OWG000016 WCDMA-CS basic conception, principle and basic call flow intro....ppt

8/11/2019 OWG000016 WCDMA-CS basic conception, principle and basic call flow intro....ppt

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HUAWEI TECHNOLOGIES CO., LTD.

www.huawei.com

HUAWEI Confidential

Security Level:

OWG000016 WCDMA-CSbasic conception, principle

and basic call flow

introductionISSUE 2.0


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HUAWEI TECHNOLOGIES CO., LTD. HUAWEI Confidential Page 2

Upon completion this course, you will be able to :

Master the basic conception of signaling and

trunk network

Master the protocol function listed in the slideMaster the conception of mobility

communication

Master the basic call flow


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Chapter 1 basic conception of signaling network

Chapter 2 basic conception of trunk network

Chapter 3 SS7 basic protocol introduction

Chapter 4 mobility communication basic

conception introduction

Chapter 5 basic call flow introduction


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1.1 Whats signaling

1.2 signaling network

1.3 basic conception of signaling network


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Whats signaling

Signaling is the control signal transferred betweencommunication devices( include user termination,switch devices, etc).

In the communication network, except the signalused to transfer services information, there isinformation transferred in the network , and suchinformation is not for voice, images or charactersabout services, but the control signal betweencommunication devices, such as occupancy,release, the busy or free state of devices, thecalled number, etc. that all are control signals


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Signaling classification-by signaling transfer mode

CAS (Channel Associated Signaling ):

Channel Associated Signaling is in-band signaling inwhich user call data and signaling are combined.

CCS (Common Channel Signaling ):

Common Channel Signaling is a signalingsystem used in telephone networks thatseparates signaling information from userdata. Usually TS16 (Timeslot 16) on a E1

interface and TS1 (Timeslot 1) on a T1interface, are exclusively designated to carrysignaling relating to other traffic channels.


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Channel Associated Signaling

Switch network Switch network

Signaling device Signaling deviceCommon control Common control

Switch A Switch Btrunk


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Common Channel Signaling

Switch network Switch network

Signaling deviceSignaling device

Common controlCommon control

Switch A Switch Btrunk

Data link


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1.1 Whats signaling




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Signaling network

No.7 signaling network is a specific network which is used to transfer the No.7signaling

It is composed of SP, STP and signaling link

Signaling network is a independent network form telephone network, in china theNo7 signaling network has 3 layers

HSTP

LSTP

SP

Between two SP (SP or STP) there is a signaling link


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The dual plane structure of signaling network

AHSTP

HSTPHSTP

HSTP

HSTPHSTP

SP

LSTP

LSTP

SP

SP

LSTP

LSTP

LSTP

LSTP

SP

SP

SP

B

A

B D

A

CB

DA

C

D

F

E

C


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1.1 Whats signaling




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SP and STP

SP: SP is a node of signaling network to send orreceive the signaling message, and is a initiation

or destination of the signaling message

OPC: it is a signaling point to generate the

signaling message

DPC: it is a signaling destination

STP: if some signaling point is neither OPC nor

DPC, its function is only to transfer the signaling

message from one signaling link to another

signaling link, this SP is STP

SP SP

STP

OPC DPC

STP


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Signaling point

24-bit signaling point combination

14-bit signaling point combination

SLSDPC

CIC

8 4

OPC


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Signaling link and signaling link set Signaling link:

signaling link is between 2 signaling points, and there are at most 16

signaling links between 2 signaling points which are connected to

each other directly; If there more than 16 signaling links between 2

directly connected signaling points, the local or the peer end should

add new signaling point

Signaling link set:Signaling link set is a group of signaling links which have same

property, and these signaling links are between 2 adjacent signaling

points

SPa

Link set

Link 0

Link 1 SPbLink n


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(SLC) Signaling link code and link number

SLC is the number of signaling link, SLC is unique between 2

adjacent signaling point, SLC has 4 bits, so SLC is from 0-15

Link number is a number to distinguish the link in local office, it

is unique in local office

SPa

Link set

Link 0

Link 1

SPb

Link n

Link 2

Link 3

Link n

slc0

slc1slc2

SPcLink 2

Link 3

Link n slc0slc1

slc2 Link 0

Link 1Link n


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Direct connection and similar direct connection

Direct connection

Similar direct connection


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SLS and SLSM

SLS: SLS has 4 bits (000F), is used to select signaling link for

No.7

SLS is circularly changed, in order to grantee the symmetrical

burden of each link or link set

SLSM

signaling link (link set) selection mask, it is indicated by a 4 bit

code

backupCIC

SLS

OPC DPC

4 8 4 24 24


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Signaling link (set) selection setting principle

Setting principle , suppose there are 4 link or link set:

SLS 1 1 0 1

SLSM 1 0 1 0

These bits will be ignored

This bit acts as lowest bit

This bit acts as lower bit

1 0

0 0 1 0%4

2

Add 0in the high bits to constitutes the 0010=0x2

The signaling link number which have the same priority

result


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Signaling route

Signaling route is a logical conception which is used to indicate a

path the signaling message go through from OPC to DPC

SPA SPB SPCLink set AB

Link set ABSignaling RT AB

Signaling RTAC1Link set AB

SPBLink set AB

Signaling RT AC2Link set AB

Link set ABSignaling RT A

B


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Questions

What is CAS, CCS, and No.7 is owned to which type ?

What is the difference of signaling link number and SLC, how many

signaling links can be configured between 2 signaling points, why?


