gsm fundas

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GSM Fundamentals & RF

GTL welcomes you to the Basiccourse on GSM Fundamentals &

RF (GTL-GSM RF-001)



hat you will learn here!" Basic Telecom conce#ts

" $arious ireless Technolo%ies

" ellular conce#ts & 'rinci#al o cellular omm

" GSM *etwor+ ,rchitecture

" GSM channel ,rchitecture

" all Flows in GSM

" GSM 'lannin% ste#s (*ominal 'lan & RF sureys)

" GSM .#timi/ation Ste#s ( 'erormance rie testin% &

Benchmar+in%)



B,S2 Tele#hony

•Off Hook

•Dial Tone

•Dialing Digits

•RBT

•Conversation

•Ring

•Off Hook &

Conversation

•Signaling•Traffic

SWITCH / EXCHANGE



ireless ommunication

" ,lternatie means o wireless communication

3 Walkie - Talkie

3 Pagers

3 Trunked private radios

" Mo4ile 'hone - the ma%ic technolo%y that ena4les

eeryone to communicate anywhere with any4ody



ireless Tele#hony

BSC

BTS BTS

Mobile Sbs!"ibe"###

MSC



ierent Standards orldwide

" Till 1567 ellular Systems were e8clusiely ,nalo% Radio

Technolo%y

" ,danced Mo4ile 'hone Serice (,M'S)

3 9S standard on the 600 M:/ Band

" Total ,ccess ommunication System (T,S)

3 9; standard on 500 M:/ 4and

" *ordic Mo4ile Tele#hone System (*MT)

3 Scandinaian standard on the <=0 & 500 M:/ 4and



GSM $ %GSM $ %

T'e te"( GSM$% is se) fo" an* GSM s*ste( +'i!' o,e"ates in an* % MH- ban)#

.$GSM $ %

.$GSM$% ban) is t'e ,"i(a"* ban) fo" GSM$% "e0en!* ban) fo" ,"i(a"* GSM$% 1.$GSM$%2 3 4 5

46 MH-

7% 8 %96 MH- fo" MS to BTS 1,link2

%:6 8 %; MH- fo" BTS to MS 1)o+nlink2

E$GSM $ %

In so(e !ont"ies< GSM$% is allo+e) to o,e"ate in ,a"t o" in all of t'e follo+ing e5tension ban)# E$GSM$

% 1E5ten)e) GSM$%2 ban) in!l)es t'e ,"i(a"* ban) 1.$GSM$%2 and t'e e5tension ban) 3

77 8 7% MH- fo" MS to BTS 1,link2

%46 8 %:6 MH- fo" BTS to MS 1)o+nlink2

R$GSM$%R$GSM$%

R$GSM$% 1Rail+a* GSM$%2 ban) in!l)es t'e ,"i(a"* ban) 1.$GSM$%2 an) t'e follo+ing e5tension

ban)3

7=; 8 7% MH- fo" MS to BTS 1,link2

%49 8 %:6 MH- fo" BTS to MS 1)o+nlink2

GSM$97GSM$97

"e0en!* ban)3 4 5 =6 MH-

9=9 8 9=76 MH- fo" MS to BTs 1,link2

976 8 977 MH- fo" BTS to MS 1)o+nlink2




2ndustry $s Technolo%y S#read

" Telecom Serice 'roiders>.#erators

3 GSM

3 M,

3 Basic-LL

3 2nternet Serices

3 Lon% istance

" $endor

" Telecom onsultancy



,nalo% Mo4ile Tele#hony

" ?nd o 1560@s ,nalo% Systems una4le to meet continuin%

demands

3 Seerely conined s#ectrum allocations

3 2ntererence in multi#ath adin% enironment

3 2ncom#ati4ility amon% arious analo% systems

3 2na4ility to su4stantially reduce the cost o mo4ile

terminals and inrastructure reAuired



i%ital Mo4ile Tele#hony

" S#ectrum s#ace - most limited and #recious resource

" Solution - urther multi#le8 traic (time domain)

" an 4e reali/ed with i%ital TechniAues only



GSM :istory and .r%ani/ation

" 155 ?uro#e wide reAuency 4and resered or

ellular

" 1567 CGrou#e S#eciale Mo4ileD created within

?'T

" 156E GSM had ull time in 'aris

" 1566 ?TS2 ta+es oer GSM ommittee

" 1550 The #hase 1 GSM Recommendations

ro/en

" 1551 GSM ommittee renamed CS#ecial Mo4ile

Grou#D and GSM renamed as CGlo4al

System or Mo4ile ommunicationD

" 1557 GSM launched or commercial

o#erations



Serice 2ndustry" Serice 'roider is not a ?Aui#ment Manuacturer

" The Serice 'roider has a license to o#erate in a

%eo%ra#hical 4oundary (state>circle> country)

" 2t 4uys eAui#ment rom .?M Su##liers ($endors)

" 2nstalls & commissions the eAui#ment thus ma+in% it@s

own *etwor+

" 'roides the desired serice to it@s su4scri4ers



$endor

" $endor is a ?Aui#ment Manuacturer

" 2t su##lies 'roduct onsultancy and Trainin%s

" Serice #roider has the o#tion o ta+in% the onsultancy

and Trainin%



ellular ommunication" , cellular system lin+s Mo4ile su4scri4ers to 'u4lic

Tele#hone System or to another Mo4ile su4scri4ers

" 2t remoes the i8ed wirin% used in a traditional tele#hone

installation

" Mo4ile su4scri4er is a4le to moe around #erha#s can trael

in a ehicle or on oot & still ma+e & receie call



,danta%e o ellular

ommunication" Mo4ility

" Fle8i4ility

" oner%ence

" Greater .S

" *etwor+ ?8#ansion

" Reenue>'roit



:,T 2S ?LL9L,R T?L?':.* !

