Hệ Thống Phủ Sóng Di động trong tòa nhà IBS

Bo Co Thc Tp Tt Nghip

LI NI U---------------o0o--------------

Ha nhp vi s pht trin chung ca nn kinh t th gii, nn kinh t Vit Nam ang tng bc y mnh pht trin kinh t, x hi Trong , dch v vin thng ang l mt trong nhng ngnh kinh t mi nhn nhm p ng nhu cu trao i thng tin ang tng ln c v s lng ln cht lng. S lng cc nh khai thc vin thng trong v ngoi nc tham gia vo th trng vin thng ngy mt tng, s cnh tranh gia cc nh khai thc ngy cng tr nn cng thng. Cng vi s pht trin nhanh chng ca nn kinh t, c s h tng th cng ngy mt i mi, cc khu nh cao tng ang mc ln ngy mt nhiu hn. Phn ln cc to nh cao tng ny u l vn phng lm vic ca cc cng ty trong v ngoi nc, khch sn, siu th, khu chung c y l ni m nhu cu lin lc rt ln v l nhng khch hng quan trng ca cc nh khai thc vin thng. Vn vng ph v dung lng u rt quan trng v cht lng thoi di dng nh hng trc tip n uy tn ca nh cung cp dch v. V vy c th m bo nhu cu lin lc, p ng nhu cu ngy cng cao ca khch hng c bit l cc khch hng cao cp, cc nh khai thc vin thng ang tng bc tp trung nng cao cht lng vin thng trong cc to nh cao tng. Tuy nhin, do c trng vng ph ca nhng khu vc ny rng hoc tri di theo chiu dc, sng v tuyn t trm BTS bn ngoi ta nh (BTS outdoor macro) b suy hao nhiu khi xuyn qua cc bc tng b tng dn n cng tn hiu khng t yu cu, nn gii php ph sng trong ta nh hin nay c nhiu nh cung cp dch v di ng la chn. Vic xy dng mt h thng ph sng di ng trong cc ta nh ny tr nn cn thit c bit l hai thnh ph ln H Ni v Tp H Ch Minh. Trong bo co Tm hiu h thng ph sng di ng trong ta nh ny, Em s trnh by quy trnh kho st, thit k, kim nh cht lng v vn hnh, bo tr h thng ph sng in thoi di ng cho mt ta nh mu t c th trin khai rng cho cc ta nh cao tng khc.. Bo co c t chc thnh ba chng nh sau: Chng 1: Tng quan v mng GSM Chng 2: Gii php ph sng di ng trong to nh Chng 3: Kho st v thit k h thng ph sng di ng trong to nh Chng 4: Xy dng h thng IBC cho ta nh Kt lun v hng pht trin ti: Phn ny s trnh by cc kt qu t c ca bo co, v mt s hn ch cha khc phc c, t a ra mt s hng pht trin trong tng lai. Do cn nhiu hn ch v trnh v thi gian nn bo co khng th trnh khi nhng thiu st, rt mong nhn c kin ng gp ca cc thy c v bn c. Em xin chn thnh cm n! H Ni, thng 11, nm 2011 Phan Quang Trung

Sinh vin: Phan Quang Trung - Lp: H09VT9

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THUT NG VIT TT--------------------o0o--------------------

A AMPS ARIB B BCCH BCH BER BSC BSS BTS BSIC BCN BLER C CCCH CDMA C/I CPICH CS CSPDN CS-ACELP D DCCH DPCCH DAS E EIRP F FACCH FACH FCCH FDD FDMA

Advanced Mobile Phone System

H thng in thoi di ng tin tin Association Of Radio Industries Lin hip cng nghip v kinh And Business doanh v tuyn Broadcast Control Channel Broadcast Channel Bit Error Ratio Base Station Controller Base Station Subsystem Base Tranceiver Station Base Station Indentifization Code Broadband Convergence Network Block Error Rate Common Control Channel Code Division Multiple Access Carrier to Interference Ratio Common Pilot Chanel Circuit Switch Circuit Switched Public Data Network Conjugate Structure Algebraic Code Excited Linear Pradiction Dedicated Control Channel Dedicated Physical Control Chanel Distributed Antenna System Knh qung b iu khin. Knh qung b T s bit li B iu khin trm gc Phn h trm gc Trm v tuyn gc M nhn dng trm gc Mng hi t bng rng Tc li khi Knh iu khin chung a truy cp chia theo m T s sng mang trn nhiu Knh hoa tiu chung Chuyn mch knh Mng s liu chuyn mch knh cng cng D bo tuyn tnh kch thch theo m i s cu trc phc hp Knh iu khin dnh ring Knh iu khin vt l ring H thng phn phi anten

Equivalent Isotropically Radiated Cng sut pht x ng hng Power Fast Associated Control Channel Forward Access Chanel Frequency Correction Channel Frequency Division Duplex Frequence Division Multiple Access Knh iu khin lin kt nhanh Knh truy nhp ng xung Knh hiu chnh tn s Ghp knh song cng phn chia theo tn s a truy cp phn chia theo tn2



s G GOS GSM GPRS GMSC GGSN GPS H HLR I IMT-2000 IMSI ISDN IBC IBS L LAC LAI LA M MS MSC ME MCC MNC N NAS NSS O OM OCQPSK P PCCH PCH PCS PLMN Grade Of Service Global System for Mobile Communication General Packet Radio Services Gateway Mobile Service Switching Center Gateway GPRS support Node Global Positioning System Home Location Register International Mobile Telecommunication International Mobile Subscriber Identity Integrated Servive Digital Network Inbuilding Coverage Inbuilding Solution Link Access Control Location Area Indentify Location Area Mobile Station Mobile Service Switching Center Mobile Equipment Mobile Country Code Mobile Network Code Non-Access Stratum Network and Switching Subsystem Cp phc v Thng tin di ng ton cu Dch v v tuyn gi chung Trung tm chuyn mch di ng nh hng Node h tr GPRS cng H thng nh v ton cu B nh thng tr Tiu chun thng tin di ng ton cu S nhn dng thu bao di di ng quc t Mng s a dch v Ph sng trong ta nh Gii php ph sng ta nh iu khin truy nhp lin kt Nhn dng vng v tr Vng nh v Trm di ng Tng i di ng Thit b di ng M quc gia M dng di ng Tng khng truy nhp H thng chuyn mch

Operation and Management Khai thc v bo dng Orthogonal complex quadrature Kha chuyn pha vung gc trc Phase Shift Keying giao Paging Control Chanel Paging Channel Personal Communication Services Public Land Mobile Network Knh iu khin tm gi Knh nhn tin Dch v thng tin c nhn Mng di ng mt t cng cng


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PSTN PRACH Q QxLevel R RACH RRC RxLevel RSSI RSCP S SCH SS SGSN SQI T TACH TCH TDMA TDD U UTRAN UMTS W WCDMA WDM

Public Switched Telephone Network Mng chuyn mch thoi cng cng Physical Random Access Channel Knh truy cp ngu nhin vt l RF Signal Quality Random Access Channel Radio Resource Control RF Signal Level Receive Signal Strength Indication Received Signal Code Power Synchronization Channel Switching Subsystem Servicing GPRS Support Node Speech Quality Index Traffic and Associated Channel Traffic Channel Time Division Multiple Access Time Division Duplex Cht lng thu Knh truy cp ngu nhin iu khin ti nguyn v tuyn Mc thu tn hiu Biu th tn hiu thu Cng sut m tn hiu nhn Knh ng b Phn h chuyn mch Node h tr GPRS Cht lng thoi Knh lu lng v lin kt Knh lu lng a truy cp phn chia theo thi gian Ghp song cng phn chia thi gian

Universal Terrestrial Radio Access Mng truy nhp v tuyn mt Network t ton cu Universal Mobile H thng thng tin di ng Telecommunnication System chung Wideband Code Division Multiplex Wavelength Devision Multiplexing a truy cp chia theo m Ghp knh phn chia bc sng

MC LC----------o0o----------

THUT NG VIT TT................................................................................................2Sinh vin: Phan Quang Trung - Lp: H09VT94


MC LC.........................................................................................................................4 CHNG I: TNG QUAN V MNG GSM...............................................................61.1 Cc c tnh v dch v ca mng GSM.............................................................................................6 1.2.1 H thng GSM.............................................................................................................................7 1.2.2 H thng con chuyn mch (SS)..................................................................................................8 1.2.3 Trm di ng(MS) ......................................................................................................................9 1.2.4 H thng con BSS.....................................................................................................................10 1.2.5 H thng khai thc v h tr (OSS)...........................................................................................10 1.3 Cu trc a l ca mng GSM.......................................................................................................11 1.4 Cc c trng ca GSM...................................................................................................................11 2.2.3 Phn t bc x..........................................................................................................................21 2.4 Kt lun............................................................................................................................................24

CHNG III: TIN HNH KHO ST V THIT K H THNG PH SNG DI NG TRONG TO NH......................................................................................253.6.2 Cc tham s lp k hoch..........................................................................................................36

CHNG IV: XY DNG H THNG IBC CHO TO NH...............................424.1 Phn tch kt qu kho st................................................................................................................43 4.2.5 Thit k h thng IBS theo trc ng........................................................................................49 4.2.6 Lp t phng BTS room..........................................................................................................53

THUT NG VIT TT................................................................................................2 MC LC.........................................................................................................................4 CHNG I: TNG QUAN V MNG GSM...............................................................61.1 Cc c tnh v dch v ca mng GSM.............................................................................................6 1.2.1 H thng GSM.............................................................................................................................7 1.2.2 H thng con chuyn mch (SS)..................................................................................................8 1.2.3 Trm di ng(MS) ......................................................................................................................9


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Bo Co Thc Tp Tt Nghip1.2.4 H thng con BSS.....................................................................................................................10 1.2.5 H thng khai thc v h tr (OSS)...........................................................................................10 1.3 Cu trc a l ca mng GSM.......................................................................................................11 1.4 Cc c trng ca GSM...................................................................................................................11 2.2.3 Phn t bc x..........................................................................................................................21 2.4 Kt lun............................................................................................................................................24

