tai lieu gsm

Bi thi cui kho

Kho st h thng thng tin di ng GSM

CHNG I TNG QUT H THNG THNG TIN DI NG GSM I.1 .GII THIU CHUNG I.1.1 Lch s pht trin ca thng tin di ng GSM in thoai di ng ra i nhng nm 1920 khi in thoi di ng ch dng nh nhng phng tin thng tin lin lc gia cc n v cnh st M . Mi n nm 1980 ngi ta nhn thy rng cc h thng t ong tng t khng loi b c cc hn ch c hu ca cc h thng ny. Gii php duy nht loi b nhng hn ch trn l phi chuyn sang s dng k thut thng tin s cho thng tin di ng cng vi cc k thut a truy nhp mi . H thng thng tin di nh s s dng k thut a truy nhp phn chia theo thi gian (TDMA) u tin trn th gii c ra i chu u v c tn gii l GSM. Ban u h thng ny gi l nhm c trch di ng (Group Special Mobile). Sau tin cho vic thng mi ho GSM c gi l h thng di ng ton cu (GSM:Global System for Mobile communication ). H thng thng tin di ng GSM bt u pht trin t nm 1982 khi cc nc Bc u gi ngh n CEPT (Conference of European Postal and Telecommunications - Hi ngh cc c quan (qun l vin thng v bu chnh Chu u ) quy nh mt dch v vin thng chung Chu u tn s 900MHZ. Nm 1985 ngi ta quyt nh xy dng h thng thng tin di ng k thut s . n nm 1986 ti Pari mi hon thnh vic nh gi nh hng cc gii php ca cc nc khc nhau tin ti la chn phng n cng ngh TDMA bng hp. pht trin, nghin cu v nhm nng cao mng li dch v thng tin di ng GSM, u nm 1992 mt s nc Chu u thnh lp hip hi GSM MOU nhm trao i, hp tc trong kinh doanh v bo v quyn li cho cc nh khai thc GSM trn ton th gii. Thng 5/1987, 13 nc Chu u k GSM MOU ha h ln nhau v v vic hon thin cc ch tiu k thut, nhn cng nhau hp tc m rng th trng rng ln cho GSM v tho thun mi nc s c mt mng GSM hot ng 01/7/1991. Song v mt s nguyn nhn, cui nm 1992 mi c 13 thnh vin ca mng GSM ca nc v n nay c 253 thnh vin mng GSM ca 109 nc Vit Nam, GPC v VMS hin nay ang khai thc hai mng thng tin di ng s VinaPhone v MobiFone theo tiu chun GSM. I .1.2.Mt s tnh nng t c th h hai cng (GSM) - Cc dch v mng mi v ci thin cc dich v lin quan n truyn s liu nh nn s liu ca ngis dng, s liu chuyn mch knh tc cao, dch v v tuyn gi chung v s liu 14,4kbps. - Cc tnh nng lin quan n dch v ting nh: Codec a tc thch ng v khai thc t do u cui cc Codec ting. - Cc dich v b sung nh: chuyn hng cuc gi, hin tn ch cuc goi chuyn giao cuc gi v cc dch v cn gi mi. - Ci thin lin quan n dch v bn tin ngn (SMS: Short Message Service) nh: mc nicc SMS, m rng bng ch ci, m rng tng tc gia cc SMS. - Cc cng vic lin quan n tnh cc nh: cc dich v tr tin thoi trc, tnh cc nng v h tr cho u tin vng gia nh. - Tng cng cng ngh SIM. - Dch v mng thng minh nh CAMEL

SVTH: Nguyn Th Lan Anh

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- Cc ci thin chung nh: chuyn mng GSM-ASMP, cc dch v nh vtng tc vi cc h thng thng tin di ng v tinh v h tr nh tuyn ti u. I.2 CU TRC MNG GSM I.2.1 S mng GSMAUC

ISDN PSPD NNNN NN CSPDN N PSTN PLM N

SS VLR

HLR

EIR

MSC OMC

BSC BSS BTS

Truyn dn tin tc.

MS

Kt nicuc giv truyn dn tin tc Hnh I.1.S gii thiu chung h thng thng tin di ngGSM Cc k hiu chung : SS : H thng chuyn mch AUC : Trung tm nhn thc VLR : B ghi nh v tm tr HLR : B nh v thng tr EIR : Thanh ghi nhn dng thng tr MSC : Trung tm chuyn mch cc nghip v di ng (goi tt l tng i v tuyn ) BSS : H thng trm gc BTS : i v tuyn BSC : i iu khin trm gc MS : My di ng OMC : Trung tm khai thc v bo dng ISDN : Mng s lin kit a dch v PSPDN : Mng chuyn mch cng cng theo gi CSPDN : Mng chuyn mch s cng cng theo mch PSTN : Mng chuyn mch in thoicng cng PLMN : Mng di ng mt t cng cng I.2.2. Gii thiu cc thnh phn ca mng di ng GSM H thng GSM c chia thnh h thng chuyn mch (SS) v h thng trm gc (BSS). Mi h thng ny cha mt s khi chc nng thc tt c cc chc


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nng ca h thng. H thng c cu trc nh l mt mng gm nhiu v tuyn k cn nhau cng m bo vng ph sng min phc v . Mi v tuyn c mt trm v tuyn gc (BTS) lm vic vi mt tp hp cc knh v tuyn. Cc knh ny c s dng cc ln cn trnh nhiu giao thoa. Mt b iu khin trm gc (BSC) iu khin mt nhm BTS, BSC iu khin cc chc nng nh chuyn giao v iu khin cng sut . Mt trung tm chuyn mch cc nghip v di ng MSC phc v mt s b iu khin trm gc. MSC iu khin cc cuc gi n t mng chuyn mch in thoi cng cng PSTN mng s liu a dch v ISDN, mng di ng mt dt cng cng PLMN, cc mng s liu cng cng PSDN v c th l cc mng ring . I.2.2.1. H thng chuyn mch SS : H thng chuyn mch bao gm cc chc nng chuyn mch chnh ca GSM cng nh c s d liu thu bao v qun l di ng ca thu bao, chc nng chnh ca SS l qun l thng tin gia nhng ngi s dng mng GSM vi nhau v vicc mng khc . *Trung tm nhn thc AUC: L b phn trong phn cng HLR, trong h thng RSM c nhiu bin php an ton khc nhau c dng trnh s dng tri php, cho php bm v ghi li cuc gi. ng v tuyn cng c AUC cung cp m bo mt chng s nghe trm, m ny c thay i ring bit cho tng thu bao. C s d liu ca AUC cn ghi nhiu thng tin cn thit khc v thu bao v phi c bo v chng trm mi thm nhp tri php. *B ghi dnh v tr thng tr HLR: L c s d liu trung tm, quan trng nht ca h thng GSM, lu d cc d liu v thu bao ng k trong mng ca n v thc hin mt s chc nng ring ca mng thng tin di ng. Trong c s d liu ny lu tr nhng s liu v trang thi thu bao, quyn thm nhp ca thu bao, cc dch v m thu bao ng k, s liu ng v vng m ang cha thu bao ca n (Roaming).Trong HLR cn to bo hiu s 7 trn giao din MSC. *B nh v tr tm thi VLR: c kt hp trong phn cng ca MSC, trong VLR cha cc thng tin v tt c thu bao di ng ang nm trong vng ph sng ca MSC ny, gn cho cc thu bao t vng phc v MSC/VLR khc ti mt s thu bao tm thi. VLR cn thc hin tao i thng tin v thu bao Roaming vi HLR . *B ghi nhn nh thit b EIR: Bo v mng PLMN khi s thm nhp ca nhng thu bao tri php, bng cch so snh s IMEI(International Mobile Equipment Identity: nhn dng thit b trm di ng quc t ) ca thu bao ny gi ti khi thit lp thng tin vi s IMEI lu tr trong EIR. Nu khng tng xng thu bao s khng th truy nhp c . *Trung tm chuyn mc cc dich v di ng MSC: h thng thng tin di ng chc nng chuyn mch chnh c thc hin bi MSC, nhim v chnh ca MSC iu phi vic thit lp cuc gi n cc ngi s dng mng thng tin di ng. Mt mt giao din vi BSC mt khc n giao din vi mng ngoi c gi l MSC cng. Vic giao din vi mng ngoi m bo thng tin cho ngi s dng mng thng tin di ng i hi cng thch ng IWE(IWE:Interworking Function-chc nng tng tc ). Mng thng tin di ng cng cn giao din vi mng ngoi s dng cc kh nng truyn ti ca cc mng ny cho vic truyn ti s liu ca ngi s dng hoc bo hiu gia cc phn t ca cc mng. Chng hn mng thng tin di ng c th s dng mng bo hiu knh chung s 7 (CCS 7). MSC thng l mt tng i ln iu khin v qun l mt s cc b iu khin trm gc (BSC). I.2.2.2 H thng trm gc BSC


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C th ni BSS l mt h thng cc thit b c th ring cho cc tnh cht t ong v tuyn ca GSM. BSS giao din trc tip vi cc trm di ng MS thng qua giao din v tuyn, v th n bao gm cc thit b pht v thu ng v tuyn v qun l cc chc nng ny. Mt khc BSS thc hin giao din vi cc tng i SS. Tm li BSS thc hin u ni MS vi cc ngi s dung vin thng khc. BSS cng phi c iu khin v vy n phi c u ni vi OSS cc giao din bn ngoi ca BSS nh hnh I.2

Lung iu khin Lung lu lng OSS

MS Cc k hiu:

BSS

NSS

Hnh I.2 cc giao din bn ngoi ca BSS NSS : Mng v h thng con chuyn mch BSS : H thng trm gc OSS : H thng trm khai thc MS : Trm di ng BSS bao gm hai loi thit b : BTS giao din vi MS v BSC giao din vi MSC * BTS: Mt BTS bao gm cc thit b pht v thu, anten x l tn hiu c th cho cc giao din v tuyn, C th coi BTS l cc modem v tuyn phc tp c thm mt s chc nng khc. Mt b phn quan trng ca BTS l TRAU (Transcoder and rate adapterunit: Khi chuyn i m v thch ng tc cao ).TRAU l thit b m qu trnh m ho v gii m ting c th ring cho GSM c tin hnh. Ngoi ra TRAU cn thc hin nhim v nn /gin tc cc knh thng tin s lm cho mng tit kim c ng truyn dn thng tin t MSC n BSC v BTS . Bi v mt MSC thng c vi BSC v nhiu BTS c phn b nhng ni cch xa nhau m TRAU th c t gn MSC cho nn khi truyn dn gia MSC vi BSC v BTS ta gin c 4 ln cc lung E1. Mt khc do cc yu t knh thoi 16 bit/s nn dng TRAU nn gin nh vy l hp l.TRAU giao tip vi MSC qua giao din A v BSC qua giao din Abis. Hin nay, MSC3/VLR th b thch ng v chuyn m c tn l TRAU7 c t MSC3/VLR Nng .SVTH: Nguyn Th Lan Anh Trang 4

Bi thi cui kho


Nn 4 lung E1 (2Mbit/s) 32 knh 64 bit/s Gin 16kbit/s =13kbit/s (voice) +3kbit/s (LAPD) 1 lung E1 (2Mbit/s) 128 knh 16kbit/s

* BSC: BSC c nhim v qun l tt c cc giao din v tuyn thng qua lnh iu khin t xa BSTv MS. Cc lnh ny l cc lnh ch yu n nh, gii phng knh v tuyn v qun l chuyn giao (handover). Mt pha BSC c ni vi BTS cn pha khc c ni vi MSC ca SS.Trong thc t BSC l mt tng i nh v c kh nng thanh ton ng k. Vai tr ch yu ca n qun l cc knh giao din v tuyn v chuyn giao (handover - l s thay i n mt knh thng tin mi trong qu trnh MS thit lp cuc gi trng thi bn. Mng s quyt nh s thay i ny. MS ch gi cc knh thng tin lin quan n cng tn hiu v cht lng truyn dn n BTS). Mt BSC trung bnh c th qun l ti vi chc BTS ph thuc vo lu lng ca cc BTS ny, giao din gia BSC vi MSC c gi l giao din A, cn giao din gia n vi BTS c gi l giao din A bis

Hnh I.3 Cu trc bn trong ca BSS I.2.2.3. Trm di ng MS a. Chc nng :SVTH: Nguyn Th Lan Anh Trang 5