.*S2?R,T2.*S -

FR?9?*

S9BSR2B?R

?*S2T

.$?R,G?

Base Station

Base Station

Base Station

Base StationBase Station

Base Station



The ell" ellular Radio inoles diidin% a lar%e serice area into

re%ions called CcellsD

" ?ach cell has the eAui#ment to switch transmit and receie

calls

" ells - Reduce the need o :i%h #owered transmission

" ells - onentionally re%arded as 4ein% he8a%onal 4ut in

reality they are irre%ularly sha#ed

" ell sha#e is determined 4y the nature o the surroundin%

area e% :ills tall 4uildin% etc



ell Si/e

" Lar%e ells

" H= ;m

" Remote ,reas

":i%h Transmission'ower

" Few su4scri4ers

" Small ells

" *ear a4out 1 ;M

" 9r4an ,reas

"Low Transmission'ower

" Many Su4scri4ers



oera%e & a#acity

" oera%e

3 'ercenta%e o the %eo%ra#hical area coered 4y cellular

serice where mo4ile tele#hony is aaila4le

" a#acity -

3 *um4er o calls that can 4e handled in a certain area

within a certain #eriod o time 3 a#acity can also reer to the #ro4a4ility that users will

4e denied access to a system due to the sim#le

unaaila4ility o radio channels



FreAuency S#ectrum

Designation Abb"e>iation /"e0en!ies /"ee$s,a!e Wa>elengt's

Very Low Frequency VLF 9 kHz - 30 kHz 33 km - 10 km

Low Frequency LF 30 kHz - 300 kHz 10 km - 1 km

Medium Frequency MF 300 kHz - 3 MHz 1 km - 100 mHigh Frequency HF 3 MHz - 30 MHz 100 m - 10 m

Very High Frequency VHF 30 MHz - 300 MHz 10 m - 1 m

Ultr High Frequency UHF 300 MHz - 3 !Hz 1 m - 100 mm

"u#er High Frequency "HF 3 !Hz - 30 !Hz 100 mm - 10 mm

$%tremely High Frequency $HF 30 !Hz - 300 !Hz 10 mm - 1 mm



GSM - 2* ?LL9L,R

T?L?':.*" ?ach ell in the ellular *etwor+ consists o one or more

RF carriers

" ,n RF carrier is a #air o radio reAuencies

3 .ne used in u#ward direction 4y MS - 9#lin+

3 .ther used in downward direction 4y BTS - ownlin+

3 The transmit and receie reAuencies are se#arated 4y a%a# o <= M:/ in GSM o = M:/ in S

" There are 17< carries in GSM Band ith each carriercarryin% timeslots only 17< 8 I 6E6 calls can 4e madeJ

" FreAuency Reuse is the solution



FreAuency & ,RF*

l ?

7 %

& t o

% 9 6

M H -

) l ?

% : 6

t o % ;

& M

H -

l1n2 ? 7%# @ 1#42 n MH-

)l1n2 ? l @ 6 MH-

+'e"e n ?ARCN 9 n 94



.o+e"

"e0en!*

Ti(e

FDMA

"e0en!*

.o+e" Ti(e

TDMA

"e0en!*CDMA

.o+e"

Ti(e

Multiple Access Methods



/ " e 0

e n ! *

T i ( e

.o+e"

TDMA

/ " e 0

e n ! *

T i ( e

.o+e"

DMA

/ " e 0

e n ! *

T i ( e

.o+e"

CDMA

C O D E

DMA3 AM.S & NAM.S

•$ch u&er occu#ie& #ri'te Frequency(#rotected )rom inter)erence through #hy&icl&e#rtion )rom other u&er& on the &me)requency

•TDMA3 IS$9:;< GSM

•$ch u&er occu#ie& &#eci)ic )requency *utonly during n &&igned time &lot+ ,he)requency i& u&ed *y other u&er& duringother time &lot&+

•CDMA•$ch u&er occu#ie& &ignl on #rticulr)requency &imultneou&ly with mny otheru&er&( *ut i& uniquely di&tingui&h*le *ycorreltion with &#ecil code u&ed only *ythi& u&er

Multi#le ,ccess Methods



FreAuency Reuse 'attern

Three ty#es o reAuency reuse #atterns

" ell reuse #attern

" < cell reuse #attern

" H cell reuse #attern



H Site Reuse 'attern!4

!9

!:

a9

a4

a:

b9

b4

b:

!9!4

!:

Cell Re$se



Cell Dia ? R

FR?9?* R? - 9S?

3 FreAuency Re-use

7/21 cell cluster

1

3

.