CHNG III: TIN HNH KHO ST V THIT K H THNG PH SNG DI NG TRONG TO NH......................................................................................253.6.2 Cc tham s lp k hoch..........................................................................................................36

CHNG IV: XY DNG H THNG IBC CHO TO NH...............................424.1 Phn tch kt qu kho st................................................................................................................43 4.2.5 Thit k h thng IBS theo trc ng........................................................................................49 4.2.6 Lp t phng BTS room..........................................................................................................53

CHNG I: TNG QUAN V MNG GSM 1.1 Cc c tnh v dch v ca mng GSM T cc khuyn ngh ca GSM ta c th tng hp nn cc c tnh ch yu sau: S lng cc dch v v tin ch cho cc thu bao c trong thng tin thoi v s liu ln. S tng thch ca cc dch v trong GSM vi cc dch v ca mng c sn (PSTN-ISDN) bi cc giao din theo tiu chun chung. T ng cp nht v tr cho mi thu bao di ng. linh hot cao nh s dng cc u cui thng tin di ng khc nhau nh my xch tay, my cm tay t trn t. S dng bng tn s 900MHz vi hiu qu cao nh s kt hp gia TDMA (Time Division Multiple Access) vi FDMA (Frequency Division Multiple Access). Gii quyt s hn ch dung lng nhi vic s dng li tn s tt hn. Cc dch v c tiu chun GSM: Cc dch v thoi: Chuyn hng cc cuc gi v iu kin, cuc gi khi thu bao di ng bn v khng bn, cuc gi khi khng n c MS, cuc gi khi nghn v tuyn. Cm tt c cc cuc gi i, cuc gi ra quc t, cuc gi ra quc t tr cc nc PLMN thng tr, cuc gi n khi lu ng ngoi nc c PLMN thng tr. Gi cuc gi, i gi, chuyn tip cuc gi.Sinh vin: Phan Quang Trung - Lp: H09VT96


Hon thnh cc cuc gi n cc thu bao bn. Nhm v s dng khp kn, dch v ba pha, thng bo cc ph. Dch v in thng khng tr cc. Nhn dng s ch gi, s thoi c ni, cuc gi him th. Cc dch v s liu: Truyn dn s liu. Dch v bn tin ngn, hp th thoi. Pht qung b trong cell.

1.2 Cu trc mng GSM Cc khi chnh trong mng GSM:

OSS: H thng khai thc v h tr BSS: H thng trm gc AUC: Trung tm nhn thc BSC: i iu khin trm gc HLR: B ghi nh v thng tr OMC: Trung tm khai thc v bo dng SS: H thng chuyn mch PSPDN: Mng chuyn mch gi cng cng VLR: B ghi nh v tm tr EIR: Thanh ghi nhn dng thit b BTS: i v tuyn gc ISDN: Mng s lin kt a dch v MS: My di ng PLMN: Mng di ng mt t cng cng MSC: Trung tm chuyn mch cc dch v di ng PSDN: Mng chuyn mch in thoi cng cng CSPDN: Mng s liu chuyn mch knh cng cng

Hnh 1.1: S cu trc mng GSM 1.2.1 H thng GSM H thng ny c chia thnh h thng chuyn mch SS v h thng trm gc BSS, mi h thng ny c mt s chc nng ti thc hin tt c cc chc nng ca h thng. V nhng khi chc nng ny c thc hin cc thit b khc nhau. H thng c thc hin nh mt mng gm nhiu cell v tuyn cnh nhau cng m bo tonSinh vin: Phan Quang Trung - Lp: H09VT97


b vng ph sng ca vng phc v. Mi cell mt trm v tuyn gc BTS lm vic mt tp hp cc knh vo tuyn. Cc knh ny khc vi cc knh c s dng cc cell ln cn trnh nhiu giao thoa. Mt b iu khin trm gc BSC s iu khin mt nhm BTS. BSC iu khin cc chc nng nh chuyn giao v iu khin cng sut. Mt MSC (trung tm chuyn mch cc dch v di ng) phc v mt s b iu khin trm gc, MSC iu khin cc cuc gi ti v i t mng chuyn mch in thoi cng cng PSTN, mng s lin kt a dch v ISDN, mng di ng mt t cng cng PLMN v cc mng s liu cng cng PSDN, v c th l cc mng ring. Cc khi ni trn u tham gia vo vic ni thng gia mt trm di ng MS v mt thu bao di ng PSDN. Nu khng th thc hin mt cuc gi n MS ta s thng cn bt c mt thit b no khc. Vn ny sinh khi ta mun thc hin mt cuc gi kt cui MS, ngi gi hu nh khng bit MS c gi u. V th cn mt s c s d liu mng theo di MS. C s d liu quan trng nht l b ng k thng tr HLR. Khi mt thu bao di ng mua mt ng k t mt hng khai thc GSM, thu bao di ng ny s c ng k HLR ca hng ny. HLR cha cc thng tin v thu bao nh cc dch v b xung v cc tn s nhn thc, quyn thm nhp ca thu bao, cc dch v m thu bao ng k, cc s liu ng v vng m ang cha thu bao ca n (Roaming), trong HLR cn to bo hiu s 7 trn giao din vi MSC. Ngoi ra s c thng tin v v tr ca MS tc l hin thi v tr ca MS u thuc MSC no. Thng tin ny thay i khi MS di ng. MS s gi thng tin v v tr thng qua MSC/HLR n HLR ca mnh, nh vy m bo phng tin thu mt cuc gi. 1.2.2 H thng con chuyn mch (SS) H thng con chuyn mch (SS): bao gm cc chc nng chuyn mch chnh ca GSM cng nh cc c s d liu cn thit cho s 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 vi mng khc. MSC thc hin cc chc nng chuyn mch chnh, nhim v chnh ca MSC l iu phi vic thit lp cuc gi n nhng thu bao ca GSM, mt mt MSC giao tip vi h thng con BSS v mt khc giao tip vi mng ngoi qua G-MSC. Khi SS cng cn giao tip vi mng ngoi s dng kh nng truyn ti ca cc mng ny cho vic truyn ti s liu ca ngi s dng hay bo hiu gi cc phn t ca mng GSM. Chng hn SS c th s dng mng bo hiu knh chung s 7, mng ny m bo hot ng tng tc gia cc phn t ca SS trong mt hay nhiu mng GSM. MSC thng l mt tng i ln iu khin v qun l mt s cc b iu khin trm gc BSC. Mt tng i MSC thch hp cho mt vng th v ngoi c dn c vo khong mt triu (vi mt thu bao trung bnh). Khi IWF: kt ni MSC vi mt s mng khc cn phi thch ng cc c im truyn dn ca GSM vi cc mng ny. Cc thch ng ny gi l chc nng tng tc IWF. IWF bao gm mt thit b thch ng giao thc v truyn dn. IWF c th thc hin trong cng chc nng MSC hay c th thit b ring, trng hp hai giao tip gia MSC v IWF c m. Khi HLR:Sinh vin: Phan Quang Trung - Lp: H09VT98


Gi cc thng tin lin quan ti vic cung cp cc dch v vin thng khng ph thuc vo v tr hin thi ca thu bao v cha cc thng tin v v tr hin thi ca thu bao. Thng HLR l mt my tnh ng ring khng c kh nng chuyn mch nhng c kh nng qun l hng trm ngn thu bao. Mt chc nng con ca HLR l nhn dng trung tm nhn thc thu bao AUC. Khi trung tm nhn thc AUC: c ni n HLR chc nng ca AUC l cung cp cho HLR cc tn s nhn thc v cc kho mt m s dng cho bo mt. ng v tuyn cng c AUC cung cp m bo mt chng 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 mi thm nhp tri php. B ghi nh v tm tr VLR: L mt c s d liu cha thng tin v tt c cc MS hin ang vng phc v ca MSC. Mi MSC c VLR. Ngay c khi MS lu ng vo mt vng MSC mi. VLR lin kt vi MSC s yu cu s liu v MS t HLR. ng thi HLR s c thng bo rng MS ang vng MSC no. Nu sau MS mun thc hin mt cuc gi, VLR s c tt c cc thng tin cn thit thit lp mt cuc gi m khng cn hi HLR c th coi VLR nh mt HLR phn b. VLR cha thng tin chnh xc hn v v tr MS vng MSC. Tng i di ng cng GMSC: Tt c cc cuc gi vo cho mng GSM /PLMN s c nh tuyn cho tng i v tuyn cng Gateway-MSC. Nu ngi no mng c nh PSTN mun thc hin mt cuc gi n mt thu bao di ng ca mng GSM. Tng i ti PSTN s kt ni cuc gi ny n MSC c trang b mt chc nng c gi l chc nng cng. Tng i MSC ny gi l MSC cng v n c th l mt MSC bt k mng GSM. GMSC s phi tm ra v tr ca MS cn tm. iu ny c thc hin bng cch hi HLR ni MS ng k. HLR s tr li khi MSC ny c th nh tuyn li cuc gi n MSC cn thit. Khi cuc gi n MSC ny, VLR s bit chi tit hn v v tr ca MS. Nh vy c th ni thng mt cuc gi GSM c s khc bit gia thit b vt l v ng k thu bao. 1.2.3 Trm di ng(MS) MS l mt u cui di ng, c th t trn t hay xch tay. Ti GSM c mt khi nh gi l modun nhn dng thu bao SIM, l mt khi vt l tch ring chng hn l mt IC Card cn gi l card thng minh SIM cung vi thit b trm hp thnh trm di ng. Khng c SIM, MS khng th thm nhp n mng tr trng hp gi khn. Khi lin kt ng k thu bao vi card SIM ch khng phi vi MS. ng k thu bao c th c th s dng trm MS khc nh ca chnh mnh. iu ny lm ny sinh vn MS b ly cp, v khng c bin php chn ng k thu bao nu b ly cp th khi s cn mt c s d liu cha s liu phn cng ca thit b: thanh ghi nhn dng thit b EIR (nhng hin nay Vit Nam th ngi ta khng dng thit b ny na bi v khi c EIR th n yu cu my c ch tiu cht lng tt. Do kinh t th trng th khng phi ai cng c th mua mt my c cht lng t yu cu ). EIR c ni Vi MSC qua mt ng bo hiu. N cho php MSC kim tra s hp l ca thit b. Bng cch ny c th cho mt MS khng c thm nhp.