Bi thi cui kho


Trm di ng l mt my u cui di ng hay Mobile Phone .V hnh thc cc my di ng c th khc nhau, my di ng cng c nhiu hnh nh : (my cm tay, my xch tay, hay my t trn cc t ). Loi thit b nh cm tay s l thit b trm di ng ph bin nht, ngoi vic cha cc chc nng v tuyn chung v x l cho giao din v tuyn MS cn phi cung cp cc giao din cho ngi s dng (nh: micro, loa, mn hin th bn phm qun l cuc gi ) hoc giao din vi mt s thit b khc (nh:giao din vi my tnh ci nhn, FAX). Trm di ng khng hon ton ph thuc cht ch vo ngi s dng, m s ph thuc ny thng qua mt th nhn dng thu bao SIM (Subscriber Identity Module: m un nhn dng thu bao ) c gn trn my di ng .S nhn thc c kim tra bi mng, xt xem liu thu bao c hp vi my di ng hay khng, sau mi c nhp vo h thng .Mt m c nhn c dng km theo SIM-PIN trnh s s dng tri php th SIM. b.Cu trc ca MS: My thu bao di ng gm hai phn: Modulle nhn dnh thu bao SIM (Subscriber Identity Modulle) v thit b thu pht bo hiu ME (Mobile Equiment). Trc ht SIM l mt ci kho cho php MS c dng, ci kho ny gn cht vi ngi dng trong vai tr thu bao duy nht c th lm vic vi cc thit b ME khc nhau, tin cho vic thu mn cc ME tu thu bao. SIM c nhng phn cng v phn mn cn thit vi b nh c th lu tr hai loi tin tc: tin tc c th c c hoc c thay i bi ngi dng .SIM s dng mt khu PIN (Peronal Indentity Number) bo v quyn s dng ca ngi s dng hp php . ME l phn cng thu bao truy cp mng, ME c s nhn dng l IMEI (International Mobile Equipment Indentity). Nh khim tra MIEI m ME b mt cp s khng c phc v . SIM l mt card in t thng minh gn vo ME, dng nhn dng thu bao v tin tc v loi dch v m thu bao dng k s dng, nh cung cp mng GSM s bn SIM cho thu bao ng k, GSM thit lp ng truyn v tnh cc da vo ISMI. ME: thit b my di ng v thu bao ch tip xc vi ME m thi c 3 loi ME. - Trn xe (lp t trong xe, ngten ngoi xe ) . - Xch tay (ngten khng lin t hp cm tay ) . - Cm tay (ngten lin t hp, ton b my cm tay nm gn trong lng bn tay)

Hnh I.4. Chc nng mt trm di ng. I.2.2.4.H thng h tr v khai thc OSS H thng khai thc OS(Operation system) thc hin khai thc v bo dng tp trung cho mng thng tin di ng . *Khai thc: L cc hot ng cho php ca cc nh khai thc mng theo gii hnh vi ca mng nh: ti ca h thng, mc chn, s lng chuyn giao (handever) gia hai nh vy nh khai thc c th gim st c ton b chtSVTH: Nguyn Th Lan Anh Trang 6

Bi thi cui kho


lng ca dch v m h cung cp cho khc hng v kp thi s l cc s c. Khai thc cng bao gm vic thay i cu hnh gim nhng vn xut hin thi im hin thi, chun b tng lu lng trong tng lai, tng vng ph sng.Vic thay i mng c th thc hin mm qua bo hiu (chng hn nh thay i thng s chuyn giao thay i bin gii gia hai ) hoc thc hin cng i hi s can thip ti hin trng (chng hn b sung thm dung lng truyn dn hay lp t mt trm mi ). *Bo dng: C nhim v pht hin, nh v v sa cha cc s c, hng hc. N c mi quan h vi khai thc, cc thit b mng vin thng hin i c kh nng t pht hin mt s s c hay d bo s c thng qua t kim tra.Trong nhiu trng hp ngi ta d phng cho thit b thit b s c c th thay th bng thit b d phng .S thay th ny c th thc hin t ng. Ngoi vic gim nh s c c th c thc hin bi ngi khai thc bng iu khin t xa .Bo dng cng bao gm c cc hot ng ti hin trng nhm thay th thit b, b s c. *H thng khai thc v bo dng : C th c xy dng trn nguyn l TMN(Telecommunication Management Network- mng qun l vin thng ). Lc ny mt mt mng khai thc v bo dng c ni n cc phn t ca mng vin thng (cc MSC, BSC, HLR, v cc phn t mng khc tr BTS, v truy nhp n BTS c thc hin qua BSC) mt khc h thng khai thc v bo dng li c ni n mt my tnh ch ng vai tr giao tip ngi my. H thng ny thng c gi l OMC (Operation and Maintenance Cente- Trung tm khai thc v bo dng). *Qun l thu bao: Bao gm cc hot ng dng k v qun l thu bao. Nhim v u tin l nhp v xo thu bao khi mng, ng k thu bao cng c th rt phc tp bao gm nhiu dch v v cc tnh nng b sung .Nh khai thc cm phi thm nhp c tt c cc thng s ni trn, mt nhim v khc ca nh khai thc l tnh cc cc cuc gi, Qun l thu bao mng GSM ch lin quan n HLR v mt s thit b OSS chng hn mng ni HLR vi cc thit b giao tip ngi v my ca cc trung tm giao tip vi SIM card cng ng vai tr nh mt b phn ca h thng thu bao . *Qun l thit b di ng : Qun l thit b di dng c b ng k nhn dng thit b EIR( thanh ghi nhn dng thit b )thc hin, EIR, lu gi cc d liu lin quan n trm di ng MS. EIR c ni n MSC qua ng bo hiu kim tra s c php. II.2.3 Nguyn l hot ng chung ca GSM: Hnh I.1 gii thiu m hnh ca h thng thng tin di ng GSM. M hnh ny bao gm phn h chuyn mch SS v phn h trm gc BSS, trong mi BSS c mt b iu khin trm gc BSC iu khin mt nhm BTS v cc chc nng nh chuyn nh chuyn giao v iu khin cng sut .Cn trong mi SS, mt trung tm chuyn mch ca PLMN gi tt l tng i mng di ng MSC, phc v nhiu BSC hnh thnh cp qu l lnh th gi l vng phc v MSC, bao gm nhiu vng nh v, biu th phn cp cu trc a l ca mng di ng v cell () c hiu nh sau. Cell: l mt n v nh nht ca mng, c nhiu kiu cell khc nhau nhng cell l hnh lc gic u (cu trc t ong ) t c hiu qu ti u nht. Trong mi cell c mt trm gc BTS lm nhim v lin lc v tuyn vi tt c cc MS c mt trong . Tu theo lu lng cc cuc gi trong cell m ngi ta s dng mt hay v tn s trong mt cell v c cch mt khong nht nh no th ta c th s dng li cc tn s cho cc cell khc. Trong thc t, nu nh lu lng tng trng mt cch qu mc th ngi ta c th chia mt cell thnh cc cell nh hn, thng thng cc cuc gi khng th xong trong mt cell. V vy, h thng thng tin di ng GSM phi c cc chc nng iu khin v chuyn mch chuyn giao cuc gi t cell


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ny sang cell khc m cuc gi c chuyn giao khng b nh hng g v yu cu ny lm cho mng di ng khc vi mng c nh. Vng phc v GSM (tt c cc nc thnh vin ) Vng phc v PLMN (mt hay nhiu vng mt nc ) Vng phc v MSC (vng c iu khin bi mt MSC) Vng nh v (vng nh v v tm gi ) Cell() (vng c mt trm gc ring )

Hnh I.5 V d v phn cp cu trc a l ca mng di ng GSM. qun l mt my di ng MS ca mng di ng GSM i hi phi c mt c s d liu ln. B ng k nh v thng tr HLR chc cc thng tin v thu bao nh cc dch v m thu bao la chn v cc thng s nhn thc. V tr hin thi ca mt my di ng MS c cp nhp qua b ng k nh v tm tr VLR cng c chuyn n HLR. Lc ny trung tm nhn thc c chc nng cung cp cho HLR cc thng s nhn thc v cc kha mt m, mi MSC c mt VLR. Khi my di ng MS i vo mt vng phc v MSC mi no th VLR yu cu HLR cung cp cc s liu v v khch di ng MS ny, ng thi VLR cng thng b cho HLR bit rng my di ng ni trn ang vng phc v MSC no. Nh vy VLR c tt c cc thng tin cn thit thit lp cuc gi theo yu cu ngi dng. Mt MSC c bit gi l (MSC cng ) c PLMN giao chc nng kt ni gia PLMN vi cc mng c nh.V d thit lp cuc gi n mt my di ng MS, th cng MSC hi HLR v v tr hin thi ca my di ng MS thuc v vng no nh tuyn ti MSC ca my di ng MS xt. Khi cuc gi t ti MSC ny, th VLR s cho bit v vng nh v ca my di ng MS xt. Tip theo l s thng bo qung b tm gi my di ng MS xt c thc hin. My di ng thc cht l thit b u cui v tuyn ca thu bao, nh c thit b ny m ngi s dng c th truy cp vo mng.Thnh phn chnh ca mt my di ng gm c hai phn:Modulle nhn dng thu bao SIM v thit b thu, pht, bo hiu ME . Trong phn h chuyn mch SS cn c: Thanh ghi nhn dng EIR (Equipment Identity Reggister)cha s liu phn cng ca thit b -EIR c ni vi MSC qua mt ng bo hiu, nh vy MSC c th kim tra s hp l ca thit b. Trm gc BS l thit b kt ni my di ng vi tng i di ng MSC, thng trm gc BS c chia thnh trm thu pht gc BTS v khi iu khin trm gc BSS, Trm thu pht BTS c th dt c lp vi khi iu khin trm gcBSS. Trm thu pht BTS c th t c lp vi khi iu khin BSC hoc t cng BSC, n bao gm mt hoc nhiu b thu pht gc, khi iu khin trm gc BSC c chc nng iu khin v qun l h thng cho mt hoc nhiu BTS .Khi BSC nhm trao i bn tin vi c BTS v MSC. Mt s on tin bo hiu c th truyn thng n cc BSC khc nhau. Tng i di ng hoc h thng tng i di ng MSC c nhim v chuyn lu t mng di ng n mng c nh hoc n mng di ng khc . Trn hnh I.1 cn c phn h khai thc v h tr OSS, chc nng ca n cng c trnh by trn .


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Trn c s nhng iu trnh by trn, chng ta trc ht cn bit n nhng khc bit ln trong mng c nh v mng di ng. Trong mng c nh, thit b u cui ni kt c nh vi mng. Do , tng i mng c nh lin tc gim st c trng thi nhc, t (t hp my in thoi) pht hin cuc gi n t thu bao, ng thi thit b u cui lun lun sn sng tip nhn chung (c cuc gi n thu bao xt ). Nhng trong mng di ng, v s knh v tuyn qu t so vi s thu bao MS, nn knh v tuyn ch dc cp pht theo kiu ng. Hn na, vic gi c v thit lp cuc gi i vi MS cng kh hn. Khi cha c cuc gi, MS lng nghe thng bo tm gi n nh mt knh c bit, knh ny l knh qung b (chung cho vng nh v ). Mng phi xc nh c MS b gi ang l vng nh v no. Mt cuc gi lin quan ti MS yu cu h thng cho php MS truy cp n h thng nhn c mt knh. Th tc truy cp c thc hin trn mt knh c bit theo hng t MS n trm gc. Knh ny v knh qung b u l l knh chung v n ng thi phc v nhiu MS trong cell. Knh m MS c cp pht thc hin mt cuc gi l knh dnh ring. Vy MS c 2 trng thi chnh: - Trng thi ch : My di ng lng nghe knh qung b . - Trng th truyn tin: My di ng MS c cp pht knh truyn tin song cng truyn tin song cng .Th tc truyn tin l mt chc nng ca my di ng MS cho php n chuyn t trng thi ch sang trng thi truyn tin .Khi MS trang thi truyn tin, MS c th di ng t cell() ny sang cell() khc, i hi phi chuyn i knh dnh ringv s ph thuc tng ng t mng m khng nh hng g n cuc gi ang tin hnh .Qu trnh gi l chuyn giao, vic chuyn giao i hi hai chiu: mng phi pht hin nhu cu chuyn giao, mng phi pht hin nhu cu cu chuyn giao, mng phi cp pht v chuyn mch n knh dnh ring mi.S hp tc gia cc mng thng tin to iu kin MS c chuyn giao trong bt k phm vi no. Ngi ta ch nh giao din v tuyn chung MS c th truy cp n tt c cc mng. MS c b phn ME y phn cng v phn mm cn thit phi php vi giao din ni trn. Phn SIM c nhiu tnh nng cn ni r thm. Trc ht SIM l mt ci kha cho php MS c dng. Nhng l mt ci kha vn nng hin nay cho php ci kha ny gn cht ci kha ny gn cht vi ngi dng trong vi tr mt thu bao duy nht, c th lm vic vi cc thit b ME khc nhau, tin cho vic thu, mn cc ME ty thu bao. SIM cng c cc phn cng, phn mm cn thit vi b nh c th lu tr loi tin tc: tin tc c th c c hoc thay i bi ngi dng SIM, s dng mt khu pin bo v quyn s dng ca ngi s hu hp php. SIM cho php ngi dng s dng nhiu dch v v cho php ngi dng truy cp vo cc PLMN khc nhau.


