Phan 4 m ng truyen dan

, , "LffiNOIDAU Nhfun giup h,rcluc;mgky thu~t cua TAngCong ty M~g lucriViertel nfun duQ'c cac thu~t ngfr, khai ni~m ca ban trong ky thu~t viSn thOng, TAng Cong ty M~g lucriViertel ban ha

, , "

LffiNOIDAU

Nhfun giup h,rcluc;mgky thu~t cua TAngCong ty M~g lucriViertel nfun duQ'c cac thu~t ngfr, khai ni~m ca ban trong ky thu~t viSn thOng, TAng Cong ty M~g lucriViertel ban hanh tai li~u "sA tay kY thu~t vi~n thong- Quy~n 1 -Cae thu~t ngfr kY thu~t vi~n thong" danh cho can be)va nhan vien ky thu~t dang lam vi~c trong T6ng Cong ty.

Tai li~u dS c~p dSn cac thu~t ngfr, khai ni~m lien quan dSn cac lInh VVCViertel dang khai thac, duQ'cbien so~ theo tieu chi chinh xac, dS hiSu, ng1fugQn

va co anh x~ vao m~ng lucricua Viettel Ne)idung tai li~u bao g6m 8 phfrn:

Phfin 1:TAng quan m~ng vi~n thong.

Phfin 2: M~ng di o{)ng.

Phfin 3: M~ng e8 oinh.

Phan 4: M~ng truyen dan.

Phfin 5: M~ng truy~n tai IP.

Phan 6: H~ tang.

Phfin 7: CO"oi~n.

Phfin8: Phfin m~m quanly kYthu~t.

Cac d6ng chi can be)va nhan vien ky thu~t cua TAngCong ty co thS tim dQc ULili~unay theo cac ngu6n:

1 PhfrnmSm quan ly tai li~u: hrtp://tailieu.viettel.vn.

2 Lien M trgc tiSp vcriPhOng Ky thu~t Cong ngh~ - T6ng Cong ty M~ng lucriViertel.

Vcri xu thS cong ngM phat triSn khong ngimg, PhOng Ky thu~t Cong ngh~ kinh mong nh~n duQ'cy kiSn dong gop til de)ingii ky thu~t Viertel dS tiSp tvc b6 sung, hoan thi~n tai li~u cho phu hgp han trong qua trinh phat triSn mlimglucri MQi y kiSn dong gop xin gui vS PhOngKy thu~t Cong ngM - T6ng Cong ty Ml;\ng lucri Viertel theo email: kt_vtnet@viertel.com.vn ho~c s6 di~n thol;\i:04.62660291

MUCLUC

if

DANH MVC T VIET TAT •••.•• •• •• •.• •.•• • •.• • • ••• •• •.• • •.•.• 3

C'ac ",a, nlfm Cd an cua m{lng Vlen k l "'A b •• :: th ong• ••••••••••• ••••••••••••• •••••••••• ••••••••A 5 pHAN 1 TONG QUAN M;NG VIEN THONG •.• ••.• •• •• • •.• 5

L IL M {lng vien tllong Viettel .• • • • •.• ••• • ••.••• • • • • • 7

IlL Mvt sa d{mg iluifng iii clia cuvc g{Ji thoq,i (Call flow) • • •••.• • •• • 10

. .

-PHAN 2 MANG DI BONG •••• •.•.• • •.••••• •.• •• •• • •.• . , . 11.

A M {lng vo tuyen • ••• •• •• • • • • ••• •• ••• •• ••.• • •• 11

L Khtii ni?m ch ung •••• • • •• • •• • •.•• •• •••.•• •.•.• •11

, 1 Nh6m kl,tii ni?m ve vung phil • • • • ••• •• ••••• • •11

, , ", ~" . '" 2 Nhom kllal nlf!m ve tal nguyen • •• •.•.• • •••.•• •• • • • •• • • 12

3 Nhom khai nifm vi hanh vi tieu dung • 13

4 N"om "I' kh' '" al nlf!m ve tin ~, h.'" If!U•.•.•• •••••.•••.• ••••••.• • •••••.••••• •••••••••••.•.••••• •••••.••••.•.• 14

, M {In g vo t uyen 2G •• ••.•.• •.• • •• •• ••• • •.•.• 15

, , Thanl, phlin m{lng vo tuyen 2G • •.• •• ••• • ••.• •.15

Khai nifm vi tai nguyen, dung IU(lng mq,ng 2G • 15

Vh"'A ~ vu' h • 17 .ll.j al nl{!m ve ng p U••••••• • •••••••.• •••• •••••••••••• ••• ••••••••••• • ••••.•

, " M~t so khdi ni?m ve chat lu(11tg d;ch v(l •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 19 , M (lng vI) tuyen 3G •.• •.•.• • •••.• • • • • • ••.••.••• • • •••.•• •.•.• 20

IL 1 2 3 4 IlL , 1 Thanh phlin m{lng 3G.• •.•• • • •.• ••.••.•• • • ~O 2 Khai ni?m vi tai nguyen, dung lu(11tg 36 20 , ", ~" h • 21 :J Khal nlf!m ve vung p u ~~ • • • • • • •• ~• •• • •.•

, , , 4 M~t so khai ni?m ve chat lU{lng dich v{l •• • • •••• • ••• • ••.•.••.• •23

5 M~t sli hanh i/~ng tlii leu.• •• •.•• • • • • •• •• • ••• • 25

B M {In g loi di il~ ng •.••• •••••••• • •.••••••.••.•.• •••••.•.••.•••••• •• • •••••••• • ••••••.•.•• •••••27

, L Thiinh p han•.• •••• • • ••.•.• • • • • • ••• • •••.• •2 7 1 Mq,ng CS (Circuit Switching - M{mg chuyin mq,ch kenh) 27 2 Mq,ng PS (Packet Switching - M{mg chuyin mq,ch goi) 27 3 Mq,ng VAS, IN (Value Added Services, Intelligent Network) 28 IL Khdi ni?m chung 29 '" ~" '" 29 1 Khdi nifm ve tal nguyen • • • •• • •• •.• •.•• • • •.•

, '" ~"h"A d' 29 2 Khal nlf!m ve han VI tleu ung • • •.•• •.•••• • •.• •• •

IlL Cac chi tieu ilanh gia chat IU(lng mq,ng /Oi • 30

1 M {lng CS • • ••• •.••.• •.•• • •• • • • • •.•.• •• •• •• • 30

, -Cong ngh? tTuyen dan s{li quang • •• : •.• • •.• •.• • •.•• 43

, -M f!ng IT uyen dlin Viettel •• •.•.•• • •.• • • • •.• • • •50

, IV Thiet bi va ph!, ki?n trong phong mdy ••.• • ••.•.• • •• ••52

2 M {lng PS 30 3 M {In g VAS, IN ••• •.•.• •.• •.•• •• • ••••• • • • •••.••31

pHAN 3 MANG~ CODINH ••.•• • • •• • 32.~ - .

PHAN 4 M;NG TRUYEN DAN • • • •.•• •.••• • • ••• • • ••36

L Cap quang, ph(l ki?n cap quang ••.•.•.• ••• • • • •.•.•.•• • •• •.• 36

IL

IlL

1

Ouvin 1:Cae thutit ngu kf thutit viin thOng MUCLUC

Mpi sokhdi n i?m ch ung ••.• •.• •• •.• • • • •.•.••.•.•• ••.•.• •• • •.59

Cae dich vu tren mang IP Viettel •.• • •• •• • • •• •., , . .

PHAN 6 H~ TANG •• •.• • • • •.• • ••• • ••.•.•• • •

-PHAN 7 CO DIlJN • •• •• • •• •.••••.•• •.•• • •.• •.•

H? t/Jong tiep ddt clJong set •.•• • ••.•.• •.•.•• •.••••• • •.•• 86

M tiy ph tit ili?n • •.•.•.• • ••.• • • • • ••• ••.••• •.••••• • •

Ouvin 1:Cae thuat ngu Jdithuat viin thOng

Danh muc tir viit tiit

~ffli~:i~t:I~t~ll~iJ~~r~'li~3j~tt~!:~g~!t[~gi~~ ;5i~~~;~{)~1~[~~~g!yi~tjfr@'g';g~llii~~vt~~iM1;;

mobile network generation)

mobile network generation)

Line

Center

Communications

Access

3

Oupin 1: Cae tltutlt ngir Iff tltutlt viln thOng Danlt mue tir viit tdt

,;,+<4';,- ",.;i"~;I:'i:.~\'" 7 i'i';J":~':'~-, ' i

;~'2';;ii;i!@~gj1f9g~;#~Ii~:;~~«';i!,:<?t'< :'!;;S~~~~~S~lsrig~i~t'tti9Jj:~:a{f~~g:bZ?~;;:;~'

"~\:Vietetiit'1\i,

,tOi:!;'~;~"'-,_;',:",i" _._.;'~~?i

STM-l Synchronous Transport Module 1 Kh5i truyen tiii d6ngbQ Clip 1, t5c dQ

155,529 Mbps

CUOl

Quyin 1: Cae thuq.t ngir kjJ thupt viin thong Phan 1 Tang quan mfJng viin thOng

I Cae khai ni~mcoo ban ella m\lng vi~n thong

Khlii niem/Dac di~m

La t~p hqp thiet bi vi€n thong duqc lien ket voi nhau bangdUOng truy€n dan d6 cung cAp dich Vl,lvi€n thong, dich Vl,lUngd\ll1g vi€n thong