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1.2.4 H thng con BSS L mt h thng c th ring cho 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 thu pht ng v tuyn v qun l cc chc nng ny. Mt khc BSS thc hin giao din vi cc tng i SS. Tm la, BSS thc hin u ni cc MS vi tng i v nh vy u ni nhng ngi s dng cc trm di ng vi nhng ngi s dng vin thng khc BSS cng phi c iu khin, do n c u ni vi OSS. BSS bao gm hai loi thit b: BTS giao din vi MS v BSC giao din vi MSC. Khi BTS: Mt BTS gm cc thit b thu pht, anten v x l tn hiu c th cho giao din v tuyn. C th coi BTS l cc Modem v tuyn phc tp c thm mt s cc chc nng khc. Mt b phn quan trng ca BTS l TRAU l khi chuyn i m v thch ng tc . TRAU l thit b m qu trnh m ho v gii m ting c th ring cho GSM c tin hnh, ti y cng thc hin thch ng tc trong trng hp truyn s liu. TRAU l mt b phn ca BTS, nhng cng c th t cch xa BTS v thm ch cn t trong BSC v MSC. Khi TRAU: Khi thch ng v chuyn i m thc hin chuyn i gia ting 64kbit/s lut A v ting RPE LTP 13 kbit/s cng nh thch ng tc gia cc khung 3.6, 6, 12 kbit/s s dng giao din v tuyn. TRAU c iu khin bi BTS. Nu n c t bn ngoi BTS th vic iu khin c thc hin bi bo hiu trong bng bng cch s dng mt s bit d tr trong khung 320 bit ca cc knh lu lng 16 kbit/s trong ch c 13 kbit/s c s dng cho vic truyn lu lng cc bt d tr ni trn l cc bit iu khin. Khi BSC: BSC c nhim v qun l tt c giao din v tuyn thng qua cc lnh iu khin t xa BTS v MS. Cc lnh ny ch yu l lnh n nh, gii phng knh v tuyn v chuyn giao. Mt pha BSC c n vi BTS cn pha kia ni vi MSC ca SS. Trong thc t BSC l mt tng i nh c kh nng tnh ton ng k. Vai tr chnh ca n l qun l cc knh giao din v tuyn v chuyn giao. Giao din gia BSC v MSC l giao din A, cn giao din gia BTS v BSC l giao din Abit. 1.2.5 H thng khai thc v h tr (OSS) c ni ti tt c cc thit b h thng chuyn mch v ni n BSC. OSS c cc chc nng chnh sau: Qun l mng t bo : Ti PLMN ln cn x l rt nhiu s liu, cc th tc chi tit, cc cng c qun l ph thuc c quan chu trch nhim v mng. S liu tng i v s liu h thng in thoi di ng, c s d liu ny cha tt c cc ni dung ca c s d liu v d liu ang c gi ti MSC/BSC. C th kim tra ti ch trc khi a n vo hot ng. Qun l ng k thu bao: Bao gm cc hot ng ng k thu bao. Nhim v u tin l nhp v xo thu bao khi mng, ng k thu bao rt phc tp gm nhiu dch v v tnh nng b xung. Nh khai thc phi c th thm nhp tt c cc thng s ni trn. Mt nhim v quan trng khc ca khai thc l tnh cc cc cuc gi.Sinh vin: Phan Quang Trung - Lp: H09VT910


Qun l cht lng : C mt s chc nng o c GSM, ni dung chc nng o c s cp ny c thc hin phn t mng chu trch nhim v i tng o, chng hn cc s liu nh hng theo cuc gi c thc hin MSC sau, s lng o s cp c gi ti OSS v c lu tr y. Cc php o l: o lu lng cc tuyn. o lu lng cc loi lu lng. o v phn tn lu lng i tng chnh o mng v tuyn l cell. 1.3 Cu trc a l ca mng GSM Mi mng in thoi cn mt cu trc nht nh nh tuyn cc cuc gi vo tng i ng do tnh lu thng ca cc thu bao trong mng. Vng mng: Tng i v tuyn cng GMSC kt ni cc ng truyn gia mng GSM/PLMN v mng PSTN/ISDN khc hay cc mng PLMN khc s mc tng i trung k quc gia hay quc t. Tt c cc cuc gi vo cho mng GSM s c nh tuyn n mt hay nhiu tng i v tuyn cng GMSC. Vng phc v MSC/VLR: Vng MSC l mt b phn ca mng c mt MSC qun l. nh tuyn mt cuc gi n mt thu bao di ng, ng truyn qua mng s c ni n MSC vng phc v MSC ni thu bao ang . Vng phc v nh l mt b phn ca mng c nh ngha nh mt vng m c th t n trm di ng nh vic MS ny c ghi li mt b nh v khc(VLR). Mt vng mng GSM c chia thnh mt hay nhiu vng phc v MSC/VLR. Vng nh v (LA-location Area): Mi vng phc v MSC/VLR c chia thnh mt s vng nh v. Vng nh v l mt phn ca vng phc v MSC/VLR m mt trm di ng c th chuyn ng t do m khng cn cp nht thng tin v v tr cho tng i MSC/VLR iu khin vng nh v ny. Vng nh v ny l mt vng m thng bo tm gi s c pht qung b tm mt thu bao di ng b gi. Vng nh v c th c mt s cell v ph thuc vo mt hay vi BSC nhng n ch ph thuc vo mt MSC/VLR. H thng c th nhn dng vng nh v bng cch s dng nhn dng vng nh v LAI. Vng nh v c h thng s dng tm mt thu bao ang trng thi hot ng. (cell): Vng nh v c chia thnh mt s , l mt vng bao ph v tuyn c nhn dng bng nhn ng ton cu (CGI). Trm di ng t nhn dng mt bng cch s dng m nhn dng trm gc (BSIC). 1.4 Cc c trng ca GSM Trong cc h thng in thoi di ng hin c cung cp cho cc thu bao v nh khai thc nhiu u im hn mt mng in thoi tiu chun. Nhng cn nhiu hn ch. GSM khc phc c nhng hn ch v c th hin qua cc c trng sau.Sinh vin: Phan Quang Trung - Lp: H09VT911


Tnh tng thch: Do s pht trin nhanh chng ca cc mng t bo Chu u, hin c nhiu h thng t bo khc nhau m khng tng thch vi nhau. V vy, hin nhin l cn phi c mt tiu chun chung cho h thng thng tin di ng. V mt hi ng thc thi c thit lp vi mt nhim v phc tp l phn nh chung-ring mng tiu chun mi. Tiu chun GSM c qui nh v pht trin cc nc Chu u ang hot ng khai thc chung vi nhau . Kt qu l mt h thng t bo c thc hin khp Chu u. S thun li do tiu chun GSM em li, s c mt th trng ln i vi cc thit b GSM. Ngha l cc nh sn sut s cung cp cc hit b vi cht lng cao hn v gi thnh r hn. Cc thnh cng ca GSM c chp nhn v thc hin trn khp th gii. H thng thng tin di ng s GSM tng thch vi h thng bo hiu s 7 v s dng bng tn (890-915 ) MHz truyn tn hiu t my di ng n trm gc v bng tn (935960) MHz truyn dn tn hiu t trm gc n my di ng. Loi b cc tp m: Trong cc h thng in thai t bo hin nay, my di ng thng tin vi cell bng cc tn hiu v tuyn tng t. Mc d k thut ny c th m bo mt cht lng thoi rt tt (n c s dng nhiu i v v tuyn qung b stereo), nhng n d b tp m xm nhp. Tp m s giao thoa vi h thng hin hnh, c th c pht sinh bi cc nguyn nhn sau : Mt ngun cng sut mnh hoc ko di , gn vi h thng thng tin di ng (nh h thng nh la trn t , st ...). S truyn dn cc my di ng khc nhau trn cng mt tn s (nhiu knh chung). S truyn dn cc my di ng khc nhau, theo kiu xuyn ngang t mt tn s ln cn (nhiu knh ln cn ). Nhiu nn xm nhp v tn hiu qu yu. i ph vi nhnh vn gy ra nhiu trong h thng t bo mi ngi ta s dng cc tn hiu s thay cho tn hiu tng t. Cc tn hiu c pht trn mt giao din v tuyn s c th c bo v chng li cc li pht sinh do tp m. Vic bo v ny s hnh thnh t s m ho ca tn hiu, m c ch l do s quyt nh ca phn mm v s dng gii m viterbi. Cc c ch ny cho php pht hin v sa cha cc li mt tn hiu. Kt qu l c mt giao din v tuyn mnh hn nhiu. Thng tin di ng s c th chu c mc nhiu cao hn so vi cc h thng tng t hin c, dn n vic ci thin c cht lng ln hiu qu h thng thng tin di ng. Tnh linh hot v tng thm dung lng: Vi giao din v tuyn tng t hin c, mi kt ni gia mt thu bao di ng vi mt Cell i hi phi c sng mang RF ring, iu dn n i hi Cell phi lp t thm modul (phn cng ) RF. V vy, m rng dung lng ca mt Cell th phi tng thm s lng cc knh v cc modul RF c cht lng tng ng phi c a thm vo thit b ca Cell. Do , vic m rng h thng l tn nhiu thi gian, tin ca v cng sc Nh vy, cc hng khai thc cng bao hm c vic lp k hoch RF rt phc tp. khai thc mt cch hp php, tt c cc h thng phi s dng mt khong tn s RF oc qui nh cht ch, ch trong khong tn s (872-960 MHz). R rng ph tn s b nhiu hn ch v ch mt s lng c hn cc cuc m thoi l c th chn c trn mt s lng knh v tuyn cho, do , thng xuyn c s qu tiSinh vin: Phan Quang Trung - Lp: H09VT912


