01 Basic(Cdma)

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Basic knowledge for CDMA system

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Agenda

architecture of CDMA system

Interface between different entitiy

numbering plan

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digital public land mobile communication network(PLMN)

BSC MSC/VLR

HLR/AUC EIR MSC/VLR

OMC

SC

PLMN

PSTN

ISDN

PSPDN

BTS

Um

Abis

A

BTS

No.7 BSSAP

No.7 MAP

No.7 MAP TUP

No.7 TUP

X.25/ No.7

X.25

Signaling voice

BSS

MSS

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Concept

BSC:Base Station Controller

BTS:Base transceiver station

MSC:Mobile Switching CenterHLR:Home Location Register

VLR:Visitor Location Register

AUC:Authentication CenterSC:Short Message Center

OMC:Operation and Maintenance Center

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1.Main components of CDMA

MSS(mobile switching sub-system)

BSS(base station sub-system)

MS(mobile station)

OMM(operation and maintenance sub-system)

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1.1 Base Station sub-System

FunctionIt provides trunks between wireless partand fixed part of PLMN network.

---BSC

---BTS

BTS is in charge of wireless transmission,

BSC performs the control function and management

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FunctionIt performs CDMA switching function as wellas manage mobile subscriber data and database for mobile

service. It is a interface between CDMA network and other

network (such as other PLMN,PSTN etc.).

It includes 4 function units

---MSC ---VLR

---HLR ---AUC

1.2 Mobile Switching sub-System

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1.2.1Mobile Switching Center(MSC)

It is responsible for setting up,managing and clearing connections

as well as routing the calls to the proper user.

It provides the network interfaces,the charging function and the

function of processing the signaling.

MSC get data for call handling from 3 databases:

VLR/HLR/AUC

GMSC(gateway):When a non-CDMA end subscriber calls a

CDMA subscriber, the call will first be routed to a MSC of the

CDMA network (i.e. GMSC), which will inquire about the

corresponding HLR, and route the call to the MSC where the

called subscriber is located in.

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1.2.2Visitor Location Register(VLR)

VLRis a dynamic database used by MSC for information index.,itstores all related information of mobile subscribers that enter into its

coverage area,which enables MSC to set up incoming and outgoing

calls.

subscriber parameters include: subscriber number, location area

identity(LAI),users status , services which subscriber can use and so

on.

When the subscriber leaves this area, it should register in anotherVLR,and old VLR will delete all the data about this subscriber.

VLR can be built together with the MSC or set separately.

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HLR:It is a static database . when a user apply for mobile service, all

data about this subscriber will be stored in HLR.

Information:

----subscriber information (ESN, MDN, IMSI, MIN), service

information, current location and valid term,

----the mobile subscriber location (MSC/VLR address),so as to set up

the call route to the MS.

HLR can be built together with the MSC or set separately.

1.2.3 Home Location Register(HLR

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1.2.4 Authentication Center

Conceptionit is a entity to prevent illegal subscribers from

accessing CDMA network..it can generate the parameter to

confirm the subscribers identity .at the same time it can

encrypt users data according to users need.

Composition

databasesave MIN,ESN, authentication key)

Generator of random number

Algorithm(CAVE algorithm)

AUC can be built together with HLR or set separately

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1.3 Operation and maintenance center (OMC)

OMC provides operation and maintenance services to the

network operator, manages the registered subscriber information

and conducts network planning to enhance the overall working

efficiency and service quality of the system.

Based on the main maintenance functions, there are two types of

operation and maintenance centers: OMC-S and OMC-R. The

OMC-S is mainly responsible for maintenance of MSS while theOMC-R is mainly for BSS.

We also call OMC as background.

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Agenda


Interface between different entitiy

numbering plan

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The difference between interface and protocol:

The interface:the connection point between 2 adjacent entities.

The protocol: illustrate the rules followed when information

exchanged at the connection point.

The interface and protocol between enti ties

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The interface between enti ties

SCP

MSC/SSP

PSTN

ISDN

PSPDN

VLR

MSC

BSCBTS

MS

HLR SCPSC

SME AUC

A B

CD

E

N T2

HM

Abis

U

m

Q

OMC

Q Q

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Um interface defines the communication interface between MS and

BTS, also called air interface.

it realizes the compatibility between all kinds of MS and different

BTS, so that the MS can roaming.(it is a open interface)

it adopts some anti-jamming technology and measurements to

reduce interference and improve the frequency spectrum efficiency.

It realizes the physical connection between MS and CDMA

network.(that is wireless link)at the same time it is also in charge

of transferring of the information about RR, MM and CM.

1 . Um interface:

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Note:

RR:radio resource management

MM:mobile management

CM:connection management

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2. Abis interface:

the intra- interface between the BTS and BSC,used for

remote connection

2.048 Mb/s PCM digital link

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3 .A interface and protocol

It is a interface between BSC and MSC

It is based on 2.048Mb/S PCM digital links

The standard protocols for this interface include IS-634,

IOS2.4 and IOS4.0, etc.A-Interface is mainly used to transmit the followinginformation:

BSS management information

Call processing

Mobility management

It is a open interface.

