2.OWA310005 GSM&UMTS Softswitch Core Network Principle ISSUE 3.2

8/17/2019 2.OWA310005 GSM&UMTS Softswitch Core Network Principle ISSUE 3.2

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Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

!"#$"T! !o%t!witch Core &etwor'

(rinciple


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Page2Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

)*+ectives

$pon completion o% this course, you will *e a*le to

-escri*e the so%t switch core networ' structure

-escri*e the so%t switch core networ' wor'ing principle

-escri*e the so%t switch core networ' technical%eatures


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Contents

. !o%t !witch Core &etwor' !tructure

2. !o%t !witch Core &etwor' /or'ing (rinciple

. !o%t !witch Core &etwor' Technical 1eatures and

Advantages


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Contents

1. Soft Switch Core Network Structure



Advantages


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3GPP R99 3GPP R4 3GPP R5

GSM→CS

GPRS→PS

C& is composedC& is composed

o% C! domain and (!o% C! domain and (!

domaindomain

Adopt /C-"AAdopt /C-"A

$TA&$TA&

3u inter%ace3u inter%ace*etween A& and*etween A& and

C& is *ased on AT"C& is *ased on AT"

CS：Softswitch

PS

C! domainC! domain

change control ischange control is

separated %romseparated %rom

*earer*earer

(ac'et voice(ac'et voice

supported *y C!supported *y C!domain, supportingdomain, supporting

AT", 3(, T-"AT", 3(, T-"

Tr1) Tr1)

!!4# !3TA&!!4# !3TA&

CS：Softswitch

PS

Adopt 3"! domainAdopt 3"! domain

3(3(

IMS

aise o% !o%t !witch Core&etwor'


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$"T! 5 Core &etwor'!tructure

GSM /GPRS BSS

BTS

BSC

NodeB

RNC

PC

U

UTRN

SCPSMS

SCE

PSTN/P!MN

I"te#"et$I"t#a"et

HLR/AuC

SGSN

CGBG

GGSN

GPRS%ac&%o"e

MGWMGW MGWMGW

'MSC Se#(e#

GMSC Se#(e#

IP/TM Bac&%o"eCSDomain

PSDomain

I)*CS

I)*PS

SS7

+the# P!MN


7/59Page,Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

5 !o%t !witch C& !tructure

UTRN

SS,

PSTN/IS-N

BSS

SIGTRN

SCP SMS

SCE

HLR

PP Se#(e#

.240

BICC'MSC Se#(e#

IP1TM Bac&%o"eMGW MGW

MR/RTP1!2

GMSC Se#(e#

.240

RNP

GSM/R P!MN

IP Netwo#&

T-M

!2 T-M

T-M

IP

BSSP

MP/CP


8/59Page0Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

1eatures o% !o%t !witch C&

!eparated structure o% !ignalling and 6earer

"ulti voice transport modes T-", AT", 3(

"ulti signalling transport modes

T-" *ased !!47

3( *ased !3TA&

Adopts 63CC, H.258 protocol and Tr1) technology.


9/59PageCopyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

1unction o% "!C !erver

The signalling %unctions o% "!C and L %unctions

The *illing %unction

The control o% "/s via H.258 protocol

The inter9wor'ing %unction o% other "!C !erver via 63CC

protocol

MG

MSC Se#(e#

H.248

MSC Se#(e#

H.248

BICC

MG



1unction o% "/

The switching %unction o% voice service.

The trans%orm o% various transport %ormat: T-"#AT"#3(;

(roviding the media related resource

Cooperate with "!C server via H.258 protocol

MG

MSC Se#(e#

H.248

MSC Se#(e#

H.248

BICC

MG



1unction o% !ignalling ateway

(roviding the trans%orm o% !!4 protocol stac' and !3TA& protocol

stac' :!3TA& "$A #!CT(#3( !!4 "T(#2#;

! can *e a stand alone e?uipment or com*ined with "!C

!erver#"/#!T(

SG MSC Se!e PS"#

"DM IP

IP

SCTP

M3U

ISUP

MTP

MTP2

MTP3

ISUP



Contents


2. Soft Switch Core Network Working Principle


Advantages




2.1 Equipment Number

2.2 Area &um*er

2. &etwor' 3nter%aces

2.5 Typical /or'ing (rocedures

Contents



"!3!-&

CC NDC SN

National ( Significant ) Mobile Number

MSISDN: Mobile Station International ISDN number

CC: Country Code

NDC: National Destination CodeSN: Subscriber number



3"!3

MCC MNC MSIN

3 digits 2/3 digits

Not more than ! digits

IMSI (International Mobile Subscriber Identity)