La dich Vl,lgiri; truyen, nh~ va xu lythong tin giua hai ho~cmOt nhom nguai su dl,mg dich Vl,lvi€n thong, bao g6m dich Vl,l

co ban va dich Vl,lgia tri gia tang

La dich Vl,l su dllng dUOng truyen diin vi€n thong ho~c m~gvi€n thong d6 cung cAp dich Vl,lUng d\ll1g trong linh VlfC congngM thOng tin, pMt thanh, truy€n hinh, thuong m~i, tai chinh,ngan hang, van Ma, thong tin, yte, giao dllC va linh vl1'CkMc

La dich Vl,lduqc truyen ruc thai thong tin qua m~ng vi€n thOng(bao g6m ca Internet) rna khong lam thay d6i lo~i hinh ho~cnOi dung thOng tin Day la lo~i dich Vl,lt6i thi6u (dan giannhAt) rna nha cung cAp dich V1,l cAp cho khach hang, dl1'a trennang ll1'Cco ban Clla nha cung cAp dich Vl,l

La dich Vl,llam tang them gia tn thong tin clla nguai su dllngdich Vl,lb~ng cach hoan thi~n lo~i hinh, nOi dung thong tinho~c cung cAp kha nang lUll trU, khoi phllC thong tin do tren co

sa su d\ll1g m~g vi€n thOng Nhiing dich Vl,lnay thu~ ti~nhan cho nguai su d\ll1g, khong chi ket n6i thiet bi dliu cu6i, cokha nang cung cAp rOng khfrp va tinh cuoc linh ho~t

La doanh nghi~p duqc thanh l~p theo pMp lu~t Vi~t Nam vaduqc cAo giAy ohep kinh doanh dich Vl,lvi€n thOng

La to chuc, ca nhan cung cap dich Vl,lvi€n thOng cho nguai sudllng dich Vl,lvi€n thong thOng qua hqp d6ng d~i ly kY vmdoanh nghi~p vi€n thong d6 huang hoa h6ng ho~c ban l~i dichVl,lvi€n thong d6 huang chenh l~ch gia

La to chUc, ca nhan giao ket hqp dong su dllng dich Vl,lvi€nthOng voi doanh nghi~p vi€n thOng ho~c d~i ly dich Vl,lvi€nthOng

La nguai su d\ll1g dich Vl,lvi€n thong co gan voi vi~c an dinhtai nguyen vi€n thong ho~c dUOng truy€n diin vi€n thOng Cllth6

La thiet bi ky thu~t, bao gom philn cUng va phan mem, duqcdung d6 thl1'c hi~n vi€n thong

La thiet bi vi€n thOng co dinh ho~c di dOng duqc dau noi vaodi6m ket cu6i clla m~g vi€n thOng d6 giri, truy€n, nh~ va xU

IvthOng tin clla nguai su d\ll1g

La thiet bi dliu cu6i clla thue bao vi€n thong

La thiet bi vi€n thong duqc lap d~t tren m~g vi€n thong debao dam vi~c cung cAp dich.Vl,l vi€n thong

La t~p hqp thiet bi vi€n thOng dung de xac l~p mOt phan ho~c

Quyin 1:Cdc tltuf.t ngir kgtltuf.t viln t/tOng Pltlin 1.Tang quan m(Jng viln t/tOng

M~g truyen dan dong vai tro rat quan trQng trong cac Mth6ng vi~n thop.g Nola n6n tang, la cO"sa h~ tfrng cho vi~cth\Ic hi~n truyen tai thong tin, dich Y\l

D\Ia vao moi truOng truy6n dfut rna phan thanh hai 10~i:

Truy6n dfut hfru tuy€n va truy6n dfut vo tuy€n

- Truy6n dfut ~fru tuy€n: ,ThuOng su d\lng hai 10~itruy6n dfutquan U:Qng_nhatla c~p dong va cap quan¥

- Truyen dan vo tuyen: Trong m~g truyen dfut Viettel su d\lUghai 10~itruy6n dfut vo tuy€n la: vi ba, VSAT

t/tOng

d~t vao do

qUY6nquan Iv cua Vi~t Nam

t/tOng

va su d\lUg dich Y\lvi~n thong

La ~p hQ'Pten va so thui)c quyen quan 1:9cua Vi~t Nam duQ'c

Internet

m~g va ten, s6 khac theo quy diOOcua cac t5 chUc vi~n thong, ,

va Internet quoc teo

La tooo bQ dai tan so vo tuyen di~n

GHz truy6n Ian tv do trong khong gian, khong co dfut song

tuyen ili?n

OOant~o

La thaOOphan cua m~g vi~n thong ?o chUc nang thiet l~p mQtkeOOphil hQ'Ptil mQt thue bao mlY den mi)t thue bao khac.Trong m~g di~n tho~i, phfut chuy~n m~ch duQ'cgQi la cac

21

tren cac m~ch ket noi cac tong dai v6i OOau

Hi~n nay, co 2cong ngh~ chuy~n m~ch dang duQ'cap d\lUg

Do la cong ngh~ chlly~n m~ch kenh (CS - Circuit Switching)

va cong ngM chuy~n m~ch goi (PS - Packet Switching)

Trong m~g vi~n thOng, h~ thong bao hi~u duQ'ccoi la mi)tphuang ti~n d~ chuy~n thong tin va cac l~nhtil di~m nay d€n

Iti?u

chuc nang chiOO:

- Chuc nang gilim sat (gilim slit dUOng day thue bao, trungk€ )

Quyin 1:Cae thuqi ngit kY thup-t viin thOng Phlin 1.rang quan m{lng viin thong

- ChUc nang tim chQn (dieu khien va chuyen thOng tin dia chi)

- ChUc nang khai thac va v~ hanh m~g

Khlii niem!Dac diem

M~g di dQng Viettel duQ'cchia lam 4 lap:

- Lap nguai dimg: G6m thiet bi 'd~u cu6i nguai dung, thiet bi didQng

- Lap truy nh~p: G6m cac tn;un BTS, BSC (m~g 2G), NodeB,

GMSC, STP, cac nut h6 trQ'GPRS (SGSN, GGSN)

- Lap tmg d\lng: Cac Mth6ng m~ng thong minh (lN/OCS), cac M

th6ng quan ly tin nhilo (SMS/MMS), va cac h~ th6ng dich V\l giatri gia tang khac (CRBT, MCA, BGM )

- Lap truy nh~p (Access Layer): La lap tf\!c tiep ket n6i vai cacnode access cua cac m~g dich V\l (BTS/Node B, DSLAM, PSTN,khach hang thue kenh ) Dung luqng: STM-l, STM-4

- Lap nQi tinh (Provincial Layer): La lap lOi cua tUng tinh,ket n6ilap lien tinhva lap truy nh~p, chuy~n tai lUll luqng dich V\ltlr lap

truy nh~p len lap lien tinh (dung lUQ'ngSTM-16 tra len).

- L6'p lien tinh (Inter-Provincial Layer):np trung lUll luqng dichV\lacac tinh/ thanh ph6, chuy~n tai v~ cac trung tiim dich V\lt~icac thanh ph6 Ha NQi, Da N~ng, H6 Chi Minh (dung lUQng400Gbps, hi~n t~ chi dimg 50 Gbps)

- Lap tf\lC qu6c gia (National Backbone Layer): Ket n6i lUll luqngcac vimg mi~n, truy~n tai dich V\lB~c-Nam, ket n6i cac hu6'og diQu6c te (dung luqng N x STM-64)

M~g truyen tai IP Viettel thlJC hi~n truyen tai toan bQ lUll luqngdich V\l c6 diM (ADSL, FTTx, IPTV, Office WAN ), dich V\1 didQng2G/3G (tho~i, dft li~u, dich V\l gia tang) M~g truy~n tai IPduQ'c chia lam 04 phan lap:

- M~g truy nh~p Metro Ethernet: ThlJc hi~n gom toan bQ lUll

MPBN

- M~g IPBN: Truy~n tai lUll luqng dft li~u nQi m~g, trong nuac

va qu6c teo

- M~g MPBN: Truy~n tai lUll luqng tho~i 2GI 3G

- M~g DCN: Giam sat, auan Ivcac M th6ng vi€n thong

- DSLAM: T~p trung duang day ADSL va Leasedline (dung luqngnho) cua cac thue bao

- Site Router:

• Ket n6i den DSLAM, Node B, Leasedline (dung luqng 16'0),cackhach hang su d\lOg dich V\l cap quang va chuy~n dft li~u tlr caethanh phk d6 len m~g laL

- Core xii, Core huy~n, Core tinh, Core khu VlJC:

• np trung lUll luqng tlr 16'pduai va chuy~n len 16'ptren

Quyin 1:Cac thul)t ngil kjithul)t viin thOng PhOn 1.Tang quan mgng viin thOng

a thue bao co th~ lien l~c chi~u gQi di, su d\lllg cac dich Y\l gia tri

ia tang (GTGT - n€u con ti~n) va nh~ lien l~c chi~u gQi d€n

a thue bao bi ch~ chieu gQi di, khong su d\lng duQ'c cac dich Y\lTGT (trir dich Y\l GTGT da thanh toan ti~n ti.rtruac nhu Imuzik,

