nghip v di nghng hi gi cp cu, khn cp v an ton bng DSC. 3.2.2.2.Cc tn s cho cp cu khn cp v an ton bng VT thoi trong h thng thng tin mt t

Di tn MF/HF: Cc tn s 2182 khz, 4125 khz, 6312 khz, 12577khz v 16804.5 khz c dng thng tin cp cu, khn cp v an ton bng VT thoi ch J3E hoc H3E. Trong trng hp trn khng c cc thng tin lin quan n cp cu, khn cp v an ton th cc tn s ny c th c dng gi v bt lin lc cho thng tin thng thng bng VT thoi, nhng thi gian gi v cng sut ca my pht phi c hn ch mc nh cn thit.

Di tn VHF:+ Tn s 156.8Mhz (knh 16) c dng cho thng tin thng tin cp cu, khn cp v an ton bng VT thoi. Trong trng hp trn khng c cc thng tin lin quan n cp cu, khn cp v an ton th cc tn s ny c th c dng gi v bt lin lc cho thng tin thng thng bng VT thoi, nhng khng c ko di qu mt pht + Tn s 156.3Mhz (knh 6) c th c dng cho hot ng phi hp tm kim v cu nn gia cc i tu v i my bay. Tn s ny cng c th c dng cho mc ch thng tin an ton gia cc i my bay v i tu. + Tn s 121.5Mhz trong bng tn 117.975 Mhz n 136 Mhz dng cho mc ch cp cu v khn cp trong nghip v di ng hng khng bng VT thoi. 3.2.2.3.Cc tn s cp cu, khn cp v an ton bng phng thc thng tin NBDP

Tn s 490 khz l tn s quc gia ginh ring cho cc i duyn hi pht cc thng bo khtng, thng bo hng hi v cc thng tin an ton cho cc tu bng thit b truyn ch trc tip bng hp.

Tn s 518 khz l tn s ca h thng Navtex dnh ring cho cc i duyn hi pht cc thngbo kh tng, thng bo hng hi b cc thng tin khn cp cho cc tu bng thit b truyn ch trc tip bng hp.

Cc tn s2174.5 khz, 4177.5 khz, 6268 khz, 8376.5 khz, 12520 khz v 16695 khz l tn s dnhring cho cc thng tin cp cu, khn cp v an ton bng thit b truyn ch trc tip bng hp. Cc tn s ny khng c php s dng cho cc mc ch thng tin khc.

18

Cc tn s 4210 khz, 6314 khz, 8416.5 khz, 16804.5 khz, 19680.5 khz, 22376 khz v 26100.5khz l cc tn s dnh ring cho cc i duyn hi pht cc thng tin an ton hng hi bng thit b truyn ch trc tip bng hp. 3.2.2.4.Cc tn s cp cu, khn cp v an ton trong h thng thng tin v tinh. Cc tn s 406-406.1 Mhz l tn s dnh ring cho cc phao nh v VT bng v tinh trong h thng COSPAS-SARSAT. Bng tn 1544-1545 Mhz c dng cho cc hot ng cp cu, khn cp v an ton chiu t v tinh xung cc trm mt t, bao gm:

Pht chuyn tip cc tn hiu nh v v tuyn v tinh xung cc trm mt t. Pht chuyn tip ng tn hiu bng hp t v tinh xung cc trm di ngBng tn 1626.5-1645.5Mhz c dng cho cc mc ch cp cu v an ton chiu t mt t ti v tinh trong nghip v di ng hng hi. Bng tn 1645.5-1646.5Mhz c dng cho cc cp cu, khn cp v an ton chiu t mt t ti v tinh, bao gm:

Vic pht t cc EPIRB v tinh Pht chuyn tip cc loan bo bp cu t cc v tinh tm thp qu o cc ti cc trm mt t3.2.2.5.Tn s cp cu, khn cp v an ton s dng trn cc xung cu sinh.

Cc thit b VT thoi dng trn xung cu sinh phi c kh nng thu v pht trn tn s 156.8Mhz trong bng tn t 156-174 Mhz v phi c thm t nht mt tn s khc trong bng tn ny

Thit b pht tn hiu nh v trn xung cu sinh phi c kh nng hot ng trn bng tn s9200-9500 Mhz.

Thit b gi chn s DSC trn xung cu sinh hot ng trn cc bng tn s:+ T 1605-2850 khz th phi c kh nng pht trn tn s 2187.5 khz + T 4000-27500 khz th phi c kh nng pht trn tn s 8414.5 khz + T 156-174 Mhz th phi c kh nng pht trn tn s 156.525 khz Bng 3.1 trnh by cc tn s dng trong cp cu, khn cp v an ton trong thng tin lu ng hng hi ca cc thit b thng tin mt t.

Di tn(khz) 410-535 1605-4000 4000-27500

DSC(khz)

Thoi (khz)

2187.5 4207.5

2182 4125

NBDP (khz) 490 518 2174.5 4177.5 4209.5 4210 6268 8376.5 8416.5 12520

Ghi ch Navtex quc gia Navtex quc t

i b pht navtex i b pht thng bo an ton

6312 8414.5 12577

6215 8291 12290

19

16804.5

16420

12579 16695 16806.5 19680.5 22376 26100.5

156-174mhz

156.650mhz Cho hot ng tm kim v cu nn (knh 13) 156.8mhz (knh 16) Bng 3.1: Cc tn s dng trong cp cu, khn cp v an ton trong thng tin lu ng hng hi ca cc thit b thng tin mt t. 3.2.2.6.Bo v v chng can nhiu cc tn s cp cu, khn cp v an ton. Ngoi tr nhng iu khon qui nh v vic s dng cc tn s cp cu, khn cp v an ton, ngoi ra nghim cm bt k vic pht no gy ra can nhiu hoc c th gy can nhiu ti cc thng tin cp cu, thng bo cp cu, bo ng cp cu, khn cp hoc an ton trn cc tn s: 500 khz, 2174.5 khz, 2182 khz, 2187.5khz, 4125 khz, 4207.5 khz, 6215 khz, 6312 khz, 8291 khz, 8376.5 khz, 8414.5 khz, 12290 khz, 12520 khz, 12577 khz, 16420 khz, 16695 khz, 16804.5 khz, 121.5 Mhz, 156.525 Mhz, 156.8 Mhz, hoc tn s trong bng tn 406-406.1 Mhz, 1544-1545 mhz v 1645.5-1646.5 Mhz. Trc khi pht cc thng tin lin quan n mc ch cp cu, khn cp v an ton trn cc tn s cp cu, khn cp v an ton nh ni mc 3.2.2. phi lng nghe chc chn rng trn tn s khng c cc cuc gi cp cu, khn cp v an ton hoc cc thng tin lin quan n cp cu, khn cp v an ton ang c tin hnh. Nghim cm tt c cc cuc pht x bt k tn s no trong di tn s t 2173.5-2190.5 khz, tr cc tn s 2182 khz, 2174.5 khz, 2177 khz, 2187.5 khz, 2189.5 khz m c nhng qui nh ring v vic s dng cc tn s . Nghim cm tt c cc cuc pht x bt k tn s no trong di tn s t 156.7625- 156.8375 Mhz, tr tn s 156.8 Mhz m c th gy can nhiu ti cc i lm nghip v thng tin di ng hng hi lm vic trn tn s 156.8 Mhz.

156.525mhz knh 70

3.3. TRC CANH THNG TIN CP CU, KHN CP V AN TON. 3.3.1. Trc canh chu k im lng i vi tn s cp cu thoi 2182 Khz.Tt c cc i lm nghip v thng tin lu ng hng hi u phi thc hin vic trc canh cc chu k im lng ca tn s cp cu thoi 2182 Khz trong gi nghip v ca mnh, t pht 00 n pht th 03 v t pht th 30 n pht th 33 ca mi gi trong ngy t 00 gi n 24 gi UTC. Do nghim cm tt c mi pht x trn tn s 2182 Khz trong cc chu k im lng ni trn, tr cc cuc gi cp cu hoc cc thng tin lin quan n cp cu. Ngoi ra cc i lm nghip v thng tin lu ng hng hi trong gi nghip v ca mnh cng phi thc hin vic trc canh cp cu, khn cp v an ton trn cc tn s cp cu, khn cp v an ton trong cc di tn lm vic c ng k ca cc i .

3.3.2. i vi cc i duyn hi. 20

Tt c cc i duyn hi lm nghip v thng tin cng cng trong h thng thng tin GMDSS lm vic vi h thng ca h thng thng tin mt t, s phi c trch nhim duy tr vic trc canh t ng bng DSC vi nhng chu k, thi gian v trn nhng tn s m c ng k trong danh b cc i duyn hi.

3.3.3. i vi cc i b mt t.Tt c cc trm i b mt t lm nghip v thng tin cng cng trong h thng thng tin GMDSS lm vic vi h thng thng tin v tinh, s phi c trch nhim duy tr vic trc canh t ng, lin tc i vi nhng cuc pht chuyn tip cp cu ca cc v tinh.

3.3.4. i vi cc trm i tuTt c cc trm i tu m c trang b cc thit b thng tin trong h thng GMDSS trong khi hnh trnh trn bin s phi duy tr vic trc canh t ng bng DSC trn nhng tn s gi cp cu, khn cp v an ton trn nhng bng tn m tu ang khai thc. Nhng trm i tu m c trang b cc thit b thng tin nh vy cng s phi duy tr vic trc canh trn nhng tn s thch hp c th t ng thu nhn nhng thng bo kh tng v nhng thng tin an ton hng hi c lin quan n hng hi c lin quan n hng hnh ca tu.

3.3.5. i vi cc trm i tu mt t. (SES)Nhng trm i tu mt t phi duy tr vic trc canh thu nhn nhng chuyn tip loan bo cp cu chiu t tu trn nhng knh chung hoc nhng knh dnh cho cp cu v an ton. Theo tt c cc trm i tu SES u phi duy tr vic trc canh thng qua my thu EGC.

3.4.

BO NG V GI CP CU.

Mt thng tin cp cu bao gm ba giai on: - Tn hiu bo ng cp cu - Gi cp cu v - Bc in cp cu Bo ng cp cu c th c pht qua h thng thng tin v tinh vi mc u tin cao nht trn knh thng tin chung hoc h thng thng tin VT mt t trn nhng tn s ginh ring cho thng tin cp cu ca cc bng tng MH, HF v VHF dng k thut gi chn s. Cc cuc gi cp cu l cc cuc gi khng c a ch v nhng cuc gi cp cu v cc bc in cp cu nh vy ch c pht i bi thuyn trng hoc ngi c u quyn ca thuyn trng hoc ngi c trch nhim trn tu. Bt k mt bo ng cp cu no cng phi bao gm nhn dng ca i b nn v v tr ca n. Mt bo ng cp cu nh vy c th thc hin t ng hoc nhn cng. Trong nghip v thng tin lu ng hng hi cc cuc bo ng v gi cp cu ch c pht i t cc i di ng.