NMSI

"CC "o*ile Country Code "&C "o*ile &etwor' Code

"!3& "o*ile !u*scri*er 3denti@cation &um*er

&"!3 &ational "o*ile !u*scri*er 3dentity



T"!3

TMSI Temporary "o*ile !u*scri*er 3denti%y !unction Ta'ing the place o% 3"!3 to *e trans%erred in radio

inter%ace to ensure the security o% su*scri*ers in%ormation.

Structure consists o% 5 octets, and the structure and coding

can *e chosen *y agreement *etween operator and

manu%acturer in order to meet local needs.

T"pe

T"!3, used in C! domain, allocated *y L7

Note# the T"!3 has only local signi@cance :i.e. within a L

and the area controlled *y a L;.


17/59Page,Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

3"B3

"#C SN$ S%#$&

digits' digits

IM&I (International Mobile &uiment Identity)

* digits

The 3"B3 is composed o% the %ollowing elements :each

element shall consist o% decimal digits only;

Type Allocation Code :TAC;. 3ts length is 8 digits7

!erial &um*er :!&; is an individual serial num*er uni?uelyidenti%ying each e?uipment within each TAC. 3ts length is

digits7

!pare digit this digit shall *e Dero, when transmitted *y the "!



"!&

MS$N "o*ile !tation oaming &um*er

!unction to route calls to called "!#$B

Structure the same as "!3!-&

Note#

The "!& must not *e used %or su*scri*er dialling.

The "!& normally uses num*er segment diEerent %rom that o%

"!3!-&.

"!& is allocated *y the L that the called "! is visiting.




2. B?uipment &um*er

2.2 %re& Number



Contents


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Area &um*er

$e%%Se!i$e

aea

PLMN B

PLM# A

Lo$a&ion

aea/

Rou&in'

aea

MSC/(LR

aea

SGS#

aea

PLM#

aea


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(L"& 3denti@er

(L"& 3denti@er is used to uni?uely identi%y a

(L"& networ' in the world.

MCCMCC

M#CM#C

PLM# ID

"CC "o*ile Country Code7 "&C "o*ile &etwor' Code.


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!ervice Area 3denti@er The !ervice Area 3denti@er is used to identi%y an area consisting

o% one or more cells *elonging to the same Location Area. !ervice

Area can *e used %or indicating the location o% a $B to the C&.

MCCMCC M#CM#C

Se!i$e Aea I)en&i*ie

LACLAC SACSAC

!A3 = LA3 G !AC

!AC !ervice Area Code, 2 octets, using a %ull

heFadecimal representation


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MCCMCC M#CM#C

Ce%% G%o+a% I)en&i*i$a&ion

LACLAC CICI

Cell lo*al 3denti@cation

C3, Cell lo*al 3denti@cation, the uni?ue identi@er o%

a Cell in the (L"&.

C3 = LA3 G C3

C3 Cell 3dentity, is o% @Fed length with 2 octets and it

can *e coded using a %ull heFadecimal

representation. Cell 3dentity must *e uni?ue within a

location area.


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2. B?uipment &um*er

2.2 Area &um*er

2.' Network Interf&ce#


Contents


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!o%t !witch C& 3nter%aces

UTRN

SS,

PSTN/IS-N

BSS

SIGTRN

SCPSMS

SCEHLR

PP Se#(e#

H.248

BICC'MSC Se#(e#

IP1TM Bac&%o"eMGW MGW

MR/RTP1!2

GMSC Se#(e#

H.248

RA#AP

GSM/R P!MN

IP Netwo#&

T-M

!2 T-M

T-M

IP

BSSP

MP/CP

Nc

McI) UP

I) CS CP

#+

ISUP


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Page2,Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

3nter%aces List


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3nter%aces List


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MGW

"c "c

&*

&cMSC

Se!e

MGW

GMSCSe!e

RTP !2 'oice

U-P/IP TM PCM

&ew 3nter%ace o% !o%t !witchC&


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"c 3nter%ace

The "c inter%ace is a standard inter%ace *etween :;"!Cserver and "/. The protocol con%orms to H.258 protocol

de@ned *y 3T$9T and 3BT1 together, and the de@nition o%

H.258 Transaction and (ac'age %or special re?uirement o%

((. This inter%ace ena*les :;"!C server to control static and

dynamic resources o% various transmission modes

:3(#AT"#T-"; in "/ during call processing.