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CHNG II C S L THUYT V PHNG PHP NGHIN CU II.1Giao din v tuyn v truyn dn II.1.1.Qu trnh s l cc tn hiu v bin i vo sng v tuyn : Qu trnh ny c trnh by nh s di yA/D Phn on M ha knh M ha knh Ghp xen mt m ha lp khun cm iu ch

3KHz 160mu,3 bt 260bt/20ms 456bt/20ms 22,8kbps

270Kbps khe thi gian(Ts)

D/A

Gii m ting

gii m viterbi

gii php xem

Gii mt m

Cn bng vitirbi

My thu /gii diu ch

Hnh II.1 X l tn hiu s v bin i sng v tuyn MS II.1.2.Cu trc knh. Knh c t chc theo quan im truyn dn hoc tin tc. Nu theo quan im truyn dn th l knh vt l, nu theo quan im tin tc th l knh logic. a.T chc a truy cp bng cch kt hp gia FDMA v TDMA. Truyn dn v tuyn GSM c chia thnh cc cm (Burst) cha hng trm bit c iu ch. Mi cm c pht i mt khe thi gian c rng l 15/16 (577s) mt knh tn s c rng l 200 KHz. Mi mt knh tn s cho php t chc cc khung truy cp theo thi gian mi khung gm 8 khe thi gian t 0 n 7 (TSo, TS1...TS7). Tn s (FDMA) A)) 200 KHz 7 0 1 2 3 4 5 6 7 0 1 2

(khe thi gian) 15/26 ms

Thigian(TDMA)

Hnh II.2. a truy nhp kt hp FDMA v TDMS b. Cc knh vt l : Trong h thng thng tin di ng, kh nng m tt c cc MS lin lc c vi nhau cng mt thi in l hon ton khng th xy ra c. Bi v khong thi gian m tn s v tuyn c MS s dng m thoi l ngn v cc yu cu m thoi l rt ngu nhin, do tht v ngha nu phn phi cc knh v tuyn cho cc MS mt cch c nh (nh mng PSTN) cho bt k mt MS no cng c th lin lc bt k mi thi in. Nu s lng cc MS c th lin lc ng thi hn ch mt s lng xc nh v cc knh v tuyn ri cng c phn phi theo yu cu


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lin lc th vic s dng sng v tuyn c th t hiu qu cao, v vy khi thit k h thng thc t cn phi xc nh cc quan h v lng gia 4 yu t sau: - Tn sut ca cc yu cu v thi gian m thoi. - Mc cc yu cu khng c chp nhn. - S lng knh v tuyn c th s dng c. - S lng MS c th p ng. a truy cp phn chia theo thi gian TDMA l h thng phn chia cc knh lin lc theo thi gian, trong MS c phn chia cc tn s ring bit cc khe thi gian c th Cc knh vt l c coi l cc cp tn s v khe thi gian dng truyn ti thng tin gia trm di ng MS v trm thu pht gc BTS. Phn b tn s GSM c quy nh nm trong gii bng tn nh sau : 890-915MHz cho ng ln (MS pht ) 935-960MHz cho ng xung(BTS pht) Khong cch gia cc sng mang l 200KHz. Trong tng lai khi m rng n h thng DCS-1800 bng tn c s dng s l : 1710-1785 MHZ ng ln 1805-1880MHz ng xung m bo cc quy nh v tn s bn ngoi bng phi c mt khong bo v gia cc bin ca bng (200KHz). V th GSM 900 ta c 124 knh tn s v tuyn bt u t 1710,2MHz. Mi mt knh tn s v tuyn c t chc thnh cc khung TDMA c 8 khe thi gian, c nh s t 0-7. Tt c ngi dng mt tn s u chung mt khung 8 khe. MS c cp pht 1 khe trong khung, n ch pht trong khe ny v tt 7 khe cn li. Mi mt khe thi gian c di 15/26ms (577s). 8 khe thi gian ca mt khung TDMA c di gn bng 4,62ms.Vy mt knh ngi dng tng ng 200KHz/8 =25KHz. Khung TDMA 7 0 1 2 3 4 5 6 7

TDMA Frame 4651ms Hnh II.3 Mt khung TDMA BTS cc khung TDMA tt c cc knh tn s trn ng xung c ng b . ng b cng c p dng nh vy vi ng ln .Tuy nhin khi u ca khung TDMA ng ln tr mt khong thi gian c nh 3 khe .L do tr cho php MS s dng cng mt khe thi gian c ng ln ln ng xung m khng phi thu pht ng thi .S tr ni trn c m t hnh II.4 di y . ng xung knh tn s ng xung knh tn s ng ln knh tn s Khung Khung Khung TDMA TDMA TDMA Khung Khung Khung TDMA TDMA TDMA Khung Khung Khung TDMA TDMA TDMA


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Bi thi cui kho


ng ln knh tn s

Khung TDMA

Khung TDMA

Khung TDMA

3Ts Hnh II.4: Cc khung TDMA c. Cc knh logic. L knh c t chc theo quan im tin tc.GSM phn bit knh lu lng truyn a d liu ngi dng vi knh iu khin truyn a bo hiu qun l mng v knh. Cc knh logic c c trng bi thng tin truyn gia BTS v MS cc knh logic ny c t vo cc knh vt l c xt trn. C th chia cc knh logic thnh 2 loi tng qut: cc knh lu lng (TCH: Traffic Channel) v cc knh bo hiu iu khin. *Cc knh lu lng TCH: Cc knh lu lng gm hai loi nh ngha sau. + Ting thoi: Bm hay TCH ton tc (TCH/F), knh ny mang thng tin ting hoc s liu tc 13 kbps; Lm hay TCH bn tc (TCH/H), knh ny mang thng tin tc vo khong 6,5 kbps. + S liu: 12 kbps (cho tc lung c s 9600 bps); 6 kbps (cho tc lung c s 4800 bps); 3,6 kbps (cho tc lung c s 2400 bps). *Cc knh bo hiu iu khin: Cc knh bo hiu iu khin c chia thnh ba loi: cc knh iu khin qung b, chung v dnh ring. c tnh ca cc knh iu khin c m t di y. Knh qung b: BCH = BCCH+FCCH+SCH. - BCH ch dng cho mc hng xung, cung cp cho MS tin tc MS ng b vi mng. - BCCH (Broadcasting Control Channel: knh iu khin qung b chung) cung cp cc tin tc, BCCH ch dng cho ng xung. - FCCH (Frequence Corretion Channel: knh hiu chnh tn s) cung cp h thng ca tn s ca h thng cho MS. - SCH (Synchronization Channel) cung cp chui hng dn MS lm vic ti u, ngoi ra cn cung cp thng tin nh thi v thng tin nhn c dng trm gc. SCH ch s dng cho ng xung. Cc knh iu khin chung: CCCH = RACH + PCH +AGCH - CCCH phc v thit lp knh dnh ring gia mt MS vi BTS. - RACH (Random Access Channel: knh truy cp ngu nhin) l knh hng ln MS a ra yu cu knh dnh ring. - PCH (Paging Channel: knh nhn tin) c BTS dng gi MS. - AGCH (Access Grand Channel: knh chp nhn truy cp) mang tin tc phc p ca BTS i vi bn tin yu cu knh ca MS. Knh iu khin dnh ring DCCH: DCCH dng trao i tin tc, bo hiu ,phc v cp nht v tr, ng k v thit lp cuc gi, phc v va bo dng knh. Trong DCCH c SDCCH (Standalone CSDL dedicated Control Channel) knh iu khin dnh ring ng mt mnh phc v thubao chuyn giao bo hiu gia MS vi BTS o(1) (6) II.2.Cc k thut iu khin ng truyn v tuyn : (4)

II.2.1 iu khin kt ni : a. iu khin khi u cuc gi .I (2) SVTH: Nguyn Th Lan Anh (5) (6) II

III (3) (5) (6) (5)

IV

V

Knh ting(5) Trang 12

Bi thi cui kho


Knh iu khin C-CH D-CH

Trm di ng

Hnh II.5 Khi u cuc gi Trong : I. L trm gc v tuyn II. L trm gc thit b iu khin III. L tng i thng tin di ng IV. L mng in thoi chung V. L cc thu bao chung Hnh II.5 m t qu trnh iu khin kt ni khi mt thu bao bt u gi trn mng thng tin di ng h thng analog. (1) Khi thu bao nhp s cn gi v n nt pht, trm di ng t ng chuyn t knh tm gi (Pch) ch ch sang knh iu khin truyn (Ach) trong vng v tuyn c trm di ng v truyn tn hiu. (2) Trm gc thu tn hiu c pht i t trm di ng v chuyn chng ti n v iu khin di ng. (3) n v iu khin trm di ng truyn cc tn hiu v s ca trm gc ti tng i thng tin di ng. (4) Tng i truy nhp ti trm nh thng tr, lu tr d liu v thu bao ang gi, c d liu v so snh chng vi tn hiu va nhn c . (5) Nu d liu tng ng, tng i thng tin di ng chn mt mch gi gia cc trm gc. Tng i cng phi chn mt mch gi truyn ti thit b nhn cuc gi .Vic la chn ny c tin hnh theo hai cch sau : *Truyn ti mng c nh : Th tc ging nh th tc ca cc cuc gi in thoi truyn thng cc s c x l v mch gi c chn . *Truyn ti trm di ng khc : S dng s cn gi t trm di ng sn sinh cuc gi nhn dng trm nh thng tr ca trm di ng c gi v d liu trn thit b c c, sau mch gi c chn. Khi mch truyn c chn, s cn gi c truyn i. ng thi trm gc c thng bo bit mch gi no c chn tin hnh kim tra ni thng mch .Khi trm gc nhn thng bo v mch gi, trm chn mt knh ri trong vng v tuyn ca n v ch kt qu kim tra kt ni t tng i thng tin di ng (6) Khi trm gc nhn c kt qu kim tra, thng qua knh iu khin truyn, dn (Ach)n s thng bo cho trm di ng bit knh no c chn. Sau trm gc tin hnh kim tra kt ni knh gia n v trm di ng v gii kt qu ti tng i di ng. Khi tng i c thng bo rng kt qu thun li, n ch s tr li t thu bao b gi v khi nhn c s tr li ny, tng i bt u tnh cc. b. iu khin kt cui cuc gi.(2) (3) SVTH: Nguyn Th Lan Anh Knh tuyn

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Bi thi cui kho (5) (6)


V Knh iu khn

I

P-CH(Knh tm gi) (2)II

III

IV

VI (5)

VII II

C-CH(4)(3) (6)(5)

D-CH(1)(3) (4)(5) (6)

Trm di ng

Hnh II.6 Kt cui cuc gi Trong I . L trm v tuyn gc II. L thit b iu khin trm gc III. L tng i thng tin di ng IV. L tng i thng tin di ng gn nht V. L CSDL thu bao VI. L mng in thoi chung VII. L thu bao thng Hnh II.5 Cho chng ta thy cc th tc kt cui cuc gi h thng tng t. (1) Tng i thng tin di ng trong mt vng truyn cc tn hiu tm gi ti cc n v iu khin di ng. (2) n v iu khin di ng s dng cc s v tr trong tn hiu nhn c chn knh tm chung. n v iu khin di ng truyn tn hiu nhn c ti trm di ng b gi thng qua knh iu khin ca tt c cc trm gc. (3) Trm di ng b gi t ng pht tn hiu tr li thng qua knh tm gi (Pch).Trm gc chuyn cc tn hiu tr li ti n v iu khin di ng, ti y n so snh s thu bao c trong cc tn hiu ny vi s nhn c t tng i thng tin di ng. Nu s khp vi nhau, s c gn vi s ca trm gc truyn ti tng i di ng. (4) Nu s khp nhau, tng i thng tin di ng chn mt mch gi trong s cc trm gc, thng bo cho cc trm gc bit mch no c chn v iu khin vic kim tra kit ni .khi trm gc bit c mch ang gi, n chn knh ri trong vng v tuyn ca mnh v ch kt qu kim tra kt ni t tng i thng tin di ng . (5) Khi trm gc nhn c thng bo kt qu kim tra kt ni, n s dng knh iu khin truyn dn (Ach) thng bo cho trm di ng knh no c la chn. Trm gc iu khin vic kim tra kt ni gia n v trm di ng v thng bo kt qu ti tng i thng tin di ng. (6) Khi tng i bit rng kt qu kt ni l thun li, n truyn tn hiu ti thit b gi i t khi u rung chung . N cng truyn hi m chung ti ngi gi. II.1.2 iu khin chuyn giao : Khi mt trm di ng ang tin hnh cuc gi chuyn vo vng v tuyn khc, trm di ng c chuyn sang s dng knh gi trong vng v tuyn mi m bo cuc gi lin tc. iu ny c gi l iu khin chuyn giao. Cc vng v tuyn khng c bin gii r rng. Sng v tuyn dn dn gim v thay i tht thng .Ti bin gii gia hai vng, sng v tuyn c pht i t cc trm gc ca mi vng chng cht ln nhau , tng sng li thay i bt thng. iu khin chuynSVTH: Nguyn Th Lan Anh Trang 14

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giao trong iu kin bin thin nh vy c tin hnh bng cch chn vng c tn hiu thu ln nht v ni ti knh ca vng .C 3 kiu iu khin chuyn giao nh sau : - Chuyn i c tin hnh gia cc vng trong cng mt n v iu khin di ng qu l - Chuyn i c tin hnh gia cc n v iu khin di ng trong cng mt tng i thng tin di ng . - Chuyn i c tin hnh gia cc tng i thng tin di ng . iu khin chuyn giao theo kiu th nht c thc hin nh sau

8 C-CH D-CH 5 6 8 9 3 3

8

dich toi o khac

1 2 6

kenh thoai kenh dieu khien

tram di dong

4 6 7

4

Hnh II.7 M t iu khin chuyn giao tng t . (1) Khi trm di ng ang trong qu trnh gi i qua vng v tuyn v mc thu ca knh gi gim xung di mc ngng cho php, tram gc kt lun rng trm di ng ny ang ri khi vng v tuyn . (2) Khi trm gc pht hin ra mc thua xu, n thng bo cho n v iu khin di ng. (3) n v iu khin di ng ch dn cc trm gc trong cc vng v tuyn hng ti cc knh trm di ng c th dch chuyn n gim st cc mc thu ca cc knh gi . (4) Khi nhn c lnh, nhng trm gc ny s dng my thu o mc thu t trm di ng chng bo co kt qu v n v i khin di ng . (5) Khi nhn c bo co, n v iu khin di ng chn vng v tuyn c mc thu ln nht, thng bo s ca trm gc mi cho tng i thng tin di ng v ch dn tng i chuyn knh. (6) Tng i thng tin di ng chn mt mch gi ri ni n vi trm gc mi, thng bo cho trm gc bit mch c chn v tin hnh kin tra kt ni. Khi trm gc bit c mch chn, n chn knh ri trong vng v tuyn ca n v ch kt qu kim tra kit ni t tng i thng tin di ng. (7) Khi bit c rng cc kt qu thun li, trm gc thng bo cho n v iu khin di ng knh c chn . (8) Khi n v u khin di ng nhn c thng bo v knh gi, n thng bo cho trm gc v knh mi thng qua knh gi ca trm gc cho ti lc ny c s dng cho cuc gi.ng thi, n chi dn tng i thng tin di ng ni knh gi trc ti knh mi v tng i s lm ng nh vy.