xy ra ti gi cao im ca nhu cu, kt qu l call blocking (tc thu bao s nghe mt cho bit ng truyn ang bn ), hu qa l s khng tho mn ca thu bao. Khi m giao din s c s dng h thng GSM s a n vic gii quyt vic s dng ph v tuyn c sn mt cch hiu qu hn. Tm cuc gi ng thi c thc hin trn mt sng mang RF. iu c ngha l mi modul RF ring s p ng cho tm thu bao cng mt lc, v nh vy h thng s c m rng, yu cu thay i modul RF thng t hn so vi cc h thng c. Do h thng l rt linh hot v n c th thay i dung lng bng mt b phn khc ca mng bng cch t li cu hnh t c s d liu ca h thng. S dng cc giao din tiu chun: Trong mng t bo mi thit b c s dng l c ch to bi mt nh sn sut. iu l v mt hng sn xut ch sn xut thit b c thit k thng tin vi nhau. Tnh trng ny c th rt c li cho cc hng sn xut nh h c nh hng ln ln s nh gi cc sn phm ca h, nhng li l iu khng c li i vi ngi s dng in thoi di ng v nh khai thc mng v gi thnh thit b cao. Vi h thng thng tin di ng s GSM th ngc li, v do cc giao din tiu chun nh C7 v X25 c s dng trong ton h thng. iu ny c ngha l cc nh qui hoch h thng c th la chn thit b vi gi thnh khc nhau ca cc hng sn xut khc nhau. V vy, s cnh tranh gia cc hng sn xut vi nhau s tng ln v gi thnh s h xung. Ngoi ra, cc nh thit k mng s c nhiu linh hot hn khi t mua cc cu kin ca mng, tc l h c t to ra nhiu hiu qu s dng cc ng truyn mt t m h ang khai thc. An ton v bo mt tuyt i: Vn an ton c xem ng u danh mc cc vn s c cnh tranh ca cc nh khai thc cc h thng tng t. Trong mt vi h thng th h u c khong 20% cuc gi b n cp. bo mt s liu v thoi c tt, GSM a ra ngh bo mt c v phng php truyn dn trn giao din v tuyn v c cch thc lu lng c x l trc khi truyn dn. Cc d liu c iu khin v bo hiu s c mt m cng vi cc k thut nhn thc thu bao tinh vi s loa tr vic n cp cuc gi. h thng GSM thit b di ng s c nhn dng mt cch c lp t thu bao di ng. Mi my di ng c mt s nhn dng c m ho cng khi sn xut kim tra nu nh n c khai bo l b mt cp. H thng GSM m bo mt mc cao tnh bo mt cho cc thu bao, cc cuc gi s c s ho, m ho v sau c gi mt m trc khi pht ln khng gian. Chuyn vng nhanh hn: Chuyn vng xy ra khi my di ng di chuyn gia cc cell. Mt cuc gi s c chuyn t mt knh ny n knh khc v t mt cell ny n mt cell khc duy tr cuc gi c lin tc. Trong cc h thng tng t hin c, ch c thu bao rt tt mi nhn ra mt chuyn vng xy ra. Cn h thng GSM gii quyt vn ny v qu trnh chuyn vng c iu khin cht ch hn nhiu. GSM cho php a nhiu yu t vo tnh ton v c tnh ton chi tit hn (o cng tn hiu ca cc cell ln cn). Nhn dng thu bao: So vi cc h thng tng t, mi thu bao di ng c nhn dng bi s my in thoi m n c gn ln thit b di ng ca n. V vy nu thu bao mun thu/pht cc cuc gi th cn phi c thit b di ng. Trong h thng GSM, thu bao v thit bi di ngSinh vin: Phan Quang Trung - Lp: H09VT913


c nhn dng mt cch ring r. Thu bao c nhn dng bng mt card thng minh (Smart card),c bit nh mt khi nhn dng thu bao SIM. Ngha l ngi s dng ch cn mua thu bao mt h thng di ng nhng c kh nng s dng cho nhiu kiu thit b di ng khc nhau (Fax, Computer, in thoi di ng). Ngha l khi di chuyn thu bao ch cn mang theo SIM card ca n. V SIM card nhn din ngi s dng nn bt k ni no cc cuc gi ca thu bao to ra, ho n tnh cc s lun lun c c gi ti b ghi nh v thng tr (HLR) ca thu bao. Tnh tng thch vi ISDN: ISDN l mt tiu chun m hu ht cc nc ang pht trin cam kt thc hin. y l mt mng thng tin mi v tin tin c thit k truyn thoi v s liu thu bao trn cc ng truynthoi tiu chun. Mng GSM c thit k khai thc vi h thng ISDN v s cung cp cc c tnh c th tng thch vi n.

CHNG II: GII PHP PH SNG DI NG TRONG TO NH2.1 t vn Ngy nay, m rng th phn ngoi vic cnh tranh v gi c, dch v gi tr gia tng, chm sc khch hng... cc nh cung cp dch v di ng cng khng ngng tp trung pht trin mng li c vng ph rng, ph su, cht lng ph sng tt. Tuy nhin, ngay c i vi cc cng ty cung cp dch v di ng ph sng 63/63 tnh thnh c mt vn cn quan tm l ti mt s thnh ph ln nh H Ni, TP. H Ch Minh l cht lng ph sng trong cc to nh, c bit l cc to nh cao tng ca khch sn, vn phng ca cc cng ty trong v ngoi nc, khu chung c cao cp y l ni m nhu cu lin lc rt ln v l nhng khch hng quan trng ca cc nh cung cp dch v vin thng. V vy c th m bo nhu cu lin lc, p ng nhu cu ngy cng cao ca khch hng c bit l cc khch hng cao cp, cc nh khai thc vin thng ang tng bc tp trung nng cao cht lng vin thng trong cc to nh cao tng.


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Hnh 2.1: M hnh h thng ph sng di ng trong ta nh Ti cc tng thp thng c tnh trng sng yu, chp chn, cc tng cao th nhiu (nht l i vi cc nh khai thc chia s chung bng tn GSM) dn n kh thc hin v rt cuc gi. Tuy nhin, do c trng vng ph ca nhng khu vc ny rng hoc tri di theo chiu dc, sng v tuyn t trm BTS outdoor macro b suy hao nhiu khi xuyn qua cc bc tng b tng dn n cng tn hiu khng t yu cu, nn gii php ph sng trong ta nh IBS (Inbuilding Solutions) hay IBC (Inbuilding Coverage) hin nay c nhiu nh cung cp dch v di ng la chn. Trong cc phn tip theo ngi thc hin s i su vo vic thit k h thng IBC.


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Hnh 2.2: H thng IBS s m bo c vng ph tt trong cc ta nh Gii php truyn thng: S dng cp feeder 7/8 v 1/2 truyn tn hiu. Thch hp vi cc ta nh qui m va v nh (di 23 tng, di 100 000 m2). Lp t d dng v nhanh chng, s dng cc quang i dc trc gim suy hao tn hiu Chia tch h thng thnh tng phn nh, trong mi phn s dng cp feeder 7/8 chy dc trc. C thm cc b repeater quang iu khin tn hiu. Thch hp vi cc ta nh din tch ln, cao trn 30 tng. Di y l nhng u im khi s dng h thng Inbuilding: m bo vng ph sng di ng mi lc mi ni bn trong ta nh, gip

kh nng truy cp mng v lin lc khng b gin on cho vic giao dch, hi ngh Cc dch v thng tin, d liu, mobile u c cung cp vi cht lng n nh mang li hiu qu cng vic tt nht v li nhun cho khch hng. Ti u ha thit k v kinh ph thit b s dng v kh nng ph sng. Trnh ph sng ra ngoi phm vi ta nh gim thiu kh nng nghn mng ngoi mun. H thng In Building l mt h thng c lp khng ph thuc vo h thng outdoor bn ngoi nn vic s dng h thng ny bo m tnh bn vng n nh cht lng vng ph sng cho ta nh H thng c kh nng tch hp tt c cc mng ang s dng trn ton quc nh cng mt lc c th dng chung cc mng nh Vinaphone, Mobifone,Vietteltrn mt h thng Inbuilding lp trc, c kh nng linh hot thay i cu hnh, nng cp cu hnh bo dng mng.Sinh vin: Phan Quang Trung - Lp: H09VT916


Nn tng cho cc ng dng h thng wireless, mobile broadband, mobile TV2.2 Tng quan gii php IBC cho ta nh cao tng

C th ni hin nay i vi cc ta nh ln nh l sn bay, ga in ngm, vn phng cao tng, siu th kinh doanh hng ha rng ln th vn vng ph v dung lng u rt quan trng v cht lng thoi di dng nh hng trc tip n uy tn ca nh cung cp dch v. Tuy nhin, do c trng vng ph ca nhng khu vc ny rng hoc tri di theo chiu dc, sng v tuyn t trm BTS bn ngoi ta nh (BTS outdoor macro) b suy hao nhiu khi xuyn qua cc bc tng b tng dn n cng tn hiu khng t yu cu, nn gii php ph sng trong ta nh hin nay c nhiu nh cung cp dch v di ng la chn. H thng inbuilding bao gm ba phn chnh: ngun tn hiu, h thng phn phi tn hiu v phn t bc x. Trong h thng phn phi tn hiu l im khc bit in hnh gia h thng inbuilding so vi h thng mng BTS outdoor macro thng thng.