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Trunk network

A area B areaB area A area

trunk

TMSC1

TMSC2

VMSC VMSC

TMSC2

VMSC VMSC

TMSC1

TMSC2

VMSC VMSC

TMSC2

VMSC VMSC

A province B province


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Relationship between signaling network and trunk network

trunkSignaling link

TMSC1

TMSC2

VMSC

HSTP

LSTP

SP(TM)

HSTP

LSTP

SP(TM)

SP(INTS)

TMSC1

TMSC2

VMSC

A province B province


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Office direction

There is a office direction if there is direct trunk connection between 2 switch

Attention: G9 has office direction to the direct connected office, but just

MSOFTX3000 has office direction, UMG8900 has no office direction

MSC

GMSCSCP

RNC

HLR

SMC

BSC

MSC2

0

23

1

TMSC2-A

TMSC2-B

VMSC-A VMSC-B


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SRT and RT

SRT

If there is a direct voice channel between two offices, it is taken that there

is a sub-route between them

RT

For an office direction, the set of all sub-routes to it is called a route, Oneroute may contain multiple sub-routes, and different routes may contain the

same sub-routes

A B

C

D

SRT 1

SRT 2

SRT 3


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Trunk circuit and trunk group

Trunk circuit:

The trunk circuit is the component constituting a trunk group, and one

trunk circuit corresponds to one timeslot in E1 line

Trunk group

The trunk group is the component building a sub-route, and it is a setof trunk circuits with the same properties. It can be composed of one or

multiple PCM systems.

The trunk circuits to the same office direction are grouped into one trunk

group

The SS7 trunk group is generally bi-directional, and used to carryoutgoing or incoming traffic.


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CIC (Circuit Identification Code)

The CIC is used to identify a circuit between two SPs. CIC fields only existin the TUP and ISUP messages of circuit switched services. Because a CICfield is 12 bits long, there can be 4096 circuits between two SPs inmaximum

CIC E1#1 E1#0 CICTS0 0000000 00000TS1 0000000 00001

TS31 0000000 111110000001 11111 TS31

7 bits 5 bits CIC

PCM system number PCM timeslot number

0000001 00000 TS00000001 00001 TS1


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CIC number principle

......

......

CIC=0,

CIC=1,

CIC=m1

CIC=0,

CIC=1,

CIC=m2

SLC=0,

SLC=1,

SLC=n1

SLC=0,

SLC=1,

SLC=n2

SPoffice direction 1 office direction 2


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Questions

Whats office direction, if MSOFTX3000/UMG8900 has the conception of office direction ?

Whats the difference and relationship between RT and SRT ?

In which range CIC is unique, and how many CIC can be configured between 2 signalingpoints ?


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Corresponding Relations of SS7 with OSI Seven-layer


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INAP OMAP MAP

TCAP

SCCP

ISUP TUP

MTP(2

)

MTP(1

)

MTP(3

)

MT

P

Message Transfer

Part

OSI 7 layer model

Application Layer

Presentation layer

Session Layer

Transfer Layer

Signaling network layer

(Network layer)

Signaling Link Layer

( Data Link Layer)

Signaling data link layer ( physical Layer)

HLR VLR

Architecture


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MTP123 protocol

MTP3 implement the functions of the network layer of the OSIreference model, and is used to enable management messagetransmission between the signaling points for the purpose ofensuring a reliable transfer of the signaling messages over thesignaling network in case that signaling links and signalingtransfer points fail

It is used to transfer signaling to a data link. The level 2 functions

together with a level 1 signaling data link provide a signaling linkfor reliable signaling transfer between two directly associatedsignaling points; MTP2 can provide signal unit delimitation, signalunit alignment, error detection, error correction, initial alignment,processor outage, level 2 flow control and signaling link errormonitoring

It is equivalent to the physical layer of the OSI reference modeland is used to generate and receive the signals through thephysical channels. It defines the physical, electrical and functionalcharacteristics of a signaling data link and the means to access it.

Signaling data link (MTP-1)

Signaling link functions(MTP-2)

Signaling network functions(MTP-3)


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ISUP and TUP

ISUP (ISDN User Part ):

It defines the signaling messages, functions and procedures

required to control voice and non-voice services (for example,

circuit switched data communication). The ISUP can not only

implement the functions of the Telephone User Part (TUP) and the

Data User Part (DUP), but also achieve the ISDN services on awide basis, thus having a spacious application scope

TUP (Telephone User Part )

The TUP function is similar to ISUP, but can not support data type

applications


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SCCP protocol

SCCP protocol (Signaling Connection Control Part ):SCCP is one of the user parts in the hierarchical architecture of the

Signaling System No. 7, and resident at the functional level 4.

The SCCP provides additional functions to the Message Transfer Part

(MTP) to cater for both connectionless as well as connection-oriented

network services to transfer circuit related and non-circuit related signaling

information and other types of information between exchanges and

specialized centers in telecommunication networks through a SS7 network


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MAP protocol

MAP protocol (Mobile Application Part ):

MAP defines how information is exchanged between mobile

system communication network entities for the purpose of

achieving Mobile Station (MS) roaming function .

MAP can support location update, authentication, encryption,

hand over functions for MS


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CAP protocol

CAP (CAMEL Application Part ):CAP is from INAP, and it is used for the IN services

CAP enables signaling interworking between GSM Service Switching

Function (gsmSSF), GSM Specialized Resource Function (gsmSRF) and

GSM Service Control Function (gsmSCF) of radio IN functional entities, for

the purpose of supporting CAMEL services


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Questions

Whats the function of MTP123 ?

Whats the function of SCCPTUP/ISUPMAPCAP protocol ?


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Thank you!

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OWG000016 WCDMA-CS basic conception, principle and basic call flow intro....ppt