Download pdf - EE11--E2 CM E2 CMtraining.bsnl.co.in/digital_library_source/upgradation/E1... · 2019. 3. 15. · BSNL-Circle1 NLD HLR GMSC 6. RRB_resp 5. ISD TAX KOLKATTA UK 5.RRB Spice/VSNL GMSC

E1E1--E2 CM E2 CM TECHNICALTECHNICAL

For internal circulation of BSNLonly

MOBILE INTELLIGENT MOBILE INTELLIGENT

NETWORKNETWORK

Topics

• Prerequisite for mobile communication.

• Basic structure of CCS#7 Protocol Stack and there

functions as applicable to Mobile IN.

• Types of routing messages in Mobile IN.• Types of routing messages in Mobile IN.

• Call flows in IN.

• Discussions


Prerequisite for mobile

communication

• GSM follows the ETSI recommendation.

• All the messages, number, nomenclature used in

GSM/GPRS are standardized by ETSI so that inter-

operator-ability can be realized easily.operator-ability can be realized easily.


Description of some numbers

• IMSI ( E212)/(E214)

– E212 = MCC(3)+MNC(2/3)+MSIN(<=10)

– E214 = CC(2)+ NDC(2)+ MSIN(10)

• MSISDN (E164)• MSISDN (E164)

– E164 = CC(2)+NDC(2)+SN(8)


Description of some numbers

• TMSI(32 Bits)-Coded Hex decimally

• LAI:- Identity of LAC

– MCC+MNC+LAC(16 Bits)

• MSRN:- Local MSISDN number used for mobile terminating calls.• MSRN:- Local MSISDN number used for mobile terminating calls.


Basic Structure of CCS#7 Stack


How Various layers works


Types of message routing in CCS#7

Two types of routing

• Based on SPC (OPC & DPC).

• Based on GTT.• Based on GTT.


SPC Based Message Routing

• Each machine has a point code(14/24 bits) in the network and it is

known with this address.

• Message has a OPC ( Originating Point Code) & DPC ( Destination

Point Code).

• Message also has user part description that which part of machine is • Message also has user part description that which part of machine is

going to use it.


SP Based Message Routing


GT Based Routing

• Routing of message is based on SP as well as a sub system number.

The subsystem number is called as Global Title (GT).

• GT based routing is used when SP is not known.

• GT is local number either a IMSI or MSISDN depending upon the

agreement.agreement.


GT Based Routing


CAP Signalling over Signalling System 7

(ITU-T standard SS7 recommendations)

gsmSSF

MSC/VLR

gsmSCF

Service...…

...…

…...

CAP Signalling EntityTransaction Capability Application Part

Signalling Connection Control PartMessage Transfer PartPhysical Network

gsmSSF

TCAP

SCCP

MTP

gsmSCF

TCAP

SCCP

MTP

SCCP

MTP

MSC/VLR STP SCP

GT Translation


GSM Recall


CAMEL


CAMEL Phase-1


CAMEL Phase-2


CAMEL Phase-3


Call FlowsService Provisioning


� Originating Charged call

� Terminating Charged call

� Refill

Call Flows

� Refill


Originating Charged Call 1(3)

HLR

VMS

SCP

(G)MSC/

VLR

S

S

F

A

S

T

-

D

R

1

2 3

4

IVR

VMSRating Engine



HLR

VMS

SCP

(G)MSC/

VLR

S

S

F

A

S

T

-

D

R

5

IVR

VMSRating engine



HLR

VMS

SCP

(G)MSC/

VLR

S

S

F

A

S

T

-

D

R

7

6

8

IVR

VMSRating Engine


Terminating Charged Call 1(4)

HLR

VMS

SCP

(G)MSC/

VLR

S

S

F

A

S

T

-

D

R

1

3

2

IVR

VMSRating Engine



HLR

VMS

SCP

(G)MSC/

VLR

S

S

F

A

S

T

-

D

R

4 5

6

IVR

VMSRating Engine



HLR

VMS

SCP

(G)MSC/

VLR

S

S

F

A

S

T

-

D

R

7

IVR

VMSRating engime



HLR

VMS

SCP

(G)MSC/

VLR

S

S

F

A

S

T

-

D

R

9

8

10

IVR

VMSRating engine


Refill 1(2)

HLR

VMS

SCP

(G)MSC/

VLR

S

S

F

A

S

T

-

D

R

1

IVR

VMSRating enginr

2 3


Refill 2(2)