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(9) Trm gc mi iu khin kim tra kt ni ca knh gi gia n v trm di ng. Khi n xc nhn c vic chuyn i sang knh gi mi, trm gc truyn mt lnh ti tng i thng tin di ng chuyn i cc knh tng i v trm gc c gii phng knh gi c khng dng na .Nu knh c c chuyn c chuyn sang knh trong vng v tuyn do tng i thng tin di ng khc qu l, vic chuyn i li c tin hnh nh vic s dng tng i mi v cc ng tn hiu qua li . II.2. M ha thoi v m ha knh: M ha v gii m l qu trnh bin i tn hiu tng t thnh tn hiu s truyn qua mi trng v tuyn v ti to tn hiu t nhng d liu s nhn c. N l k thut gii quyt nhiu v phading ca mi trng Ceellular . II.2.1 M ha thoi : Cc yu cu i vi m ha thoi l : - d ni ti ca thoi phi c lc b, sau m ha ch gia li tin tc ti thiu khi phc thoi my thu - Bo m cht lng truyn thoi n my thu - Ngng pht khi khng tch cc thoi x l s tn hiu thoi, b m ha thoi (CODEC) trong h thng GSM thc hin khong 8 triu lnh /s, vic x l tn hiu truyn n ch mt khong 50 n 100ms .S sau trnh by qu trnh m ha v gii m thoi .

MIC

Lc thng di 300 400

A/D

M ha thoi

M ha knh

iu ch

Mi truyn

Lc thng thp

D/A

Gii m thoi

Gii m knh

Gii iu ch

LOA Hinh II.8 Qu trnh s l thoi ADC ly mu vi chu k 125s(tn s ly mu 8KHz) v lng t ha u 13 bit cho mt mu . y l tc bit ca tn hiu thoi DAI(Digital Audio Interface-giao din m tn s)tuy vy d vn cn nhiu (khong lng khi hai bn khong tch cc thoi ).C hai phng php dng loi b d ny l : - Phn tch LPC-RPE(Linear Predictive Coding-Regular Pulse Excitation) y l nguyn l gim d da vo c tnh tng quan ngn 1ms gia cc mu. - Phn tich LTP(Long Term Prediction) y l nguyn l gim d thoi da vo tng quan di ,sau ln gim d ny ta c tc thoi u ra ca CODEC l 13Kbit/s hay 260bit/20ms. II.2.2 M ha knh truyn: GSM l mt h thng s m m thoi li la tn hiu tng t nn phi c s ha .Phng php m ISDN v h thng in thai hin ti dng cho cc ng ghp knh thoi truyn qua trung k gc cao, cp quang l iu ch m xung (PCM). PCM c tc bit l 64Kbps, l mt tc cao c th truyn qua lin kt v tuyn, GSMc nhiu thut ton m ha ting ni trn c s cht lng ting ni thc v phc tp (lin quan n gi c, x l tr v tiu th cng sut ).Trc khi a nSVTH: Nguyn Th Lan Anh Trang 16

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chn la phng php xung u_m ha d on tuyn tnh (RPE_LPC) vi vng d on di v c bn, thng tin t cc mu trc khng thay i nhanh dng d on mu hin ti. Cc h s kt hp tuyn tnh ca cc mu trc, cng thm dng m ha ca phn cn li, sai s gia mu d on v mu thc, s biu din tn hiu. Ting ni ly mu chu k l 20ms, mi mu m ha thnh 260bit, vi tc bit l 13Kbps. y l m ha ting ni ton tc. Gn y, vi nh iu hnh GSM 1900 Bc M thc hin thut ton m ha ting ni ton tc cp cao (EFR). Phng php ny tng cht lng ting ni da trn tc ang s dng l 13Kpbs. M ha knh truyn thm cc bit d vo dng d liu cho php pht hin. thm ch c sa li bit sinh ra trong qu trnh truyn. Thut ton m ha ting ni a ra mt khi 260bit. Mi bit l 20ms (ngha l tc l 13Kbps) trong b gii m cc khi bit ting ni c gi m v bin i thnh nhng mu ting ni, m ng dng 13bit. 260bit ca khi ting ni phn thnh hai nhm 78 bit loi II t quan trng v khng c bo v. 182 bit loi I c ct thnh 50 bit loi Ia v 132 bit loi Ib (xem hnh sau)

Mu ting ni : 1 khi = 260 bit (20ms) u tin cc bt loi Ia c bo v bi 3 bit parity pht hin li. Sau cc bit loi Ib c cng vo thm 4 bit ui trc khi a vo m nhp vi tc r = v chiu di bt buc K = 5. Kt qu l 378 bit cng vo vi 78 bit loi II bo v cho kt qut l mt cung m ting ni hon ton 456 bit (trong hnh)

Kiu truyn TCH_FS II.2.3 M pht hin li GSM chun dng m 3 bit li d cho php nh gi s chnh xc ca bit trong khung thoi (50 bit loi Ia). Nu mt bit b sai, th iu ny s to ra mt nhiu ln thay cho phn ting ni 20ms. Pht hin nhng li ny cho php khi b sai c thay th bng mt vi nhiu t hn (nh l mt php ngoi suy ca khi d on).SVTH: Nguyn Th Lan Anh Trang 17

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a thc trnh by ny m pht hin li bit Ia l G (X) =X3 + X + 1. Bn thu hot ng tng t v nu php chia c d li c pht hin v m thanh c loi b II.3 Qun l ti nguyn v tuyn: Gii thiu chung: Giao din v tuyn rt c trng v rt quan trng i vi PLMN.S quy chun giao din v tuyn lm cho my MS ca hng sn xut khc nhau v tng thch c vi cc mng di ng ca cc nh khai thc khc nhau, to iu kin chuyn giao, thm ch ra ngoi quc gia .S quy chn giao din v tuyn nhm mc ich t c hiu sut s dng ph tn s v tuyn cao nht, tc l t hiu qu kinh t cao nht. t c mc ch , ngi ta dng rt nhiu bin php: t chc knh sao cho ti a cuc gi ng thi khi gii ph tn xc nh ,chng can nhiu do s dng li ph tn s, iu khin cng sut ng truyn dn giao din v tuyn c thit lp theo yu cu, ch trong thi gian cn thit cho cuc gi. dy chng ta xem xet vic qun l ti nguyn v tuyn, l nhim v chung ca MS, BTS, MSC v l mt phn chc nng ca MSC.Ta cn lu khi chuyn giao cn phn bit hai loi MSC :MSC neo v MSC chuyn tip .khi MS di ng t vng phc v MSC ny sang vng phc v ca MSC khc ,th vic chuyn giao lin quan n hai MSC ,tuy nhin vai tr ca hai MSC c khc nhau : - MSC neo l MSC theo di mt cuc gi t m u n hon tt, lun tham gia iu khin cuc gi v m nhin tnh cc . - MSC chuyn tip trc tip lm vic vi BSC.

Hnh II.9 khi nim v MSC chuyn tip v MSC neo II.3.1 Chc nng qun l ti nguyn v tuyn: Chc nng RR lin quan n vic qun l ng truyn dn khng ch giao din v tuyn m cn sut t MS n MSC neo: truy cp mng, nhn tin, truyn bo hiu thoiv s liu , o lng phc v chuyn giao ,qun l cng sut qun l v knh v tuyn ,vic cp pht knh dnh ring a. k han RR: Khi mtM ang trong cuc gi, th c ngha l mt ng truyn dn thu bao v mt ng bo hiu gia MA vi MSC neo ang c duy tr .S duy tr bt u t lc MS ri b trng thi ch bc vo trng thi truyn tin n lc tr v trng thi ch.V pha c s h tng ca PLMN , ng truyn dn tuy rng duy tr lin tc, nhng c th thay i rt nhiu, nht l lc chuyn giao ,chng ta gi thi k ni trn l k hn RR ,n ti thiu bao gm: - Phng tin truyn dn bo hiu gia MS vi MSC neo qua BTS, BSC, MSC chuyn tip v mt knh v tuyn dnh ring. - Nhng tham chiu qun l cng vic cn thit cc giao din BTS-BSC, BSC-MSC.SVTH: Nguyn Th Lan Anh Trang 18

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- Phng tin gim st cuc ni v tuyn v quyt nh s chuyn giao khi cn BSS. Cc ni dung ti thiu ny cho cc yu cu cp nhp v tr, truyn bn tin ngn v qun l dch v phc .Hnh II.10 trnh by trng hp truyng thoi yu cu hai s kt ni: bo hiu v thoi, cc ti nguyn dnh ring cho truyn ring thoi chng hn nh b chuyn m thoi. C nhiu c trng cho k hn RR c th thay i oc, l do qun l : - C hai lai knh dnh ring giao din v tuyn . - Cc mode truyn dn khc nhau trn knh dnh ring . - Cc c trng khc, chng hn nh c hay khng dng mt m.

Hnh II.10 Ni dung k hn RR * Khi to: MS chuyn t trng thi ch sang trng thi truyn tin l bc u s khi to ca k hn RR, gi l truy cp .S truy cpc th c khi ng bi yu cu t pha MS, hay t pha c s h tng PLMN, tuy nhin th tc u ging nhau v pgait bt u t MS .Khi mng mun thit lp mt k hn RR, n nhn tin cho MS. MS trng thi ch vn lng nghe knh nhn tin thuc PAGCH, nu bit rng: bn thn MS c nhn gi th n bt u th tc truy cp, ging nh khi bn thn n mun gi i. *Truy cp: MS pht bn tin xin truy cp vo RACH(Radow Access Grant Channel- knh truy cp ngu nhin), h thng pht tr li bn tin ch nh v knh chp nhn truy cp v nhn tin. S truy cp kt thc vi vic cp pht mt knh v tuyn cho MS s dng.Vic ny c gi l ch nh knh ban u hay l ch nh knh tc th. Nu xem chc nng truy cp khi ng l k hn RR th phi gn vn truy gp vi chc nng khc nhau *Nhn tin v thu gian on: Cc bn tin ch nh ban u v nhn tin truyn bng PAGCH v cng vic chnh v nhn tin c BSS m trch . Khi c mt cuc gi n MS, th MSC/VLR yu cu BSS nhn tin gi n cell ca BSS bng cch cung cp cho n nhn dng thu bao v danh sch cell. BSC vi vai tr qun l PAGCH s phn nhm. V lp k hoch thi gian cho cc bn tin nhn gi v ch nh ban u, khi nhn tin chng ta phi cung cp cc th tc sau. - Phng thc MSC bit thu bao no phi gi . - C ch BSCiu khin vic cp pht bn tin nhn gi . - Cch thc ch bo cu hnh PAGCH cho tt c MS. II.3.2 Cu trc v cc th mc:


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Bi thi cui kho


BSC thc hin cc chc nng qun tr ti nguyn v tuyn nh mt ngi ch huy dn nhc m cc din vin trong gian nhc l MS,BTS,TRAU,MSC.Tuy rng BSC khng lin quan nhiu n chc nng truyn dn, nhng BSC chm sc tnh thng nht ca dy truyn dn. MSC quyt nh c tnh ca dy truyn dn cho ph hp vi dch v, nhng MSC ch c vi tr khin tn trong qun tr ti nguyn v tuyn .MSC neo thc thi cc chuyn giao tip sau gia cc MSC, theo quyt nh cu BSC.MSC chuyn tip thc thi cc chuyn giao gia cc cell khc vng nh v. MSC chuyn tip cng thip lp mch truyn dn t bn thn n n cc BSC trong vng phc v .MSC chuyn tip l nt trung chuyn ca bo hiu gia MSC neo vi BSC, MS .Vy MSC chuyn tip c chc nng qun tr ti nguyn v tuyn BTS l cng vo ca PLMN ca s liu o lng, BSC qun l k hoach tn s v d liu cu trc cell. BSCv cc MSC trao i tin tc v lu lng. vic chuyn giao c thc s sun s, trong sut vi ngi dng, th rt nhiu tin tc cn phi c truyn a v s l theo thi gian thc trong PLMN. BSS qun tr ti nguyn v tuyn v quyt nh cng vic chuyn giao trong k hn RR .C hai cch chc nng x l lu lng . - Cc MSC thong bo mc lu lng ca cc BSC bao quanh cho BSC xt. - Hoc MSC can thip vo thut ton chuyn giao t gc x l lu lng. Sau khi thc hin chc nng Rri hi th tc gia MS v mng, m ngi i thoi thay mt mng l BSC, th tc trn cn c tn gi l RIL3-RR. II.3.3 Quy trnh khai thc ti nguyn v tuyn: S truy cp v ch nh ban u. MS a yu cu khi to cuc gi t 3 l do sau y . - Cp nht nh v. - Tr li nhn tin. - Thu bao MS khi xng cuc gi i (m thoi ,dch v thoi, bn tin nhn) Quy trnh ny gm 3 bc :hnh II.11 biu th quy trnh truy cp, -MS gii bn tin yeu cu knh RIL3-RR nh knh truy gp ngu nhin RACH. -PLMN phc p bng bn tin ch nh thc th RIL3-RR gii vo PAGCH, bn tin ny miu t knh cp pht theo yu cu MS. -Thit lp ng truyn bo hiu v knh ch nh gii bn tin bo hiu u tin, bn tin nhn dng thu bao v l do yu cu cuc kt ni