This inter%ace ena*les maintenance and management o%

"/ independent o% the calling


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ConteFt and Termination o%H.258

The entities or o*+ects that can *e controlled *y the "!C server inthe "/ are descri*ed through two concepts ConteFtI and

TerminationI in 5 networ' connection model.

Termin&tion )ne termination means the source or terminal point

%or media#control stream in "/, e.g. time slot, 3( address andports, (3#C3.

Conte(t )ne conteFt is the a*stract o% the association o% a group

o% terminations. 3% conteFt includes more than one *earer

termination, the conteFt descri*es the topological relation *etweenterminations, media com*ination and#or switching parameters.


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&c 3nter%ace

&c inter%ace is the standard inter%ace *etween :;"!Cservers. The 63CC protocol de@ned *y the 3T$9T is

used to provide inter9oJce call control capa*ility

independent o% *earer technology on user plane and

signaling transmission technology on control plane %or

$"T!#!" C! service.

The 63CC signaling o% &c inter%ace is downward

compati*le with 3!$( to support *asic call procedures

and supplementary services.


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&c 3nter%ace

The newly added Application Transport "echanism:A("; mechanism o% 63CC ena*les interaction o%

*earer9related in%ormation *etween call control

nodes o% &c inter%ace, such as *earer address,

connection re%erence, *earer setup mode.


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3A" initial address message, to transport *earer

setup related in%ormation.

A(" Application transport message, to transport

*earer related and siganlling in%ormation.

AC" address complete. The answer o% 3A".

A&" answer message. The receiver pic'up the

phone.

BL release message.

LC release complete message.

"ain "essages o% 63CC(rotocol


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&* 3nter%ace

&* inter%ace *etween "/ per%orms the %unction o% *earingthe service Kow in the internal 5 core networ', and

managing the creation, release, and maintenance o% service

Kow connection through *earer control signaling.

AT", 3( or T-" can *e adopted %or &* inter%ace as thephysical *earer mode.

&* inter%ace has two protocol planes

&* control plane is used to create#release the *earer *etween

"/.

&* user plane is used to trans%er the voice over the *earer.


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2. Soft Switch Core Network Working Principle2. B?uipment &um*er

2.2 Area &um*er


2.) T"pic&l Working Proce*ure#

Contents


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Classi@cation o% C! (rocedures

Mobilit" M&n&gement proce*ure# Location $pdating

Authentication and ciphering

C&ll control proce*ure#

!etup elease

Ser+ice rel&te* proce*ure#

!upplementary service


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R#C,-

HLR

MSC Se#(e#*+

MG*+

RNP

MP

BICC

.240 !2

MG*T

MSC Se#(e#*T

R#C,"

MR/RTP

IPBac&Bo"e

RNP

!2.240

MP

T5 T2 T3 T4

U75 U72

$B Call $B in !o%t !witch C&


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S7TUP

2C!! PR+C77-ING

4S7TUP

5C!! C+N8IRM

Get MSRN withi"te#act with .!R

Pagi"g$ )the"ticatio"

3IM

1rom the !BT$( to CALL con@rm message, the process is

similar to !"

The C3C in 63CC 3A" de@ne a call instance not a circuit.

MG*+Se#(e#*+ MG*T Se#(e#*TU7 U72RNC*+ RNC*T

$B to C& "essage


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6--9#e:（ C; T;）

--9#s


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--9#e:（ C T;）

--9#s


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3 C+T

2N%UP I"it #e:

N%UP I"it ac&

%RB9SSIGN9#s<

NT89#e:1T2

NT89#s


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3 C+TMG*+Se#(e#*+ MG*T Se#(e#*TU7 U72RNC*+ RNC*T

1co"ti")e

5 RB9SSIGN9#e:

RB9SSIGN9#s<

4 --9#e:（ C2 T;）

--9#satio"

"!C !erver9T order "/9T to allocate the access side *earer

resource

"!C !erver9T order &C9T to setup adio Access 6earer.