3.4.1. Bo ng v gi cp cu bng DSC.Theo cng c quc t v an ton sinh mng trn bin SOLAS/1974 b sung v sa i nm 1988, trong h thng an ton v cu nn hng hi ton cu GMDSS, cc thit b gi chn s DSC l cc thit b c bn cho mc ch thng tin an ton v cu nn hng hi ton cu. Ni dung camt bo ng cp cu bng DSC gm:

Tn hiu bo ng cp cu S nhn dng (ID) ca tu b nn V tr ca tu b nn (v , kinh ) 21

Thi gian b nn (UTC) Tnh cht b nnNhng ni dung trn c th c truy cp t ng hoc bng tay. Nu trng hp thng tin v v tr ca tu b nn khng c truy cp hoc khng c xc nh th thit b s t ng pht i 10 con s 9 lin tip. Nu trng hp thng tin v thi gian ca tu b nn khng c truy cp hoc khng c xc nh th thit b s t ng pht i 4 con s 8 lin tip. 3.4.1.1.Cuc gi cp cu (tc thi) bng DSC. Kiu gi ny p dng cho trng hp khai thc vin khng c thi gian chun b cc bc in cp cu m ch vic n vo nt Distress, mt s thng tin quan trng ca mt cuc gi cp cu trn y c th thc hin trn mt tn s cp cu duy nht hoc nhiu tn s gi cp cu trong bng tn MF v HF. Trong di tn VHF ch dng mt tn s gi duy nht 156.525 Mhz (knh 70) Ni dung ca cuc gi gm:

Format: Position: Time: Natural: Telecommand:

DISTRESS

Self identification: MMSI (ca tu pht cp cu)c cp nht trong my c cp nht trong my La chn mt trong 8 trng hp b nn Telephone

3.4.1.2. Cuc gi cp cu trong trng hp c thi gian chun b bc in cp cu- c thc hin bi khai thc vin. Trong trng hp c thi gian khai thc vin chun b bc in gi cp cu th khai thc vin phi truy cp mt s thng tin quan trng ca mt cuc gi cp cu nh sau:

v tr b nn Thi gian b nn Tnh cht b nn Phng thc v tn s thc hin thng tin cp cu Chn tn s cp cu DSC thch hp gi cp cu.

3.4.2. Cc trng hp bo ng cp cu v chuyn tip bo ng cp cu.3.4.2.1.Bo ng cp cu c pht bi mt i tu hoc mt i tu mt t. Mt bo ng cp cu c pht bi mt i tu hoc mt i tu mt t khi tu hoc nhng ngi trn tu ang trong tnh trng cp cu, yu cu c tr gip ngay lp tc. Mt bo ng cp cu c ni dung v cch tin hnh nh sau:

Pht tn hiu bo ng cp cu Nhn dng ca i tu ang trong tnh trng cp cu v tr b nn Tnh cht b nn

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3.4.2.2.Pht chuyn tip bo ng cp cu chiu t b n tu. Trong trng hp mt trung tm phi hp cu nn khng th tin hnh cu tr ngay lp tc th mt i b hoc mt trung tm phi hp cu nn s pht chuyn tip bo ng cp cu ti mt tu, mt nhm tu thch hp hoc ti tt c cc tu bng cc thit b thng tin v tinh INMARSAT hoc bng cc thit b DSC. Trong cuc gi chuyn tip cp cu phi ch ra s nhn dng ca i pht chuyn tip cp. Ni dung ca cuc gi chuyn tip cp cu ging nh ni dung ca cuc gi cp cu m i nhn c. 3.4.2.3.Pht chuyn tip bo ng cp cu bi mt i tu khng b nn. Mt i di ng hoc mt i di ng v tinh khi nhn thy rng mt i di ng khc ang trong tnh trng cp cu s pht mt bo ng chuyn tip cp cu trong nhng trng hp sau:

Khi mt i di ng trong tnh trng cp cu nhng khng t pht c bo ng cp cu. Khi thuyn trng hoc ngi c trch nhim trn tu nhn thy rng vic gip l cn thit. Format: all ships(or ships in geographical area or individual station) Address: Nu cuc gi all ship th khng cn a a ch, nu gi geographical area or Category: DISTRESS Self identification: +9 s nhn dng MMSI ca i pht chuyn tip Distress ship ID: 9 s nhn dng MMSI ca tu b nn Message: Repeat of original alert information. MMSI (of station in distress) Distress co-ordinates Position Time Type of subsequent communications

Ni dung ca mt chuyn tip bo ng cp cu:

individual station phi a a ch vng a l hoc ID ca i cn gi.

3.4.3. Gi cp cu bng VT thoi.Th tc mt cuc gi cp cu bng thoi gm:

Tn hiu bo ng cp cu Gi cp cu Pht bc in cp cu MAYDAY MAYDAY MAYDAY This is (hoc DE-delta echo- trong trng hp ngn ng kh khn) H hiu hoc s nhn dng ca tu b nn-pht 3 ln

C th:

Ni dung ca mt bc in cp cu bao gm

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Tn hiu cp cu MAYDAY H hiu hoc s nhn dng khc ca tu b nn V tr b nn Nhng yu cu tr gip

Nhng thng tin khc nu c 3.4.4. Gi cp cu bng cc thit b thng tin v tinhTrong cc thit b thng tin v tinh c hai phng thc c bn gi cp cu:

Gi cp cu bng telex. Gi cp cu bng thoi

3.4.4.1.Gi cp cu bng telex i vi trm SES INMARSAT C Gm hai phng php sau: A/ Dng phm DISTRESS ALERT pht mt bo ng cp cu. p dng trong trng hp b nn nhng khng c thi gian son bc in chi tit, bng cch n v gi nt DISTRESS ALERT trong khong 5 giy. Ch : mt s thng tin v v tr, thi gian, tc v hng tu khng c trong loan bo cp cu nu cc thit b ca SES khng c cc thit b cp nht cc thng tin lin tc. B/ son tho Bc 1: son in vi ni dung sau:

Tn hiu cp cu MAYDAY Tn tu hoc s nhn dng khc v tr b nn Thi gian b nn Tnh cht b nn Yu cu tr gip Nhng thng tin khc Lu bc in va son vo file v t tn file Format: Distress (selected) Type: Telex (selected) File name LES ID: (entered)

Bc 2: Bc 3: Lm th tc chuyn bc in cp cu gm:

Bc 4: Tin hnh pht in cp cu.

3.4.4.2.Gi cp cu bng thoi thng qua cc thit b thng tin v tinh.

Nhc handset

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n phm EMERGENCY hoc phm * v gi trong 5 giy. Nhp ID ca trm LES gn nht Quay s in thoi ca RCC gn nht Pht li ku cu v bc in cp cu.

3.5. BO NHN MT CUC GI CP CU. 3.5.1. Th tc bo nhn mt cuc gi cp cu.3.5.1.1.Bo nhn cp cu t mt i duyn hi, mt i v tinh mt t CES hoc t mt trung tm phi hpcu nn RCC. Cc i duyn hi v cc i v tinh mt t thch hp khi nhn c mt bo ng cp cu phi chc chn rng ni dung ca loan bo cp cu s c gi ti mt trung tm phi hp cu nn RCC thng qua mt i duyn hi hoc mt trm v tinh mt t khi nhn c mt loan bo cp cu s phi tin hnh pht xc nhn loan bo cp cu. cng sm cng tt. Mt i duyn hi s phi pht xc nhn mt cuc gi cp cu ti tt c cc tu bng k thut gi chn s DSC trn tn s gi cp cu m i duyn hi nhn c mt cuc gi cp cu . 3.5.1.2.Bo nhn cp cu t mt i tu hoc mt i tu mt t. Cc i tu hoc cc i tu mt t khi nhn c mt loan bo cp cu s phi thng bo cho thuyn trng hoc ngi c trch nhim trn tu nhng thng tin ca cuc gi cp cu cng sm cng tt. Nhng vng bin m chc chn s thng tin c vi mt hoc nhiu i duyn hi, cc i tu khi nhn c mt loan bo cp cu s phi tr hon vic xc nhn ca munh cho cc i duyn hi xc nhn trc. Mt i tu nhn c mt loan bo cp cu trn di tn HF s khng xc nhn loan bo cp cu , nhng s phi thc hin vic trc canh trn cc tn s cp cu vi nhng phng thc thng tin thch hp. Nu trong khong thi gian 3 pht m khng c mt i duyn hi no pht xc nhn loan bo cp cu th s pht chuyn tip loan bo cp cu . Mt i tu khi pht xc nhn mt cuc gi cp cu s phi:

Pht xc nhn cuc gi cp cu bng thoi trn tn s ginh cho cp cu v an ton bng thoi N u vic xc nhn cuc gi cp cu bng thoi trn cc tn s gi cp cu ca di tn MF

ng vi bng tn dng nhn cuc gi cp cu. hoc VHF khng thnh cng, th vic xc nhn c th c thc hin bng thit b gi chn s DSC trn mt tn s DSC thch hp.