Ngun tn hiu

H thng phn phi tn hiu

Phn t bc x

Hnh 2.3: Cc thnh phn chnh ca h thng IBC2.2.1 Ngun tn hiu ph sng cho indoor c th dng

Ngun tn hiu bng trm outdoor:

Hnh 2.4: Vng ph trong ta nh t mt t bo macro trong mng BTS outdoormacro y l gii php n gin nht cung cp vng ph cho cc to nh vi tn hiu t cc trm macro bn ngoi to nh. Gii php ny c khuyn ngh nu lu lng trong ta nh khngcao, hoc ch ta nh khng cho php lp t thit b v i cp trong ta nh hoc vic trin khai gii php dnh ring cho n khng kinh t. Khi vng ph c cung cp bng cch:Sinh vin: Phan Quang Trung - Lp: H09VT917


Tn hiu s thm nhp vo to nh t bn ngoi. iu ny ch thc hin c i vi cc ta nh c khong h ln i vi bn ngoi hoc t tng, ca s kim loi. t BTS trn cc ta nh xung quanh v hng anten ti ta nh cn ph. Khi khng cn n h thng phn phi tn hiu na v phn t bc x chnh l anten ca trm BTS outdoor macro . u im ca gii php ny l chi ph thp, khng mt nhiu thi gian trong trin khai, c th ph c ngoi nh (outdoor) v trong nh (indoor). Nhc im ca gii php ny l vng ph hn ch, tc bit thp i vi cc dch v d liu, dung lng thp v cht lng khng th chp nhn c mt s phn trong to nh. Suy hao tng dn khi tn s cng cao, do vy kh cung cp vng ph cho to nh mc tn hiu tt. Suy hao c th khc phc bng cch tng cng sut t cc trm ngoi nh nhng nhiu s tng. Vic thit k tn s gp nhiu kh khn do qu tn s hn hp (nht l i vi cc nh khai thc chia s chung bng tn GSM). Ngun tn hiu dng trm lp Repeater: Ngoi cch ph sng trong nh bng trm outdoor c th s dng trm lp (repeater) lm ngun v tuyn cung cp cho h thng phn phi. Khi vng ph ca trm outdoor hin c c m rng. Nhng gii php ny t c s dng trong thc t v cng tn hiu, cht lng, s n nh, dung lng ph thuc vo trm BTS bn ngoi v vic thit k cho trm lp (qu ng truyn, mc cch ly 2 hng) mc d gi thnh thp, trin khai nhanh, d dng. V c nhiu nhc im ni trn nn trn thc t rt t nh cung cp dch v di ng s dng gii php ny, tr trng hp bt kh khng. Ngun tn hiu bng trm indoor dnh ring:

Hnh 2.5: Vng ph cho ta nh c cung cp bi trm indoor dnh ring Gii php ny c th tng thm dung lng cho nhng vng trong nh yu cu lu lng cao. Vn chnh y l cung cp dung lng yu cu trong khi vn m bo vng ph tt ca to nh m khng lm nh hng ti cht lng dch v ca mng BTS outdoor macro. V vy gii php ny c cc nh cung cp dch v di ng trong khu vc s dng nh SingTel, Digi...Sinh vin: Phan Quang Trung - Lp: H09VT918


u im ca gii php ny l ngun tn hiu t bn ngoi n nh, mc tn hiu tt, m rng dung lng h thng d dng. Nhc im ca gii php l gi thnh cao, yu cu phi c cch b tr tn s/knh c th v xy dng h thng truyn dn m bo tnh m thut.2.2.2 H thng phn phi tn hiu

H thng phn phi tn hiu c nhim v phn phi tn hiu t ngun cung cp i n cc anten hoc phn t bc x khc v c phn loi thnh: H thng th ng:

Hnh 2.6: Gii php h thng anten phn phi cp ng th ng H thng th ng l h thng anten c phn phi bng cp ng trc v cc phn t th ng. y l gii php ph bin nht cho cc khu vc ph sng inbuilding khng qu rng, c c im: - Trm gc c dnh ring cho to nh: Tn hiu v tuyn t trm gc c phn phi qua h thng n cc anten. Vng ph cho to nh c gii hn ng thi khng lm nh hng n cht lng mng BTS outdoor macro. Nhng yu cu k s thit k phi tnh ton qu ng truyn cn thn v mc cng sut mi anten ph thuc vo s tn hao m cc thit b th ng c s dng, c bit l chiu di cp. - Cc thit b chnh gm: cp ng trc, b chia (splitter/tapper), b lc (filter), b kt hp (combiner), anten. H thng ch ng: H thng ch ng l h thng anten phn phi s dng cp quang v cc thnh phn ch ng (b khuch i cng sut). Vic s dng cp quang t BTS ti khi iu khin t xa c th m rng ti tng v tr anten ring l bng cch: tn hiu RF t BTS c chuyn i thnh tn hiu quang ri truyn n v c bin i ngc li thnh tn hiu RF ti khi iu khin t xa trc khi c phn phi ti mt h thng cp ng nh. Ngoi ra, h thng cn s dng cc thit b khc trong vic phn phi tn hiu: Hub quang chnh, cp quang, Hub m rng, khi anten t xa.


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Hnh 2.7: S mt h thng anten phn phi ch ng cho khu trng s Gii php ny thng c s dng cho nhng khu vc ph sng inbuilding rt rng, khi m h thng th ng khng p ng c ch tiu k thut suy hao cho php. Khi mt BTS phc v c nhiu ta nh trong mt vng, thng l cc khu trng s. Cc kt ni khong cch xa (hn 1 km) s dng cp quang, s phn phi gia mt tng v cc phn trong to nh c th dng cp xon i dy. Nhng nhc im d nhn thy l chi ph cao.

Hnh 2.8: S mt h thng anten phn phi ch ng cho mt to nh cao tng H thng lai ghp:

Hnh 2.9: S h thng lai ghp H thng ny l s kt hp gia h thng th ng v ch ng. Gii php ny dung ho c c u nhc im ca hai h thng th ng v ch ng. V n va mSinh vin: Phan Quang Trung - Lp: H09VT920


bo cht lng tn hiu cho nhng khu vc ph sng trong nh c quy m ln li va tit kim chi ph. 2.2.3 Phn t bc x Phn t bc x c nhim v bin i nng lng tn hiu in thnh sng in t pht ra ngoi khng gian v ngc li. Do h thng trong nh c s dng nhng khu vc c vng ph sng c bit nh nn i vi tng cng trnh c th i hi phi c phn t bc x thch hp. o Anten: s dng thch hp vi nhng vng ph c khuynh hng hnh trn hoc hnh ch nht. l v anten cho vng ph sng khng ng u, vic tnh qu ng truyn ph thuc nhiu vo cu trc ca to nh. Phm vi ph sng ca anten di GSM900 l 25m 30m; GSM1800 l 15m 18m. C 2 loi anten thng c s dng l anten v hng (omni) v anten c hng (yagi). Anten v hng c tnh thm m, nh gn d lp t nn c th kt hp hi ho vi mi trng trong to nh, cn anten c hng c tng ch cao thch hp khi ph sng trong thang my.

Hnh 2.10: H thng phn phi cp r o Cp r: c im ca cp r (cn gi l cp tn x) l c cng tn hiu ng u theo mt trc chnh nn thng c dng cho cc vng ph phc v ko di c bit nh: hnh lang di, xe in ngm, ng hm... Phm vi ph sng ca cp d ch vo khong 6m nhng li c u im hn hn so vi anten l h tr c di tn s rng t 1 MHz 2500 MHz. 2.3 Cc thit b dng trong h thng DAS 2.3.1 Cc loi anten dng cho h thng Anten Omni 3dBi, Omni Direction 2400 4.5dBi, Panel 14 dBi, h tr di tn t 800-2500 MHz.


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Hnh 2.11: Anten Omni vi s bc x theo chiu ngang v dc 2.3.2 Cp feeder s dng cho h thng H thng c thit k theo kiu backbone nn cp trc chnh thng dng l feeder 7/8 v cp nhnh cho cc tng l feeder 1/2. Bng 3.5 Suy hao ca cc loi feeder ca hng Rosenberger (c): Loi feeder Tn s 1800MHz Tn s 2100MHz 1/2 7/8 10,7dB/100m 6,11dB/100m 11,5dB/100m 6,63dB/100m

Hnh 2.12: Cc loi slipter dng trong IBC Cng thc tnh suy hao trong Slipter: Cng thc tnh suy hao: Slipter loss= 10log (tng s ng ra) + 0.1dB V d: Slipter 1:3 th suy hao ti mi ng ra l: 10log(3)+0.1dB = 4.87dB


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Hnh 2.13: Suy hao ca Slipter 1:3 2.3.3 B chia khng u (Coupler) Suy hao cc b Coupler ca hng Telestone (Trung Quc): Coupler type Directional Coupler 5 dB Directional Coupler 10 dB Directional Coupler 15 dB Directional Coupler 20 dB Directional Coupler 30 dB Coupling Value (dB) 5 10 15 20 30 Insertion Loss (dB) 1,65 0,46 0,14 0,04 0

Hnh 2.14: Coupler chia tn hiu ra cc anten c cng sut 3.5 5dBm 2.3.4 B POI (Point of Interface) Chc nng ca POI trong h thng IBC l kt hp cc Operator t BTS ri phn phi ra h thng DAS thng qua feeder.

Hnh 2.15: V tr ca POI trong h thng IBC


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Phn A l tn hiu t BTS outdoor ca cc nh cung cp dch v c a vo BTS indoor ca h thng IBC, hin ti c 3 nh cung cp dch v chnh nc ta: Vietel, VMS Mobifone v Vinaphone u dng tn s GSM 900MHz v DCS 1800MHz. Phn B l b POI kt hp tn hiu ca tt c cc nh cung cp dch v c ly t Phn A thnh mt ng sau truyn n h thng DAS phn C.

Hnh 2.16: Cc tn s c kt hp vo b POI Phn C l h thng DAS bao gm cc linh kin th ng nh feeder, anten indoor, slipter phn phi cng sut t BTS a ti. y, ngi thc hin s dng b Hybrid 2 ng vo v 4 ng ra c chc nng tng t nh b POI. 2.4 Kt lun Qu trnh truyn sng trong mi trng trong nh rt phc tp v kh d on chnh xc do cu trc, kt cu, vt liu xy dng ca cc cng trnh khc nhau, mc ch s dng cng khc nhau: sn bay, ga in ngm, vn phng cao tng, khu vc kinh doanh hng ha rng ln... V vy phi cn nhc khi chn gii php thit k sao cho ph hp nht vi tng cng trnh bng cch kt hp linh hot cc la chn trong ba khi thnh phn chnh ca h thng trong nh. Trong nhng nm gn y, cc gii php inbuilding ngy cng c trin khai nhiu v c cc mng di ng quan tm nhm p ng nhu cu ca ngi s dng vng ph mi ni. ng thi y cng l c hi cc nh khai thc m rng vng ph, ci thin dch v, gia tng lu lng mi cho nhng vng m trc y gi l h en do mng macro khng c kh nng phc v c. Vi vng ph trong nh chng ln v cng vi vng ph mng macro s lm tng tng dung lng v vng ph ca ton mng di ng.