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1co"ti")e

6!7RTING CM

!7RTING, M+-9#e:（ T3）

M+-9#s


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1co"ti")e

2 M+-9#e:（ T）

M+-9#s


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+*

HLR

M, M"

2 3

-. I#M !

MGWMGW

MSC Se!e MSC Se!e

RNC

'

. #%M

0

2

3

-

!RNC

$B Call $B in !o%t !witch C&


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Contents



'. Soft Switch Core Network Technic&l !e&ture#

&n* %*+&nt&ge#


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'. Soft Switch Core Network Technic&l !e&ture#&n* %*+&nt&ge#

'.1 Technic&l !e&ture#

.2 Technical Advantages

Contents


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Advantages o% 3( pac'et statistical9multipleFing To reduce the times o% voice encoding and decoding,

improve voice service ?uality, and save the construction

cost through pac'et *earer networ'.

To eEectively utiliDe the networ' *andwidth.

To greatly reduce operation cost due to simple

con@guration, eFpansion and easy maintenance o% the

networ'.

To reduce construction cost *y sharing the *ac'*one

networ' and data networ'.

The 3mport o% 3( technology


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MGW RNC

S?a== Cit@

MGW

RNC RNCMGW

RNC PSTN G

RNC

S?a== Cit@

Mi"i

S?a== Cit@

+"=@ Sig"a==i"g

sig"a==i"g %ea#e#

La'e Ci&0

BICC

SCPSMS

SCE .!R PP Se#(e#

MP/CP MP/CPMSC

Se#(e# MSC

Se#(e#

-istri*uted &etwor'ing


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'. Soft Switch Core Network Technic&l !e&ture#&n* %*+&nt&ge#

. Technical 1eatures

'.2 Technic&l %*+&nt&ge#

Contents


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Advantage o% Large egional&etwor'

1leFi*le networ'ing CentraliDe the "!C !erver and distri*ute the "/s, thus

solve the pro*lem o% coverage, capacity.

Basy to eFpand

Add a new "/ to serve a new area, no need to

allocate !( and modi%y many data con@guration.

Basy to implement new service

)nly the "!C !erver is needed to *e upgraded %or new

service.


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Principle a physical "!C !erver is divided into multiple

diEerent logical "!C !erver#L. Bach "!C !erver is identi@ed *y

a "!C &um*er and servers as an independent entity logically.

Ch&rging with multi "!C &um*er 1unction, su*scri*er *ills will

*e normally generated in each local networ', as covered *y many

"!C !erver. At the same time, other &Bs oJce data need no

change.

$o&ming $e#triction when a physical "!C !erver covers

multi local networ', roaming restriction will *e implemented *y

sending right "!C 3- to HL.

irtual "!C 1unction


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Large Capacity and High (rocessingA*ility

MG

MSC Se#(e#

H.248

MSC Se#(e#

MG

H.248

BICC

-ea=i"g with sig"a=i"g$=a#ge ca


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MGW MGW

R#C R#C

MSC

Se!eDPC6IP

-&e SP

Ba$u MSC Se!eDPC6IP2DPC26IP3

MGW MGW

R#C R#C

-&e SP

MSC

Se!eDPC26IP4

Dua% H-ME Dua% H-ME

Mini,%eMini,%e

-)a=i"g .o?i"g

f)"ctio" i?


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+M fo# MSC Se#(e# is the &e@ wo#& i" co#e "etwo#& which ce"t#a=i>ed ?ai"te"a"ce fo#

"etwo#& se#(ices$ co"t#o= f)"ctio" a"d sig"a=i"g ed ?ai"te"a"ce fo# MSC Se#(e# ca" "ot o"=@ #ed)ce o


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!ummary

!o%t switch core networ' adopts the separatedstructure o% control and *earer, and owning the

advantages o% distri*uted networ'ing and centraliDed

maintenance.

!o%t switch core networ' adopts T-"#AT"#3( methods

to transport the voice.

!o%t switch core networ' adopts the traditional T-"

*ased !!4 mode and 3( *ased !3TA& mode to

transport the signalling messages.


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2.OWA310005 GSM&UMTS Softswitch Core Network Principle ISSUE 3.2