3.5.2. Th tc bo nhn gi cp cuTt c cc cuc bo nhn cp cu u c thc hin bng nhn cng m khng c ch t ng xc nhn cuc gi cp cu trong tt c cc thit b thng tin trong h thng GMDSS. 3.5.2.1. Th tc bo nhn cp cu bng DSC Vic bo nhn mt cuc gi cp cu bng DSC thng c p dng cho cc i Duyn Hi, v s c pht trin cng tn s cp cu DSC m tu b nn dng pht bo ng cp cu . i vi cc i tu khi nhn c mt bo ng cp cu bng DSC s phi ch mt khong thi gian t 3 n 5 pht cho cc i Duyn Hi xc nhn trc. Nu trong khong thi gian trn, khng c bt k mt i no pht xc nhn th di tu s lm th tc bo nhn cuc gi cp cu bng thoi nu thy s

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tr gip l cn thit. Mt i tu khng b nn khi nhn c mt bo ng cp cu bng DSC ch thc hin vic bo nhn bng DSC khi bit chc chn rng bo ng cp cu nm ngoi vng ph sng ca cc i Duyn Hi m chc chn rng bo ng cp cu nm ngoi vng ph sng ca cc i Duyn Hi m chc chn s khng c bt c mt i no c kh nng nhn c bo ng cp cu . Cn lu rng khi i tu pht xc nhn cuc gi cp cu bng DSC cho tu b nn, th i tu phi pht chuyn tip loan bo cp cu ti mt i Duyn Hi v phi chc chn rng i tu mnh ang trong vng ph sng ca t nht mt i Duyn Hi gn nht. Cc lu trong hnh 3.1, hnh 3.2 v 3.3 trnh by cc trng hp xc nhn mt loan bo cp cu trong vng bin A1, A2, A3. Ni dung ca mt cuc xc nhn cp cu bng DSC bao gm: Format : ALL SHIPS Category : DISTRESS Self dentification : 9 s nhn dng MMSI ca i tu pht xc nhn Telecommand : DISTRESS ACKNOWLEDGENMENT Diastress Ship's ID : 9 s nhn dng MMSI ca tu b nn. 3.5.2.2. Th tc bo nhn cp cu bng thoi Th tc bo nhn mt cuc gi cp cu bng v tuyn in thoi trong h thng thng tin GMDSS c p dng cho cc i tu hoc cc i tu mt t nh sau: - Tn hiu cp cu "MAYDAY" - Mt ln. - H hiu hoc s nhn dng ID ca tu b nn - pht 3 ln; - "THIS IS" hoc DE (Delta E cho trong trng hp ngn ng kh khn). - H hiu hoc s nhn dng ID ca i bo nhn cp cu - pht 3 ln; "RECEIVED" hoc RRR (Remeo Romeo Romeo trong trng hp ngn ng kh khn). - Tn hiu cp cu "MAYDAY".

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Nhn c bo ng cp cu bng DSC

Canh nghe trn knh 16 trong vng 5 pht

C bo nhn ca i DH or RCC khng? Khng Thng tin cp cu c thc hin khng? Khng Bo ng cp cu DSC c tip tc khng? Khng

C

Tu c kh nng tr gip khng? C C

Khng

C

Xc nhn bo ng cp cu bng thoi trn knh 16 ti tu b hn

Thng bo ti i Duyn Hi hoc RCC

a thit b v trng thi hot ng bnh thng

Nhp cc thng tin nhn c vo file log

Hnh 3.1. Hnh ng ca tu khng b nn khi nhn c bo ng cp cu bng DSC knh 70/VHF

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Nhn c bo ng cp cu bng DSC

Canh nghe trn VHF knh 16trong vng 5 pht

C bo nhn ca i DH or RCC khng? Khng Thng tin cp cu c thc hin khng? Khng Bo ng cp cu DSC c tip tc khng? Khng

C

Tu c kh nng tr gip khng? C C

Khng

C

Xc nhn bo ng cp cu bng thoi trn knh 16/182khz ti tu b hn

Thng ti Duyn hoc RCC

bo i Hi

a thit b v trng thi hot ng bnh thng

Nhp cc thng tin nhn c vo file log

Hnh 3.2. Hnh ng ca tu khng b nn khi nhn c bo ng cp cu bng DSC knh VHF/MF

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Nhn c bo ng cp cu bng DSC

Canh nghe trn knh 16/218khz trong vng 5 pht

C bo nhn ca i DH or RCC khng? Khng Thng tin cp cu c thc hin khng? Khng Pht chuyn tip cp cu bng HF/DSC ti DH

C

Tu c kh nng tr gip khng? C

Khng

C

Xc nhn bo ng cp cu bng thoi trn knh 16/182khz ti tu b hn

a thit b v trng thi hot ng bnh thng

Nhp cc thng tin nhn c vo file log

Hnh 3.3. Hnh ng ca tu khng b nn khi nhn c bo ng cp cu bng DSC trn di tn HF

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3-5-2-3. Th tc bo nhn cp cu bng TLX. Th tc bo nhn mt cuc gi cp cu bng TLX trong h thng thng tin GMDSS c p dng cho cc di tu nh sau: - Tn hiu cp cu "MAYDAY"; - H hiu hoc s nhn dng ca tu b nn; - H hiu hoc s nhn dng ca tu bo nhn cp cu; - Tn hiu cp cu "MAYDAY". Vic bo nhn cp cu bng TLX i vi mt cuc gi cp cu t mt di tu v tinh mt t s c thc hin bi mt di b v tinh mt t bng vic pht li s nhn dng ca di tu pht loan bo cp cu.

3.6. THNG TIN CP CUThng tin cp cu c thc hin bi cc thit b thng tin v tuyn in MF, HF v VHF ca h thng thng tin mt t; v cc thit b ca h thng thng tin v tinh, nh INMARSAT AIB hoc INMARSAT C, bng cc phng thc thng tin thoi hoc telex. thng tin cp cu c u tin cao nht, nn tt c cc loi thng tin khc. Thng tin cp cu bao gm tt c cc bc' in lin quan dn vic yu cu tr gip ngay lp tc ca mt tu ang trong tnh trng p cu, n cng bao gm c nhng thng tin tm kim v cu nn v nhng thng tin in trng. Thng tin cp cu c th c thc hin trn cc tn s cp cu. Cc bc din cp cu chuyn bng phng thc thoi cng nh bng TLX u bc in cp cu c bt u bng tn hiu ci cu MAYDAY. Tt c cc bc in cp cu bng tlx, theo qui nh trc khi bt u bc in phi xung dng v li vo mt ch, sau l tn hiu cp cu MAYDAY v ni dung bc in cp cu. Khi thng tin cp cu c thit lp bi tu b nn bng thit b NBDP, th phi chn ch FEC thc hin thng tin ch ARQ cng c lc dc s dng khi thng tin cp cu d dc pht trc o bng ch FEC. Trung tm phi hp cu lut s chu trch nhim iu khin cc hot ng tm kim v cu nn. Tt c cc di khi nhn c mt cuc gi hoc thng tin cp cu phi ngay lp tc ngng tt c cc vic pht m c tri can nhiu ti thng tin cp cu v phi lng nghe trn tn s dng gi cp cu. Cc trung tm phi hp tm kim v cu nn hoc cc i duyn hi c th yu cu cc i ang gy nhiu ti cc thng tin cp cu phi ngng pht v gi im lng. Ch dn ny c th c a li tt c cc hoc ch cho mt di. Th tc nh sau: Trong thng tin thoi s dng tn hiu: "SEL LOD MAYDAY" c pht m theo ting Php l "siletlcc m'aider". V d: - Mayday - Hello all stations. - This is. - Name or call sign or ID of RCC or Coast station. - Seelonce mayday. - Nu dng TLX bng cc thit b NBDP ch FEC s dng tn hiu "Silence mayday".

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3.7. THNG TIN HIN TRNGThng tin hin trng l nhng thng tin gia mt i lu ng ang trong tnh trng cp cu v cc i lu ng lm nhim v cu tr, v gia cc i lu ng vi n v hot ng phi hp tm kim v cu tr. n v lm nhim v phi hp hot ng tm kim v cu tr c trch nhim iu khin thng tin hin trng. Tt c cc i lu ng c th tham gia vo vic thng tin c lin quan n trng hp b nn. Nhng thng tin ny u c s dng trn cc tn s thng tin simplex. Cc tn s 156,8 mhz v 2182 khz s c dng cho thng tin hin trng i vi phng thc thng tin thoi. Tn s 2174,5 khz cng c th c dng cho thng tin hin trng gia tu vi tu bng thit b truyn ch trc tip bng hp ch FEC. b sung cho tn s 156,8 mhz v tn s 2182 khz, cc tn s 3023 khz, 4125 khz, 5680 khz, 123,1 mhz v 156,3 mhz (knh 6/VHF) cng c dng cho thng tin hin trng gia tu v my bay. n v hot ng phi hp tm kim v cu nn s c trch nhim la chn v quyt nh cc tn s cho thng tin hin trng. Thng thng, n v hot ng phi hp tm kim v cu nn s thit lp mt tn s cho thng tin hin trng, tt c cc i lu ng khc c tham gia vo thng tin hin trng s phi duy tr lin tc vic trc canh trn tn s d c la chn ny.

3.8. HTHNG PHAO NH V V TUYN TRONG THNG TIN CP CU, KHN CP V AN TON - EPIRBS.Thit b EPIRB l mt b phn quan trng trong thng tin cp cu khn cp v an ton ca h thng GMDSS, v theo quy nh th tt c cc tu chy bin u phi trang b thit b ny. Trong h thng GMDSS, EPIRB c quy nh l loi t ni v kn nc. Thng thng, EPIRB c t trn mt gi mt v tr thch hp trn boong tu, sao cho nu trng hp tu b chm m th h thng kch hot s t ng kch hot EPIRB v pht tn hiu bo ng cp cu. Tn hiu pht i t EPIRB s bao gm tn hiu bo ng cu nn ph hp vi h thng v tuyn in thch hp, tn hiu nhn dng ca tu hay phng tin b nn v mt s thng tin cn thit khc phc v cho vic nh v tu b nn. Thit b phao nh v v tuyn - EPIRB bao gm 2 loi: - EPIRB trong h thng COSPAS - SARSAT, v - EPIRB trong h thng INMARSAT.