/

D D=R (3N)

where N is Cluster size



'rinci#al . Sectori/ation

" .mni irectional ells

" 170 de%ree Sectors

" E0 e%ree sectors

3 ?ach Sector in a Site has its own allocation o Radio

arriers

" ,danta%e

3 By reAuent reuse o reAuency more ca#acity can 4e

achieed



Multi#th Fding re&ult& in 'rition& in &ignl &trength which i& known &

2yleigh Fding+

2yleigh Fding #henomenon i& de#endent on #th di))erence nd hence

)requency o) rece#tion+

)&t mo'ing mo*ile my not e%#erience &e'ere e))ect o) thi& )ding &incethe #th di))erence i& continuou&ly chnging+

&low mo'ing mo*ile 4 or hlted mo*ile 5 my e%#erience &e'ere

deteriortion in qulity+

6ut( i) the )requency o) rece#tion i& chnged when thi& #ro*lem occur&(

could &ol'e it+ ,he )ding #henomenon i& )&t nd lmo&t continuo&( thi& men& the

)requency chnge &hould l&o *e continuo&+

,hi& #roce&& o) continuou&ly chnging )requency i& known & Frequency

Ho##ing+

FreAuency :o##in%



Frequency Ho##ing i& done in *oth U#link nd 7ownlink +

Frequency i& chnged in e'ery ,7M Frme

Mo*ile cn Ho# on m%imum . )requencie&

,he &equence o) Ho##ing cn *e 8yclic or 9on-8yclic

,here re 3 9on-8yclic Ho##ing &equence& #o&&i*le

7i))erent Ho##ing &equence cn *e u&ed in the &me cell+

68H ,ime&lot cn ne'er H:;( *ut the remining ,ime&lot& cn

'ery well ho#+

FreAuency :o##in%



Re)!tion in A>e"age Inte"fe"en!e

Wit' "e0en!* Ho,,ing !onsistent inte"fe"en!e +ill be!o(e b"st*#

So e>en t'og'< bot' t'e !o$!'annel !ells +ill be sing t'e sa(e set of ARCNs fo"

Ho,,ing< inte"fe"en!e +ill not be !ontinos#

T'is is be!ase< GSM !ells a"e not "a(e s*n!'"oni-e)< an) !'ange in f"e0en!* is"elate) to "a(e nos#

If sa(e HSN is se) in t+o !ells< t'en eit'e" t'e inte"fe"en!e +ill be nil < o" if a ,'ase

!o""elation e5ists t'en it +ill be !ontinos#

So t'e t+o !ells s'ol) ,"efe"abl* se )iffe"ent HSNs #

Se!to"ial !ells 1 !ont"olle) b* t'e sa(e BTS2 !an se sa(e HSN< sin!e t'e se!to"s )ont

!o(e , at t'e sa(e ti(e# Cells if t'e* a"e s*n!'"oni-e)< !an se sa(e HSN< if ea!' !ell 'as an offset of so(e

TDMA f"a(es#

Offset of TDMA f"a(es is also "e0i"e) to a>oi) SACCH o!!""ing at t'e sa(e ti(e in all

s*n!'"oni-e) !ells< as t'e* kills a+a* t'e obe!ti>e of DTX#

FreAuency :o##in%



a9

a4

a:a:

aa;

a6

ell Sectorisation

OMNI CEFF

9 ANTENNA

b9

b4

b:

94O CEFFS

: ANTENNAS

;O CEFFS

; ANTENNAS



Features o GSM" om#ati4ility

" *oise Ro4ust

" 2ncreased a#acity & Fle8i4ility

" 9se o Standard .#en 2nteraces

" 2m#roed Security & onidentiality

" leaner :andoers

" Su4scri4er 2dentiication" 2S* om#ati4ility

" ?nhanced Ran%e o Serices



:andoers

Ha") Han)off

Analog< TDMA an) GSM

Soft Han)off

CDMA

Brea+ 4eore Ma+e Ma+e 4eore Brea+



94&

979

9%7

4&&

9:4

B9

BB

;%

=6

99:

47

=9

=:

=&

7&

=

7

9994

9: 9;9=

97

9%

4&

44

46

:4

9=9

9=:

9=6

974

97=

9%%

4&9

49:

49B

496

49;

497

49%

44&

449

444

446

:andoers



leaner :andoers" The mo4ile measures u# to H7 adKacent cells or

3 Si%nal Stren%th (R8Leel)

3 Si%nal uality (R8ual)

3 u#dated eery <60 mS and sends to BTS" So#histicated :andoer 4ased on

3 R8Leel

3 2ntererence

3 R8ual

3 Timin% ,dance

3 'ower Bud%et



BT

S

BT

S

BT

S

BT

S

BT

S

BTS

BT

S

BT

S

BSC

F

R

HF

R EI

R

OM

C

SMS

CBC

A

C

MSC

MS

C

A b i

s

A

MS

BTS

BTS

BTS

BTSBTS

BTS

BTS

BTS

BSC

BSC

.STN

FR

TRAHFR

EIR

OMC

SMSC

BC

AC

MSC

MSC

A b i

s

A

:ML

GSM *?T.R; ?L?M?*TS



Mo4ile Station 2dentities

MSISDN < Humn =dentity u&ed to cll Mo*ile "ttion

IMEI< "eril num*er unique to e'ery Mo*ile "ttion

IMSI < 9etwork =dentity unique to "=M

3

digit&

digit&

10

digit& ,M"= < =dentity unique in L=

M"29 < Mo*ile "ttion

2oming 9o88 978 "9

%7 XXX 94:6

M88 M98 M"=9

XX 94:6

,8 F8 "92 "

digit& digit& digit& 1 digit



GSM *etwor+ om#onents" Mo4ile Station consists o two #arts-

3 Mo4ile ?Aui#ment (M?)

3 Su4scri4er 2dentity Module (S2M)

" M?