Hnh II.11 Quy trnh MS truy cp vo mng a. S truy cp ngu nhinSVTH: Nguyn Th Lan Anh Trang 20

Bi thi cui kho


Vic truy cp ca MS l ngu nhin nn rt c th hai hc nhiu MS cng pht trong mt khe thi gian. Khi c th mt MS c tn hiu gi n BTS mnh, tri hn MS khc nn truy cp c.Vy s va chm ny l nguyn nhn tn tht bn tin: lu lng cng ln th s va chm cng nhiu, lm tng tn tht .Thng sau khi truy cp khng thnh cng th MS s truy cp li . trnh va chm li trong khi truy cp li, mng PLMNquy nh thi gian trung bnh cho php gia cc ln truy cp ca mt MS v s ln ti a cho php lp li s truy cp khng thnh cng. Nhng quy nh ny di dng cc thng s c qung b u n trn BCCH bn ln 1s. S qu ti v lu lng gy tc nghn v thng tin c th xy ra khng nhng RACH v v khng knh pht cho nhu cu cuc gi pht sinh trong cell.Mt khng ch s qu ti khng nht thit m bo lu lng ti a trn RACH, m c PAGCH v v khng knh pht cho nhu cu cuc gi pht sinh trong cell.Mt c ch khng ch qu ti khng nht thit phi m bo lu lng ti a trn ton mng . chng qu ti trn RACH, BSC c th pht bn tin t chi n MS ,cm MS truy cp vo mng trong thi gian nht nh (bn tin t chi ch nh tc th RIL3-RR) Mt phng n gii quyt qu ti l chia thu bao thnh nhiu nhm, cng bao hm cc nhn dng thu bao SIM.Bnh thng th tt c cc nhm u c truy cp khi mun.Nhng trong tnh hung phi ct gim lu lng th BSC s c la chn mt hay nhiu nhm cm truy cp,danh sch ny c thng bo trn BCCH. *Ni dung bn yu cu knh RIL3-RR: Bn tin ny v cng ngn, ch c 8 bit ,xem hnh v di y ,5 trong 8 bit c MS chn mt cch ngu nhin ,nh l mt du hiu phn nh gia MS cng gi bn tin trong k hn cng mt khe thi gian .3 bit cn li dng MS thng bo cho mng bit l do truy cp ca MS.Tin tc tuy it i nhng cng gip cho mng x l vic t chi khi tc nghn mt cch hp l v cng gip cho mng chn mt knh thch hp cp pht cho MS.

X

X

X

X

X

L do truy cp Tr li nhn tin Gi khn cp Gi li Yu cu ngi s dng S phn nh ngu nhin

Hnh II.12 Ni dung ca mt cm truy cp trong RACH * S ch nh knh ban u : BTS sau khi gii m bn tin yu cu ca knh MS,BTS gi ban tin yu cu knh RSM n trong bn tin ny c c tnh v c truyn dn lm c s cho quyt nh s sm nh thi . Trong tnh hung bnh thng BSC chn mt knh ri (TACH/8 hoc TACH/F) thng bo cho BTS.BTS xc nh thng bo ny v to bn tin ch nh knh ban u pht trn PAGCH, bn tin ny bao hm s miu t knh cp pht cho MS v thamSVTH: Nguyn Th Lan Anh Trang 21

Bi thi cui kho


chiu cho MS.S khung tin ca bn tin yu cu knh c truyn n BSC,ri li phn hi li v cho MS nh l cng c nhn dng qua mi quan h vi MS.Mt khi MS truy cp vo mng, n phi lng nghe PAGCH (cng khe thi gian nh RACH c dng truy cp ) ng thi MS cng lin tc gii m cc bn tin BCCH thit lp tham s RACH trong khe thi gian thc .Thi gian thu tin ny ko di 40 cm trong chu k 51x8 cm l bt buc i vi MS. *Bn tin ban u: Sau khi nhn dc ch nh knh ban u, MS thay i cu hnh ca n cho ph hp vi c tnh thi gian v tn s trn knh mi .Trn knh mi ny, MS pht i mt khung phc v ni bn tin bo hiu trong mode: - Mode nhn tin trn phc v x l ng cu hnh PAGCH. - Mode nhn tin thm phn knh k tip . b. Cc th tc i vi mode truyn dn v s khi to cuc gi : Vo lc khi to cuc gi, BSC chn mode truyn dn .Ch nh knh ban u thng l mode bo hiu duy nht khng mt m knh s dng c th lTCH/8 hay TACH/F .Sau trong k hn RR, MSC chn mode truyn dn ph hp vi nhu cu thng tin, MSC c th thay i bt k lc no sau khi thit lp cuc gi .MSC quyt nh thay i mode bng s bt u th tc ch nh yu cu BSC iu hnh s thay i, BSC bo co xc nhn thay i xong cho MSC bit, trong trng hp c trc trc. BSC pht bn tin khng hon thnh ch nh, trong trng hp c s ch nh khng c thi hnh ngay, th phi xp hng ch cp pht, lc ny BSC li pht bn tin ch xp hng. Trong bn tin yu cu ch nh m MSC gi ti BSC cn c nhn dng c ng truyn c cp pht mi gia BSC v MSC .Sau khi BSC nhn c bn tin yu cu ni trn BSC so snh vi mode truyn dn yu cu v BSC c th yu cu tng ng sau . -Nu hai mode khng khc nhau th BSC khng cn lm g c, tr vic gi bo co hon thnh ch nh . -Nu hai mode ch khc nhau v tin tc truyn dn nhng cng cng mt loi knh th BSC thc thi th tc bin i mode trc khi bo co nhn thc. -Nu mode thay th cn n loi mode khc vi mode c, th BSC thc thi th tc ch nh tip sau (chuyn cuc ni vo knh mi )ri sau mi bo co nhn thc. c. S thc thi chuyn giao : Quy trnh chuyn giao buc MS ang trng thi truyn tin bng knh dnh ring no phi chuyn sang mt knh khc thuc v mt cell khc .Quy trnh chuyn giao khc vi th tc ch nh tip sau my cng vic sau: qun tr s sm thi gian, phi c cc d liu v cell mi, chu mt s hn ch. MSC chn cell thit lp, khi to ni knh TACH/8. Sau khi cuc ni phc v cuc gi th mang PLMN chn mt cell tt nht cho cuc gi vo knh dnh ring cho MSC l TACH/F thut ton chn cell ca MSC v ca PLMN l khc nhau nn c th xy ra phi chuyn giao ngay sau khi khi to .Vic thc hin chuyn giao phi thc hin da trn hai tiu chun sau y. - Tiu chun th nht lin quan n s sm nh thi. - Tiu chun th hai lin quan n v tr chuyn mch c s h tng. * Thit lp ng truyn mi : Sau khi chuyn giao im chuyn mch huy ng cc thnh vin ca PLMN nhp cuc.Thng bo cho cc thnh vin ny thng tin cn thit thc hin chuyn giao v qun r cuc ni mi. -Mode truyn dn - Mode mt m -Nhn dng cell cSVTH: Nguyn Th Lan Anh Trang 22

Bi thi cui kho


-Xp hng ca MS d.S ti lp cuc gi: Ch trng ca pha inh thng lm cho cc cuc gi b ct cuc gi.Theo quan im t chc mng ,vic khi to chuyn giao ti lp cuc gi c th do mng PLMN hay do MS thc hin. u im ca vic MS khi to chuyn giao l c th thit lp nhanh s chuyn giao . u im ca vic PLMN khi to chuyn giao l s hiu bit ca n v tnh hnh ton th mng y hn MS. S ti lp cuc gi b ct t ngt c th xem l s chuyn giao do MS khi to Qu trnh ny gm hai giai on: -Giai on u, MS ng vai tr ch o - Giai on sau l cng vic khi to ca mng Yu cu ti lp cuc gi tht nhanh khi tn tht hon ton cuc gi .Vic u tin l chn mt cell mi, sau MS thu nhn bn tin BCCCH (knh qung b iu kin) kim tra tiu chun truyn dn v tuyn. e.Gii phng k hn RR. Gii phng k hn RR l cho php MS tr v trng thi ch v ton b ti nguyn lien quan n cuc ni ti MS c gii phng .Th tc gii phng bnh thng c kch bi neo v BSC qun tr vic chuyn MS v trng thi ch trc khi gii phng n ti nguyn BSS. f.Th tc qun tr ti nguyn. Trn mt bng RR c mt th tc cho php MSC v BSC x l tnh hung qu ti, cc th tc ny bao gm c bin php trao i tin tc gia cc thit b sao cho chng u nhn c tin tc gia cc thit b sao cho chng u nhn c tin tc v nc ti hiu thi,cc th tc ny cng ch dn cc hn ch qu ti. *Ti knh chung: cc knh chung RACH (knh truy cp ngu nhin )v PAGCH (knh chp nhn truy cp v nhn tin ).V BTS o chnh xc trn cc knh ny, nn BSC cng bit c tin tc v ti trn cc knh chung,qua thng bo ny bn tin ch bo ti knh chung . *Ti knh lu lng: BSC nm chc thng s knh dnh ring ang c s dng trong cell MSC s dng tin tc v ti knh lu lng cn bng ti gia cell. S knh ang c cp pht c bo co trong bn tin ch bo ti nguyn. Chuyn giao c th gip cn bng lu lng gia cc cell khc phc qu ti mt cell no . *Qu ti knh chung: cc th tc BSSMAP v RSM c mt phn ni dung cp n s qu ti chung, s khng ch qu ti nhm mc ch gim lu lng xung mc tng ng vi ti nguyn. CHNG III S TRAO I BO HIU TRONG MNG GSM III.1 Bo hiu GSM III.1.1. Mng bo hiu Kt ni ting Mnh bo hiu l h thng c d dng truyn cc thng tin bo hiu ca cc Tng i B nhm ngi s dng khc nhau nh: in thoi, s liu , khai thc v bo dng .., mng bo hiu bao gm cc dim bo hiu SP(Signalling Point)hiucc on ni bo on ni bo v hiu SL(Signalling link)hay c th hn :mng truyn dn bao gm cc tng i (im STP nt) thng tin vi nhau qua knh bo hiu .

S P SVTH: Nguyn Th Lan Anh

Tp cc on ni bo hiu SP Trang 23

Tng i A

Tng i B

Bi thi cui kho


Trong: SP-im bo hiu STP-im truyn bo hiu Hnh III.1 Mng bo hiu Cc phn t ca mng bo hiu : +Cc on ni bo hiu (SL:Signalling Link) Cc on ni bo hiu l cc phn t c bn trong mt mng bp hiu dng ni hai im bo hiu vi nhau .SLm bo iu khin vic truyn cc bn tin khng mc li v trnh tr truyn cc bn tin. +Cc im bo hiu (SP :Signalling Point). im bo hiu l mt nt trong mng bo hiu c kh nng pht hin hoc kt ni cc thng ip bo hiu. Cc im bo hiu m bo cc chc nng ca mng bo hiu v c th pht /thu tn hiu t /ti cckhc ngi s dng khc nhau .(c th hin hnh a sau ) ThoiA D B

Lin kt bo hiu

C

Hnh a.Cc im bo hiu Cc tng i c cc tuyn trc tip vi nhau bao gm cc mch thoi v mt lin kit bo hiu . Nu tng i A gii bo hiu n tng i D th : +Tng i A c gi l im bo hiu gc +Tng i D c gi l im bo hiu ch III.1.2 Bo hiu knh chung s 7 (CCSN7) GSM. H thng bo hiu knh chung s 7 ca CCITT (nayl TTU T)l mt h thng bo hiu knh chung c thit k cho vit bo hiu gia cc h thng iu khin bng chng trnh .H thng bo hiu s 7 c th d dng thc hin cc chc nng nh cc h thng bo hiu thng thng, nhng vi k thut hn cho cc h thng s .Trong lnh vc vin thng, chc nng chnh ca bo hiu l thit lp v gii phng cc cuc gi qua cc ng dy gia cc tng i .C hai loi bo hiu trong mng in thoi :bo hiu lin quan ti trng thi ca ng dy, bo hiu thanh ghi cho bit thng tin v cuc gi v c s dng thit lp mt mch in thoi. SVTH: Nguyn Th Lan Anh Trang 24