CA, ) do h€t thai h~ sir d\lllg (m~c du tai khoan con ti~n ) d6i

ai TB tra truac ho~c chua thanh toan cuac thang truac d3i vm

ue bao tra sau

hue bao khai hao: S6 thue bao khai hao tren M thOng HLR,illing, OCS

Thue bao active: S6 thue bao kich ho~t goi cuac tren OCS

Khlii niemtDac di~m

a thue bao dang b~t may rna M thOng tong dai dang quan ly t~i

00 di~m th3ng ke la thai di~m lfiy s3 li~u theo yeu cau C\lth~ nao

do (hao cao co quan quan ly,lfiy dfr li~u dlinh gia tang truang thue

ao h\lc V\lcong tac u ho~ch, chi€n luQ'c )

a thue bao dang b~t may ho~c thue bao da tat may nhung chua

ua 24h tinh d€n thai di~m th3zi ke

a thue bao co pMt sinh it nbat 01 dong doanh thu trong thangbao g6m ca doanh thu khuy€n m~i ho~c doanh thu a bfit CIItaioan nao - 3c/ khu €n m~i)

• Dinh tuyen dfr li~u

- Router P: Dung d~ chuy~n m~ch nhanh gifra cac viIng, cac khllV\fC;k€t n6i sang phful chuy~n m~ch goi cua lap Core di dQng

- BRAS: Dung d~ Ullnly dia chi, dnh cuac, di~u khi~n bao m~t Cac thanh phan trong m~ng PSTN:

- DLU: La thi€t bi t~p trung va di~u khi~n cac dUOngday thue baot~i mQt khu vvc nhfit dinh ChUc nang DLU g6m: cung cftp pin,bao v~ qua ap, cung cftp dong chuong, gilim sat dau cu3i thue bao,rna bOa va giai rna, chuy~n d6i 2 day/4 day, ki~m tra

- Host: La thi€t bi t~p trung cac DLU ho~c/va cac dUOngday thuebao

- Tandem: T6ng dai trung chuy~n luu IUQ1lgnQi tinh

- TOLL: T6n dai trun chu ~n luu IUQ'n lien tinh, lien m~

Quyen 1:Cae ay thuat ngw viin thOng Phlin 1 Tang quan m(lng viin thOng

lflnh 1: T6~g quat mgng Viettel

9

Quyin 1: Cac thuV-t ngu kY thuq.t viin t/tOng Phan 1 Tang quan mpng viin t/tOng

III Mqt sa d~ng dU'O'ngdi clla cuqc gqi tho~i (Call flow)

- TruOng hqp cimg khu vvc: Di dQng +-7BTS/Node B +-7BSCIRNC +-7MSC +-7GMSC+-7TOLL +-7Tandem +-7Host +-7c6 dinh

- TruOng hqp khlic khu vvc: Di dQng +-7BTS/Node B +-7BSCIRNC +-7MSC +-7GMSC+-7TOLL(1) +-7TOLL(2) +-7Tandem +-7Host +-7c6 dinh

- TruOng hqp dmg MSC: Di dQng +-7 BTS +-7 BSC +-7 MSC +-7 BSC +-7 BTS +-7Homephone

Di dQng Viettel +-7BTS +-7BSC +-7MSC +-7GMSC Viettel +-7TOLL Viettel +-7TOLL m~g khlic +-7Tandem +-7Host +-7c6 dinh m~g khlic

c6 dinh Viettel +-7Host +-7Tandem +-7TOLL Viettel +-7 TOLL m~g khlic +-7Tandem +-7Host +-7c6 dinh m~g khlic

6 Til"thue hao di d9ng 3G truy nh~p internet

Di dQng +-7Node B +-7RNC +-7SGSN +-7GGSN +-7Internet

Quvln 1: Cae thuDt ngii kgthuDt viin thOng

pHAN 2 MANG DI DONG .

Hinh v~ tren the hi~n m~t dt dimg cua song

vo tuyen duqc pMt di til antenna

- Tia Upper va tia lower la t~p hqp cac diem cocUOngdi) b(suy hao 3dB so vai cUOngdi) thuduqc clla diem tuang (rng nfim tren trl,lcCllablip song chinh thea m~t dt dimg

- Goc hqp bai 2 tia nay la 7 di) va duqc gQi lagoc suy hao 3dB

I Khai ni~m chung

1 Nhom khai ni~m v~ vimg phil

1 Goe n an Tilt, dun vi do: do

Khai ni~m:

- La goc xac diOOdi) Cl,lP,ngfulg

clla anten, co tac dl,lfig di€u

chiOOviIng pM song clla cell

- Co 3 lo~i Tilt: Tilt co, tilt dien

Tilt t6ng = Tilt co + Tilt

di~n

Ti!t cO': duqc thay d6i bfutg cach

dieu chiOOC(J khi h~ th5ng ga

clla antenna Tilt co duoc tiOO

b~g goc hqp bai m~it' phfutg

nam ngang (song song vai m~t

dAt) va dUOng thfutg vuong goc

vai m~t Clla antenna (goc nay

ciiJ}gbfutg goc OOQnt~o bai m~t

phang antenna va dUOng th~g

vo goc vai m~t dAt)

Tilt di~n: dl!<Jcdi€u chiOObfutg

cach thay doi pha clla tin hieu

vao m6i chAn tlr Clla ante~a

Tilt di~n duqc tinh bfutg goc ~o

antenna va trl,lc Clla blip song

chinh

Tblfc ti~n: Antenna co tilt t6ng

cang 16'n (C1,1ptilt) thi blin kiOO

phll cang bi thu h~p Nguqc l~i,

ant~nna co tilt t6ng cang 006

(ngang tilt) thi ban kiOO phll

cang dU<JCrna ri)ng

11

Khai ni~m: La goc duQ'c ~o Mi

tia vuong goc v&i mi;itantenna va

chieu kim d6ng h6

Th,!c ti~n: Goc phuong vi xac

dinh huang pM song clla cell va

duQ'Cthi€t k€ theo mvc dfch pM

song Trong do, uu tien 1: pM

song khu VlJCdan cu, uu tien 2:

e (degrees)

o °gain (dBi)

Hinh 3: Mijt edt ngang cua song va tuy€n au(!c

, phat ai tit antenna

3 Do cao anten (dun vi do: m :

La dQ cao treo anten, tinh tU day anten den mi;itdilt va duQ'c thiet ke de dam bao '1Jj ':,"

M song Cllatr{lill

4 Do cao cot aun vi do: m :

Khai ni~m: La dQ cao Clla CQttreo anten, Hnh tU dinh cQt den chan cQt

Th,!c ti~n: f)Q cao CQtduQ'c thi€t k€theo mvc dfch pM song va di;icdi~m Clla vi tri di;itcQt.f)Q cao CQt h6 bi€n CllaViette11a: 36m, 42m, 48m, 54m va 60m

1 (Grade of Service - oS = 2%, nghla la t~i mQt thai di~m co 100 cUQcg9i tren

eel dQ dich V\l, ~g thi 2 cUQcg9i khong th~ thvc hi~n duQ'c do khong con

Phlin 2.Mgng di tlpng

• LUll luqng dap Ung (Ed): LUll luqng rna h~ th5ng cokhA nang h6 trQ' duQ'c tra til bang Edang B Ung vai s5kenh TCH toan t5c va e&pd(>dich Y\l (GoS) la 2%

+Ml}.ng3G:

• LUll luqng gia cao di~m, duQ'ctinh bfulg tBng lUll luqngtho~i (Ed) va data (MB), trong d6 Ed duQ'c quy dBi radon vi MB theo cong thuc 1 Ed =45 ME

• LUll luqng dap dUng cua 1 ce1l3G la 1800 MB

Gilii thieh: cach quy dBi 1 Ed = 45 MB

Khai niemIDae di~menh r6i con g9i la nghen m~g)

a thong so duQ'c su d\ll1g de danh gili hi~u swit su d\ll1gtaiguyen vo tuy~n cua m~g (cell, BTS/ Node B, tinh, khu c, toan m~g) TU duQ'ctinh theo cong thuc:

Luu h.rgng gia cao di~m

-LUll lU'(;mg dap ll'ngTrong do:

+Ml}.ng2G:

• LUll luqng gia cao di~m (Ed): LUll luqng duQ'c lAytil

s5 li~u th5ng ke lUll luqng vao gia cao di~m hang ngay

Khai niem/ Dae di~m

a don vi do cua lUll luqng (traffic) tren M thOng, duQ'ctinh

eo cong th(rc:

nlltt

A(Erl)=-T

rong d6: A la lUll luqng do bfing Ed; n la s5 Cll(>Cg9i, t la d(>

ai trung binh cua m6i cu(>cg9i, do bfing giay (s), T lathai gian

o thuan T= 3600s);

La don vi do cua lUll luqng data tren Mth5ng

GiaPeak tho~i (peak CS):

La gia rna lUll luqng tho~i cua m~g 160 nh&t (la khoang thai

gian nhi€u thue bao g9i nh&t,gia peak tho~i muc m~g thuang

tiI 19h d~n 20h hang ngay)

Gia Peak data (peak PS):

La gia rna lUll Iuqng data cua m~g 160 nh&t (la khoang thai

gian tfme bao download dfi' li~u nhi€u nh&t, gia peak data cua

m~ng thuang til 20h d~n 23h hang ngay)

La t6ng s6 yeu du cue)c g9i tho~i vao t6ng dai trong gia caodi~m (cue)c g9i do co th~ duqc t6ng dai k~t n6i thfmh congho~c khong thfmh cong) Blnh thuang, BHCA trung blnh clla 1thue bao la 1,2 BHCA/thue bao.