3 :ardware e% Tele#hone Fa8 Machine om#uter

" S2M

3 Smart ard which #lu%s into the M?



M? (lassmar+ 2normation)" Reision Leel

3 'hase o the GSM s#ecs M? com#ly with

" RF 'ower a#a4ility

3 Ma8 #ower M? is a4le to Transmit

" i#herin% ,l%orithm 9sed

3 'resently ,=

3 'hase 7 s#eciies ,l%orithms ,=>0 to ,=>

" FreAuency a#a4ility

" SMS a#a4ility



T*,i!al

Settings

Mo4ile ?Aui#ment

lass 'ower .>#

1 70

7 6

H =

< 7

= 06



S2M(2MS2)" 2MS2(2nternational Mo4ile Su4scri4er

2dentity)

3 Transmitted oer ,ir 2nterace on initiali/ation

3 'ermanently stored on S2M card

3 1= di%it ecimal



S2M (TMS2)

" Tem#orary Mo4ile Su4scri4er 2dentity

3 'eriodically chan%ed 4y the System Mana%ement on

instances li+e location u#date etc

" Reason or use o TMS2

3 To #reent a #ossi4le intruder rom identiyin% GSM users

TMS2 is used

" Mana%ement

3 ,ssi%nment ,dministration & 9#datin% is #erormed 4y

$LR



Transcoder

" onerts E< ;4#s 'M circuits rom MS to 1E ;4#s

BSS circuits

" ?ach H0 channel 7 M4#s 'M lin+ can carry 170 GSM -s#eciied oice channels



Base Station System (BSS)

" BSS (Base Station System)

3 BS (Base Site ontroller)

3 BTS (Base Transceier Station)

3 R (Transcoder)

Net+o"k

S+it!'ing

S*ste(

1NSS2XCDR

BSC

BTS



Base Station System (BSS)

" BS

3 ontrols u#to <0 BTS

3 oneys inormation to>rom BTS

3 onnects terrestrial circuits & ,ir 2nterace hannels

3 ontrols handoers 4etween BTSs under itsel

" BTS

3 ontains RF :ardware

3 Limited control unctionality

3 1 - E carriers in a BTS a4inet

3 - <6 simultaneous calls #er BTS



BSS oni%uration

" ollocated BTS

" Remote BTS

" Star oni%uration

" aisy hain BTS Loo# oni%uration

BSC

6,"

6,"

6,"

AllBTS

on9E9

BSC

6,"

6

,"

6,"

6,"



*etwor+ Switchin% System(*SS)

" *SS (*etwor+ Switchin% System)

3 MS (Mo4ile Switchin% entre)

3 :LR (:ome Location Re%ister)

3 $LR ($isitor Location Re%ister)

3 ?2R (?Aui#ment 2dentity Re%ister)

3 ,9 (,uthentication entre)

3 2F (2nterwor+in% Function)

3 ? (?cho anceller)



GSM *etwor+ om#onent

" MS

3 all Switchin%

3 .#eration & Mana%ement Su##ort

3 2nternetwor+ 2nterwor+in%

3 ollects call 4illin% data

" Gateway MS 3 MS which #roides interace 4etween 'ST* & BSS@s

in the GSM *etwor+



:ome Location Re%ister (:LR)

" Reerence data4ase or the Su4scri4er #roiles-

3 Su4scri4er 2 (2MS2 & MS2S*)

3 urrent $LR ,ddress

3 Su##lementary Serices su4scri4ed

3 Su##lementary Serice 2normation

3 Su4scri4er Status (Re%istered>dere%istered)

3 ,uthentication ;ey and ,9 unctionality

3 TMS2

3 MSR*



$isitor Location Re%ister ($LR)

" Tem#orary ata which e8ists as lon% as the su4scri4er is

actie in a #articular oera%e area

"ontains the ollowin%- 3 Mo4ile Status (Busy> Free> *o ,nswer>etc)

3 Location ,rea 2dentity (L,2)

3 TMS2 3 MSR* (Mo4ile Station Roamin% *um4er)



?Aui#ment 2dentity Re%ister (?2R)

" ontains ata4ase or alidatin% 2M?2

3 hite List (alid M?)

3 Blac+ List (Stolen M?)

3 Grey List (Faulty M?)



" 'roides unction to ena4le the GSM System to

interace with 'u4lic>'riate ata *etwor+s

" The 4asic eature o the 2F are 3 Rate onersion

3 'rotocol ada#tation

" 2F incor#orates Modem Ban+e% GSM T? 'ST* T?

2F ,nalo%ue Modem

2nter or+in% Function



?cho anceller

" ?cho is a##arent only in Mo4ile - Land conersation

& is %enerated at the 7 wire to < wire interace

" To aoid it ?cho anceller (?) is used

3 ?cho is irritatin% to MS Su4scri4er

3 Total Round Tri# delay o 160 ms in the GSM system

3 ? is #laced on the 'ST* side o the Switch

3 ancellation u# to E6 ms with ?