3.8.1. EPIRB trong h thng COSPAS - SARSATH thng Cospas - Sarsat l mt h thng v tinh tr gip tm kim v cu nn, c thit lp xc nh v tr ca thit b EPIRB da trn nguyn tc hiu ng Dopple, trn tn s 121,5 mhz v 406,025 mhz. H thng c s dng phc v tt c cc t chc trn th gii c trch nhim tm kim v cu hn trn bin, trn khng v trn t lin. 3.8.1.1. c tnh ca h thng COSPAS-SARSAT. c tnh ca h thng COSPAS - SARSAT c trnh by trong bng sau:

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Cc tnh cht - Kh nng pht hin - Kh nng nh v - chnh xc nh v - Kh nng loi b nh - Dung lng hot ng cng mt lc - Vng bao ph

EPIRB 121,5 Mhz Khng p dng 0,9 17,2 km 0,73 10 Tc thi

EPIRB 406 Mhz 0,98 0,9 90% trong vng 5km 0,96 90 Tc thi v ton cu

Bng 3.2. c tnh ca h thng COSPAS - SARSAT S pht trin ca EPIRB 406 mhz c xem nh khc phc nhc im ca EPIRB v tinh 121,5 mhz. Cc loi EPIRB 406 mi c cc c tnh nh sau: - Tng chnh xc nh v tr v loi tr tnh a tr. - Tng dung lng ca h thng, tc l tng s lng ca beacon pht ng thi trong cng tm quan st ca mt v tinh c th x l c. - C tnh bao ph ton cu. - Mi beacon ch c mt s nhn dng cu nn. Mt EPIRB 406 mhz bc x cng sut 5w trong khong thi gian 0,5 giy vi chu k lp li l 50 giy. Chu k lp li di cho php truy nhp nhiu ng. Vi mt h thng, cho php x l ng thi ti 90 beacon trong tm quan st ca v tinh v tiu hao cng sut trung bnh thp. Cc EPIRB v tinh loi hai tn s 121,5/406,025 mhz cho php s dng cc vng c s kim sot khng lu. Tu loi beacon (hng hi, hng khng hay trn t lin) cc beacon c th c kch hot nhn cng hay t ng. 3.8.1.2. Th tc khai thc v ni dung bc in EPIRB Phn ny s trnh by v d liu bo ng, nhng thng tin v h thng v ni dung chnh ca mt bc in trong EPIRB. D liu bo ng. D liu bo ng cho ngi s dng l nhng d liu cho hot ng ca SAR. Thng tin h thng cho ngi s dng l nhng vn t chc c bn trong k thut ca h thng COSPAS - SARSAT. D liu bo ng c hai loi: in pht ra t phao tin m ho v in bo ng t LUT/MCC. Cc tn hiu pht i t cc EPIRB c kch hot s cung cp u vo ban u to ra tn hiu bo ng. Khi trm LUT thu v x l in EPIRB m ho th d liu bo ng ctruyn ti MCC quc gia phn pht. Tu theo cc yu cu v th tc m mi MCC pht d liu bo ng cho cc quc gia trong vng dch v ca n khi t c tho thun nhn nhng d liu ca SAR c th c tin hnh ngay lp tc. Hn na, bt k mt MCC no khi thu vng no trn th gii, th cn phi pht li thng tin cho MCC thch hp hoc c quan c thm quyn ca SAR. Thng tin h thng Thng tin h thng bao gm nm loi in h thng nh sau: - Thng tin lch thin vn hoc vect qu o: c s dng ly v di theo v tinh nhm tnh ton cc v tr ca EPIRB.

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- in hiu chnh thi gian: Cn thit cho vic xc nh chnh xc ca php nh v EPIRB. - in d liu Telemetry: Cung cp cc thng tin v tnh trng ca cc thit b SAR trn tu. - Cc thng tin iu hnh v tinh: c pht ln trong qu trnh pht cc th tc kim tra sa cha cc li hoc cc tnh trng sai st qu gii hn. - in phi hp: c dng thng tin cc tin tc chung cn thit khai thc h thng COSPAS SARSAT. Ni dung cc bc in: Cc bc in ca EPIRB 121,5 mhz ch bao gm cc tn hiu bo ng c pht ln v tinh v cc v tinh ca h thng COSPAS - SARPAT s xc nh v tr ca EPIRB. Cc bc in ca EPIRB 406 mhz bao gm tn hiu bo ng, s nhn dng ID ca tu b nn, quc tch ca tu b nn, v tr ca tu b nn s do v tinh trong h thng COSPAS - SARSAT xc nh da trn hiu ng Dopple. Vi cc EPIRB 406 mhz loi mi, trong ni dung cc bc in ngoi s nhn dng, quc tch ca tu b nn, cn cha ng nhng thng tin v v tr, tnh cht b nn...

3.8.2. EPIRB ca h thng INMARSAT.EPIRB v tinh bng L hot ng qua h thng v tinh INMARSAT (INMARSAT - E) c th dng nh mt phng tin bo ng cu nn cho cc tu hot ng trong cc vng bin A1, A2, A3 nh l mt s la chn vi EPIRB 406 mhz. EPIRB v tinh bng L cho php bo ng cu nn khn cp (khong 10 pht vi cng sut bc x ca EPIRB l 1W) trong vng bao ph t 70 v bc n 70 v nam, h thng cho php x l ti 20 cuc bo ng ng thi trong khung thi gian 10 pht, vi kh nng thao tc nhn cng hoc t ng cp nht thng tin v v tr vo EPIRB. EPIRB bng L c th c kch hot bng nhn cng hoc t ng khi tu chm m. Sau khi kch hot, EPIRB v tinh bng L pht mt bc in bo ng cu nn. Cc thng tin ny c lp li theo mt chu k nht nh. Sau khi c v tinh INMARSAT pht chuyn tip, tn hiu bo ng cp cu c a ti trm i b NCS (hoc LES) bng tn s n nh ring, c h thng my tnh x l tn hiu nhn dng v gii m bc in. Bc in bo ng cp cu sau c gi ti cho mt trung tm phi hp cu nn RCC thch hp.

3.9. BO YN CP CUKhi thng tin cp cu c kt thc trn cc tn s cp cu, Trung tm phi hp cu nn iu khin cc hot ng tm kim v cu nn s pht mt bc in trn cc tn s cp cu ch ra rng thng tin cp cu c kt thc. Khi nhn c bc in bo yn cp cu nh vy, cc i lm nghip v lu ng hng hi s kt thc qu trnh trc canh thng tin cp cu v tr li cc hot ng nghip v bnh thng ca cc i . Trong thng tin VT thoi, ni dung mt bc in bo yn cp cu bao gm: - Tn hiu cp cu "MAYDAY". - "Hello all station" "CQ" (pht m l CHARLIE QUEBEC trong trng hp ngn ng kh khn) pht 3 ln; - "This is" hoc "DE" (pht m l DELTA ECHO trong trng hp ngn ng kh khn) - pht 1 ln; - H hiu hoc s nhn dng (ID) ca i pht bc in ; - Gi ng k bc in bo yn (gi UTC); - Tn v h hiu ca i lu ng b nn; - "SEELONCE FEENEE" pht m theo ting Php l "Silence fini".

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i vi cc phng thc thng tin bng TLX, ni dung mt bc in bo yn c bn ca ging trng hp thoi, bao gm: - Tn hiu cp cu "MAYDAY" - CQ - DE - H hiu hoc s nhn dng (ID) ca i pht bc in bo yn; - G ng k bc in bo yn - Tn v h hiu ca i lu ng b nn; - "SILENCE FINI" Tm tt cc qu trnh gi cp cu v thng tin cp cu trong h thng GMDSS c trnh by theo lu hnh 3.3.

3.10. HU B MT CUC GI CP CUTrong h thng thng tin GMDSS, mt bo ng cp cu t mt i di ng Hng hi s ngay lp tc c chuyn ti mt RCC gn nht thng qua cc i Duyen Hi hoc i NCS (hoc LES), RCC s nhanh chng t chc v tin hnh cu tr. Do , khi c mt loan bo cp cu nhm c pht i, v bt c l do no, di tu pht loan bo cp cu nhm phi ngay lp tc bng cc thit b v phng thc thng tin trn nhng tn s u tin thch hp, thng bo cho RCC qua cc i Duyn Hi hoc trm NCS (hoc LES) hu b loan bo cp cu nhm . Ni dung bao gm: - Hello all stations; 3 ln. - This is; - H hiu hoc s nhn dng ca tu 3 ln. - V tr; - Cancel my DSC Distrees alert of (date), (time) UTC. - Over.

3.10.2. Hu b mt cuc gi nhm cp cu c pht bi thit b NBDPKhi c mt bc in bo ng cp cu nhm c pht qua thit b NBDP, v bt k l do no, cng phi ngay lp tc thng bo ti cc i Duyn Hi gn nht v cc di tu ln cn trn tn s u tin cp cu hu b bc in cp cu nhm . - Ni dung ca bc in thng bo hu b bc in cp cu bao gm: - CQ; - DE; - H hiu hoc s nhn dng ca tu; - V tr; - Cancel my DSC Distress Alert of (Date), (time) UTC. = Masterr +

3.10.3. Hu b mt cuc gi nhm cp cu trn thit b INMARSATMt bo ng cp cu nhm c pht qua thit b INMARSAT - A/B hoc C v bt k mt nguyn nhn no, cng phi ngay lp tc thng bo ti RCC thch hp hu b loan bo cp cu nhm bng vic pht mt bc in u tin cp cu bng thoi trn knh 16/VHF hoc tn s 2182 khz qua mt i Duyn Hi gn nht, v mt bc in u tin cp cu bng telex (i vi INMARSAT C) Hoc bng

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thoi (vi INMARSAT A/B, M) gi qua trm NCS hoc LES m loan bo cp cu nhm c chuyn qua . Th tc hu b bo ng nhm bng thoi thc hin trn knh 16/VHF hoc tn s 2182 khz nh trnh by trn. Ni dung ca bc in thng bo hu bot mt loan bo cp cu nhm c thc hin bng thit b INMARSAT C bao gm: - Tn tu; - H hiu hoc s nhn dng IMN; - V tr; - "Cancel my INMARSAT - C Distress alert of (date). (time) UTC. = Master +. i vi INMARSAT - A/B hoc M, tu pht cuc gi cp cu nhm s bng phng thc thng tin thoi INMARSAT vi mc u tin cao nht (mc s 3) gi ti mt RCC gn nht hoc qua NCS m cuc gi cp cu nhm gi ti thng bo vic hu b cuc gi cp cu nhm.

3.10.4. Hu b mt cuc gi cp cu nhm c pht bi EPIRB - 406.Khi c mt loan bo cp cu nhm pht qua thit b EPIRB - 406, v bt c l do g, cng phi ngay lp tc thng bo ti cc i Duyn Hi gn nht bng phng thc thng tin thoi trn knh 16 VHF hoc trn tn s 2182 khz, hoc trn tn s cp cu thoi thch hp, hu b loan bo cp cu nhm . Ni dung bao gm: - Hello all stations; 3 ln. - This is; - H hiu hoc s nhn dng ca tu 3 ln. - V tr; - Cancel my DSC Distrees alert of (date), (time) UTC. - Over.

3.11. THNG TIN HIN TRNG - ON - SCENE COMMUNICATIONSThng tin hin trng l thng tin gia mt i di ng ang trong tnh trng cp cu v i di ng tham gia cu tr; v gia cc i di ng vi n v phi hp hot ng tm kim v cu nn. n v phi hp hot ng tm kim v cu tr s chu trch nhim iu khin cc thng tin hin trng. Trong thng tin hin trng s s dng cc knh simplex, nu dng thit b thc thoi, s dng trn knh 16/VHF (tn s 156,8 mhz) v tn s 2182 khz; trng hp thng tin hin trng gia tu vi tu bng thit b NBDP s thc hin trn tn s 2174,5 khz ch FEC. Trong phng thc thng tin thoi, b xung cho cc tn s 156,8 mhz (knh 16/VHF) v tn s 2182 khz c th dng cc tn s 3023 khz, 4125 khz, 5680 khz, 123,1 mhz v 156,3 mhz (knh 6/VHF) cho thng tin hin trng gia tu bin v my bay. Cc tn s cho thng tin hin trng s o n v phi hp tm kim v cu tr la chn v quyt nh. Thng thng, mt tn s cho thng tin hin trng s c thit lp, cc i di ng s duy tr vic trc lin tc bng cc thit b thng tin thch hp trn tn s c la chn.