BnCA(Busy

Hour Call

yeu cau cUQC

gQi trong giir

4 Nhom khai ni~m v~ tin hi~u

liong d6i

hi~u vo tuy~n Vi d\l: 1W= 30 dBm

anten dinh hu6ng

ling feh elia

Duqc xac dinh bing tY s6 gina de) 160 Clla cong suit hUc x~ clla

anten dang xet t~i me)t di~m ~heo hu6ng chinh ta:n clla bup song

Suy hao cuirng Tbl}'c ti~n: M~ng 2G, 3G

-Khu V1JCtrung tam thfmh ph6 (Dense Urban): ~25 dB

4 dQ tin bi~u gifta - Khu V1JCngof;li0 thanh ph6, thi xa (Urban): ~20 dB

-Khu V1JCd6ng b~ng dong dan cu (SubUrban): ""15dBngoai nba

- Khu V1JCnong thOn (Rural): -10dB

- Khu V1JCmi€n nui: ~ 10dB

Gia tri thlJc t~ clla timg khu V1JCdia hlnh sf: duqc do ki~m If;li

trong qua trinh t6i uu

Quyin 1: Cae thu(it ngii kjithuW viin thOng

Phan 2 Mgng di ilpng

- 1;a kh&i ehuepang di€u khi€n, giam sat cae BTS,quan Iy tai nguyen votuyen tren h~ thong, co cae ehuc nang nhu:

• Quan Iy tr~ BTS: ThiSt l~p cAuhinh, tful s&,neighbour ;

• Quan ly m~g vo tuySn: Xu ly cac ban tin bao hi~u, di€u khi€n;

• quan ly kenh vo tuySn: Kh&i t~o, An dinh, giai ph6ng kenh votuyen;

BQ di€u • np trung lun IUQ11gcua cac thue bao dang kSt n&i;

g&c) Adaption Unit: Kh&i chuy€n d6i rna va thich Ung t&cdQ);

- Quan ly m~ng truy€n dan dSn MSCI SGSN va BTS:

• BSC kSt n&i vai MSC qua giao di~n A cho dich Vl,ltho~i, kSt n&ivai SGSN qua giao di~n Gb cho dich Vl,ldfr 1i~u(data)

• BSC kSt n&ivai BTS qua giao di~n Abis'

- Cac BSC cua Viettel do cac Trung tam Ky thu~t Khu V1JCqUlln ly t~p' ~

- BTS III phful ill kSt n&i gifra cac thue bao di dQng (MS) va m~g" (thong qua BSC) BTS co cae chuc nang sau:

'\ :

• Quan Iy thul pMt bao hi~u va thong tin tren kenh v~t ly; ,

pMt g&c) I- BTS kSt n&i vai MS qua giao di~n vo tuySn Urn, vai BSC qua giao

~i~nAbis

I- Cac BTS cua Viettel duqc giao cho cac Chi nhinh Viertel tinhl TP

~uan ly

I- MS bao g6m ME (Mobile Equipment - ThiSt bi di dQng) va SIM

• ME: La may di~n tho~i di dQng

3 Subscriber - • SIM: La the nha thOng minh duqc gful tren ME, co lun trfr thongThue bao di

tin v€ s&thue bao, rna s&m~g di dQng, cac rna s&ph\lc Vl,lcho vi~cdQng)

nh~ th1,1'Cthue bao

I- MS kSt n&ivai m~g thOng qua BTS tren giao di~n vo tuySn Urn'

Quyin 1: Cac thuQ.tngit kj thugl viin t!tOng PhOn 2 M{lng di ilpng

Thvc ti~n

D6i vai bang tfut 2G, Viette1 duQ'cdp phep va su d\ll1gthi~t bi thu

Mt vo tuy~n di~n cong ngh~ GSM hOl;ltd9ng & bang tfut 900 MHz va

1800 MHz Trong do:

• Bang tfut 900 MHz: Viette1 duQ'cdp 41 kenh, m6i kenh co d9 r9ng

200 KHz, thu tv kenh ill 43 d~n 83;

• Bang tfut 1800 MHz: Viette1 duQ'cdp 100 kenh, m6i kenh co d9r9ng 200 KHz, thu tv kenh ill 712 d~n 811;

?~~4 _TRX s6 1uqng-rp:nhi€u hay it ph\! thu9C vao m~t d9 thue bao tl;l~~;.~

a thOng so cho bi~t tOC,d9rna hoa thol;li duQ'c dung cho kenh thol;lila FK;~~E~ull Rate - Tow toc: Toc d9 tuong (eng tren giao di~n Urn 1a 13 kbps) hav;:~,N,, , , {hr}n{"(Half Rate - Ban toc: Toc d9 tuong (eng tren giao di~n Urn 1a6,5 kbp~1! ~l;~"

i 1uu 1uqng ml;lllgtang cao, 01 khe thai gian duQ'c danh rieng cho tm :1'"

ue bao dang hOl;ltd9ng & ch~ d9 FR ( 01 kenh FR) duQ'c di€u khi€n tach"hanh 02 kenh HR d€ ph\!c Vl) cho 02 thue bao Nhu v~y, dung 1uqngl;lllgco th€ duQ'ctang g& dol

y thuyet: La 1uu 1uqng thol;lico the dap (eng duQ'ctoi da tren 1 b9 thu pMtTRX)

1JCti€n:

Luu 1uqng thol;lisu d\!ng t6i da tren 1 b9 thu pMt (TRX) d€ dam bao s6ell co tY 1~nghen kenh TCH < 2% chi~m <1 % t6ng s6 cell cuatow ml;lllgusau:

Cell du hinh 2TRX: 6.5 ErVTRX; tuong (eng vai 13 Ed/CellCell du hinh 4TRX: 8.6 ErVTRX; tuong (eng vm 34.4 Ed/Cell

a,nang ph\lc V\ldang thi'ri: " •

a so thue bao thol;li (su d\ll1g kenh toan tOc) toida co the ph\!c Vl) duQ'c6ng thai cua m9t cell DuQ'cxac dinh nhu sau:

s6 thue bao thol;lid6ng thai = 8* s6 TRX - 1 TS BCCH - s6 TS khai bao

ho SDCCH - s6 TS khai bao dwh rieng cho EDGE

i d\!: cell co 2TRX, khai bao 2 kenh SDCCH va 1 TS danh rieng choDGE 7t6ng s6 thue bao thol;lico th€ chl;l d6n thai 1a: 8*2 - 1 - 2 - 1

Quyin 1: Cae thuvt ngu kj thuvt viln tltOng PhOn2.M{lng di tlpng

12

hi nang ph1}cV1}:

ng vai muc dQ su d\!ng cua thue bao la 30 mErVSub/gia, 1 cell cfiu hinhTRX co dung hrQ'llgh6 trQ't6i da la 13 Ed se dap (mg duQ'c433 thue baoron 1 gia Tuan tv cell cAuhinh 4TRX da Un duQ'c 1147 thue bao.

3 Khai ni~m v~ VilDg phu

Ly thuySt

~a tBng cong suAt pMt t~i dAu ra cua cac kh6i thu pMt (TRX) duQ'c cfiu'

tan ho~t dQng va lo~i tU cua vendor l}ao

dBm/TRX doi vai Cell diu hinh 2 TRX, ~42 dBm/TRX doi vai Cellcfiu hinh 4TRX

La thong so bi~u di~n cong suat tin hi~u vo tuyen 2G thu duQ'c t~i MS ,

La thong s6 bi@udi~n chAt IUQ'llgtin hi~u vo tuy€n m~g 2G thu duQ'ct~i

Chat lU(1ngMS, duQ'c do bfulg tY s6 cong suA!tin hi~u thu duQ'Cva nhi~u t~i may thu.ell dng 100 thi chAt IUQ'llgcua tin hi~u cang t6t, it co nhi~u va nguQ'c I~i.

Thrrc ti~n:

(CIl, don vi

• Muc t6t: > 15 dBdo: dB)

• Muc chApnh~n duQ'c: 12-15 dB

• Muc t6i: < 12 dB

17

Khu Y\lC ngo~i a thanh phD, thj xli

Lythuy~t

La khoang each til chan tr~m d€n diem xa nh~t theo huang bUp song

hinh rna dich V\l con dam bao ch~t IUQ'Ilg.

BKPS ph\! thuQc vao dQ cao treo anten, goc ngAng (Tilt), tfuI s6 sir

\lOg va cong su~t pMt clla anten Ngoai ra, BKPS con ph\! thuQc vao dia inh, moi truOng truy€n song.

Urban), vai dQ cao anten trimg binh -25m:

Khu Y\lC ngoliri0 thanh pho, thj xli (Urban), 550m- 800m

vm dQ cao anten trung binh -30m:

Khu Y\lC dong bang dong dan cu (SubUrban), vai dQ cao anten trung 1.3km- 2.5km

binh-36m:

Khu Y\lC nang than (Rural), vai dQ cao 3 km-4 km

anten trung binh -42m Khu Y\lC mien nui, vai dQ cao anten trung binh-57m:

Ly thuy~t:

La di~n tich clla hinh I\!c giac co dUOng kinh Ia ban kinh phll song clla rnQt cell.

ThU'ctiin:

Di~~ tich pM song tmg v6'i cuOng dQ tin hi~u t6i thi€u trong nha.

(RxLevei ~ -90dBm (di?n t[ch tuem Un

Quvln 1:Cae thu{it ngii kji thu{it viin thOng Phlin, 2. M{lng di ilpng

L

Khu V\l'C dong bang dong dan cu

(SubUrban), v6i dQ cao anten trung binh • 2

- Vimg 16m lit viIng/khu vvc/dol;lIl du<mg khong co song ho~c song rAt

\l~U,duQ'c xac dinh qua thong s6 RxLev do duQ'c ho~c s6 v~ch song tren

• V &i khu VVCthitnh pM dong bang, RxLev <-90 dEm. >rONG

• V&i khu VVCmi€n nlii, RxLev < -95 dBm '~~tltU

1 SI?CCH vilOgia cao SCRp khong duQ'cdo hSt kSnh/ t6ng s6 lfuI ySu

Ti l~ nghen kSnh tho;;U (T6ng s6 lfuI dp pMt kSnh TCH khong

2

vao gia cao di~m (Peak) TCRp duQ'cdo het kSnh / t6ng s6 lfuI ySu du d.p 0.6

pMt kSnh TCH)* 100%.