Bi thi cui kho


CCSN7 ng bo hiu tch ring vi ng ting, mng ny khng nht thit phi c mt knh bo hiu trn mi on ni . iu ny c ngha rng cc bn tin bo hiu c th c cc on ni khc vi ng dn n c im nhn, trnh nhm ln ngi ta gn cho tng bn tin .Knh bo hiu c th chim mt khe thi gian bt k trn cc ng truyn dn 2Mbps (tr khe Tso)v c s dng truyn tt c cc bo hiu ca cc knh thoi on ni tng ng .CCSN7 c rt nhiu u im : +Dung lng truyn bo hiu cao mt knh bo hiu c th m bo du hiu cho 5000 mch ting +Cho php s dng nhiu dch v mi . +Cho php gim kch thc ca cc thit b v khng cn thit phi n nh thit b bo hiu ring cho tng mch ting . + tin cy cao (nh c d phng ) Hnh di dy l m t qu trnh ca mng bo hiu s 7


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Bi thi cui kho


III.1.3 Bo hiu BSS: a.Giao din A. y l giao din gia MSCv BSC ca h thng con tram gc, giao din ny c s dng cho cc bn tin gia MSC,BSC v c bn tin gia MSC v MS s dng cc giao thc sau : +CM(Connection Managemet-Qun l ni thng ) c s dng iu khin qun l cc cuc gi (thit lp gii phng v gim st cuc gi ), qun l cc dch v b sung v qun l cc dch v bn tin ngn . +MM(Mobitily Management-Qun l di ng ) c s dng qun l v tr cng nh tnh bo mt ca trm di ng . b.Giao din A-bis y l giao din gia BSC v BTS, cc bn tin c trao i giao din ny c nhiu ngun gc v ni nhn khc nhau: bn tin gia BSC v BTS ( iu khin BTS ),gia MS vi cc phn t khc nhau ca mng v cc bn tin ny c th xut x t cc MS khc nhau (trn cc knh v tuyn khc nhau ). Ngoi ra cn c mt s giao din c s dng trong GSM(c th hin trong hnh v di y ) Trong Abis : BTC-BSC B : MSC-VRL A : BSC-MSC D : VLR-HLR C : MSC-HLRA F : MSC-EIR E : MSC-MSC H : HLR-AUC G : VLR-VLR


Trang 26

Bi thi cui kho


Hnh.III.2.Cc giao din GSM III.2 S trao i bo hiu trong mng GSM: III.2.1 Cp nht v tr : Thu bao di ng c thng bo cuc gi n bng thng ip nhn gi qua knh chp nhn truy cp v nhn tin (PAGCH) ca mt cell.Mt bn tin c pht trn mi cell trong mng cho mt cuc gi, mt khc chng ta c th thng qua cc thng ip cp nht v tr s pht n cc cell ring l cha v tr hin ti ca thu bao di ng . iu ny yu cu cc thng ip nhn gi phi tht chnh xc. Th tc cp nht v tr v nh tuyn cuc gi n sau s dng MSC v hai b ghi v tr: b ghi thng tr (HLR) v b ghi tm tr (VLR), khi trm di ng chuyn sang v tr mi hoc tng i PLMN khc th phi ng k vi mng v tr hin ti .Trong trng hp bnh thng thng ip cp nht v tr gi ti MSC/VLR mi, lu thng tin vng v tr v sau thng bo v tr n HLR ca thu bao. Thng tin gii ti HLR thng l a ch SS7 ca VLR mi, mc d n c th l mt s nh tuyn. Nu thu bao c quyn truy cp dch v, HLR gii mt phn thng tin ca thu bao cn iu khin cuc gi n MSC/VLR mi v gii thng ip n MSC/VLR c hy ng k trc . m bo tin cy hn, GSM cng c th tc cp nht v tr theo chu k.Nu mt HLR hoc MSC/VLR sai, ng thi cng c ng k cng mt thu bao c s d liu, s dn n qu ti. Do c s d liu c cp nht khi cp nht v tr. Nh iu hnh quy nh cp nht theo chu k, nu di ng ng k li sau chu k cp nht, thu bao s b xa tn. Mt th tc lin quan n vic cp nht v tr l gn v g s nhn dng thu bao di ng quc t (IMSI).Vic g cho mng bit trm di ng khng tip cn c v trnh phi ch nh knh truyn v gii thng ip ngn tha. Vic gn tng t nh cp nht v tr v bao cho h thng bit thu bao di ng truy cp tr li. Hot ng ca vic gn v g IMSI ph thuc vo nh iu hnh cell. III.2.2 Nht thc v bo mt Bt k ai cng c th cp nht vo sng v tuyn, nhn thc ngi s dng xc nh ngi s dng l ai, cng chnh l yu t rt quan trng trong mng di ng. Nhn thc gm hai phn l SIM CARD trong my di ng v trung tm nhn thc (AUC). Mi thu bao c cho mt kha m ch lu trong SIMCARD v AUC. Trong sut qu trnh nhn thc, AUC pht mt s ngu nhin gii ti di ng. Sau c di ng v AUC s dng s ngu nhin , kt hp vi m ha ca thu bao pht hin du tr li tr li AUC. Nu di ng gi s ging AUC th tnh thu bao c nhn thc.Vic m ha l mt ty chn gy o gic, nn tn hiu c m ha, chn vo v pht theo phng thc TDMA, do cho php bo v hu ht cc i tng tr nhng tn nghe trm l lm Mt mc khc ca vic bo mt l thc hin trn thit b di ng. Mi thit b u cui nhn dng bng ch s IMEI duy nht. Mt danh sch IEMI trong mng lu trong b ghi nhn thcthit b (EIR). Trng thi tr v EIR tng ng vi s IMEI nh sau : - Danh sch trng : thit b cho php kt ni mng . - Danh sch xm :thit b c mt s vn c mang gim st - Danh sch em :thit b c bo mt cp hoc khng c chp thun.Thit b khng cho php kt ni mng . III.2.3 Mt s trng hp bo hiu : III.2.3.1Bt tt my trm di ng : Khi MS bt ngun n phi thc hin ng k ln u chp nhn mng,qu trnh ny c thc hinh nh sau :


Trang 27

Bi thi cui kho


- Trc ht trm MS qut tm c tn s ng knh FCCH(knh hiu chnh tn s ) - Sau tm n knh ng b SCH nhn c s khung TDMA cho ng b. - Cui cng n thc hin cp nht v tr thng bo cho VLR ph trch v HLR v v tr ca mnh .Cc c s d liu s ghi lai LAI hin thi ca MS. Ging nh cp nht v tr bnh thng, thng tin v LAI c MS nhn t knh BCCH. Bt u t lc MSC/VLR cng nhn l MS tch cc v nh du c truy nhp v tr tch cc vo trng d liu ca mnh. C ny gn vi mt s nhn dng thu bao : IMSI (nhn dng thu bao di dng quc t).

HLR(2)(3)

(4)

VLR MSC BSC

(1)

K hiu: cp nht v tr LAI mi yu cu cph nht v tri (SIM MSC mi) chp nhn cp nht v tr cng nhn cp nht v tr Hnh III.3 ng k ln u khi bt ngun Khi tt mt trm MS hay ly SIM CARD s xy ra qu trnh ri b ISMI. Cc trao i bo hiu trong trng hp ny c thc hin nh sau: -MS yu cu mt knh bo hiu pht i bn tin thng bo cho mng rng MS chun b vo trng thi khng tch cc, iu ny c ngha rng mng khng th t n MS na . -MSC s gii tin IMSI n VLR. Bn tin ny khng c tr li cng nhn v MS s khng nhn c tr li cng nhn v MS s khng chp nhn tr li. VLR s thit lp c ri b IMSI v t chi cc cuc gi n trm MS. -Thng tin ri IMSI c th c lu gi tai VLR. Ty chn c ri mng c th cng c thit lp HLR v cng nhn c gi tr li VLR III.2.3.2. Cuc gi khi xng t trm di ng: (MOC: Mobile Originated Call) Khi tram di ng MS trng thi tch cc v dng k MSC/VLR ph trch , MS c th thc hin cuc gi. Qu trnh thc hin cuc gi c th hin hnh v di y . (1) Bng knh truy cp ngu nhin RACH (Random Access Chanel) MS gi yu cu knh bo hiu n BTS. (2) MS thng bo rng n mun thit lp cuc gi. S nhn dng trm di ng c phn tch v MS c nh du bn VLR (3) Qu trnh nhn c thc hin kin tra tnh hp l ca MS (4) Qu trnh mt m ha c thc hin bo v b mt thng tin . (5)MSC nhn c bn tin thit lp t MS c th cha thng tin v loi dch v m MS yu cu, s thoi b gi B. MSC kin tra l MS khng c cc dch v cm gi ra (dch v ny c th thu bao hoc bi cc nh khai thc ), nu khng c gi raSVTH: Nguyn Th Lan Anh Trang 28

Bi thi cui kho


qu trnh thit lp cuc gi c tin hnh.Gia MSCvBSC ng truyn c thit lp v knh lu lng c chin. MSC gi yu cu n BSC n nh mt knh lu lng cho ng v tuyn (6) BSC kim tra nu c knh lu lng ri n n nh knh ny cho cuc gi v yu cu BTS tch cc knh ny. BTS gi tr li cng nhn khi vic tch cc knh lu lng hon thnh. H thng con iu khin l lng s phn tch cc ch s ca s thoi B v thit lp kt ni n thu bao b gi. Cuc gi c kt ni thng qua chuyn mch nhm. (7) Bo chung s c gi n trm di ng MS cho thy rng pha b gi ang chung.Tng chung c to ra tng i pha thu bao B v c gi qua chuyn mch nhm n MS. Nh vy tong chung c gi qua ng vo tuyn ch khng tao ra MS. (8) khi thu bao B tr li mng gi bn tin kt ni n my di ng MS thng bo rng cuc gi c chp nhn kt ni, nh vy vic thit lp cuc gi hon tt.(1a) (1b)

VLR(2 )

BSC

MSC

(3)

(4) (5) (6) (7)

K hiu: 1a,1b: Thit lp kt ni RR 2: Ch th dch v 3:Nhn thc 4: M ha 5: khi u cuc gi 6: n nh knh TCH 7: Khng nh cuc gi 8: Chp nhn cuc gi

Hnh III.4 Thit lp cuc gi khi xng t MS khng c OACSU III.2.3.3. Cuc gi kt cui trm di ng: (MTC:Mobile Terminated Call) Cuc gi MTC phc tp hn MOC v pha gi khng bit hin thi MS ang u. Ta xt mt cuc gi vo mng di ng t mng c nh, qu trnh bo hiu cho cuc gi ny c trnh by nh hnh di y. (1) Pha ch gi quay s thu bao di ng b gi: l s thuc ISDN ca thu bao di ng. nu cuc gi c khi u t mng c nh PSTN th tng i sau khi phn tch s thoi s bit rng y l cuc gi cho mt thu bao GSM. (2)Cuc gi c nh tuyn n tng i GMSC gn nht, y l mt tng i c kh nng hi v nh li tuyn. Bng phn tch MSISDN tng i GMC tm ra ni MS ng k .


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Bi thi cui kho


(3) GMSC hi HLR giao tip vi VHR nhn c s lu ng thu bao MSRN, y l mt s thoi thng thng thuc tng i MSC. (5) VLR gi MSRN n HLR, sau HLR chuyn s ny n GMSC (6) Bng MSRN,GMSC c th nh tuyn li cuc gi n MSC tng ng.GMSC gi bn tin nhn c t PTSN n MSC (7) MSC bit c v tr ca MS v n gi bn tin tm gi n tt c cc BSC ang qun l vng nh v ny . (8) MSC gi LAI (nhn dng vng nh v ) xung cc BSC v BSC phn pht bn tin tm gi n cc BTS. (9) tm gi MS, IMSI c s dng, c th s dng s nhn dng tm thi TMSI m bo b mt. (10) Ngay sau khi nhn dng c bn tin tm gi MS gi yu cu knh bo hiu. MSC c th thc hin nhn thc v khi u mt m ha nh xt phn trn. MSC c th gi n thng tin v cc dch v c yu cu :ting, s liu, Fax.. By gi BSC s lnh cho BTS tch cc knh lu ng :TCH v gii phng knh bo hiu,bo chung c gi i t MS cho thy rng tong chung c to ra MS. Tng chung cho thu bao ch gi c to ra MSC. Khi thu bao di ng nhc my MS gi i bn tin kt ni. Mng hon thnh ng ni thng v gi bn tin cng nhn kt ni n MS .(2) GMSC (6a) (6b) VLR MSC (7) (9) (8)(1 0)

PSTN(1)

Tng i ni ht

(3) HLR (5) (4)

BSC (8) (9)B T S B T S

Hnh III.5:Cuc gi t mng c nh kt cui MS(MTC) III.2.3.4 Chuyn giao. a. Chuyn giao trong cng mt BSC Chuyn giao gia 2 thuc mt BSC th hin c th hnh III.6 (1) Trong qu trnh gi MS lun lun o cng trng, cht lng knh TCH(knh lu thng ) ca mnh v cng ca cc ln cn .MS nh gi gi tr trung bnh ca kt qu o.Hai ln trong 1 giy n gi bo co kt qu o n BTS cng vi kt qu o ca cc ln cn nht. (2) BTS b sung thm kt qu n o c chnh knh TCH v gi bo co v BSC. BSC chc nng nh c tch cc quyt nh xem c cn chuyn giao cuc gi n khc do cht lng xu hoc nhiu ln ang phc v hay khng.SVTH: Nguyn Th Lan Anh Trang 30