3.12. TH TC PHT TH CP V AN TONVic pht cc tn hiu th ch c thc hin khi thc s cn thit v phi c hn ch v thi gian v cng sut trnh gy can nhiu, c bit khi th trn cc tn s cp cu v an ton. Bt k u khi

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tin hnh vic pht th phi thc hin mc cng sut thp nht, phi thng bo c s phi hp vi cc i xung quanh. Vic th trn cc tn s gi cp cu v an tpn phi thc hin bng thoi. Cc i pht tn hiu th phi lun km theo s nhn dng ca i pht th v phi ch r ra rng i ang pht th. Trc khi thc hin vic pht th, khai thc vin phi lng nghe trn tn s nh pht th chc chn rng khng c cc thng tin lin quan n cp cu, khn cp v an ton ang c tin hnh trn cc tn s .

3.13. TH TC THNG TIN KHN CP V AN TON TRONG H THNG GMDSSNhng th tc c trnh by sau y ch p dng cho cc trng hp khn cp v an ton.

3.13.1. Cc loi thng tin khn cp v an tonNhng thng tin c gi l khn cp v an ton l nhng loi thng tin nh sau: - Nhng thng bo hng hi v nhng thng tin khn cp; - Nhng thng tin an ton hng hi gia tu vi tu. - Nhng thng tin v thng bo hng hnh. - Thng tin phc v cho cc hot ng tm kim v cu tr; - Cc bc in khn cp v an ton khc, v - Nhng thng tin lin quan n hng hi, s di chuyn v nhng vn cn thit khc ca tu v cc bc in thi tit gi cho mt c quan lm cc dcn v thng bo kh tng.

3.13.2. Quy nh chung i vi thng tin khn cp v an ton.Tt c cc loi thng tin khn cp v an ton c quyn u tin trn tt c cc loi thng tin khc tr cc cuc gi cp cu v cc thng tin lin quan n cp cu. Cc cuc gi khn cp v an ton v cc bc in khn cp v an tpn c th c thc hin trn tn s hoc knh ginh cho gi v thng tin cp cu tng ng vi cc phng thc thng tin m n ang tin hnh trong trng hp trn cc tn s khng c cc cuc gi cp cu hoc cc thng tin lin quan n cp cu. Vi cc bc in di lin quan n khn cp hoc an ton c th thc hin trn cc tn s hoc knh lm vic. Cc cuc gi khn cp v an ton c th gi cho tt c cc tu All Ships hoc gi cho mt trm no c a ch, v trong cc cuc gi nh vy, i gi phi ch ra c tn s v phng thc thng tin tip theo dng chuyn cc bc in .

3.13.3. Th tc v thng tin khn cpTn hiu khn cp "PAN PAN" c dng trong cc cuc gi v cc thng tin khn cp ch ra rng c mt bc in rt cp bch c lin quan n vn an ton ca tu, ca my bay hoc ca mt ngi no trn tu. Trong h thng thng tin mt t, cc cuc gi khn cp v loan bo mt bc in khn cp cu v an ton c trnh by mc 3.2.2. Trong trng hp mt bc in khn cp di hoc bc in khn cp ang pht lp li th c th c pht trn tn s lm vic. Khng cn thit phi thc hin mt cuc gi khn cp c pht qua dch v thng tin v tinh di ng hng hi. Tn hiu khn cp v cc bc in khn cp cng c th c pht trn mt hoc nhiu tn s ca cc tn s dng cho thng tin cp cu v an ton, hoc pht qua dch v thng tin di ng v tinh hng hi, hoc trn cc tn s khc s dng cho mc ch ny.

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Trong trng hp gi khn cp bng thit b DSC, v c bn ging nh mt cuc gi cp cu bng DSC, ni dung nh sau: - Format: All ships (Selected) - Category: Urgent (Selected) - Position: Lat ........., (Selected) - Time: ....................... UTC (Selected) - Telecom: ................. (Selected) - DSC freq: ................ (Selected). Thng tin v s nhn dng ca tu (ID) c ci t trc trong cc thit b DSC v t ng pht i trong cc cuc gi. Cc thng tin v v tr v thi gian (trong tnh trng khn cp) ch phi t trong trng hp thit b DSC khng c cp nht lin tc. i vi phng thc thng tin thoi, tn hiu khn cp l "PAN PAN", c gi khn cp (trong trng hp khng gi bng DSC), bao gm tn hiu khn cp "PAN PAN" nhc li 3 ln, theo sau l h hiu hoc s nhn dng (ID) ca i pht bc in khn cp.

V d: Mt cuc gi khn cp nh sau: - PAN PAN, PAN PAN, PAN PAN; - ALL STATIONS ALL STATIONS ALL STATIONS. - THIS IS; - JALAGPAL; JALAGPAL; JALAGPAL Sau cuc gi khn cp l bc in khn cp; PAN PAN THIS IS JALAGOPAL 15 MILES SOUTHWEST OF CALF OF MAN LOST ENGINE CONTROL AND DRIFTING NORTHNORTHEAST ANCHORS NOT HOLDING REQUIRE TOW URGENTLY JALAGOPAL CALLSIGN ATRZ OVER. i vi trng hp dng phng thc TLX qua thit b NBDP, mt bc in khn cp cng phi c bt u bng tn hiu khn cp "PAN PAN" km theo s ARQ c th c s dng cho mc ch ny ch khi trc bc in khn cp c pht ch FEC. Tt c cc cuc gi khn cp v tn hiu khn cp ch c pht i khi c lnh ca thuyn trng hoc ngi c trch nhim trn tu. Khi tnh trng khn cp ca i di ng pht bc in khn cp khng cn cn thit th i c trch nhim vi vic pht bc in khn cp phi hu b tnh trng khn cp cng sm cng tt.

3.13.4. Th tc thng tin an tonCc cuc gi an ton v cc bc in an ton c bt u bng tn hiu an ton "SECRITY". Cc cuc gi an ton hoc tn hiu an ton ch ra rng i gi ang c mt thng bo quan trng lin quan n hng hnh hoc kh tng cn c pht i.

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Cc bc in an ton c pht trn tn s lm vic sau khi pht mt loan bo cuc gi an ton v cc bc in an ton l cc cuc gi an ton. Hu ht cc cuc gi an ton v cc bc in an ton c pht sau cc chu k im lng ca thoi. - i vi phng thc thng tin thoi, knh 13/VHF c dng pht cc thng bo an ton hng hi gia tu vi tu. Vi cc i Duyn Hi, vic pht cc thng bo an ton c th c thc hin trn cc knh/ tn s khc c ng k trong danh b cc i Duyn Hi hoc s c ch r trong cc cuc gi an ton. Trong h thng GMDSS, khi dng thit b DSC gi an ton, trong bc in loan bo DSC bao gm nhng thng tin sau: - Format: All ships (Selected) - Category: Urgent (Selected) - Position: Lat ........., (Selected) - Time: ....................... UTC (Selected) - Telecom: ................. (Selected) - DSC freq: ................ (Selected). V d: Mt cuc gi an ton bng thoi s thc hin trn knh 16/VHF nh sau: - SECURITY SECURITY SECURITY; - ALL STATIONS ALL STATIONS ALL STATIONS - THIS IS - CALL SIGN/ IDENTIFICATION (pht 3 ln); - LISTRN FOR NAVIGATIONAL WARNING ON CHANNEL 13. Tip theo sau cuc gi an ton l bc in thng bo an ton nh sau: - SECURITY SECURITY SECURITY; - ALL STATIONS ALL STATIONS ALL STATIONS - THIS IS NONSUCH, NONSUCH, NONSUCH, - LARGE RED CONTAINER SPOTTED AT 1030 UTC IN POSITION 52,02 NORTH 003,36 WEST VESSEL KEEP SHARP LOOKOUT AND REPORT, OUTnhng

3.13.5. Vn chuyn y t (Medical transports).Nhng tn hiu ring biit trong nghip v "Medical transports" c th c dng bi cc n v y t hoc cc i thc hin nhng thng tin lin quan n vic bo v nhng ngi trong khu vc ang xy ra chin tranh. Thut ng "Medical transports" c nh ngha trong hi ngh Geneva "Geneva Conventions and Additional Protocols" vo thng 12 nm 1949, ch rng dng tr gip nhng ngi b thng trong chin tranh, b m v nhng tu b m chm. Nhng tu ca cc quc gia trung lp khng tham gia vo cuc chin tranh s tin hnh cc cng vic tr gip khi c yu cu ca mt hoc nhiu thnh vin khc khng tham gia vo cuc chin tranh v c s bo v t bt k mt hnh ng th nghch no. loan bo v nhn dng vic vn chuyn y t, mt cng vic phi c bo v theo cc cng c Geneva 1949, tn hiu radio nhn dng s bao gm tn hiu khn cp v km theo t MEDICAL i vi

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phng thc TLX trong cc thit b NBDP, v t MAY - DEE - CAL pht m theo ting php trong thng tin thoi, v th tc tin hnh c thc hin ging nh cuc gi khn cp. V d: Khi dng phng thc thoi loan bo s thc hin nh sau: PAN PAN PAN - DEE - CAL (3 ln) THIS IS NONSUCH (h hiu hoc s nhn dng) (3 ln). Sau khi thc hin mt loan bo v vic vn chuyn y t, bc in v thng tin vn chuyn y t phi c truyn i cng sm cng tt trn nhng tn s lm vic thch hp. Trc cc bc in thng tin y t c bt u bng tn hiu khn cp v bc in phi bao gm nhng thng tin nh sau: - H hiu hoc s nhn dng khc ca n v tham gia vn chuyn y t - V tr; - S hiu v kiu, loi ca phng tin tham gia vn chuyn y t; - Tuyn ng i; - D kin thi gian trn tuyn hnh trnh v thi gian n v thi gian ri; - V nhng thng tin khc nh tn s trc canh, ngn ng s dng, kiu, m ca radar, ... Radar transponder c th c s dng cho vic nhn dng v nh v nhng vn chuyn y t trn bin.