TY l~rat kSnh bao hi~u (T6ng s6rat kSnh bao hi~u danh riSng /

(peak)

l~p thanh cong)* 100%.

Ti l~ thiSt l~p cUQCgQi (Tong so cUQcgQi duQ'cthiSt l~p thanh

4 thanh cong gia cao di~m CSSRp cong /t6ng s6 lfuIthiet l~p cUQc 99.44

[Tong so cUQcgQi bi rat/(tong so cUQcgQi

5 Ti l~rat cUQcgQi gia cao

CDRp dii duQ'cthiet l~p+t6ng s6 CUQC HO vao

0.59 di~m (Peak) thanh cong - t6ng s6 cUQcHO ra thanh

cong)]* 100%

Ti l~ chuySn giao cUQc (Tong so cUQcHandover ra kh6i cell thanh

6 gQi thanh cong gia cao HOSRp cong / T6ng s6 cUQcHandover ra kh6i 98.96

19

Quyin 1: Cae tltul)t ngii kY tltul)t viin thOng

III. Mlolngvo tuy~n 3G

1.Thimh phin mlolng3G

i- La khf,i cht'rc nang di~u khi~n, giam sat cac Node B, qwin ly tainguyen vo tuy~n tren M thf,ng, c6 cac chi'rc nang nhu:

• Qwin ly tr~ Node B: Thi~t l~p cAuhinh, tAn sf"

?

np trung lUll luQ'ng clla cac thue bao dang k~t nf,i;

thu~ kh6a, cac kh6a bao m~t va toan vt(n du li~u duQ'c d~tvaoRNC;

k~t nf,i v6'i MSC/SGSN qua giao di~n Iu-cs/ Iu-ps RNC k~tnoi v6'i Node B qua giao di~n Iub'

- Cac RNC clla Viertel do cac Trung tam Ky thu~t Khu VlJC qwin

Y t~p trung t~i cac t6ng tr~m

- Node B la phAn tir k~t nf,i giua cac thi~t bi di dQng (UE) vam~g Node B c6 cac cht'rc nang co ban nhu di~u phf,i da truy nh~p:::honhi~u thi~t bi nguai dung, cAp phat tai nguyen vo tuy~n, t~p

- Node B Viertel ho~t dQng tren dlii tAn 2110 - 2170 MHz

- Node B k~t nf,i v6'i RNC qua giao di~n Iub'

- Cac Node B clla Viertel duQ'c pharr cho cac Chi nhanh Viertelinh/ TP qulin ly

UE bao gom dau cuoi nguCYidUng (UE) va khoi nh~n d~ng thue)ao (USIM):

- UE: Bao g6m di~n tho~i di dQng ho~c cac thi~t bi dAu cuf,i truy

'J"odeB qua giao di~n vo tuy~n Uu.

- USIM: La the nh6' thOng minh, duQ'c gAn tren UE, lUll trU nhunghOng tin nhu sf, di~n tho~i, rna sa m~g di dQng, cac rna sf, phvc V\l

cho vi~c nh~ thgc thue bao

Bang tan di

ilpng 3G

1

2.Khai ni~m v~ tiii nguyen, dung hrQ'ng 3G

Lythuy~tBang tAn la diUtAn sf, duQ'cgi6'i h~ b6'i 1 tAn sf, thAp nhAtva 1 tAn sf,aonhk

Quyin 1: Cac thuQ-tngickj thuQ-tviin thong Phan 2.M{lng di a(jng

thong 5 MHz! kenh), trong do 4 kenh lien 1\Jcill 2115 d€n 2135 MHz.

Kenh tful s6 con I~i dang dung chung, chua co phan djnh ra rang v€

I phl;lillvi sir d\mg v6'i m~g Vietnamobile

Tai nguyen m.rc cell (carrier):

- Tai nguyen cong suAt cltr<mgxu6ng: Trong m~ng Viertel dang khaibao cong suAtph6 bi€n la 20W/cell (song mang) TAt cac cac k€t n6itho~i, data, bao hi~u d€u tieu t6n mi)t Im;mg cong suAt nhAt dinhtrong t6ng 20W tren

_Tai nguyen ma tr,!c giao cltr(mg xu6ng (code): Dung d~ trai ph6tin hi~u clla ngm'ri dting, m6i mi)t cell 3G co 128 rna trlJc giaoSF128 M6i mi)t dich vv khac nhau thi tieu t6n rna trvc giao khacnhau

- Vi dV: M6i mi)t cUQcgQi tho~i cful 1 rna SF128, tuy nhien m6i mi)tk€t n6i data v6'i t6c di) 128 Kbps, cful mi)t IUQ1lgtai nguyen tuemgduemg v6'i 8 SF128

- Tai nguyen nhi~u cltri'rnglen

Tai nguyen m.rc NodeB:

- Tai nguyen CE (channel elecment): la tai nguyen xir Iy clio mi)tcui)c gQi (cll tho~i, bao hi~u va data) G6m 2 dUOng: CE UL va C~\

- M6i mi)t dich V\l khac nhau thi t!eu ~6ntai nguyen CE khac nhau .li~:.

Tai nguyen lub: bang th0l.!gtr;ty~n.dan tren giao di~n Iub git!a Nodlfil::1 ,'

va RNC Bang thong yeu diu toi thieu cho 1 cell 3G la 7 Mbps.$:;f

Ly thuyet: Nang IlJc dap lIng dich V\l clla cell 3Gtrong dieu ki~n bin1fthuOng 6 ml;lngViertel

Th,!c ti~n:

D6i v~ tr,m cAu hinh 1/1/1:

- Neu chi sir dVng Data:

Nang IlJc la t6c di) dt! li~u trung binh clla Cell3G

• Tr~m Inbuilding: 8 Mbps/Cell

• KV Thanh ph6: 5 Mbps/Cell

• KV Nong than: 7 Mbps/Cell

- N€u chi sir dVng thol;li: I cell 3G co th~ h6 trq~49 k€t nbi thol;lid6ng thoi, tuemg lIng voo traffic thol;lioffer la ~40 Ed

Ghi cM: V 6'i offer clla Data dang sir dl,lllgtrong m~g Viertella1800MB/gio -7 quy d6i 1 Ed = 1800MB/40Ed =45 MB

3.Khlii ni~m v~ vimg phD

do: dBm) - Cong suAtpMt ClJCdl;liclla I cell3G la: 43 dBm (20W)

21

Quv€n1:Cae thufi ngii kj thuV-tviln thOng

- Cong suilt pMt tren kenh CPICH (mong t1;rkenh BCCH): 33dBrn (2W)

Ly thuy~t

- Lil rnuc tin hi~u vo tuyen thu duQ'ct~i UE ho~c Node B; danh gia rnuc

dQ rn~yeu cua tin hi~u vo tuyen

Th1fCti~n:

f)6i VOldU'iYngxu6ng

• Muc t6t: >= -90dBrn (dAy song va 6n dinh)

• Muc chAp nh~ duQ'c: -90 den -105 dBrn (dAy song va khong 6ndinh)

• Muc t6i: < -105dBrn (khong dA song)

Ly thuyet:

- La tY s6 gifra cong suAttin hi~u thu duQ'c(Pc) tren cong suAtnhi~u(Pi)

Cach tinh 10Ig(PclPi), don vi (dB)

Dung d€ danh gia chAt lugng cua tin hi~u vo tuyen

1.8km - 2.8km

Bankfnh

va tin hi?u nhilu

>2.598km2 0.234-0.65 km2

Di~ntlch phu son

SubUrban), vai dOcao anten trung binh -33m:

Khu VlJC nong thOn (Rural), vm dO cao antentru g binh -39m:

Khu VlJC mien nui, vm do cao anten trung binh-54m:

Quyin 1: Cae thugt ngit kg thu?t viin thOng Ph/In 2 M{lng di il{jng

Ly thuy~t:

Lil di~n tich cua hinh h.IC giac c6 duang kinh = ban kinh pM s6ng cuamQt cell

Th,!c ti~n:

Di~n tich pM s6ng (mg vai cuang dQ tin hi~u trong nhil (RxLevel) ~

-90dBm (di?n tich tuang u-ngvai ban kinh hit son

(Tbng s3 RAB CS.kho~g thi€t I~p

yeu cAuthi€t l~p)* 100%

cho dich vv thOl;li

Ty I~ nghen vi~c

(Tbng s3 RAB PS kh6ng thi€t l~p

yeu cAuthi€t I~p)* 100%

cho dich vv data

SR/IOO%

+) RRC CS SR (RRC Call Serive

(Tinh giiJ peak)

CS thi'lnh cong =Tong s6 RRC CSdugc thi€t I~ptp.i'lnh~ong/ Tbng s3RRC CS yeu diu thiet l~p * 100%

23

Quvin 1:Cae thupt ngic kP thupt viin thOng PhOn2.M{lng di apng

Khai niem/die diim

Rate): Ty.I~ thi.€t l~p RRC PS tha~

(I'£nh gid' peak) yeu du thi€t l~p * 100%

+) RAB PS SR (RAB PS SuccessRate): Ty l~ thi€t l~p RAB PS thanhcong =Tang s6 RAB PS duQ'cthi€tl~p thanh cong/ Tang s6 RAB PS

6 Ti l~ rOt cUQcg9idata (I'£nh gid' peak) PS-CDRp cUQcg9i PS hi rOt + Tang s6 cUQcg9i PS giai ph6ng hinh 0.83 )

thui'mg)* 100%

TY l~ chuyen giao

m€m thimh congo

Chuy€n glao mem:A

La chuy€n giao cilng

tful s6 trong m~g

3G

truoc khi giai phong

k€t n6i vo tuy€n Cll

- UE (thi€t hi d~u

cu6i) co tir 2 k€t n6i

vo tuy€n tralen

trong hIc chuy€n

giao

Quyin 1:CaethuQ,t ngil kf thuQi viin thOng Phan 2.M(lng di i/{jng

Khai niem/dile di~m

mang(%)

Ty 1~chuyen giao tit

(T5ng s6 chuy~n giao tir 3G sang3G v~ 2G thanh

CSlRAT 2G thanh cong cho dich VI,ltho(;li/ .