Bi thi cui kho


(3)Trng hp cn chuyn giao BSC s lnh cho BTS mi c chn tch cc mt knh TCH. (4) Lnh cho BTS ny gi bn tin n MS thng bo v tn s v khe thi gian cn chuyn n . (5) MS iu chnh tn s mi v gi bn tin truy nhp chuyn giao (HO) khe thi gian tng ng. MS khng s dng bt k s nh thi trc no c,v vy cm HO l cm rt ngn ch c 8 bt thng tin .MS khng nhn c bt c thng tin no v nh thi trc cho n khi BTS pht hin ra cm HO . (6)MS cng nhn thng tin v cng sut cn s dng knh FACCH ly cp t knh ting. (7) BSC s nhn c thng tin t BTS l chuyn giao thnh cng sau khi MS gi bn tin hon thnh chuyn giao. (8) ng ting trong chuyn mch nhm thay i v BTS c c ra lnh tho g TCH c cng vi knh lin kt SACCH . chuyn giao bn trong BSC ny chnh BSC x l mi vic khng c s can thip ca MSC, MSC ch c thng bo v vic thc hin chuyn giao .(2) (1) (4) (4)B T S S

b.Chuyn giao gia hai thuc hai BSC khc nhau. (1) BSC c da trn cc bo co v kt qu o quyt nh chuyn giao n mi trc thuc mt BSC khc. BSC c gi bn tin yu cu chuyn giao cng vi nhn dng mi n MSC. (2) MSC bit BTS iu khin ny, n gi yu cu chuyn giao n BTS ny. (3) BSC lnh cho BTS mi kch hot TCH, n gi thng tin v khe thi gian v tn s n MSC. (4) MSC chuyn thng tin ny n MSC c. (5) MSC ra lnh chuyn n BSC c. (6) MS c ra lnh chuyn n TCH mi. (7)MS gi i cm truy nhp chuyn giao HO TCH mi. (8) Ngay sau khi pht hin c cm HO, BTS gi thng tin vt l cha nh trc thi gian v cng sut ra n MS. (9) BSC mi nhn c thng tin rng BTS nhn c cm HO. (10) BSC mi chuyn thng tin ny n BSC c qua MSC.


B T S S

(5) (7) (7) (6 )B T S S B T S S

(8)BSC

(3)

Hnh III.6 Chuyn giao cuc gi bn trong BSC

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(11) MSC chuyn thng tin ni trn n BSC c. (12)BTS c gii phng TCH v SACCH c. MS nhn thng tin v mi SACCH lin kt vi TCH mi. Nu ny thuc LAI mi MS phi thc hin cp nht v tr bnh thng sau khi cuc gi c gii phng(5) (6)BCSB T S S

(6)

(1)

(7)

(12)(8)B T S S

(11) (10)BCS (mi)

MCS

(9)

(2) (4)

(3)

Hnh III.7 Chuyn giao cuc gi gia cc BSC C.Chuyn giao gia hai thuc hai tng i MSC khc nhau: Qu trnh chuyn giao gia hai thuc hai tng i MSC khc nhau c xem nh hnh v di y. (1) BSC ang phc v gi yu cu chuyn giao n MSC ging nh trng hp trn. (2) MSC yu cu MSC chuyn giao (MSC ch) gip . MSC ch cp pht mt s chuyn giao (s in thoi thng thng) nh tuyn li cuc gi. (3)Yu cu chuyn giao c gi n BSC mi. (4) Nu c knh THC ri BSC yu cu BTS tch cc mt TCH mi. (5) MSC nhn c thng tin v knh TCH mi. (6) Chuyn thng tin ny tr li MSC c cng vi s chuyn giao. (7) ng truyn c thit lp n MSC mi. (8)Lnh chuyn giao c gi n MSC cng vi thng tin v tn s v khe thi gian s c s dng mi. (9) MS pht i cm HO (chuyn giao) TCH mi. (10) BSC v MSC mi c thng bo hon thnh chuyn knh. (11) Mt ng mi c thit lp chuyn mch nhm v cuc gi c chuyn mch. TCH v SACCH c c gii phng. Tng i MSC gc vn duy tr s kim tra chnh cuc gi cho n khi n c xa. MSC ny c gi l MSC neo. Giao thc MAP c thc hin gia cc MSC. Khi di chuyn vo vng nh v mi th sau khi gii phng cuc gi, n phi thc hin cp nht v tr. Do mt vng nh v khng th trc thuc hai MSC nn trng hp ny phi thc hin cp nht v tr sau khi cuc gi c gii phng. HLR cng s


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Bi thi cui kho


c cp nht v gi bn tin n VLR c, MSC ny phi xa tt c cc thng tin lin quan n thu bao.

(1)BSC MSCB T S S

(8)

(8)

(8) (10) 2 7PSTN

(10) (9)B T S S

(5)BSC MSC

(11)HLR RR

(4)

Hnh III.8 Chuyn giao cuc gi gia hai MSC

CHNG IV TNG QUAN V MNG DI NG VIT NAM GII THIU CHUNG: Hin nay Vit Nam mng thng tin di ng pht trin rt a dng v gm rt nhiu dch v:16/4/1993 mng in thoi di ng MobiFone ca cng ty thng in di ng VMS c a vo s dng -da trn cng ngh GSM-TDMA, tnh n nay c khong 1,5 triu thu bao, chim 70% dung lng, c tnh thi gian ti s tng thm 15%s thu bao mi thng. Ngy 26/6/1996 mng inh thoi di ng VinaPhone c a vo khai thc chnh thc v l mng inh thoi di ng th hai tai Vit Nam s dng cng ngh. Cui nm 1996, mng VinaPhone ch c hai tng i chuyn mch di ng MSC cng vi 53 trm thu pht v tuyn (BTS) ph sng ch yu ti hai thnh ph ln H Ni v TPH Ch Minh. Nhng ch n cui nm 1999, mng VinaPhone c thm mt tng i chuyn mch (MSC) ti Nng, cng vi 209 trm thu pht sng v tuyn (BTS).Vng ph sng rng ti 61/61 tnh, thnh ph trong c nc v s lng thu bao ca VinaPhone mi khim tn con s 126.005. phc v tt khch hng, nm 2002, VinaPhone u t lp t cc trm thu pht v tuyn (BTS) m rng vng ph sng, nng cao cht lng dch v v pht trin thm cc dch v mi. Dch v chuyn vng quc t IR(International Roaming) ra i a mng di ng VinaPhone vn rng ra khp th gii. S ra i ca loi hnh dch v mi VinaCard (thu bao di ng tr trc s dng cng ngh SN (Service Node) ca Comverse thu ht ng o khch hng s dng, thc y tc pht trin thu bao tng rt nhanh. Nm 2000 mng di ng VinaPhone tr thnh mng in thoi di ng c vng ph sng rng ln nht ti Vit Nam vi 414.570 thu bao, tng 230% so vi nm 1999.


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p ng s tng trng rt nhanh ca thu bao, trong nhng nm 2001-2002, Cng ty dch v vin thng (GPC) y mnh vic u t nng cp mng li tng dung lng. Trong c s dng trm lp t, kt hp vi trm BTS ph sng cc vng su, vng xa v cc trc l mt cch linh hot v hiu qu. n cui nm 2002, VinaPhone lp t thm hai tng i chuyn mch nng s tng i ca mng VinaPhone ln 7 tng i, 670 trm thu pht v tuyn (BTS) ph sng trn c nc. Tip VinaPhone nng cp thnh cng h thng mng di ng tr trc t cng ngh SN ca Comverse ln cng ngh mng thng minh IN(Inteligent Network )ca Eicson. ng thi VinaPhone cng a ra cc dch v gia tng hp dn nh dch v ti hnh, logo, m chung, dch v WAP. Dch v mi VinaDaily (thu bao di ng tr trc theo ngy) c ra i vi mc tiu ph cp dch v di ng ti mi tng lp khch hng.Mt trong nhng thnh tu t c trong nm 2002 l s kin mng Vinaphone cho n thu bao di ng th 1.000.000 . Tnh n thng 6/2003, Vinaphone pht trin c 1.456.000 thu bao, tr thnh mng in thoi di ng c s lng thu bao ln nht Vit Nam.Vinaphone ang chun b a bng tn1800MHz vo khai thc, th nghim cc loi hnh tin tin nh dch v truyn s liu tc cao GPRS (Gernal Packet Radio Service) dch v nhn tin a phng tin MMS(Multimedia Messaging Service). Song song vi vic pht trin cc dch v mi, trong thi gian ti Vinaphone s ch trng nng cao cht lng dch v, m rngvng ph sng ti hu ht cc khu du lch, khu vui chi gii tr, cc th x, th trn, v c bit l cc khu cng nghip c vn u t ca nc ngoi. Vinaphone d kin s pht trin thm 300.000 thu bao trong 6 thng cui nm 2003, nng s lng thu bao ca Vinaphone ln gn 2 triu thu bao. Mc d ra i sau MobiFone gn 3 nm nhng Vinaphone pht trin rt mnh v nhanh chng vt qua c Mobiphone theo thng k, mng in thoi di ng Vinaphone ca cng ty dch v vin thng (GPC) hin c khong 1,9 triu thu bao, chim 80% dung lng tng i. D bo mi thng dung lng tng i c thm 35.000 thu bao mi ( khong 18%). Qua tm hiu trn mng em c bit hin nay 2 mng ln nht l Mobiphone v Vinaphone ang c k hoch d n nng cp mng li v lp t 500 trm thu pht sng BTS. ng thi chun b mua thm v lp t 2 tng i mi H Ni v Cn th p ng thm khong 200.000 thu bao .9 tng i cn li v gn 1000 trm BTS s ln lt nng cao nng lc phc v.Thc ra cui nm 2003 Mobiphone u t nng cp thm 300 trm BTS m rng vng ph sng v chng mch ngn, ng thi lp thm mt s tng i mi v nng cp tng i c. Do nng lc phc v ca mng Mobiphone hin nay c th p ng c 1,8 triu thu bao trong khi hin nay Mobiphone ang c 1,5 triu thu bao trn mng .Nh vy c gn khong 300.000 s .Mt tin mng cho nhng ngi s dng in thoi di ng l t ngy 1/5/2004 gi cc in thoi di ng s gim, lng khch hng ng k s tng ln n 20% .Trung bnh mi thng Vinaphone pht trin thm 40.000 thu bao mi. Thc ra, cho n thi im ny Vinaphone c 2,2 triu thu bao, trong 1,95 triu thu bao ang hot ng. Mng Vinaphone c thit k phn v tuyn (Trm gc BTS ) c sc p ng c 2,2 triu thu bao, tng i v trm thng minh (IN) cng c kh nng tng t .Mi thu bao c thit k l 25mErL (Miliec-lng, tc l lu lng gi bn ca mng .Song trong thc t cc thu bao tr sau ch lm vic mc 18 mErL, thu bao tr trc mc 12 mErL, c ngha l cha ht kh nng cho php. Theo k hoch nm 2004, GPC s pht trin thm 1,1 triu thu bao ,cn VMS s thm 800.000 thu bao (k hoch trc khi gim gi cc 400.000). m bo k hoch GPC trnh ln VNPT xin ph duyt d n lp t hai tng i mi (mi tng i c th p ng 300.000 thu bao ) v VMS trnh ln d an u tnng cp m rng vi tng s tin khong 16 triu USD song ttc u ang trn giy t, v s thu bao ngy cng tng, nu khng c nng cp v m rng hai mng ny s bSVTH: Nguyn Th Lan Anh Trang 34

Bi thi cui kho


tc nghn. Ngy 11.5.2004 VMS c vn bn gi VNP cnh bo nu khng m rng dung lng mng th trong thng 6 (s thu bao chim 81%dung lng), thang7 chim 93%, thng 8 s ln ti con s 108%.Cng trong nm ny ccnh iu hnh mng thng tin di ng cho bit rng :cc th h my tnh xch tay vichc nng om thoi s dng giao thc internet ci t sn v sau l my tnh xch tay tch hp in thoai di ng s c ra i. Tuy khng th nhanh chng e do n th phn ca my in thoi di ng nhng cc sn phn ny s gp phn y mnh s ph bin ca cng ngh IP(Volp).Vic tch hp chc nng vo my tnh xch tay s mang li nhiu tin li . Nm 2005 Cng ty dch v vin thng GPC (thucVNPT) s tip tc m sng mng Vinaphone ti tt c cc huyn vng su, vng xa trong c nc, chun b cho chng trnh ny cng ty ang trin khai v lp t mi v nng cp nhiu trm thu pht sng trn c nc, v trin khai nhiu dch v mi ti nhiu thnh ph, khu cng nghip ln. Hin nay vi hn 1 triu thu bao ang hot ng, mng Vinaphone ca GPC ang chim g 61%tng s thu bao di ng v gn 20% tng s thu bao in thoi trn ton quc . Bn cnh s pht trin ca 2 mng di ng ni trn 1/7/2003 dch v S-Fone ra i s dng cng ngh CDMA(Code Division Multiple Access-k thut a truy nhp phn m) cho php ti u ha kh nng phc v thu bao gp 4-6 ln cng ngh GSM.Tuy nhin xt v chi ph u vo (chim ti71,25% nh hin nay) th S-Fone khng th theo kp ngi khng l VNPT c. Theo thng k cua S-Fone, trong nm 2003 thi gian kt ni gia S-Fone ti hai mng Vinaphone v MobiFone l 5,599 triu pht, trong kt ni vi mobiFone l 3,107 triupht ,s cn li l dng kt ni ti Vinaphone. Vic kt ni cng ngh GSMv CDMA Vit Nam ,mun kt ni oc phi thng qua tng i trung gian Toll,(cc nc khckt ni trc tip ). Chnh v l do m S-Fone mi nm phi tr trung bnh 1,4 t ng cho tng i trung gian Toll. Sp ti Vit Nam s cho n thm mt loi dch v mi l ViettetMobil s ph sng tai 64 tnh, thnh ph. Viettet l mt doanh nghip khng chim th phn khng ch, do B Bu Chnh Vin Thng (MPT) s khng chi trch nhim v qun l gi cc, nhng trc khi sn phm ny c tung ra th trng th gi cc phi c thng bo cho MP bit trc 10 ngy. Chiu ngy 14.4 Tng cng ty bu chnh vin thng va a ra bng gi cc mi,pdung t ngy 1.5.2004 .theo , gi cc ni vng tr trc l 1,550ng/30giy( bao gm VAT), ni vng tr sau 900 ng/30giy.