3.13.6. Pht thng bo an ton hng hiCc th tc chi tit ca cc i pht cc thng bo an ton hng hi ging nh th tc thng tin an ton c trnh by mc thng tin an ton 3.12.4. Thng tin an ton hng hi c th c pht qua h thng Navtex quc t trn tn s 518 khz; cc thit b NBDP trn tn s 4210 khz, 6314 khz, 6314 khz, 8416,5 khz, 12579 khz, 16806,5 khz, 19680,5 khz, 22376 khz v 26100,5 khz ch FEC, hoc pht qua h thng v tinh INMARSAT trn bng tn 1530 - 1545 mhz. Nhng thng tin an ton hng hi gia tu vi mc ch an ton hng hi trn bin c dng bng thng tin thoi trn thit b VHF tn s 156,650 mhz (knh 13/VHF).

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CHNG 4 DCH V THNG TIN LU NG HNG HI TRONG H THNG GMDSS4.1. MT S KHI NIM S DNG TRUNG DCH V THNG TIN LU NG HNG HI. 4.1.1. Trafficlist"Trafficlist" l mt nghip v ca cc i Duyn Hi lm dch v thng tin cng cng im danh cc i tu m i Duyn Hi ang c in cho cc i tu . Cc i Duyn Hi trong gi nghip v ca mnh phi thc hin cc cuc gi "Trafficlist" theo chu k thi gian v trn cc tn s nht nh. Nghip v "Trafficlist" ca cc i Duyn hi phi c ng k quc t v c h r trong danh b cc i Duyn Hi.

4.1.2. Tn s quc t v tn s quc giaTrong thng tin v tuyn n hng hi c cc tn s quc t v tn s quc gia. Tn s quc t l cc tn s do T chc lin minh vin thng quc t ITU n nh v qun l. Vic s dng cc tn s ny phi tun th theo cc quy nh ca quc t. Tn s quc gia l cc tn s do cc quc gia qui nh v qun l. Vic s dng cc tn s ny phi tun th theo cc quy nh ring ca mi quc gia, cc quy nh ny cng phi ph hp vi cc quy nh chung quc t.

4.1.3. Knh Simplex v knh Duplex.Trong thng tin v tuyn in hng hi, ngoi cch gi trc tip trn cc tn s pht (Tx) v tn s thu (Rx), n gin ngi ta cn s dng "knh" (channed) thng tin. Mt knh thng tin no l mt cp tn s bao gm mt tn s thu v mt tn s pht, mt cp tn s pht - thu c th ging nhau hoc khc nhau. Nu mt knh thng tin c tn s thu bng tn s pht (Rx = Tx), th ta gi knh thng tin l knh simplex. Trong dch v thng tin lu ng hng hi, cc cuc thng tin gia tu vi tu thng s dng knh simplex. V d: Trong bng tn VHF c cc knh simplex nh: - Knh 11 c Tx = Rx = 156,550 mhz. - Knh 12 c Tx = Rx = 156,600 mhz. - Knh 13 c Tx = Rx = 156,650 mhz. Trong bng tn HF c cc knh simplex nh sau: - Knh 428 c Tx = Rx = 4351 mhz. - Knh 429 c Tx = Rx = 4354 mhz. - Knh 836 c Tx = Rx = 8713 mhz. - .... Nu mt knh thng tin c tn s thu v tn s pht khc nhau (Rx Tx), th ta gi knh thng tin l knh Duplex.

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Trong dch v thng tin lu ng hng hi, cc cuc thng tin gia i Duyn Hi vi mt i tu thng s dng knh duplex. V d: Trong bng tn VHF c cc knh duplex nh: - Knh 23 c Tx = 157,150 mhz; Rx = 161,750 mhz. - Knh 24 c Tx = 157,200 mhz; Rx = 161,800 mhz. - Knh 60 c Tx = 157,025 mhz; Rx = 160,625 mhz. - ..... Trong bng tn HF c cc knh duplex nh sau: - Knh 401 c Tx = 4065 khz; Rx = 4375 khz. - Knh 801 c Tx = 8195 khz; Rx = 8719 khz. - Knh 1601 c Tx = 16360 khz; Rx = 17242 khz.

4.1.4. Tn s (hoc knh) chung v tn s (hoc knh) lm vicNhng tn s (hoc knh) c quy nh gi v bt lin lc m khng dng cho cc mc ch khc (tr cc trng hp cp cu, khn cp v an ton), th c gi l cc tn s (hoc knh) chung. Khi s dng cc tn s ny phi tun th y cc quy nh i vi cc tn s (hoc knh) chung. Khi s dng cc tn s ny phi tun th y cc quy nh i vi cc tn s (hoc knh) dng gi v bt lin lc. V d: - Mt s tn s (hoc knh) chung dng gi v bt lin lc nh sau: - Knh 16 VHF. - Tn s 2182 khz. - Tn s 8291 khz. - ....... Nhng tn s (hoc knh) c quy nh dng trao i thng tin gia cc i lm nghip v lu ng hng hi, th c gi l tn s (hoc knh) lm vic. Vic trao i thng tin trn cc tn s ny khng hn ch thi gian. V d: Mt s tn s (hoc knh) lm vic nh sau: - Cc knh duplex t 21 n 28 bng tn VHF l cc knh lm vic trong dch v thng tin cng cng gia i Duyn Hi v i tu. Trong cc bng tn s ca thng tin thoi v thng tin telex tr cc tn s ginh cho cp cu, khn cp v an ton, cn li l cc tn s dng trao i thng tin trong nghip v thng tin lu ng hng hi.

4.1.5. Ch pht xTrong nghip v thng tin lu ng hng hi cc loi pht x c k hiu theo nhng c tnh c bn ca cc loi pht x . Nhng c tnh c bn c k hiu bng 3 k t nh sau: - K t th nht Bng cc ch ci ch phng php iu ch tn s sng mang, bao gm: N: Pht x 1 song mang khng iu ch. A: iu ch hai bin H: iu ch n bin sng mang ton phn. R: iu ch n bin sng mang suy gim. J: iu ch n bin loi b sng mang.

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F: iu tn. G: iu pha. - K t th hai: Bng cc ch s ch tnh cht ca tn hiu iu ch tn s sng mang, bao gm: 1. Tn hiu s (tn hiu in bo) khng s dng iu ch sng mang ph. 2. Tn hiu s s dng iu ch sng mang ph. 3. Tn hiu n knh cha thng tin tng t. - K t th ba: Bng cc ch s ch loi thng tin (tin tc) cn pht i, bao gm: N: Khng c thng tin. A: in bo morse thu bng tai. B: in bo thu t ng. C: Facsimile D: Truyn s liu. E: in thoi (bao gm c pht thanh). F: Truyn hnh. Mt s ch pht x dng trong nghip v thng tin lu ng hng hi. J3E: in thoi n bin khng sng mang. H3E: in thoi n bin sng mang ton phn (ch dng cho 2182 khz). F3E: in thoi iu tn (FM). G3E: in thoi iu pha. F1B: in bo di tn khng c iu ch sng mang ph. J2B: in bo di tn c iu ch sng ph.

4.2. NHNG QUY NH CHUNG P DNG TRONG THNG TIN LU NG HNG HINhng quy nh trnh by trong phn ny khng p dng cho cc cuc gi v nhng thng tin lin quan n cp cu, khn cp v an ton. Dch v thng tin lu ng hng hi trong h thng thng tin GMDSS i vi tt c cc phng thc thng tin cng cng thng thng u phi tun th nhng quy nh di y:

4.2.1. S dng gi quc t trong thng tin v tuyn inTt c nhng ti liu lin quan n thng tin v tuyn in trn tu (ti liu ca tu, ti liu do ITU xut bn c s dng trn tu) cng nh nht k v tuyn in u thng nht s dng gi UTC (Coordinted Universal Time) tnh t 0000 gi n 23h59 pht, vo lc na m.

4.2.2. Gi nghip v v nhng quy nh v ng, m di lm nghip v thng tin v tuyn in.Gi nghip v ca cc i Duyn Hi v cc i mt t c th lm vic lin tc 24/24 hoc lm vic vi gi nghip v hn ch. Gi nghip v ca cc i ny u phi c ng k trong danh b cc i duyn hi "List of Coast Stations". Vi cc di b c gi nghip v khng lin tc s khng c ng i trc khi: + Kt thc mt cuc gi cp cu hoc nhng thng tin lin quan n cp cu khn cp v an ton.

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+ Chuyn ht lng in cho cc tu, hoc cha kt thc thng tin vi tu, m cc tu ang nm trong vng dch v ca i b. + Thc hin mt cuc gi chung cho tt c cc tu loan bo vic ng i v thi gian m nghip v nu khc vi gi nghip v bnh thng ca i . Gi nghip v ca cc i tu c th lin tc 24/24 gi, hc gi nghip v hn ch. i vi cc i tu c gi nghip v khng lin tc s khng c ng i trc khi: + Kt thc mt cuc gi cp cu hoc nhng thng tin lin quan n cp cu khn cp v an ton. + Chuyn ht lng in cho cc di b thch hp, hoc cha kt thc thng tin vi cc i b, m i b ang nm trong vng dch v thng tin ca i tu. Tt c nhng i tu c gi nghip v khng lin tc s phi thng bo cho cc i b c lin quan n gi ng v gi m li nghip v ca mnh.

4.2.3. Quy nh v chng can nhiu trong thng tin lu ng hng hiTt c mi pht x trong thng tin lu ng hng hi phi c gim mc cng sut nh nht cn thit bao ph trong vng dch v thng tin ca mnh. Tt c mi pht x trong dch v thng tin lu ng hng hi phi km theo nhn dng ca i pht. Nghim cm mi pht x khng c nhn dng, hoc mo danh nhn dng.

4.2.4. iu khin phin lin lcTrong nghip v thng tin lu ng hng hi, i no gi quyn iu khin phin lin lc, th trong phin lin lc, i s iu khin nhng vn sau: + Ch nh phng thc v tn s thng tin tip theo. + Thi gian lin lc. + Th t u tin. + Kt thc lin lc, v k c nh ch phin lin lc, ... Trong cc cuc thng tin gia i b v i tu, th i b s gi quyn iu khin phin lin lc. Trong cc cuc thng tin gia tu vi tu, th tu no ch ng gi, i tu s gi quyn iu khin phin lin lc.