8 cong d6i v&i dich V\l

tho(;li

sang 2G)* 100%

cong d6i v&i dich VI,l HOSRp T5ng s6 1k attempt chuy~n giao 3G

(duQ'ctinh t(;lilap Throughput

Tai U'u vimg _ Thay d5i cac thong s6 m~m tren M th6ng: ACCMIN, cong su~t pilat, tinh4~~~

- Thay d5i tilt, azimuth, dQ cao treo anten

- Thay d5i dQ cao/ vi trf CQtanten

- Sir d\lllg cac thi~tbi ph\l trQ'TMA TMB, Repeater

- Thay d5i lo~i ill theo bang tk dang sir d\lng (900/1800)

- L~p them tr(;lmm&i ho~c huy b6 vi tri tr(;lffikhong pM hgp

La cac tac dQng vao m(;lllg1u&i(mem/ c(eng) de nang cao chat 1ugng m(;lng:

iam nhieu, tang ch~t1ugng thO(;li Vi~c tac dQng din ClIvao k~t qua do ki~mriving test, phan anh khach hang va theo d5i cac chi s3 KPI cllaM th6ng t(;li

u VlJCdo: CDR RxQua1, CII Co cac hanh dQng sau:

- Ki~m tra, kh~c ph\lc cac 16iphk c(eng Cllatr(;lffi(n~u co)

- Thay d5i cac thong s3 m~m tren M th6ng

- Qu hO(;lch,t6i Uti l(;litk s6

La cac tac dQng vao m(;lllg1u&i(mem/ c(eng) de nang cao/ giam bat nang

gc dap (eng clla m(;lngt(;limQt dia di€m/ khu vgc C\lth€ Vi~c tlic dQng can ClI

ao k~t qua do ki~m driving test, phan anh khach hang va theo d5i hi~u su~t

~ th3ng (TU) va mlIc dQnghen (TCR, SCR) t(;likhu VlJCdo Theo mlIc dQtacQng d~n dung 1ugng, co cac hanh dQQgsau:

- Thay d5i ngu5ng HR share tai;

Quyin 1: Cac thupt ngif kji thupt viin thOng Phan 2.MfJng'di i/png

- Lap them tu (cosite, dau TG);

- Thi&tk&va Hipthem trlPll mO'L

La cac mc dQng vao m~ng luO'i(mem! cung) de thay doi vimg phu s6ng

ua m~g: thu hyp vimg phU de gifun nhi€u, mO'rQng vimg phU de tang dungUQ'Ilgm~g Vi~c tac dQng can cu vao k&tqua do kiem drivingtest, phan aMach hang va theo doi cac chi s6 KPI cua M th6ng t~i khu VVCd6: CDR,SSR, RSCP C6 cac hanh dQng sau:

- Kiem tra, kh~c ph\lc cac 16iphful Ctrng cua tr~m (n&uc6)

Thay d6i cac thong s6 m€m tren M th6ng:

- Thay d6i tilt, azimuth, dQ cao treo anten

- Thay d6i dQ cao/ vi trl CQtanten

- Sir d\lng cac thi&tbi ph\l trq Repeater

La cac tac dQng vao m~ng luO'i(mem! Ctrng) de nang cao chat lUQ'Ilgm~ng:r(;f

iam nhi€u, tang chAt luQ'Ilgtho~i Vi~c tac dQng can ~u vao k&tqua ~o kiem \ *'riving test, phan anh khach hang va theo doi cac chi so KPI cua M thOng t~i

u VVCd6: CDR, Ec/No C6 cac hanh dQng sau:

- Kiem tra, kh~c ph\lc cac 16iphAn Ctrng cua trlPll (n&uc6)

-'

La cac tac dQng vao m~g luO'i(mem! Ctrng) de nang cao/ gifun bat nang )~ ),

\IC day trng cua 11,1~gt~i mQt dia diem! khu VVCC\lthe Vi~c tac dQng can ?u~~

ao k~t qua do kiem driving test, phan aM khach hang va theo doi hi~u suat ~

~ thOng (TV) va muc dQnghen (TCR, SCR) t~i khu VVCd6 Theo muc dQtac

Qng d&ndung luQ'Ilg,c6 cac hanh dQng sau:

- Thay d6i ngu5ng HR, share tai;

- Nang/h~ cAuhinh;

- L~p them tu (cosite);

- Thi&tk&va l~p them tr~m mO'L

Ouyin 1:Cae thulit ngir leV thulit viln thOng PhOn 2 Mang Di dang

i

B.~~ngloidid9ng

I Thanh ph~n

1 ~~ng CS (Circuit Switching - ~~ng chuy~n:m~ch kenh)

MSC (Mobile Switching Center): Tong dai chuyen ml;lchdi dQng.ChUc nang chinh: ThlJc hi~c cac chUc nang di€u khi€n (thi~t l~p, dinh

MSC thuOng duqc tich hqp chUc nang cua VLR (Visitor LocationRegister), qulinIv thue baa trong vimg ph1,1cV1,1cua MSC tuong (mg.

MSS (Mobile Soft Switch): Tong dai chuyen ml;lchmem di dQng.Chilc nang chinh: ChUc nang gi6ng MSC, nhung MSS co ki~n trUckhac vcri t6ng dai MSC truy~n th6ng la tach bi~t phl1nxu ly/di~u

2 MSS J41i€n(control p!ane) va phl1ntruy~n tlii luu luqng (user plane) MSS

gom 2 thlinh phan:

MSC-Server: La thanh phlln di~u khi€n

MGW (Media Gateway): La thanh phlln truy~n tlii luu luqng

GMSC (Gateway MSC): Tong dai di dQng congo

3 GMSC ChUc nang chinh: La node ml,lfigtrung chuy€n luu luqng thol;lididQng, g&m luu luqng thol;lidi dQng gifra cac MSC; gifra ml,lfigdi dQng

va ml,lfigc6 dinh, ngol;liml;lng,cac dich V1,lVAS

STP (Signaling Transfer Point): Diem truyen tlii bao hi~u ChUc nang

4 STP chinh: np trung va chuy€n ti€p cac ban tin bao hi~u tlr node ml,lfig

nay sang node ml,lfigkhac trong ml,lfig

HLR (Home Location Register): BQ dang kY vj tri thuOng tm ChUcnang chinh: La node ml,lfigqulin ly thong tin ve dich V1,lthue bao,

xu6ng cac node VLR, SGSN trong cac tM Wc c~p nh~t vi tri cua thuebaa

2 ~~ng PS (Packet Switching - ~~ng chuy~n m~ch g6i)

SGSN (Serving GPRS Support Node): Node h6 trq dich V1,lGPRS.ChUc nang chinh: Qulin ly tinh di dQng cua thue bao, qulin ly cac

1 SGSN phien k~t n6i PDP cua thue bao, qulin ly truy c~p ml,lfig,tinh cucrc

thue bao, thlJC hi~n chilc nang chuy€n ml;lch goi tlr BSC, RNC lenGGSN va nguqc ll;li

GGSN (Gateway GPRS Support Node): Nut h6 trq cong GPRS.ChUc nang chinh: Qulin ly cac phien k~t n6i PDP cua thue bao,

cua thue bao.Tinh cucrc online thue bao, sinh ra file cucrc CDR.ThlJchi~n chilc nang chuy€n ml;lchgoi tir GGSN ra ml;lngIP va nguqc ll;li

3 PCRF PCRF (Policy Control and Charging Rules function): H~ thOng qulinly chinh sach cucrc.

27

Ourin 1: Caethulit ngii kfj thulit viin thOng PhOn 2.Mang Di dang

Ch(rc nang chinh: Dieu khien chinh sach, dieu khien tinh cucrc dgatren ~p hqp cac goi tin IP truy€n qua mQt di~m giam sat trong mlPlgtrong mQt thai gian xac dinh

WAP Gateway: Cung dip dich Vl) chuyen doi giao tMc HTTP/WAP

Gateway

3 M~ng VAS, IN (Value Added Services, Intelligent Network)

SMSC Router: Cung cap dich Y\l SMS, nhung khac bi~t vcri SMSC lachi thgc hi~n chuy~n ti€p bim tin SMS rna khong thgc hi~n luu va guiI~i SMS (n€u bim tin bi gui thllt b~i) - xu Iy tin nh~ lap I Cac bim tinthllt b~i nay se dugc gui chuy~n ti€p sang SMSC d~ thgc hi~n gi'ri Il;!i2!:!<1

MMSC (Multimedia Message Service Center): Trung tam tin nhan dadl Vim

Ji-!!ir,H

CRBT (Color Ring Back Tone): H~ thong cung cap dich V1,1 nhl;!C,ND?1.

chuong cM cho thue bao di dQng va home phone Bao g6m co M-node .i~~~~

MCA: (Missed Call Alert): H~ thOng cung cap dich Y\l thong bao cUQc

<;>inha.