HLR

VMS

SCP

(G)MSC/

VLR

S

S

F

A

S

T

-

D

R

6

4

IVR

VMSRating engine

5


Originating Call

5

3 6

Rating HLRGMSC

/gsmSSF

/gsmSCF

SCP

gsmSCF

3 61

2

7

8

HPLMN

VPLMN

MSC/VLR/

gsmSSF


HLR SCP

IN trigger

Service Logic

(MO Service)

HPLMN

IN Call Set up - MO Call

MSC

BSC BSC

GMSCVLR

MS

gsmSSF

Dialled

number:

+27 83 212

9911

VPLMN

+27 83 212 9911

(diversion address)


Terminating Call

SCP

gsmSCF

GMSC

/gsmSSF HLR

6

47

2, 8

1A

Rating

/gsmSSF

MSC/VLR/

gsmSSF

HLR

HPLMN

VPLMN

2, 8

10B


HLR SCP

IN

trigger

Service Logic

(MT Service)

HPLMN

VPLMN

SRI

PSIPSI SRI

Res

IN Call Set up - MT Call

MSC

BSC BSC

GMSCVLR

MS

gsmSSFtrigger

+27 83 212

9911

IPLMN

PSI

Res Res

Second HLR

interrogation..

.

Transit GMSC


Inbound Roamer – CAMEL

Scenarios

3. IDP2. IDP

BSNL-Circle1

NLDHLR

GMSC

6. RRB_resp

5. ISDTAX

KOLKATTA UK

GMSCSpice/VSNL5. RRB

SCCP CdPA: 44-181-SCPCgPA: 91944300020-MSC

The RRB_resp message will be modified by SRS as:

SCCP CdPA: 44-181-SCP

7. RRB_resp

4. RRB

8. CONNECT For RRBCSM, CONNECT etc

SCCP CdPA: 91-9814 -SRS MSC CgPA: 44-181-SCP

9.CONNECT

SCF

1. IDP

UK

Subscriber

VMSC

/VLR/

SSF

SRS

HLR / VMSC/ VLR / SMSCSSF/SCF

The IDP message will be modified by SRS as:

SCCPCdPA: 44-181-SCPCgPA: 91-9814-SRS MSC

CAPIMSI: 234-15-123456MSC: 91-9814-SRS MSC1VLR : 91-9814-SRS VLR1

SCCP CdPA: 44-181-SCPCgPA:91944300020(MSC)

CAPIMSI: 234-15-123456MSC:91944300020(MSC1)VLR: 91944300021(VLR1)

SCCP CdPA: 44-181-SCPCgPA: 91-9814 -SRS MSC

CdPA: 91-9814 -SRS MSC CgPA: 44-181-SCP

CAPInformation relevant to message

SRS will modify theMessage to:

SCCPCdPA: 91944300020(MSC)CgPA: 44-181-SCP



Outbound Roamer – CAMEL

Scenarios

3. IDP2. IDP

BSNL-Circle1

NLDHLR

GMSC

6. RRB_resp

5. ISDTAX

KOLKATTAUK

GMSCSpice/VSNL5. RRB

SCCP CdPA: 91-9814-SCPCgPA:44-181-(MSC)

The RRB_resp message will be modified by SRS as:

SCCP CdPA: CdPA: 91-9443-SCP

7. RRB_resp

4. RRB

8. CONNECT For RRBCSM, CONNECT etc

SCCP CdPA: 44-181-(MSC) CgPA: 91-9443-SCP

9.CONNECT

SCF

1. IDP

BSNL

Subscriber

VMSC

/VLR/

SSF

SRS

HLR / VMSC/ VLR / SMSCSSF/SCF

The IDP message will be modified by SRS as:

SCCP

CdPA: 91-9443-SCP

CgPA:44-181-(MSC)

CAPIMSI: 404-43-123456MSC:44-181-(MSC1)VLR: 44-181-(VLR1)

SCCP CdPA: 91-9814-SCPCgPA:44-181-(MSC)

CAPIMSI: 40414-19-123456MSC:44-181-(MSC1)VLR: 44-181-(VLR1)

SCCP CdPA: CdPA: 91-9443-SCP

CgPA:44-181-(MSC)

CdPA: 44-181-(MSC) CgPA: 91-9443-SCP


SRS will modify theMessage to:

SCCPCdPA: 44-181-(MSC)CgPA: 91-9814-SCPCAPInformation relevant to message


[email protected]

0942580102709425801027


for BSNL internal circulation only