Sau y l bng tnh cc mi nht tnh t 1.5.2004*Cc ha mng v cc thu bao hng thng: Cc ha mng Cc thu bao thng *Cc lin lc trong nc: Cc gi ni vng Cc gi lin vng Gi c 1.800/pht 2.700/pht Gi mi t1/5/2004 850/30giy 1.200/30giy Gi c 400.000/my/ln 120.000/my/ln Gi mi t1/5/2004 300.000/my/ln 100.000/my/ln

Quy nh v vng cc


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Bi thi cui kho


- Vng1: Cc tnh min Bc n tnh Qunh Bnh . - Vng 2: Qung Tr, Tha thin -Hu, nng,QungNgi, Bnh nh , Ph Yn, Khnh Ha, Gia Lai, Kom Tum, c Lc. - Vng 3: bao gm cc tnh v thnh ph cn li ngoi vng 1 v vng 2 *Cc lin lc quc t =(850/30giy+ccIDD/VoIP) Cc ni vng p dng theo phng thc tnh cc 30giy +30giy. Cc IDD/VoIP l cc gi vng quc t do Cng ty BCVT Vit Nam ba hnh.Phng thc tnh cc l 1pht u v block 6 giy tip theo . *Gi gi cc thng Tn gi cc G200 G400 G600 G800 S lng block 30giy min cc bao gm 200 400 600 800 Gi mua gi cc/thng 260.000 417.000 570.000 720.000

IV.1. S tng quan mng Vit Nam: Cng quc t H Ni Cng quc t Nng Cng quc t TP.HCM

Cng quc gia H Ni

Cng quc gia Nng

Cng quc gia TP.HCM

MSC1

MSC2

MSC3

Th H Ni

Thnh ph Nng

Thnh ph TP.HCM

Cc tnh pha Bc

Cc tnh min Trung

Cc tnh pha Nam


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Hnh IV.1. S mng Vit Nam IV.2 .Cc dch v trn mng di dng Vit Nam: bit tm hiu v cc loi dch v ca mng di dng Vit Nam .chng ta tm hiu v cc dch v trn mng VinaPhone,v mng ny cung cp y ccloi hnh dch v ca mng di ng Vit Nam. IV.2.1S cu trc ca mng VinaPhone: Hin nay VinaPhone l mng in thai di ng ln nht Vit Nam S dng cng ngh GSM hin i. Hin nayvi trn 700BTS, VinaPhone ph sng 61/61 tnh thnh ph v kt ni mng di ng n 37 quc gia v lnh th trn ton th gii. Vit Nam c 3 MSC t ti 3 thnh ph ln l Nng, H Ni, TP.H Ch Minh, Hnh IV.2 di y l s cu trc ca mng VinaPhone IV.2.2.Cc dch v b sung . IV.2.2.1. Dch v hin s ch gi v cm hin s ch gi . Dch v ny cho php thu nao di ng b gi hin th s my ch gi hoc cm hin th s my ch gi ln my ca thu bao b gi .Khi ng k dch v ny th VinaPhone s ci t cho bn, sau khi ci t th khi c cuc gi n my ca bn s hin th s ch gi trong cc trng hp sau: - Mng thu bao ch gi phi h tr dch hin s ch gi . - Thu bao ch gi khng ng k dch v cm hin s ch gi . IV.2.2.2 Dch v i v gi cuc gi . My di ng ca ban c th nhn cuc gi th hai khi ang lin lc vi cuc gi th nht. Khi cuc gi th hai n th my ca ban s pht ra cc tn hiu cho ban bit v thu bao gi n s nhn c tn hiu ny ca bn. Nu bn chp nhn cuc gi th ban c th lun phin noi chuyn hoc ni chuyn ri ngt mt trong hai cuc m thoi. Sau khi ng k dch v ny, khi cn s dng dch v ny bn ch cn can thip vo menu trong my kch hot n . Dch v di cuc gi cung cp cho thu bao di ng kh nng c thng bo v mt cuc gi vo khi kt cui n ang trng thi bn. Sau thu bao ny c th tr li hoc t chi, hay khng n cuc gi n ny. IV.2.2.3 Dch v chn cuc gi . Mng GSM-D900 ca VinaPhone cho php thu bao chn cc cuc gi n v cc cuc gi i nht nh. iu ny rt tin li cho bn nu bn l my ch khi cho ngi khc mn my ca mnh. Khi vic s dng my ca mnh c hn ch vd nh:ngi mn my khng gi i c ng di, khng gi i c quc t, khng gi c nhng cuc gi ma gi cc ca n cao. to hay hy b vic chn cuc gi chng ta s dng mt khu, v mt khu ny cho php thu bao l ngi duy nht iu khin cng vic ny. Dch v ny cho php mt thu bao di ng c th la chn loi cuc gi no cn thit phi chn ,di y l cc loi dch v ny. - Cm tt c cc cuc gi ra . Dch v ny thu bao di ng cm tt c cc cuc gi ra hay ch cho php cc cuc gi lien quan n mt dch v c s khi ng k thu bao thit lp cc cuc gi ny. - Cm tt c cc cuc gi i quc t. Khi thu bao dng k dch v ny, my s t ng cm tt c cc cuc gi t my i quc t - Cm tt c cc cuc gi i quc t tr cc cuc gi n cac nc c PLMN thng tr. - Cm tt c cc cucgi n. - Cm tt c cc cuc gi n khi lu ng nc c PLMN thng tr IV.2.2.4 Dch v chuyn cuc gi.


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Dch v chuyn giao cuc gi cho php thu bao di dng c phc v chuyn giao mt cuc gi n hay i c thit lp ti thu bao th ba. Dch v chuyn cuc gi sang s khc. Dch v ny trn my ca bn ghi l Divert .Vi dch v ny thu bao b gi A(nu c ng k dch v chuyn cuc gi) c th c php chuyn cc cuc gi n(cuc gi kt cui di ng MSC) sang s thoi khc, chng hn chuyn sang s thoi C. Sau y l cc trng hp chuyn chuc gi : - Chuyn cuc gi khng iu khin: trong trng hp ny ton b cuc gi n c chuyn sang cc cuc gi khc. -Chuyn cuc gi trong trng hp my bn. Sau khi bn ng k dch v ny th tng i trung tm s ci t dch v ny cho bn, nhng bn c th s dng hay khng s dng th ty thuc vo s can thip ca bn ( menu) trong my ca bn. Nhng khi mun ng k cuc gi th bn phi ng k chuyn m vng, sau y l cc trng hp tnh cc . V d : Thu bao B gi cho thu bao A v thu bao A chuyn sang cho thu bao C. * Trng hp 1: c thu bao A,B,C u l thu bao di ng . Trong trng hp ny c chia lm hai phn : - Phn 1: my B gi cho my A s tnh cc B theo vng cc trong bng cc in thoi c nh, p dng trong trng hp c nh gi di dng . - Phn 2 : my A chuyn cuc gi sang my C th s tnh cc theo vng cc trong bng cc thng tin di dng hin hnh, p dng trong trng hp di ng gi di ng. * Trng hp B,C l thu bao c nh, A l thu bao di ng : Trong trng hp ny c chia thnh hai phn: - Phn 1: cuc gi t B n A, tnh cc B theo vng cc trong bng cc inh thoi c nh, p dng trong trng hp my c nh gi my di ng. - Phn 2: cuc gi chuyn t A n C, tnh cc A theo vng cc trong bng cc thng tin di ng hin hnh, p dng trong trng hp my di dng gi my c nh . IV.2.3.Cc dch v c bn. IV.2.3.1. Dch v gi khn. Cuc gi khn l cuc gi xut pht t di ng ti trung mt trung tm (cu ha, cu thng, hay cnh st.). Dch v cuc gi sn bt u ngun t dch v in thoi thng nhng n cung cp ch n gin v thng nht thit lp cuc gi khn. GMS thc hin s gi khn chun 112 c chun ha, thm vo l cc hng sn xut thit b di dng c th cung cp phm SOS thc hin cuc gi khn bng cch bm vo cc phm . Cuc gi khn c th thc hin k c khng c modul nhn dng thu bao hay cn gi l SIMcard. Hin nay i vi Vinaphone gi khn c nh tuyn n trung tm cu thng 115. Hin gi Vinaphone ci t mt s gi tt (cuc gi khn), chng hn 114-cu ha, 115-cu thng v 113- cnh st. Cc cuc gi nhng s tt ny c nh tuyn n cc trung tm dch v ny. IV.2.3.2 Dch v thng bo ngn. Dch v ny cho php my di ng c th nhn v gi i cc bn tin c dng s hoc dang ch ti a 160 ch s. Nu thu bao nm ngoi vng ph sng hoc hay tt ngun th bn tin vn c l d v gi i khi thu bao sn sng. IV.2.3.3 Dch v pht qung b trong .


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Bi thi cui kho


Qu trnh ny cho php gi cc thng bo ngn ti 93 k t ch ci, s n tt c cc my thoi mt vng a l. C th s dng dch v ny cho nhiu mc ch khc nhau, chng hn nh thng tin v thi titt ,giao thng.. IV.2.3.4 Dch v Fax. Dch v ny cho php bn nhn v chuyn Fax t my tnh Latop, trong my tnh Latop phi ci t chng trnh chuyn, nhn Fax c tn l TriodataFax, vic thc hin chuyn nhn c thc hin qua mng GSM-D900 ca Vinaphone,vn tnh cc Fax ging nh tnh cc m thoi thng thng. IV.2.3.5 Dch v hp th thoi. s dng dch v ny b cn ng k chc nng DTMF v chuyn tip cuc gi v hp th thoi. Dch v ny cho php chyn cuc gi vo hp th thoi.Dch v ny cho php ban gi cuc gi v hp th thoi ca mnh khi ang bn, ngoi vng ph sng , tt my hoc khng mun tip nhn. Khch hng dng k dch v ny c cung cp hp th thoi (ting anh / ting vit) .S ca hp th tng ng vi s in thoi ca khch hng. Mi hp thue c mt password bo mt. Ch cn quay s 942 trc s my di ng ca mnh v nhp password mi truy cp. Ph ng k dch v ny l 2000/ln. Nu qu 6 thng m khng s dng th khi c nhu cu s dng phi ng k li . Chuyn tip cuc gi v hp th thoi min ph. IV.2.4 Tm hiu v cc sn phm ca Vina phone. IV.2.4.1 Th SIMCARD. *Loi th ny c s dng truy cp VinaPhone *Th SIMCARD s dng cho dch v prepain v postpain hon ton ging nhau, ch khc nhau cch khai bo tng i. *Cch nh s thu bao theo cch nh s thng thng v theo tng dy s thu bao phn b cho tng bu in. IV.2.4.2 Th co Vinacard. *Truy cp dch v tr trc *Trn th Vinacard c in mnh gi ca th, hng dn cch s dng v m s ca th . *Khi ban mua th th bn s c hng dn thng qua t hng dn chi tit s dng dch v ny. *Hin nay loi th ny gm rt nhiu mnh gi khc nhau, hin ang c 4 loi th Vinacard: - Th 100.000ng vi 10 ngy s dng v 15 ngy nhn cuc gi b sung . - Th 200.000ng vi 25 ngy s dng v 15 ngy nhn cuc gi b sung. - Th 300.000ng vi 45 ngy s dng v 15 ngy nhn cuc gi b sung. - Th 500.000ng vi 90 ngy s dng v 15 ngy nhn cuc gi b sung.VINACARD HNG DN S DNG TH VINACARD

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300.000 SVTH: Nguyn Th Lan Anh

1Gi 155 t my di dng VINAPHONE 2.Sau li ch dn,bm 2 nhp m th 3.Nhp m th sau y 4.Nghe thng bo ti khon v s dng 5.Quay s thc hin cuc gi theo cch thng thng. 6.Mi chi tit v dch v tr trc camng Vinaphone xin lin h151(min ph)

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