4.2.5. Th t u tin trong cc cuc gi.Trong cc dch v thng tin lu ng hng hi, cng nh dch v thng tin lu ng hng hi v tinh s p dng mc u tin cho cc cuc gi theo th t sau: + Cc cuc gi cp cu, in cp cu v thng tin cp cu. + Cc cuc gi khn cp v thng tin khu cp. + Cc cuc gi an ton v thng tin an ton. + Nhng thng tin lin quan n v tuyn nh v. + Nhng thng tin lin quan di hot ng tm kim v cu linh. + Nhng thng, tin lin quan n an ton hng hnh ca tu bin, my bay v cc bc in d bo kh tng ca cc t chc kh lng. + Cc bc in ca t chc lin hp Quc. + Cc bc in ca Chnh Ph. + Cc dch v thng tin cng cng.

4.2.6. Qui v cm pht thanh v pht hnh trn bin. 43

Cc tu khi hnh trnh trn bin, nghim cm cc dch v pht thanh, pht hnh trn bin

4.2.7. Gi v tr li cuc gi.Gi v tr li cuc gi trong dch v thng tin lu ng hng hi phi tun theo cc qui nh ca T chc t vn v tuyn in quc t - CCIR ; cc cuc gi c th c thc hin trn nhng tn s quc t, hoc quc gia dc qui nh dng cc cuc gi v bt lin lc, hoc trn nhng tn s trc canh ca cc di b hoc cc di lm dch v lu ng hng hi. Nghim cm cc cuc gi bt lin tc v lp i lp li nhiu ln; tht cuc gi ti mt i khc m c pht tch nhiu ln s cng mt lc l khng dc php. Nhng th tc qui nh trong chng ny khng p dng cho cc trng hp cp cu, khn cp v an ton.

4.3. TH TC KHAI THC DSCPhng thc thng tin bng k thut gi chn s DSC trong h thng thng tin GMDSS ngoi mc ch ginh cao cp cu khn cp v an ton, trong nghip v thng tin lu ng hng hi ch dng gi v bt lin lc, vic trao i thng tin phi s dng bng phng thc thng tin khc.

4.3.1. Tn s dng trong cc cuc gi v tr li cuc gi bng DSC.Tn s m cc i duyn hi s dng cho k thut gi chn s u c ch l trong danh b cc i duyn hi. Vic gi v tr li cuc gi bng k thut gi chn s DSC c quy nh thc hin trn nhng tn s DSC quc t, hoc quc gia ginh ring cho gi v bt u lin lc cho mc ch thng tin thng thng. Nhng tn s DSC quc t v quc gia dng cho cc cuc gi v bt lin lc trong dch v thng tin lu ng hng hi c trnh by trong bng 4.1. Cc i b cng nh cc i tu khi s dng cc thit b gi chn s trong cc dch v thng tin lu ng hng hi trn cc di tn s 415 khz, 526,5 khz, 160,5 khz, 4000 khz v di tn 40000 khz - 27500 khz u phi gim mc cng sut nh nht cn thit cho mc ch thng tin ca i . Tn s 455,5 khz l tn s DSC quc t c thit k cho tt c cc i duyn hi. gim can nhiu, tn s ny c quy nh cho cc i tu ca quc gia khc, hoc trong trng hp i duyn hi khng cn bit tn s trc canh ca i tu. Tn s 458,5 khz l tn s DSC quc t c thit k cho tt c cc i tu c bng tn DSC 415 khz - 526,5 khz. gim can nhiu, tn s ny ch c s dng gi cc i Duyn Hi khi cuc gi khng th thc hin c trn cc tn s quc gia c thit k cho cc i Duyn Hi . Tn s dng tr li cuc gi bng DSC thng thng l nhng tn s cp i vi tn s gi. Khi mt i tu gi i Duyn Hi bng k thut gi chn s DSC trong di tn 1602 khz - 4000 khz c th gi trn mt knh DSC quc gia khc bng k thut gi chn s DSC. Mt i tu gi mt i tu khc bng k thut gi chn s, s c thc nhin trn tn s DSC quc t 2177 khz v tn s ny cng c tr li cc cuc gi bng DSC gia tu vi tu. Mt i Duyn hi gi mt i tu bng k thut gi chn s DSC, c th gi trn knh tn s DSC quc t 2177 khz v tn s ny cng c dng tr li cc cuc gi bng DSC gia tu vi tu. Mt i Duyn Hi gi mt i tu bng k thut gi chn s DSC, c th gi trn knh tn s DSC m i b ang trc canh, hoc trn tn s DSC quc t 2177 khz c thit k cho tt c cc i duyn hi c thit b DSC. gim can nhiu, tn s ny c quy nh gi cc i tu ca mt quc gia khc,

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hoc s dng trong trng hp m i Duyn hi khng bit cc tn s DSC trong bng tn 1605 - 4000 khz m i tu dng trc canh. Khi gi mt i duyn hi bng k thut gi chn s DSC trong bng tn 4000 - 27500 khz, i tu c th gi trn knh tn s DSC quc gia m i b ang trc canh, hoc trn mt trong nhng tn s DSC quc t thch hp trong bng tn (xem bng tn s DSC 4-1). Nhng tn s ny c th c thit k cho tt c cc i tu. gim can nhiu, nhng tn s ny ch c s dng khi cc cuc gi khng th thc hin c trn cc tn s quc gia. Khi gi cc i tu bng k thut gi chn s trn cc tn s trong bng tn 4000 - 27500 khz, cc i duyn hi c th gi trn mt knh tn s quc gia m i duyen hi ang trc canh, hoc trn mt trong nhng tn s quc t trong bng tn . Nhng tn s ny c th c thit k cho tt c cc i Duyn hi c thit b DSC. gim can nhiu, nhng tn s ny c quy nh dng gi cc i tu ca mt quc gia khc, hoc trong trng hp cc i Duyn hi khng bit cc tn s DSC m di tu ang trc canh. Tn s 156.525 Mhz (knh 70 VHF - DSC) trong bng tn 156 - 174 mhz ngoi mc ch ginh cho cc cuc gi cp cu, khn cp v an ton bng DSC, cn c quy nh dng gi v tr li cuc gi bng DSC cho cc mc ch thng tin thng thng gia di tu vi i duyn hi, hoc gia i tu vi i tu trong trng hp trn tn s khng c cc thng tin lin quan n cp cu, khn cp v an ton. Cc tn s dng gi v tr li cuc gi bng DSC c trnh by trong bng 4.1 sau y: File no. 10 11 12 13 14 15 16 17 18 19 22 23 24 25 26 27 28 29 32 33 34 35 36 37 38 39 File name INTL - 04M INTL - 04M INTL - 2m INTL - 4m INTL - 6m INTL - 12m INTL - 16m INTL - 18m INTL - 22m INTL - 25m LOCAL1 - 4M LOCAL1 - 6M LOCAL1 - 8M LOCAL1 - 12M LOCAL1 - 16M LOCAL1 - 18M LOCAL1 - 22M LOCAL1 - 26M LOCAL2 - 4M LOCAL2 - 6M LOCAL2 - 8M LOCAL2 - 12M LOCAL2 - 16M LOCAL2 - 18M LOCAL2 - 22M LOCAL2 - 25M Tx (khz) 458.5 2189.5 4208.0 6312.5 8415.0 12577.5 16805.0 18898.5 22374.5 25208.5 4208.5 6313.0 8415.5 12578.0 16805.5 18899 22375 25209 4209 6313.5 8416 12578.5 16806.0 18899.5 22375.5 25209.5 Rx (khz) 455.5 2177 4219.5 6331 8436 12657 16903 19703.5 22444 26121 4220 6331.5 8437 12657.5 16903.5 19704 22444.5 26121.5 4220.5 6332.0 8437.5 12658 16904 19704 22445 26122 Remarkes

Bng 4.1. Bng tn s gi v tr li dng cho DSC.

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4.3.2. Trc canh bng DSCTtc c cc i tu c trang b cc thit b gi chn s DSC, u phi trc canh t ng trn nhng tn s DSC trng nhng bng tn thch hp m tu c trang b. Mt i Duyn hi lm nghip v thng tin cng cng quc t, dng cc thit b gi chn s DSC trong bng tn 1605 - 4000 khz, trong sut gi nghip v ca mnh phi duy tr vic trc canh t ng trn cc tn s gi quc gia v quc t thch hp. Gi nghip v ca mnh phi duy tr vic trc canh t ng trn cc tn s gi quc gia v quc t thch hp. Gi nghip v v cc tn s trc canh ca cc i tu duyn hi c ng k quc t v ch r trong danh b cc i duyn hi. Cc di tu khi c trang b cc thit b gi chn s DSC lm vic trong cc bng tn 1605 4000 khz v tu ch hot ng trong vng ph sng ca thit b DSC trn cc i duyn hi ng vi bng tn s , phi duy tr vic trc canh t ng bng DSC trn mt hoc nhiu tn s thch hp trong bng tn 1605 - 4000 khz. Trong bng tn 156 - 174 mhz, nhng thng tin lin quan n vic trc canh t ng bng DSC trn tn s 156.525 mhz (knh 70 VHF) ca cc i duyn hi. Cc i tu c trang b cc thit b gi chn s DSC trong bng tn ny, trong khi hnh trnh trn bin phi duy tr vic trc canh t ng trn tn s 156.525 mhz (knh 70VHF).

4.3.3. Nhng quy nh chung p dng trong cuc gi v tr li cuc gi bng DSC.Nhng quy nh trnh by trong phn ny c p dng cho cc cuc gi v tr li cuc gi trong thng tin thng thng bng k thut gi chn s, khng p dng cho cc trng hp cp cu, khn cp v an ton. Cc cuc gi v tr li cuc gi bng DSC cng phi thun th y cc quy nh v chng can nhiu, iu khin phin lin lc, th t u tin trong cuc gi, nh trnh by trong phn quy nh chung. Cc cuc gi v tr li cuc gi bng DSC cng phi tun th y cc quy nh v chng can nhiu, iu khin phin lin lc, th t u tin trong cuc gi, .... nh trnh by trong phn quy nh chung. Cc cuc gi v tr li cuc gi bng k thut gi chn s DSC trn cc tn s t 415 khz n 526,5 khz , cc i duyn hi phi dng mc cng sut cn thit nh nht bao ph vng thng tin ca mnh; i vi cc i tu phi a hn ch mc cng sut khng qu 400w. Trong bng tn 4000 khz n27500 khz cng sut ca cc i tu khng vt qu 1,5kw.