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CHNG III: TIN HNH KHO ST V THIT K H THNG PH SNG DI NG TRONG TO NH3.1 Cc bc thit k h thng IBC cho ta nh Sau khi hon tt hp ng cung cp gii php ph sng di ng cho ton nh, th k s s xin bn ch u t bn v kin trc ca ta nh, bao gm c tng hm Vic c bn v kin trc trong tay s rt thun li cho vic thit k h thng IBS: v tr lp t cc anten, h thng i dy cp

Hnh 3.1: Thit k h thng IBS cho ta nh cao tng c th nm r kin trc ca ton nh th bt buc ngi k s cn phi i kho st thc t, v trn bn v kin trc khng th hin ht nhng g trn thc t. Bn cnh , ngi k s cng cn nm r v tr a l ca ta nh (ta nh cao bao nhiu tng, mt tng rng bao nhiu mt vung, v tr t ta nh c gn trm BTS khng), t c phng hng xut ra nhng gii php c tnh kinh t nht, thun li cho cng vic lp t. Quan trng nht trong l vic kho st cht lng mng trong ta nh. Trong qu trnh kho st, da trn vic xem xt cu trc xy dng ca to nh, mt s tng c la chn kho st vng ph sng v kh nng thm nhp sng t cc trm bn ngoi vo cc tng ny a ra cc s liu c th. Thit b phc v cho vic kho st bao gm: My o TEMS8 h tr trn my in thoi cm tay Sony-Erricson K800i.Sinh vin: Phan Quang Trung - Lp: H09VT925

Bo Co Thc Tp Tt Nghip My tnh xch tay IBM T61 vi phn mm o kim Tems 8.

My nh v v tinh GPS. My nh k thut s. Chng ti tin hnh o ba thng s bao gm: Mc thu (RxLev). Cht lng thu (RxQual). T s nhiu ng knh C/I. Da trn kt qu o v kho st hai thng s ny, nh gi chng, a ra kt lun cht lng ph sng trong to nh v t a ra gii php k thut gii quyt vn trn. Lp d n mt h thng ph sng tn hiu di ng bn trong ta nh (Inbuilding Coverage - IBC) l mt qu trnh gm nhiu bc. Tt c cc bc phi c tin hnh mt cch cn thn thu c mt h thng hot ng ti u. Trong chng ny, ngi thc hin n s gii thch tng bc ca qu trnh thit k v thc hin lp t h thng ph sng tn hiu trong ta cao c. H thng ny c thit k da trn cng ngh thng tin di ng GSM 1800 v mng 3G vi tn s 2100MHz. Qu trnh lp d n IBC c chia thnh cc bc chnh sau y. Kho st v nhn dng a hnh ta nh cn ph sng. Kho st trm thu pht gc v tn hiu bn trong ta nh. Lp k hoch v tr. Thit k, lp t v cu hnh thit b. Kim tra v hiu chnh. 3.2 Mc tiu kho st Kho st l mt bc c bn v quan trng trong qu trnh lp d n IBC. Cc thng s quan trng cn cho qu trnh lp d n phi c thu thp cn trng v chnh xc trong qu trnh kho st tng khu vc c th ca ta nh. Qu trnh kho st khng c ngha l mt ai i vo ta nh v i xung quanh khp mi ni, ngoi ra cng c th thu thp cc thng tin cn thit thng qua nh cung cp dch v v ch ta nh. Tuy nhin, mt qu trnh kho st ti thc a s d dng thu thp c thng tin y v chnh xc. Nhng mc tiu phi t c trong giai on kho st: Phm vi ph sng: ton b ta nh hay mt s khu vc nht nh. Khu vc xe c c m rng ph sng trong tng lai, cc khu vc quan trng i vi khch hang. Loi cp: cp ng trc, feeder, cp quang hay loi cp khc. Liu ng dn cp cho php i loi cp c kch thc ti a l bao nhiu, gc un cong cho php ca cp trong ng dn cp. V tr i cp: cch i cp t trm thu pht gc BTS n cc anten, v tr anten i cp d nht, khong cch kt ni. V tr t anten: Liu trn gi c cho php t anten hay khng, tng loi anten c th lp trn trn gi hoc trn tng, loi anten c th (c hng, v hng, nhiu bng tn hoc mt bng tn) c ch nh bi nh khai thc (Operator). S lng anten cn thit cho mt tng, loi ta nh (vn phng, nh my, im

xe, ca hng, trung tm mua sm). Cc tng c cu trc ging ht nhau hay khng,Sinh vin: Phan Quang Trung - Lp: H09VT926


cc php o cn thit. Vic lp nhiu anten c tit kim nng lng hn l vic lp mt anten trung tm tng nh. Ngun nui cho BTS v h thng, bng c quy d phng hay ngun in xoay chiu trc tip. 3.3 Kho st ta nh v nhn dng a hnh to nh cn ph sng Trong qu trnh kho st, cc c tnh sau y ca ta nh cn c quan tm v thu thp thng tin: - Hnh dng : cao v dt, rng v thp, s lng tng, mt bng. - Kch c: Din tch bao ph (m2). - To nh c hay mi s quyt nh vic la chn phng thc truyn dn. Mt s ta nh c khng cho php s dng cc loi cp c trng lng ln, cc loi cp ng trc li to i hi gc un cong ln. Trong khi , cc ta nh mi xy dng, hin i thng c cu trc thng, t un khc, cho php s dng cc loi cp c ng knh ln. - Cc ta nh c sn h thng dy cp (VD: SMF v MMF). 3.3.1 Kiu vn phng cao c

Hnh 3.2: Ta nh cao tng M t chung: Nhiu tng c cu trc ging nhau, hnh thp, mt bng hn ch. nh hng ti IBC: + Thit k tng i gn nh vo lin kt lin tng, lng ng ten cn cho mt sn t. + D lp t IBC nh vo cu trc cc lt sn tng t nhau. + Mc s dng lu lng cao, cn n nhiu tn s, c bn thit k chi tit. + Nu to nh ln th s dng active IBC. + Ngi thit k c th lp k hoch ph sng (bao gm v tr t anten, cng sut ra anten EiRP) cho mt sn, sau p dng tng t cho cc sn khc. Lp k hoch cho tng sn trc tin, sau l ng trc backbone.

3.3.2 Kiu cng xngSinh vin: Phan Quang Trung - Lp: H09VT927


M t chung: t tng, trn cao, cc cng xng, kho bi, bi xe... nh hng ti IBC. + Din tch bao ph ln, khong cch kt ni xa. + Gim s mt ng truyn trong khng gian bi tm nhn quang. + Vic lp k hoch phc tp hn cho cc lt sn khng ging nhau. + Thun li cho vic lp t IBC do khong cch kt ni rng. + Mc s dng c bit thp, s lng thit b truyn ti t.

Hnh 3.3: Ta nh cng xng 3.3.3 Khu trng hc

Hnh 3.4: Khu trng hc M t chung: Gm nhiu to nh c th ni lin kt vi nhau, s lng lt sn hn ch, din tch mt bng hn ch, ging m hnh kiu vn phng, kch c nh hn. nh hng ti IBC: + Lin kt gia cc to nh ln hn, lin kt trong mi to nh tng i t. + Mc s dng cao, nhiu thit b truyn ti. + Thun li cho vic lp t active IBC do khong cch kt ni rng.


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+ C th kt hp m hnh h thng lai Coax/FO. FO ni khong cch gia cc to nh v Coax ni khong cch bn trong mi to nh. 3.3.4 Kiu cu trc phc tp (sn bay, ga tu in ngm)

M t chung: Gm nhiu to nh c cu trc phc tp, kch c v chiu cao lt sn khc nhau, s lng sn hn ch, mt bng rng. nh hng ti IBC: + Khong cch lin kt kt ni xa, c th phn khu. + K hoch chi tit, phc tp do mi trng v kch c cc phng khng ng nht. + Mc s dng cao vi cc trm iu hnh BTS c ni vi mt thit b IBC chung. + S lng thit b truyn ti ln do mc s dng ln. + Thun li cho vic lp t active IBC, cn thit phi c nhiu dch v bng thng.

Hnh 3.5: Cu trc nh ga sn bay 3.4 Tin hnh o cc thng s c bn 3.4.1 o mc thu RxLevel (RF Signal Level) Sau khi kt thc qu trnh kho st to nh, ngi thc hin bo co c th nhn xt v mc thu RxLevel trong to nh l yu. Kt qu thong thng ca my o cho thy, mc thu nm trong khong t 80 dBm n 112dBm. Ti tng hm ca to nh, hon ton khng c sng di ng. Ti cc tng t tng 1 n tng gia ca khch sn, mc thu nm trong khong 80 dbm n -96 dbm. Cc phng nm su trong to nh mc thu RxLevel rt thp, c bit trong thang my hon ton khng c sng. i vi cc tng trn cng, hin tng in hnh ca to nh cao tng l floating xut hin. iu ny c nh hng nghim trng n qu trnh thc hin cuc gi.


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Hnh 3.6: Tn hiu yu ti cc tng thp

Hnh 3.7: V d mc thu c kho st ca mt ta nh 3.4.2 o cht lng thu QxLevel (RF Signal Quality) nh gi cht lng thu da trn cc yu t, l mc thu RxLevel, h s li khung FER (frame error rate), interfere, handover...Sau khi kho st to nh, t kt qu cho thy ti cc tng cao, hin tng handover lin tc xy ra. Trong ton b c to nh,Sinh vin: Phan Quang Trung - Lp: H09VT930


lu lng cuc gi lun mc cao. Kt hp 2 yu t ny dn n tnh trng rt cuc gi khi chuyn giao rt cao. T l cuc gi thnh cng rt thp. Chng ta thy r hin tng handover xy ra lin tc trong th bn di. Ngng ch tiu RxQual < 2 trong tng s 90% mu tn hiu o.