.#eration & Maintenance entre

" ?ent & ,larm Mana%ement

" Fault Mana%ement

" 'erormance Mana%ement

" oni%uration Mana%ement

" Security Mana%ement



GSM Terrestrial 2nteraces

Broadly classiied into two ty#es o interaces-

" Standard 2nteraces

3 7 M4#s Trun+s (?1)

3 Si%nallin% System *o SS ( S)

3 7= ('ac+et Switched Mode)

" GSM 2nteraces



GSM 2nteraces

" 9m MS - BTS

" ,4is BTS - BS

" , BS - MS

" B MS - $LR " MS - :LR

" $LR - :LR

" ? MS - MS

" F MS - ?2R

" G $LR - $LR

" : :LR - ,9



GSM protocols are basically divided into tree layers!

"ayer #! $ysical layer% &nables pysical trans'ission (TDMA FDMA etc)% Assess'ent o* cannel +,ality% &-cept on te air inter*ace (GSM Rec ././) $CM 3. or0SDN

lin1s are ,sed (GSM Rec .2/ on Abis inter*ace and.2./ onA to F inter*aces)

"ayer 4! Data lin1 layer% M,ltiple-in5 o* one or 'ore layer 4 connectionson control6si5nalin5 cannels% &rror detection (based on 7D"C)% Flo8 control% Trans'ission +,ality ass,rance% Ro,tin5

"ayer 3! Net8or1 layer% Connection 'ana5e'ent (air inter*ace)% Mana5e'ent o* location data% S,bscriber identi9cation% Mana5e'ent o* added services (SMS call *or8ardin5

con*erencecalls etc

GSM 'rotocol Layers



Basic 'rocesses" ,9T:?*T2,T2.*

" 2':?R2*G

" R?G2STR,T2.*

" ,LL ?ST,BL2S:M?*T

" :,*.$?R > :,*.FF

" R.,M2*G



,9T:?*T2,T2.* ,LG.R2T:M

NSS

MS

HFR

AC

ATH#AFGORITHMS

A:

SIM

MS

ATH#AFGORITHMS

A:

i

RAND

RAND

COM.ARE

SRES

SRES

i

AIR INTERACE



i#herin%" ata #rotection is reAuired on air interace

" , s#eciic +ey called i#herin% ;ey (;c) is

%enerated rom R,* and ,6 al%orithm

" ,6 is on the S2M

A7

RANDi

!



i#herin%

A6Data

!

Ci,'e"e)

Data A6

!

Data



Transmission Media

" ,ccess *etwor+

3 Microwae 1= >7H G:/

" Bac+4one *etwor+

3 Microwae G:/

3 .#tical Fi4ers

3 Leased Line( From ot or any other serice #roider

on any media)



.#tical Fi4er

• ierent 'ossi4le om4inations

• Mono Mode Ste# 2nde8 10 > 17= µm

• Mono Mode Graded inde8

• Multi Mode Ste# 2nde8 100 > H00 µm

• Multi Mode Graded 2nde8 = > 1H0 µm

• Mono Mode Graded 2nde8 would hae 4een the 4est 4ut

a4rication not #ossi4le

1<0 M4#s .LT? Mono Mode Ste# 2nde8 in our case



hannels .n ,ir 2nterace

" 'hysical hannel

" Lo%ical hannel

" 'hysical hannel

3 'hysical channel is the medium oer which theinormation is carried

" Lo%ical hannel

3 Lo%ical channels consists o the inormation carried oerthe 'hysical hannel



L.G2,L :,**?LS

0 1 3 . /

3

/

encry#ted

/

encry#ted

trining

1

"

1

"

3

,

>+/

!;

3

,

6== S

6== S 5 7 ? #;96(S

TDMA "a(e

No"(al B"st

4; "a(e Mlti$f"a(e



GSM hannels



Traic hannel

TCH carries payload data - speech, fax, data

" Connection may be:

- ircuit Switched - oice or data or - 'ac+et Switched 3 data

" TCH may be:

" Full Rate (T:>F)

- one channel #er user

- 1H +4>s oice 5E +4>s data or

" :al Rate (T:>:)

- one channel shared 4etween two users

Traffic Channels

TCH!!ull rate ""#$kbitss

TCHHHalf rate %%#& kbitss

" Time is diided into discrete #eriods called CTimeslotsD



ontrol hannel

DCCH17edicted 8hnnel&2Do+nlink & ,link

CCCH18ommon 8ontrol 8hn2Do+nlink & ,link

'ynch#Channels

RACH2ndom

cce&& 8hnnel

CBCH8ell 6rodc&t

8hnnel

SDCCHStandalone dedicated

control channel

(CCH,ssociated

ontrol hannels

'(CCHSlow associated ontrol hannel

!(CCHFast ,ssociated

ontrol hannel

PCH()CH

'a%in%>,ccess %rant

!CCHFreAuency

orrection channel

Cont"ol C'annels

BCH 1 6rodc&t chnnel& 2Do+nlink onl*

*CCHBroadcast

control channel

'CHSynchroni/ation

channel



Broadcast hannels (B:)

*CH channels are all do+nlink and are allocated to timeslot ero#

hannels are

" !CCH: FreAuency control channel sends the mo4ile a 4urst o all N0@ 4its which

allows it to ine tune to the downlin+ reAuency

" 'CH: Synchroni/ation channel sends the a4solute alue o the rame num4er

(F*) which is the internal cloc+ o the BTS to%ether with the Base Station 2dentity

ode (BS2)