(Online Charging System) H~ thong tinh cucrc thai gian thgc:

- Quim ly thOng tin v€ cac goi cucrc, cach tinh cucrc va thong tin lienquan d€n vi~c tinh cucrc cua timg thue bao Quim Iy cac thong tin clluhinh va cach tinh cucrc theo cac chuang trinh khuy€n ml;!i

- Thgc hi~n tinh cucrc lien Wc theo thai gian thgc d6i vcri toim bQ cacdich Y\l (thol;!i,SMS, data va cac dich Y\l VAS khac) cua timg thue bao,dga theo oi cucrc, cach tinh cucrc tuan Un

(Voucher Center) Trung tam quim ly the cao: Quim Iy thong tin the cao(m~nh gia, seri the, rna the cao va cac thOng tin lien quan d€n vi~c nl;!pthe d6i vcri cac the da nl;! nhu thai gian nl;! , s6 thue bao nl;! , )

Ouyin 1: Cac thuiit ngir k£ thuiit viin thOng

II Khai ni~m chung

1 Khai ni~m v~ tili nguyen

CP Load: DQ chiem d\lng tai nguyen CPU, thuOng de danh gia tM cac

khi cUQcgQi duqc thi€t I~p d€n khi k€t thuc cUQcgQi

ill khi tni lai cUQcgQi d€n khi k€t tMc cUQcgQi

thai, dimg d6 danh gia nang hJc k€t n6i tho~i cua t6ng dai

TPS: Transaction Per Second - So tuong tac/giiiy, mQt tuong tac la S\l'

I\l'cxu Iy cua cacMth6ng nhu STP, WAPGW, MMSC, PCRF

SAU (Simultaneously Attached Users): Tong so thue bao nh~p m~gdang duqc quan Iy t~i SGSN t~i mQt thai di6m

Context

diem, tai nguyen nay duqc quan Iy bOi SGSN, GGSN

"

Throughput: Kha nang xu Iy luu luqng cua tong dai SGSN, GGSN "

j

MOMT/s: Tong luu luqng tin nhan chieu len (Message Originate: Tir:

Tir t6ng dai tin nh~ xu6ng thue bao) tinh trong 01 giiiy

2 Khai ni~m v~ hilnh vi tieu dung

BHCA/Sub: La so cUQcgQi den! di trung binh cua mQt thue bao vao

de ph\lCY\l djnh cO',phiin b6 h~ th6ng cho phil hqp

mErVSub: La luu luqng tho~i den! di trung binh cua mQt thue bao vao

cUQcgQi d6 ph\lc Y\l dinh cO', philn b6 Mth6ng cho phil hqp

29

g

cho phUhgp

Dung d€ danh gili so lUQ'Ilgthiet l~p phien ket noi data (ngu canh PDP

di~m

.

Ill Cac chi tit~udanh gia chit lU'qngm~ng liji

l.M~ng CS

1 LUSR

LUSR: Ty 1~c~p nh~t vi tri thanh congoTy l~ nay danh gia kh* nang

-JlPSR: Ty l~ tim gQi thanh congoTy l~ nay danh gia kha nang tim gQi

~._ AuSR: Ty l~ nh~ thvc thanh cong (nh~ thvc la tM 1\lckiem tra tinh

m~g va thvc hi~n cac dich V\l m~ng)

5

CCR: Ty l~ thiet l~p cUQcgQi thanh congoTy l~ nay danh gia khil nang

(\

2 Man PS

Att-SR: Ty l~ nh~p m~ng thanh cqng trong mien chuy€n m~ch goi

cAunh~p m~ng (attach), th6ng ke tren giao di~n Gb, Iu-PS

PDP-SR-S: Ty l~ khai t~o PDP context thanh cong tren SGSN La tY

celuthi€t l~p ngii canh PDP, th6ng ke tren giao di~n Gb, Iu-PS

cAuthi€t l~p ngii canh PDP, th6ng ke tren giao di~n Gn

Ouyin 1:Cae thufit ngirkf thufit viin thOng PhJn 2.Mang Di ilong

Intra-RAU: Ty l~ c~p nh~t vimg dinh tuyen nQi SGSN thanh congo

4 Intra-RAU La 15's6 giua s6 lfut c~p nh~t vimg d!nh tuy€n nQi SGSN thanh cong

tren t6ng s6 lfut yeu cAuc~p nh~t vilng dinh tuy€n nQi SGSN .

Inter-RAU: Ty l~ c~p nh~t vilng dinh tuyen lien SGSN thanh congo La

5 Inter-RAU 15's6 giua s6 lfut c~p nh~t vimg d!nh tuy€n lien SGSN thanh cong tren

t6ng s6 lfut yeu cAuc~p nh~t vimg dinh tuy€n lien SGSN

6 PCC-SR PCC-SR: Ty l~ truy van dieu khien tinh cu&c va chinh sach thanh

cong, th6ng ke tren h~ th6ng PCRF

3 M~ng VAS, IN

SMOSR: Ty l~ gui thanh cong tin nhan SMS ill thue bao den m~g

I SMOSR La 15's6 giua s6 ban tin thue bao gi'rithanh cong len M th6ng SMSC so

v&i t6ng s6 bim tin dil gui

SMTSR: Ty l~ gui thanh cong tin nhan SMS tiI m~g den thue bao

2 SMTSR La 15' s6 giua s6 ban tin MT gui thanh cong ill SMSC d€n thue bao

nh~ so v&i t6ng s6 bim tin h~ th6ng SMSC dil gi'ri xu6ng thue bao.MMOSR: Ty l~ gi'ri thanh c6ng tin nhan MMS ill thue bao den m~g

3 MMOSR La ti s6 giua s6 ban tin MMS Submit gui t&iM th6ng MMSC thanh

cong so v&i t6ng s6 ban tin gi'rit&i MMSC

MMTSR: Ty l~ gui thanh cong tin nhan MMS ill m~g den thue bao

4 MMTSR La 15's6 ban tin MMS retrieve gui di thanh cong so v&i t6ng s6 ban tin

dil gui cuaM th6ng MMSC

RBT_SR: Ty l~ cUQcg9i RBT thanh congo

5 RBT SR La 15's6 giua t6ng s6 cUQcg9i RBT thanh cong tren t6ng s6 cUQcg9i

RBT

31

Ouvin 1:Cae thutit ngi1'kjithutit viin thOng

ngum su d\l1lg

Cae die di~m ella dieh vu ADSL:

- HOl.it'dQngtren doi ~ap d5ng thue bao cho truy nh~p Internet tir xa v&it5c dQ cao, nh~t la dUOngxu5ng

- Bang thong truy~n du li~u dUOngxu5ng 1&0hon dUOnglen

- Dich V\lADSL co th€ tri€n khai d6ng thai cung v&i dich V\lPSTNtren 01 doi day cap d6ng thue bao

FTTx la cong ngh~ ket noi vi~n thong v&i duang truyen dfut hoan toanbfulg cap quang tu nha cung cap dich V\lt&i khach hang Bao g6m caccong ngM sau:

- FTTH (Fiber to the home): Cap quang d~n tl.iinha khach hang

- FTTB (Fiber to the building): Cap quang d~n chan toa nha va tri€nkhai cap d6ng d~n tUng can hQ bfulg cong ngM ADSL, VDSL,Ethernet,

- FTTC (Fiber to the curb): Cap quang d~n khu t~p trung va tri€n 'khaicap d6ng d~n tUng nhakhach hang bfulg cong ngM ADSL, VDSL,Ethernet,

Cae die di~m ella dich vu:

- Cung c~p k~t n5i b~g c~p quang d~n t~ nba thue bao

- Khong bi suy hao tin hi~u b&i nhi~u di~n tir, thm ti~t hay chi~u daicap nhu cap d6ng

- Cung cap cac dich V\l doi hOi bang thOng r~t cao nhu triple- play

- T5c dQ du li~u chi~u xu5ng va chi~u len bfulg nhau

Dich V\lkenh thue rieng la dich V\l cho thue kenh truyen dfut dUngrieng d€ k~t n5i giua cac thi~t bi delu cu5i, ml.iUgnQi bQ, ml.iUgvi~nthong dung rieng cua khach hang tl.iicac dia di€m c5 dinh khac nhau

Dich V\lkenh thue rieng dap tmg duQ'c cac nhu du k~t nbi t:rgc ti~ptheo phuong th(rc di€m n5i di€m giua hai delu cu5i Cllakhach hang

Cae die tinh ella dieh vu:

- Toan' quy~n su d~g keclI lien ll.iclien t\lC 24 gialngay, 7 ngay/tuc1n., '

- Tinh bao m~t, va tinh s~n sang cao (do khong phai chia se dUOng,~:Et ~

- Dap tmg mQi dich V\l: Thol.ii(IP hOZlCPSTN), fax, hinh anh, truy~n s6' ~~

- Truy~n dfut theo thai gian thlJc

- T5c dQ dap tmg yeu celucua khach hang

- Cung ca cac k~t n5i theo tieu chuAn di€m- di€m, di€m - da di€m

La dich V\l cung cap ml.ingrieng ao (VPN) tren nen hl.itang bang rQng

6Layer 3 (lap 3) d€ k~t n5i cac ml.ingmay tfnh tl.iicac vi tri dia ly khacnhau (nQi tinh, lien tinh, )

Cae d~e tinb, elll! diehV\l:

Quvin 1:Cae thuat ngfi kpthuat viln thOng Phan 3.Mang ea tlinh

- Chi phi thfip Day Iii giiii phap k6t n6i thong tin m&i vm chi phi thfip hon OOien so v&i cac cong ngM tnr&c day OOu Leasedline,

FrameReiay.