4.3.4. Th tc gi v tr li cuc gi bng DSC.Nhng th tc c trnh by sau y ch p dng cho cc cuc gi bng DSC, tr cc trng hp cp cu, khn cp v an ton. Trong cuc gi, hoc tr li cuc gi s phi bao gm nhng thng tin ch ra rng cuc gi hoc tr li cuc gi cho mt i hay nhiu i, s nhn dng ca i gi hay i tr li cuc gi; phng thc thng tin tip theo (i vi cuc gi) cng nh tn s hoc knh lm vic. Cc cuc gi t cc i Duyn Hi phi lun lun km theo cc thng tin ny, i vi cc cuc gi t cc di tu vi mt di duyn hi, thng tin v tn s hoc knh lm vic tip theo khng nht thit phi c trong cuc gi. son tho mt cuc gi v tr li cuc gi bao gm nhng thng tin nh sau: Nhng ni dung cn son tho - Format (nh dng cuc gi hoc tr li cuc gi) - Category (chn mc u tin) - Sefl - identifacation (s nhn dng ca i gi hoc i xc nhn cuc gi). Phnng php - Selected - Entered - Selected - mc nh trc

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- Telecommand inforrmation (phng thc thng tin tip theo) - Frequency information (phn s thng tin tip theo) - DSC frequency (phn s DSC) (ch i vi cuc gi)

- Selected - Entered - Entered

Sau khi son tho y nhng ni dung nh trn, cuc gi hoc tr li cuc gi s c sn sng: "Ready for calling" hoc "Ready for acknowledge". 4.3.4.1. Mt i duyn hi gi i tu Mt i duyn hi gi i tu s c hai loi gi nh sau: - Routine call; - Ship's business call. Nu cuc gi c ni mng trc tip gia thu bao v i duyn hi, th i duyn hi s yu cu thu bao v tr d on ca tu. Thng tin ny gip cho i duyn hi c th thit lp thng tin vi i tu c hiu qu hn. Nu ngi gi t my thu bao khng th cung cp c v tr ca tu th nhn vin khai thc ca i duyn hi s c gng xc nh v thit lp ng thng tin trong iu kin i duyen hi c th thc hin c, k c vic pht chuyn tip qua mt i duyn hi khc nu iu l thch hp. Mt cuc gi nh vy t i duyn hi ti i tu bng thit b DSC nh sau: - nh dng cuc gi. - a ch ca tu cn gi (9 s MMSI). - Chn mc u tin cho cuc gi. - Chn phng thc thng tin tip theo. - Chn tn s thng tin tip theo (tn s phi ph hp vi phng thc thng tin. - Chn tn s gi DSC. (S nhn dng ID ca i gi c mc nh trc tring thit b DSC v s t ng pht i km theo trong cuc gi). Sau i duyn hi s thc hin cuc gi. V d: Mt cuc gi DSC thng thng cho mt tu c ID 574357212 hn mt cuc thng tin thoi trn knh lm vic 820 nh sau: - Format : individual. - Address : 547357212. - Category : Routine - Teleccommand : J3E. - Frequency : ch 820. - DSC freq : Tx 84370. / Rx 8415.5 khz. Vic chn tn s cho mt cuc gi t cc i duyn hi ti cc i tu bng DSC, cc khai thc vin ca i duyen hi phi chn sao cho thch hp vi vic trc canh ca cc tu . Trc khi bt u cuc gi, khai thc vin ca i duyn hi phi lng nghe v kim tra chc chn rng trn tn s gi khng c bt k mt cuc gi no ang c tin hnh. Cc cuc gi s ch c pht mt ln trn duy nht mt tn s hoc knh gi c chn. Tr nhng trng hp c bit, mt cuc gi c th c pht ng thi trn nhiu tn s.

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Khi gi cc i tu, cc i duyn hi c th pht mt cuc gi hai ln trn cng mt tn s gi, thi gian ngh gia hai ln gi phi t nht l 45 giy, min rng trong khong thi gian khng c bt k mt xc nhn no. Khi gi trn cc tn s quc gia, cc di duyn hi c th pht 5 cuc gi trn cng mt tn s, nu i c gi khng xc nhn cuc gi, th cuc gi c th c pht li trn cng tn s gi (hoc trn mt tn s khc) sau mt chu k t nht l 5 pht (5 giy i vi h thng VIII, hoc UHF t ng). Thng thng n c nhc li sau khong thi gian 5 pht. Nu i duyn hi nhn c mt xc nh th s khng pht li cuc gi na, v cuc gi ch c nhc li sau t nht mt khong thi gian 15 pht. Khi mt i c gi l khng tr li cuc gi, th cuc gi s khng c nhc li sau mt khong thi gian t nht l 30 pht. Cuc gi nh vt cng s khng c nhc li qu 5 ln trong 24 gi. Tng s ln gi trn cc tn s gi m n chim trong mt cuc gi thng thng khng qu mt pht. 4.3.4.2. i tu gi l i duyn hi Khi gi mt i duyn hi, cc i tu tt nht l dng cc tn s hoc knh gi quc gia ca cc i duyn hi. Thc t trong nghip v thng tin lu ng hng hi, phng php dng pht mt cuc gi bng DSC ti mt i duyn hi hoc mt tu khc nh sau: - iu chnh my pht v knh hoc tn s DSC. - nh dng cho cuc gi trn thit b cui DSC (format). - Trn bn phm (keyboard) hoc bng cc phm chc nng, a vo my nhng thng tin sau: - a ch: a 9 s nhn dng MMSI ca i cn gi. - Chn loi cuc gi (cateloggy): trong thng tin thng thng l "routine". - Phng thc thng tin tip theo. - ngh knh hoc tn s lm vic, nu cuc gi gia tu vi tu. - Tn s DSC cho cuc gi. Sau khi tin hnh son tho xong bc in cho cuc gi, i tu s tin hnh cuc gi. i tu phi chn tn s gi DSC thch hp v phi l cc tn s trc canh ca i b. V d: Cuc gi t i tu ti mt i duyn hi c ID 005741996 nh sau: - Format : individual. - Address : 005741996 - Category : Routine - Teleccommand : J3E. - Frequency : ch 820. - DSC freq : Tx 84370. / Rx 8415.5 khz. Cuc gi t i tu ti mt i tu khc: - Format : individual. - Address : 5474100453 - Category : Routine - Teleccommand : J3E. - Frequency : ch 820. - DSC freq : Tx 84370. / Rx 8415.5 khz.

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Cn ch rng trong cuc gi gia tu vi i tu duyn hi, i tu s khng a ra knh hoc tn s lm vic, m i duyn hi s ch nh tn s hoc knh lm vic trong xc nhn bng DSC ca i duyn hi. Trc khi pht cuc gi trn tn s gi DSC, s quan khai thc tu phi lng nghe v kim tra chc chn rng khng c bt k mt cuc gi no ang c thc hin trn tn s ny. Nu mt u c gi m khng tr li cuc gi, th i tu gi s khng pht li cuc gi sau mt khong thi gian t nht l 5 pht i vi phng thc "bt tay" bng cng nhn; hoc 5 giy hoc 25 giy i vi cc trng hp t ng hoc bn t ng. 4.4. PHNG THC THNG TIN BNG V TUYN IN THOI

4.4.1. Gi v tr li cuc gi bng v tuyn in thoiTrong dch v thng tin lu ng hng hi i vi h thng tin mt t, vic gi v bt lin lc c th c thc hin thng qua thit v gi chn s DSC, hoc thit b trc tip bng phng thc thng tin thoi. Trong phn ny s trnh by phng php gi v tr li cuc gi trc tip bng phng thc thng tin v tuyn in thoi.

4.4.2. Tn s s dng cho cuc gi v tr li cuc giPhng thc thng tin v tuyn in thoi trong nghip v thng tin lu ng hng hi c quy nh dng ch thoi n bin SSB tt c cc bng tn: 1605 - 4000 khz v 4000 - 27500 khz. Cng sut ca tn hiu trong cc cuc gi s phi hn ch mc cng sut cn thit gii nht sao cho khng gy can nhiu ti cc dch v thng tin di ng hng hi ca cc bi khc trong khu vc ln cn. Nhng tn s hoc nhng cp tn s (trng hp duplex trong dch v thng tin v tuyn in thoi ca cc i duyn hi, c ch r trong danh b cc i duyn hi). Bng tn s 1605 khz - 4000 khz: Tn s 2182 khz v tn s v tuyn in thoi quc t, c quy nh gi cp cu, khn cp v an ton. Trong trng hp khng c cc thng tin lin lc n cp cu, khn cp v an ton, tn s ny cn c dng gi v tr li cuc gi cho cc mc ch thng tin thng bng v tuyn in thoi. Tn s ny cng c cc i duyn hi dng loan bo pht im danh cc tu "trappic list" sau thc hin vic im danh cc tu trn mt tn s khc. Tt c nhng cuc pht x trn tn s 2182 khz ngoi mc ch cp cu cn phi nng nghe chc chn rng khng c mt thng tin cp cu no ang c tin hnh trn tn s . Khi cc i duyn hi s dng tn s 2182 khz cho mc ch gi v bt lin lc, th cc i duyn hi phi c thit k t nht mt tn s khc vi tn s 2182 khz nm trong bng tn 1605 - 2850 khz v c kh nng lm vic ch J3E. Cc tn s ny phi c ng k trong danh b cc i duyn hi. Khi cc di tn gi cc i duyn hi, hoc di tn gi mt i tu khc bng v tuyn in thoi trn bng tn 1605 - 4000 khz c th c gi trn tn s 2180 khz. Ngoi ra mt i tu gi mt i duyn hi c th c thc hin trn mt ln s lm vic m i duyn hi ang trc thanh. V mt i tu gi mt i tu khc cng c th c gi trn mt tn s "Intership" ginh cho thng tin gia tu vi tu. Mt quy nh chung, khi cc i duyn hi gi mt i tu ca mt quc gia khc bng v tuyn in thoi trn bng tn 1605 - 4000 khz s c gi trn tn s 2182 khz. Cc i duyn hi cng c th gi cc i tu thng qua mt cuc bng DSC. Bng tn 4000 khz - 27500 khz: Cc tn s n vin "simplex": 4125 khz, 6215khz, 8591 khz, 12590 khz, 16400 khz, 18759 khz, 22060 khz, 25097 khz dng cho cc i duyn hi v cc i tu gi v bt

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lin lc bng v tuyn in thoi bng cc tn s: 4125 khz, 6215khz, 8291 khz, 12290 khz v 16.420khz c quy nh dng cho cc cuc gi cp cu v nhng thng tin lin lc n cp cu, nhng trong trng hp trn nhng tn s ny khng c cc cuc gi v