" *CCH: Broadcast ontrol hannel sends radio resource mana%ement and control

messa%es Location ,rea ode and so on

Some messa%es %o to all mo4iles others Kust to those that are in the idle state



ommon ontrol hannels (:)

CCCH contains all point to multi-point do+nlink channels (BTS to

seeral MSs) and the uplink Random ,ccess hannel

" C*CH: ell Broadcast hannel is an o#tional channel or %eneral

inormation such as road traic re#orts sent in the orm o SMS

" PCH: 'a%in% hannel sends #a%in% si%nal to inorm mo4ile o a call

" (CH: Random ,ccess hannel is sent 4y the MS to reAuest a channel rom

the BTS or acce#t a handoer to another BTS

, channel reAuest is sent in res#onse to a ': messa%e

" ()CH: ,ccess Grant hannel allocates a dedicated channel (S:) to the

mo4ile

" .CH: *otiication hannel inorms MS a4out incomin% %rou# or

4roadcast calls



edicated ontrol hannels (:)

'/CCH0 'tandalone /edicated Control Channel 1

2plink and /o+nlink

2sed for call setup, location update and '3'#

'(CCH0 'lo+ (ssociated Control Channel 1

2sed on 2plink and /o+nlink only in dedicated mode#

2plink '(CCH messages - 3easurement reports#

/o+nlink '(CCH messages - control info#

!(CCH0 !ast (ssociated Control Channel 1

2plink and /o+nlink#

(ssociated +ith TCH only#



B9RST

" The Time Slots are arran%ed in a seAuence

conentionally num4ered 0 to

" ?ach re#etition o this seAuence is called a TM,

Frame

" The inormation content carried in one time slot is

called a C4urstD



B9RST" 2normation

3 Main ,rea where the S#eech ata or ontrol ino is held

" Guard 'eriod

3 To ena4le the 4urst to hit the time slot (00H1ms)

" Stealin% Fla%s

3 7 4its are set when T: is to stolen 4y a F,:

" Trainin% SeAuence

3 For estimation o transer characteristics o #hysical media" Tail Bits

3 9sed to indicate 4e%innin% and end o the 4urst



GSM Burst & TM, Frame

0 1 3 . / . / 30 1

FRAME 1 FRAME 2

Trainin5Se+,ence

0n*or'ation 0n*or'ation

GARD

.ERIODGARD

.ERIOD

TAIF BITS TAIF BITS



Fie Ty#es o Burst" *ormal Burst

Traic & ontrol hannels Bi-directional

" FreAuency orrection Burst

F: ownlin+

" Synchroni/ation Burst

S: ownlin+

" ummy Burst

B: arrier ownlin+

" ,ccess Burst

R,: 9#lin+



all Scenarios

" Mo4ile to Mo4ile

3 2ntra-city

3 2nter-city

" Mo4ile to Land

3 2ntra-city

3 2nter-city

" Land to Mo4ile 3 2ntra-city

3 2nter-city



Mo4ile To Land SeAuence

1

3

CHANNEF REJEST

DCCH ASSIGN

SIGNAFFING FIN

ESTABFISHED

REJEST OR SERICE

SET CI.HER MODE

SET$.

EJI.MENT ID

REJEST

ATHENTICATION

MS BSS MSC FR HFR .STNEIR

RACH

AGCH

SDCCH

SDCCH

Call

Info

.

/

CR

CC



7

COM.FEFTE CAFF

CAFF .ROCEEDING

% ASSIGNMENT COMMAND

INITIAF & INAFADDRESS 1IAM2

ASSIGNMENT COM.FETE

1ACM2

9

ANSWER1ANS299

CONNECT ACNOWFEDGE

SDCCH

SDCCH

ASSIGNMENT COM.FEFTE

MS HEARS RINGTONE

ROM FAND .HONE

AFTERING

RING TONE

STO.S

CONNECT

1!'annel2

1TCH2

ACCH

ACCH

ACCH

TCH

1!i"!it2

AACH

BIFFING STARTS

HelloK

MS BSS MS

C

FR HFR .STN EIR

all ontt



Su##lementary Serices" allin% Line 2dentiication

3 'resent

3 ,4sent

" onnect Line 2dentiication 3 'resent

3 ,4sent

" losed 9ser Grou# - 9G

3 .nly incomin%

3 .nly out%oin%

" .#erator ontrolled Barrin%



ata Sericesata rates su##orted as o today areata rates su##orted as o today are

7< ;4#s7< ;4#s

<6 ;4#s<6 ;4#s

5E ;4#s5E ;4#s

G'RS & ?G? im#lementation ta+es the dataG'RS & ?G? im#lementation ta+es the data

ca#a4ility to hi%her leel o the order o 16<ca#a4ility to hi%her leel o the order o 16<

+4#s and more+4#s and more



Customer..Expectation

• Good coverage – where ever he goes

• Good quality

• No loc!i"g

• #alue added services– $M$

– #oice %ail

– MM$

–Call &orward'call waiti"g– (ata'i"ter"et at high data rates

– )re)aid



Basic Network Design Objecties

*he asic o+ectives o& a wireless syste% are,

– C-#ERAGE, )rovide su.cie"t cell sites to deliver RF coverageo& the e"tire desired area/