- TiOO liOO ho~t vii 6n djnh cao theo cac yen cAn rieng bi~t cua ~ach hang.

- Khii nang trien khai cung cfip dich Y\l OOanh chOng vii thu~ ti~n.

- K6t n6i di~n rQng: NQi tiOO, lien tinh, qu6c t6.

- H~ tAng da d~g: ADSL, ADSL2+, FTTx, , ca d6ng, ca nang.

DQ tr€ Iii khoiing thai gian tir hIe goi tin duQ'c gtri di cho den khi OO~n duQ'c goi tin phiin h6i tir phia dich.

DQ tr€ phiin anh muc dQ nghen duang truyen, dQ tr€ ti I~ thu~ v&i muc dQ nghen duang tru en.

Ty I~ mat goi Iii tY I~ gifra so goi tin bi mat vm tong so goi tin truyen qua k6t n6i trong mQt dan vi thai ian.

Ti I~ goi tin 16i Iii tY so gifra so goi tin bi 16i CRC v&i tong so goi tin truyen ua k6t n6i trong mQt khoiin thai ian.

Bi6n thien dQ tr€ Iii SlJ khac bi~t ve dQ tr€ cua cac goi tin khac OOan tren cling hu6'ng di ho~c ve.

- Toc dQ tiii dfr li~u trung biOO gom hai 10~i: Toc dQ Uli xuong trung biOO vii t6c dQ tiii len trung binh.

- T6c dQ tiii dfr li~n trung binh Iii tY s6 gifra t6ng dung Iuqng tiii len!xu6ng tren t6ng thai gian thlJc hi~n tiii Ien!xu6ng.

Bang thong Iii toc dQ dfr li~u toi da mii duang truyen co the dap (mg.

Don vi do: Bps (bit per second), Kbps (Kilobit per second), Mbps (Me abit er second), Gb s (Gi abit er second),

Hi~n suat su d1,1ngbang thOng cua mQt kenh Iii tY I~ gifra luu Iuqng ",~~,1\6.

truyen qua keOO v&i "Dung luqng khai bao" cua keOO do trong mQt ~~ (~

"D~ng Iuqng 10ai ~ao" cho keOO dU<lc xac dinh theo n&uye~ tac: ~:;;\ ;~ •

- Doi v&i cac ket noi Ethernet tT1Jc,tiep (khong qua truyen dan SDH) \~, !~~~~~

thi "Dung luqng khai bao" dUng bang dung luqng giao di~n v~t Iy ~~~51G

- D6i v&i cac k6t n6i qua SDH thi "Dung Iuqng khai bao" duQ'c xac diOO OOu sau: lxSTMI ~ 150M, lxSTM4 ~ 600M, lxSTM16 ~ 2.4G.

Thai gian thi6t I~p dich V\l duQ'c tiOO tir hIc DNCCDV vii khach hiing

kY hQ'P d6ng cung dp dich Y\l (vi d1,1:Dich Y\l ADSL) cho tm khi khach hang co the su d\lng dich V1,1 niiy.

Thai gian sua chUa 16i dich Y\l tiOO tir Iuc cac keOO tiep xuc oo~duQ'c phiin anh cua khach hiing t&i luc khic ph\lc xong I6i dich V\l vii khach hang su d\lllg dich V\l biOO thuang (slJ c6 duQ'c ghi oo~tren M th6ng BCCS)

33

Ouyin 1: Cae thuat ngir kV thuat viin thOng Phan 3 Mang cDitinh

M~g PSTN (Public Switch telephone Network) la m~g di~n tho~i

m~ch dien

Tili CP

La tY I~ phfuI tram (%) chi~m d\ll1gbQ xu Iy CPU tren node m~g (h~

- NextTV cho phep nguoi dung djch V\l xem cac keOOtruyen hinhtruyen th6ng Ngoai ra NextTV con cung cap cho nguoi dung cac djchV\ltruyen hinh ''tuang tac" OOuphim theo yeu cAu(VOD), Karaoketheo yeu cAu, Shopping Online, Giao d\!c tl:rxa

Trung tilm Truyen hinh cap (Headend System) la nai t~p hQ'Pva chQn

d~n m~g truy OO~p- thue bao

hinh s6 thaOOtin hi~u hinh dua vao TV

Djch V\l CATV (Community Access Television): La dich V\!xemtruyen hiOOqua m~g cap hfru tuy~n trong d6 tin hi~u truyen hiOO

Cae a~e di~m eua dieh V\I:

- CATV cho phep ngum dung xem cac keOOtruy8n hiOOtuan.Kt1Jva

Ouyin 1: Cae thulit ngic leV thulit viln thOng Phan 3 Mang cDilinh

cac kenh truyen hinh so co dQnet cao Ngoai ra, CATV con cung capcho nguai dung cac dich Y\ltruy nh~p Internet qua M th6ng cap d6ngtl1lCsu d\ltlg cong ngM EoC (Internet over Cable)

35

Ourin 1: Cac thuat ngii kV thuat viin thOng

Phan4 Mang truvin dan

T

1.

Sqi quang la sgi tMy tinh dugc ch~ t~o nhfun m\lC dich truy~n dful tin hi~u dum d~g song quang hQc vm t6c dQ va dung lugng l6n, suy hao th&pva khong co xuyen nhiSu Khoang cach va t6c dQ Clla truy~n dful qua sqi quang bi gim h~ boo suy hao va tan s~c.

Lap~io L<rpYO Lui

(coating) (,e.laddingl (core)

Hinh 9:C6u t(lO wi quang

L5i sqi quang la phArrtrung tam cua sqi quang ma phArrl6n cong su&t quang dugc truy~n trong do.

BUGC song nhin th&ynfun trong khoang ill 0,4~m d~n 0, 7~m sgi thuy tinh th~ch anh khohg lam t6t avimg linh sang nhin th&y Trong vimg nay song linh sang suy hao l6n d~n muc chi dUng cho cac tuy~n thong tin co CIJli ngk.Suy hao trong vimg ill ngo~ th~ chi con l6n hon Tuy nhien, trong vimg h6ng ngo~ co 3 khoang rna sqi thuy tinh lam vi~c hi~u qua, ba khoang nay quanh cac bUGCsong 850nm, 1310 nm, 1550 nm va dugc gQi 1a 3 cua s6 quang hQc.

f)uang kinh truang mode la duang' kinh cua hinh tron, tren ti~t di~n ngang cua sqi quang co cuang di}linh sang t~ ria d~t lie (trong do e 1a s6 logarit tIJ nhien 2.1828) gia tri CIJCd~ cua pharr b6 cuang di} linh sang sqi quang theo hu6ng hai bien f)uang kinh truang mode biSu tm ph~ vi pharr b6 truang di~n tu ngang cua cac mode trong m~t dt Cllasgi.

Mode song la mQt tr~g thai truy~n 6n diM cua song linh sang (ciing co thS hiSumi}t mode 1a mQt tia), m6i mQt mode song Ung vm mQt cach thuc truy~n song khac nhau f)S dS hiSu co thS hinh dung nhu sau: Anh sang truy~n d~n m~t c~t cua sgi quang vm nhi~u g6c tm khac nhau, m6i goc t6i Ung vm mQt duang di Clla linh sang trong sgi quang, m6i duang di nay co thS hiSu 1amQt mode truy~n dful cua linh sang.

Ouyin 1: Cac thuat ngir kii thuat viin thOng Phan4 Mang tTuyin dan

dun mode

Sgi dan mode (Single mode) lit sgi chi cho phep mQt mode truy~n ddn trong no Sgi dan mode co 16i r~t nh6 thuemg khoang tU 8 • 10 lJID Vu di6m cua sgi dan mode lit chi ghep mQt mode nen khong co tan s~c mode bilng tAn cua sgitang len.

Sgi da mode (Multi mode) lit sgi cho phep truy~n dful nhi~u mode trong

no, vm m6i mQt mode lit mQt mfiu cac duemg song tfUemg di~n vit truemg

tU dugc l~p di l~p l~ dQc theo sgi a cac khoang cach wang duang v6i bu6c song).

Multi.mode fiber

Sgi G.652lit sgiquang dan mode thuemg dugc sir d\lIlg ph6 biSn vm M

th6ng truy~n ddn dan bu6c song khoang cach xa

37

Ourin 1: Cae thuat ngil'kV thuat viin thOng Phlin4 Mang truy~n dan

Ban kfnh (Jlrn)

0,250,50,75

qi G.655 eo hai lo~ nbi ti6ng 1a sqi LEAF eua Corning va sqi ella rueWave eua Fujikura

Chief sua't (%)

Tan s~e la S\J dan rQng xung 8nh sang khi Ian truySn trong sQ'iquang Tan s~c Ian se lam mea tin hi~u va t~o ra hi~n tugng giao thoa giua cae kytl! (ISI- Intersymbol Interferenee) do S\J dan xung t~ eae khe thai gian h~u qua la lam eho phia thu khong pharr bi~t dUQ'etin hi~u -7 Thu sai.