Hnh 3.8: Cht lng thu ca ta nh

Hnh 3.9: Handover lin tc xy ra ti cc tng cao ca to nh 3.4.3 o t s cht lng thoi SQI (Speech Quality Index)Sinh vin: Phan Quang Trung - Lp: H09VT931


SQI c tnh ton trn c s t l li bt (BER), t l li khung (FER), cc s kin handover v vic s dng DTX trn mng. Ngng ch tiu: SQI >20 trong tng s 90% mu tn hiu o.

Hnh 3.10: Ch s SQI thp 3.4.4 o t s nhiu ng knh C/I Theo khuyn ngh ca GSM gi tr C/I b nht m my di ng vn c th lm vic tt l 9 dB. Trong thc t, ngi ta nhn thy rng gi tr ny cn thit phi ln n 12 dB ngoi tr nu s dng nhy tn th mi c th lm vic mc C/I l 9 dB. mc thp hn C/I th gi tr BER s cao khng chp nhn c v m ho knh cng khng th sa li mt cch chnh xc c.

Hnh 3.11: Ch s C/I thp khi xy ra handover 3.5 Kho st trm thu pht gc v tn hiu bn trong ta nh


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Phn ny a n cho ngi lp k hoch nhng tham s quan trng ca mt trm thu pht kt ni n h thng IBC. Tt c cc d liu phi c thu thp t cc nh cung cp dch v c th. Vi s hiu bit su sc v bn cht ca trm thu pht gc, ngi lp k hoch s cu hnh mt cch chnh xc v hiu qu v khng lm nh hng n cu trc mng BTS ca cc nh khai thc mng. Ngi lp k hoch cng c th thuyt phc nh khai thc s dng loi BTS cng sut thp, gi r, u t nhiu hn vo cc thit b IBC. 3.5.1 Cu trc BTS dng trong indoor c c mt thit k IBC ti u, cn phi la chn chnh xc loi BTS c s dng, ghi ch cc tham s quan trng ca BTS cng nh kt ni cu trc bn trong ca n, chng loi b thu pht v v tr t trm. Cc tham s sau y cn c quan tm cho qu trnh lp k hoch: - Cc loi h thng truyn thng di ng (GMS 900/1800/1900, bng thng kp, TDMA, CDMA, IDEN, ...). - S lng sng mang (tn s) cp cho trm, cng sut pht ca tng sng mang ti cng kt hp, nhy thu. - V tr BTS (ti tng no, khong cch n ng cp trc), cu hnh kt hp ca BTS (ghp TRX, sector, ), kh nng kt hp nhiu Operators. - Kh nng m rng trong tng lai, s lng sng mang ti a, m rng bng tn (bng tn n, bng tn kp). Ngi thit k s kho st BTS cng sut thp vi b ghp th ng: Mt BTS mini hay micro c cng sut pht ra khong 43 dBm (18W) c 4 sng mang ng ra kt hp b LNA hng ln iu ny s lm cn bng cng sut gia BTS v MS. Mt MS in hnh c cng sut pht cho hng ln l 30 dBm v nhy thu ca hng xung l -104 dBm cho h thng GSM, bn cnh , nhy thu ca BTS l -113 dBm. Hin nay cc nh khai thc di ng Vit Nam thng dng cc loi BTS trong indoor. Bng 3.1: Cc loi BTS thng dng trong Indoor Tn Tn s hot ng Cng sut pht ti Hng sn xut (MHz) a (dBm) Horizon II mini Indoor 900 63 Motorola RBS 2206 900/1800 63 Ericson RBS 3216 2100 45 Ericson 3.5.2 Lu lng ca h thng Vic tnh ton lin quan n dung lng ca BTS theo cch thng dng s do nh khai thc thc hin, cho nn ngi lp k hoch IBC khng nht thit phi tnh ton. S lng sng mang thng do nh khai thc a ra, v ngi lp k hoch IBC khng phi tnh ton. Tuy nhin, phn ny s gip ngi lp k hoch IBC hiu su hn yu cu v lu lng ca nh khai thc t tnh ton c i vi mi to nh s cn bao nhiu tn s v ng thi nm c nhu cu m rng h thng IBC trong tng lai. 3.5.2.1 Lu lng


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Lu lng c nh ngha l t s gia cuc gi trung bnh trn cng phc v trung bnh. Khi lu lng ca mt thu bao A c tnh theo cng thc sau: ??? = ???.???.1 3600

Trong : A: lu lng thu bao A n: s cuc gi trung bnh trong mt gi T: thi gian trung bnh ca mt cuc gi tnh bng giy (s) V d: Tnh lu lng ca thu bao A trong mng GSM c trung bnh 1 cuc gi 15 pht trong mt gi, khi lu lng ca thu bao A s l: ??? = ???.???.1 =0.25????????? 3600

Vi n = 1 v T = 15.60 = 900 (s). Nh vy, phc v cho 1000 thu bao ta cn mt lu lng l 25 Erlang. 3.5.2.2 Mt s nh ngha cho m hnh Erlang + H thng tiu hao: y l h thng m cc thu bao s b t chi thc hin cuc gi khi h thng y ti + H thng theo kiu i: y l h thng m cc thu bao s c ch thc hin cuc gi khi h thng y ti. + n v lu lng: Erlang l n v o mt lu lng. Mt Erl m t tng lu lng trong mt gi. + Cp phc v (GoS): l i lng th hin s % cuc gi khng thnh cng i vi h thng tiu hao. Cn trong h thng i th GoS l s % cuc gi thc hin ch gi li, mng hot ng vi hiu sut cao th mng cellular thng c GoS = 2 % ngha l ti a 2% lu lng b nghn, ti thiu 98% lu lng c truyn. M hnh ERLANG B

y l m hnh h thng thng tin hot ng theo kiu tiu hao. Thu bao khng h gi li khi cuc gi khng thnh. ng thi gi thit rng: Xc sut cuc gi phn b theo lut ngu nhin Poisson, s ngi dng rt ln so vi s knh dng chung, khng c knh d tr dng ring, cuc gi b nghn khng c gi li ngay.

Hnh 3.12: Xc sut nghn GoS M hnh Erlang B l m hnh thch hp hn c cho mng GSM. T cc cng thc ton hc, ngi ta lp ra bng Erlang B cho tin dng. V d: S knh dng chung l 10, GoS l 2%. Tra bng Erlang B ta c lu lng mun truyn l A = 5,084 Erl. Vy lu lng c truyn l:Sinh vin: Phan Quang Trung - Lp: H09VT934


A.(1 - GoS) = 5,084*(1 0,02) = 4,9823 Erl 3.5.3 Kho st tn hiu bn trong ta nh i vi mng GSM: -o mc thu RxLevel ( RF Signal Level ). -o cht lng thu QxLevel ( RF Signal Quality ). -o t s cht lng thoi SQI ( Speech Quality Index). i vi mng WCDMA: - CPICH Ec/No : l t s gia mt cng sut ca tn hiu CPICH trn mt cng sut ca ton bng tn. Thng s ny c s dng cho vic chn cell v cc th tc handover. Mc ch tiu Ec/No -10 dBm trn 98% din tch ta nh. - CPICH RSCP : l tn mc cng sut ca m tn hiu nhn c da trn cc bit ca knh CPICH, y l cng sut ca mt chip ch khng phi cng sut ca bit d liu. Ngoi vic phc v cho chn cell handover, thng s ny cn c s dng cho vic tnh ton pathloss cng nh iu khin cng sut trong mng. Mc ch tiu RSCP -90dBm trn 95% din tch ta nh. Khi UE ang hot ng n lun o kim v gi bo co cht lng tn hiu v cho RNC thng qua knh CPICH vi hai thng s RSCP v Ec/No ca tn s ang hot ng RNC c th thc hin th tc Handover cho UE. - PathLoss l chnh lch gia cng sut pht v cng sut thu ca tn hiu CPICH, phn nh cht lng ng truyn v c s dng khi to mc cng sut cho PRACH v qu trnh handover gia hai tn s. 3.6 Cc thng s cn thit lp k hoch v tr 3.6.1 Cc tham s v ta nh Khi lp d n cho IBC, cc thng s chi tit v ta nh cn c thu thp. Cc thng s l: Nhng khu vc cn c ph sng, nh du nhng khu vc ny trn s bn v. Din tch sn (v d 50 x 50m) hoc din tch khu vc cn ph sng, xc nh t l ca bn v hoc xc nh mt kch thc chun trn bn v. Chiu cao ca mi tng (thng thng l 4m). Vt liu ca sn, tng, trn cng nh l dy ca chng. S lng v v tr ca vch ngn, nh du v tr trn bn v. V tr ca mng cp, cc khu vc cho php hoc khng cho php dy cp i qua, nh du cc khu vc ny trn bn v. Xc nh tng loi cp cho cc khu vc c th. Xc nh v tr c th t anten, cc khu vc khng cho php t anten, cc v tr trn v tng cho php mc antena, chng loi anten, s lng anten cn thit (cng sut trn mi anten/ sng mang), v tr ca trn gi nu c. V tr ca ng cp chnh. V tr t BTS, nh du trn bn v. Tt c cc thng tin trn cn c nh du trn bn v ta nh.Sinh vin: Phan Quang Trung - Lp: H09VT935