– 03(NG'#E4C3E 5ENE*RA*-N, deliver su.cie"t sig"allevels to adequately )e"etrate uildi"gs a"d vehicles where

a))ro)riate/– *RAFFC, e"sure that "o cell ca)tures %ore tra.c tha" it ca"

ha"dle at the desired grade o& service 6i/e/7 loc!i"g)erce"tage8

– 5ERF-RMANCE, desig"7 co"struct7 a"d ad+ust the "etwor! todeliver reliale service &ree &ro% e9cessive origi"atio" a"d call

delivery &ailures7 dro))ed calls7 quality i%)air%e"ts7 a"dservice outages/

– EC-N-MC$, )rovide retur" o" i"vest%e"t su.cie"t to su))orto)erati"g a"d ca)ital e9)e"ses7 e9)a"d the "etwor! to ta!eadva"tage o& growth o))ortu"ities7 a"d retire costs o&co"structio" )rior to de)reciatio" o& the "etwor! equi)%e"t/

!i h " l D i



!igh "eel Design

0np,ts

– Covera5e ob:ectives• Area covera5e ob:ectives

• Covera5e penetration ob:ectives

– Morpolo5y data6cl,tter in*or'ation

– Terrain data and ;ector 'aps

– Tra<c ob:ectives

• N,'ber o* s,bscribers de9ned

• Tra<c per s,bscriber de9ned• Desired 5rade o* service de9ned

– City re5,lations

– BTS 7ard8are speci9cations

– "in1 B,d5et

– B,siness and "o5istical ob:ectives

• Capital b,d5et

• Ti'in5! la,nc data

• peratin5 reven,e ;s total costs

• ,tp,t

– Cell database and tra<c 'odel

– Co'posite covera5e plot

– &+,al po8er ando> bo,ndaries plot

CB + dD 2 2 ti



CBac+%roundD 2ssues 2m#actin% System esi%n

• Site ac+,isition– Availability o* s,itable candidate (b,ildin5 or land)

– 8ner interest

– Cost o* leasin5

– Fre+,ency clearance (SACFA)

– Govern'ent a,tority approval– Space constraints and oter constr,ction iss,es

• Candidate "ocation ? line o* si5t to te ob:ective

• Cl,tter type

• Terrain variations

• $ysical Bloc1in5 ? b,ildin5s oardin5s

• @ater

• M,'bai ? 7i5 end i5 tra<c areas are very close to8ater

Ma1es RF desi5n ',c 'ore callen5in5

• Deviation *ro' desired location i'pacts s,rro,ndin5

site locations



Design considerations o# Network $%&M'CDMA(

" 9nderstand %eo%ra#hical area as #er license a%reement

" eine coera%e e8#ectations in terms

3 .n road coera%e

3 2n-4uildin% coera%e (dierent #enetration mar%ins)

" a#acity considerations 3 4usy hour #er su4scri4er call attem#ts andminutes o use (?rlan%s)

" 1 ?rlan% is 1 call o 1 hour duration

" ecide num4er o sites 4ased on coera%e ca#acity reAuirement

" 'ro#a%ation tools used or this analysis

" Finali/e e8act site locations ater ield surey

" 2nitiate candidate identiication #rocess

" Site acAuisition>antenna #ositionin%

" Modiy e8istin% desi%n i site location chan%es



,r))ic ?

!rowth

nly&i&

"y&tem

:#timi&tion

"ite 8o'erge

8on)irmtion

"ite "erch ?

"election

;ro#gtion

model

'eri)iction

"y&tem@"ite

7imen&ioning

2F ?9etwork

;lnning

Mrket

2equirement

"ite cqui&ition

"ite 6uild

:#ertionl

9etwork

"ite "erch

;ln

;er)ormnceMonitoring

Flow hart or *etwor+ e#loyment



GSM 'lannin% Ste#s" $arious ste#s are listed 4elow

3 surey

3 Model Tunin%

3 *ominal 'lannin%

3 RF site Sureys 3 Reali/ed 'lannin%

3 FreAuency 'lannin%

" 2m#lementation

" .#timi/ation 3 rie Testin%

3 'erormance ,nalysis



*ominal 'lannin%

" 2t consists o #lannin% a set o sites on #lannin%

tool so as to #redict the coera%e o the tar%et

area

" Tool needs to 4e made intelli%ent so as to #redict

the coera%e as close as #ossi4le to actual

coera%e

" oera%e #lots are 4ased on customer intensiono #roidin% indoor and outdoor coera%e

M b i C E t ti B d



Mumbai ) Coerage Expectation Boundar*



Coverage Maps – Reverse Link.

Colaba

Malaba" Hill

Ma-gaon

L?:)B33 :$ +all !o>e"age

46$:)B 3 : Wall Co>e"age

4:$46 )B 3 4$: Wall Co>e"age

97$4:)B3 4$: Wall Co>e"age

9;$97 )B 3 4 Wall Co>e"age

7$9;)B 3 9$4+all Co>e"age

7 )B 3 On Roa)$9 Wall Co>e"age

)B 3 On Roa)/No Co>e"age

In)oo" Co>e"age3

.enet"ation Ma"gin Fegen)



Composite Coerage +lot

• 5ro)agatio" %odels are used to)redict coverage &ro% a )articularsite

• A co%)osite coverage )lot shows theoverall coverage )roduced y eachsector i" the :eld o& view

• *he color o& each )i9el corres)o"ds

to the sig"al level o& the stro"gestserver at that )oi"t

• $uch )lots are use&ul &or ide"ti&yi"gcoverage holes a"d overall coveragee9te"t



lutter Ty#es

" lutter ty#es

3 ense 9r4an

3 9r4an

3 Su4 9r4an

3 Rural

3 ater

3 $e%etation 3 2ndustrial

3 Forest



RF sureys

" ?ach nominal has a search rin% deined 4y the RF'lanner

" andidates needs to 4e identiied as close as

#ossi4le to the nominal within the search rin%

" :ei%ht orientations & antenna #lacement at siteare the +ey RF #arameter which are 4ased u#onthe coera%e reAuirement in the area

" MaKor o4structions and clutter ty#e in ariousdirections to 4e o4sered on RF surey



RF sureys

" ?Aui#ment reAuired or RF Surey 3 G'S

3 i%ital amera

3 Binoculars

3 Ma%netic om#ass

" There mi%ht 4e H or more candidates sureys orone site

" ?ach candidate would hae an RF surey ormand #anoramic associated with it



rie Testin%" rie testin% is an im#ortant actiity to %et statistics & %ra#hs oncoera%e Auality & ca#acity in the downlin+ direction

" rie test setu# 3 T tool ?n%ineerin% :andset G'S

accessories

" all in 7 modes"edicated 3 while the mo4ile is on call

"2dle 3 while the mo4ile is idle

2m#ortant #arameters o4sered durin% drie testin%

"oera%e 3 R8 leel (Full & Su4)

"uality 3 R8ual & S2

":andoer ro##ed call *ei%h4or list T,

&electing and ,uning



&electing and ,uning+ropagation Models

• 5ara%eters o& )ro)agatio"%odels %ust e ad+usted &orest :t to actual drive;test%easured data i" the areawhere the %odel is a))lied

• *he :gure at right shows

drive;test sig"al stre"gthsotai"ed usi"g a testtra"s%itter at a" actual testsite

• *ools auto%ate the )rocess o&co%)ari"g the %easured data

with its ow" )redictio"s7 a"dderivi"g error statistics

• 5redictio" %odel )ara%etersthe" ca" e <tu"ed= to%i"i%ize oserved error



rie Test Screen



-hat is +er#ormance Optimiation/

• *he words <)er&or%a"ce o)ti%izatio"= %ea" di>ere"t thi"gs todi>ere"t )eo)le7 viewed &ro% the )ers)ective o& their ow" +os

• $yste% 5er&or%a"ce -)ti%izatio" i"cludes %a"y di>ere"t s%aller)rocesses at %a"y )oi"ts duri"g a syste%?s li&e

– recog"izi"g a"d resolvi"g syste%;desig";related issues 6ca"?tuild a crucial site7 too %uch overla)'so&t ha"do>7 coverage

holes7 etc/8– <cluster testi"g= a"d <cell i"tegratio"= to e"sure that "ew ase

statio" hardware wor!s a"d that call )rocessi"g is "or%al

– <:"e;tu"i"g= syste% )ara%eters to wri"g out the est )ossilecall )er&or%a"ce

– ide"ti&yi"g causes o& s)eci:c )role%s a"d custo%er

co%)lai"ts7 a"d :9i"g the%– care&ully watchi"g syste% tra.c growth a"d the )role%s it

causes ; i%)le%e"ti"g short;ter% :9es to ease <hot s)ots=7 a"drecog"izi"g )role%s e&ore they eco%e critical



.#timi/ation

" .#timisation is an on%oin% #rocess o analysin% networ+ #erormance

a%ainst uality o Serice tar%ets



'erormance

"Measurements o networ+ #erormance coer

" Traic in erlan%s

" T: and S: Grade o Serice (on%estion)

" all success rate

" :andoer ailure

" oera%e area

" oera%e Auality

" Su4scri4er 4ase and %rowth

" ;ey 'erormance 2ndicators (;'2) are measura4le dynamic

#arameters that hel# to tar%et areas o concern



;'2@s

" ,##ro#riate ;'2s to use de#end on

" The nature o the networ+

" ata sources aaila4le

" Measurement tools aaila4le

" ,4ility o en%ineerin% team

" ost o networ+ inrastructure

" Sources o data include

" Sureyed data - rom drie tests" *etwor+ statistics - rom .M

" Field en%ineer re#orts



Radio 2nterace .#timi/ation" Transmission Timin%

" 'ower ontrol

" $, $oice ,ctiity etector and T

" Multi#ath Fadin%

" ?Auali/ation

" iersity

" FreAuency :o##in%

" ,ntenna 'arameters ( :ei%ht ,/imuth Tilts )



,ntenna Tilts



Benchmar+in%"Sureyed data rom test-mo4ile measurements can 4e used to

4enchmar+ system #erormance a%ainst that o a com#etitor

" 'ro4lems that may 4e identiied rom sureyed data

" 'oor coera%e

" 9ne8#ected intererence

" Missin% handoer deinitions

" 2nstallation #ro4lems at BTS

" Test-mo4ile measurements should include

" continuous calls to test coera%e

" re#etitie short calls to test call-success



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