3.6.2 Cc tham s lp k hoch Trong cc phn trn, thng tin v to nh, BTS, thit b h tr c thu thp. hon thin thng tin, thng s lp k hoch cho tng to nh c th v cho tng nh khai thc c th cn c xc nh. V nhng thng s ny thay i theo tng trng hp v khc nhau gia cc nh khai thc dch v. Chng phi c xc nh trc khi tin hnh lp k hoch IBC. Cc thng s cn cho thit k IBC nh sau: - Phn trm din tch cn bao ph (thng thng > 95%) - Mc thu thit k ( tiu chun GSM > -85dBm). - ERP ti a cho php/ng ten/1 sng mang. Mc thu thit k c tnh ton thng qua nhy thu ca my di ng, d phng phading, v suy hao bi c th ngi. suy hao ny l tham s m tn hiu pht ra t my di ng hoc tn hiu thu c t trm BTS ti my di ng s b suy hao bi u v thn ngi thu bao. d phng phading c a vo php tnh suy hao v c nhng im phading su. Thng thng suy hao thn ngi l 5 n 10dB, cn d phng phading l 10 n 15 dB. nhy thu ca my di ng c tnh nh sau: S = -174dBm + 10 log(NBW) + SNR + NF Trong : - 174 dBm l nhiu nhit. - NBW: nhiu bng thng. - SNR: h s tn hiu/nhiu. - NF: h s nhiu ca my di ng. Bng 3.2: Cc gi tr tham s in hnh NBW(10logNBW) GSM IS-136 NMT AMPS IS-95 200KHz (53dB) 30KHz (45dB) 25KHz (44dB) 30KHz (45dB) 1.5MHz (62dB) SNR 9dB 17dB 18dB 8dB -15dB NF-MS 8dB 8dB 8dB 8dB 10dB MS Typical Sensitivity level -104dBm -85dBm -104dBm -104dBm -103dBm -117/-115 -85dBm -85dBm -85dBm -90dBm

Cc tham s khc: Din tch vng ph sng: 95 ~ 100% din tch ta nh. Mc thu RxLevel: > -85dBm cho mng GSM. Cng sut pht cc i ti mi antenna indoor/sng mang:10 ~ 20 dBm. Cng sut ti u ra ca BTS: 33 ~ 43 dBm. Di tn : GSM1800 MHz v 3G WCDMA 2100MHz GoS: 2%. Lu lng cho mt thu bao: 25mErl. 3.7 Thit k, lp t v cu hnh thit b cho h thngSinh vin: Phan Quang Trung - Lp: H09VT936


3.7.1 Thit k tng quan Sau khi hon tt vic thu thp tt c thng tin v to nh, v BTS v cc ch tiu tham s cho thit k, chng ta c th bt u vi vic t k hoch. Trc ht ngi thit k phi chn mt h thng phn phi. i vi nhng to nh ln c nhng ng ni di (>200m) hoc nhiu tng i hi cng sut cn bng,n nh, h thng phn phi tch cc c khuyn co s dng v gi thnh thp ca cp si quang, chi ph lp t thp. i vi nhng h thng nh hn v ng ni ngn hn, s lng anten t (Hybrid Combiner/ POI --->Feeder --->Amplifier---->Feeder---->Anten


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Hnh 4.8: M hnh h thng IBS theo trc ng Tn hiu t trm BTS s c cho qua b ghp kt hp. B ghp kt hp( Hybrid Combiner ): C tc dng kt hp t 2 nh khai thc mng dng chung mt h thng. i vi nhng ta nh ln phi dng Amlifier khch i tn hiu (ng ngha vi vic nu Amplifier khng tt s khch i c nhiu). Sau khi qua Feeder cable s dn n h thng anten cc tng ca ta nh. Sau khi kho st xong, cng vic tip theo l bn b phn thit k h thng. Ty vo s tng cng nh din tch mt bng ca cng trnh m ngi k s quyt nh c s dng repeater hay khng. Vic tnh ton phi ht sc k lng gia vic s dng nhiu anten hay vic s dng repeater (tng cng sut pht lm tng vng ph sng ca anten). Trnh t cng vic c th nu ngn gn nh sau: Da trn bn v kin trc ca ch u t cung cp cng vi vic kho st thc t ta nh, ngi k s s bit c cc v tr thch hp t cc nten (thng thng l cc hnh lang, t khi t trong phng hay trong cn h). y, ngi thit k dng phn mm Auto Cad m cc file kin trc, sau lc b ht cc lp ni tht, lp text ch dng lp ARC-PLAN l lp kt cu tng nh. Sau th v thm lp t cc nten v i dy t BTS Room n cc anten. T bn v ngi thit k bit c chiu di dy cp t l bao nhiu (da trn t l bn v so vi thc t).


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Hnh 4.9: S b tr v tr t anten tng hm Ty theo tng tng c kt cu b tng khc nhau (dy hay mng, nhiu hay t tng chn th suy hao khc nhau), din tch khc nhau s a ra cc gii php khc nhau. Dng loi nten no (v hng hay c hng), s lng bao nhiu, i dy cp t h thng cp ng n nten (cp ng loi 1/2hay 7/8). Nu ton nh trn 15 tng th phi dng cp quang ( suy hao t). Trn l thuyt nu dng ton cp quang cho vic i dy trc ng th s cht lng tt hn nhng b li tnh kinh t khng cao v phi s dng cc b bin i quang sang in, in sang quang, kh khn trong vic bo tr dy cp (cp ng bn hn cp quang).


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Hnh 4.10: S hnh cy h thng phn phi anten

Hnh 4.11: Hnh m phng vng ph sng ca cc anten Nu dy feeder cng di th suy hao t BTS n thit b bc x cng ln. Cng sut ti nten cng ln th vng ph sng cng rng, tt nhin phi d tr suy hao do b nh hng ca cc bc tng b tng. V cng ty vo hnh dng ca mt bng, iu kin cho php m c th dng thm cc anten c hng tng cng.


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Hnh 4.12: Hnh m phng vng ph sng ca cc anten (c dng anten c hng) 4.2.6 Lp t phng BTS room Phng BTS thng c t tng hm hay tng thng ca ta nh. Sau c c ngun tn hiu bng phng php truyn dn v tuyn hay hu tuyn th dn xung phng BTS bng cp ng hay cp quang.

Hnh 4.13: Truyn dn v tuyn t BTS gn nht ca nh mng n phng BTS Ty vo s lng ngi dng cn c ph sng vi kt cu ta nh m ngi thit k c th s dng cc thit b ph tr: RF repeater, Wideband in line Boosters, Fibre Optic Repeater, Combiner..


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Hnh 4.14: La chn thit b ty theo tng mi trng kt hp tn hiu ca nhiu nh mng khc nhau, c th dng thit b combiner kt hp sng li vi nhau. Hin nay ti Vit Nam c thm mng 3G th phi dng thit b a nng hn, in hnh l Multiband Inbuilding Solution Point Of Interconnects.

Hnh 4.15: Thit b POI ca hng Comba


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Hnh 4.16: S thit k h thng ca IBC th ng ca ta nh 4.3 Kim tra cht lng tn hiu khi h thng IBC i vo hot ng Sau khi ngi thc hin n hon thnh mt h thng IBC s a h thng i vo hot ng v phc v cho cc thu bao trong ta nh. Ngi thit k s tin hnh tng bc kim tra cht lng tn hiu bn trong ta nh. o mc tn hiu trong ta nh:

S dng my o TEMS, NEMO hoc my in thoi c chc nng hin th tham s mng o. Cc im chun c xc nh nh sau: Di tt c cc anten cc tng. Cc khu vc nh: cu thang b, vng bin ca ta nh. Ti thiu 200m2 phi th hin c mt im chun. Mc thu yu cu i vi tng h thng: i vi h thng 2G: mc thu di anten: Rxlevel: -55dBm Vng bin ta nh: Rxlevel: -85dBm i vi h thng 3G: mc thu di anten: RSCP: -70dBm Vng bin to nh: RSCP: -95dBm o cht lng thoi (SQI) v cht lng thu (RxQual): Mc thu RxQual = 0. Ch tiu SQI cho cuc gi half rate phi t gi tr ti thiu l 17, i vi cuc gi full rate l 21, i vi Enhanced Full Rate l 30. Kim tra cht lng ph sng trong thang my: Thc hin cuc gi bn ngoi thang my ti tng thp nht v i vo thang my th cuc gi vn tip tc khi thang my di chuyn ln n tng cao nht. Ra khi thang my trong khi cuc gi vn kt ni, khng xy ra rt cuc gi.Sinh vin: Phan Quang Trung - Lp: H09VT955


Mc thu RxLevel trong thang my phi -85 dBm. Mc thu RSCP trong thang my phi -95 dBm. nh gi v t l thit lp cuc gi v chuyn giao T l thit lp cuc gi thnh cng (Call Setup Success Rate) 98%. T l rt cuc gi (Drop Call Rate) 1%. T l chuyn giao cuc gi (Handover Success Rate) 98%. Handover 3G sang 2G trong trng hp thu bao i t trong ta nh ra ngoi ta nh. 2G sang 3G ch p dng trong trng hp IDLE MODE (thu bao chuyn vng t 2G sang vng 3G s cp nht ngay vo 3G khi sng ln). Kim tra h thng anten, feeder S dng my o (Wiltron Sitemaster hoc Bird Site Analyzer) kim tra cht lng Anten/feeder theo thng s ca nh sn xut. Yu cu h s sng ng 1.3 (VSWR 1.3). Kt qu kim tra chi tit vng ph sng cc tng. S dng my TEMS, NEMO hoc tng ng walking test. Thc hin 2 mu cuc gi cho 100m2 (ty vo din tch tng m c s mu cuc gi tng ng). Cc cuc gi c thc hin trong khong thi gian 60 giy, thi gian ngh gia 2 cuc l 5 giy. Cc cuc gi phi c thc hin t cu dng lnh my o. Mc thu RxLevel -85 dBm trn 98% din tch ta nh. Mc thu RSCP - 95 dBm trn 98% din tch ta nh. Mc thu Ec/No - 10dBm trn 98% din tch ta nh. Kim tra dy cp H thng DAS sau khi c lp t bn trn tng th kh c th bit c cht lng ca cp. Trong nhiu trng hp sng yu hay khng c sng th nguyn nhn ch yu l o cp gy hay u connector lm khng ng k thut hoc anten b h hng. bit c nguyn nhn do u th, ngi k s c th dng my o h s sng ng kim tra. Mi anten u c thng s v h s sng ng ty theo tng bng tn. V d: Anten Omni thng c h s sng ng khong

Hệ Thống Phủ Sóng Di động trong tòa nhà IBS

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