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4. B interface:

the interface between MSC and VLR.

MSC transfer the location information of roaming

subscriber to VLR

Query subscriber data from VLR when setting up

the calls

usually VLR is built with MSC together, so the

interface turns to be an internal interface and has no

standard rules.

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The interface between MSC and HLR.

The system adopts IS-41D protocol. The interface is based on

2.048Mb/s PCM digital link.

When a MS is called,MSC must query the called MSs routing

message from HLR through this interface to locate the called

MS, and according to the record,HLR will return the routing

message(MSC/VLR number) to MSC.

5. Cinterface

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6. D interface

The interface between VLR and HLR.


2.048Mb/s PCM digital link.The interface is used for exchange of subscriber location

information, authorization information and service data

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7. E interface:

the interface between MSC and MSC.it is used for channel changeover between 2 MSC



When a mobile station roams from one MSC to another, the MSC

will perform handover to keep the subscribers' conversation

uninterrupted. In this case data exchange must be implemented

between the MSCs.

.

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8. Q interface :

Interface between SC and MSC .

The system adopts ANSI-41E protocol. The interface is based on


In submission and reception of short messages, short messagesare transferred between the short message center and the mobile

switching center. At the same time, when the subscriber's short

message capability changes, the mobile switching center needs tonotify the short message center promptly.

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9. the interface between MSC and PSTN:

The inter-office signaling interface,used for setting up voice

connection between PSTN and PLMN.

i l A ti ti

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CDMA service area

PLMN Service area

MSCService area

cell

Location area

Wireless cover area structure

wireless Area parti tion

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1.Cell

The smallest area that can not be divided.

2.Location area:

The area that MS moves without updating location.Use to

orientation and paging.

It includes some cells.

One location area has one LAI to identify each other.

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3.MSC service area:

The area that all the cell controlled by one MSC covered.

One MSC contains one or more location areas.

4 .PLMN:

It includes one or more MSCs service areas.

5.CDMA service area:

It includes global PLMN networks .

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Agenda


Interface between dirrerent entitiy

numbering plan

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1. mobile directer number(MDN)

A MDN number is the number dialed by the callersubscriber in PLMN.

Composition of a MDN number.

cc: country code( china=86)MAC: mobile service access code(china:13x)

H0H1H2H3: to identify different HLR

ABCD: mobile subscriber number

CC MAC H0H1H2H3 ABCD

International MDN

National MDN

+ + +

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2. I nternational mobile subscriber identi f ication number

(IMSI)

IMSI is a unique number that can identify a mobile subscriber

in the PLMN network.

MCC MNC MSIN

International

mobile subscriber

identificationNational mobile

subscriber

identification

Composition of an IMSI number

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MCC mobile country code(CHINA=460)

MNC mobile network code

MSIN mobile subscriber identification number, a 10-bit

algorism number, expressed as

XX: 09 In china(it is allocated by international

organization) ,HoH1H

2H

3is the same as HoH1H2H3 in the

MDN number, and ABCD is a subscriber number.

IMSI is used in all signaling in a CDMA mobile communication

network, stored in HLR, VLR and the UM card.

XX+

H0H1H2H3 + ABCD+

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3. mobile station identif ication number (MIN)

MIN is the same as MSIN;

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4. Temporary Local Digital Number (TLDN)

TLDN is a number temporarily assigned by VLR of calledparty .

In CDMA system, this number is only used when the

calling and the called are not in the same MSC/VLR .

This number is released and re-used by other subscribers

after the completion of the voice connection.

In china, its structure is: 8613344M1M2M3ABC

8613334M1M2M3ABC(reserve)

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5 .MSC/VLR number

MSC/VLR number is used in the No.7 signaling.In china :460030944+M1M2M3+100

M1M2M3: to indentify different MSC/VLR

6.HLR numberHLR number is used in the No.7 signaling .

In china : 4600309+H0H1H2H3+0000

NOTE: These number will be allocated by headquarters .

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7. Location area identi f ication number (LAI )

LAI is used to identify the location area.

Its number structure is:

MCCMNCLAC

MCC and MNC : same as the MCC and MNC in IMSI.LAC is a location area code that uniquely identifies each

location area in our digital PLMN. It is a 2-byte

hexadecimal BCD code represented by L1L2L3L4 (with

the range of 0000FFFF, able to define 65536 differentlocation areas.)

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8.Global Cell I denti f icationGCIIt identifies certain cell in a location area.

Structure:

MCC+MNC+LAC+CI

CI:2 bytes hexadecimal BCD codeMSC defines.

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9. ESN: electronic serial number

It is setting by the manufacturer of the mobile station or UIM card..

10. SID( system identify) and NID(network identi fy)

In CDMA network, system judges whether roaming occurs

according to a pair of identification codes (SID and NID).

Each mobile local network is assigned with a SID, which is decided

by the headquarters.

The NID assignment is managed by local networks.

Number plan in MAP procedure

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1. Location updating between MSCs

3

5

1

HLR

MSC/VLR1

MSC/VLR2

M

S

M

S

2

4

6


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2. F ixed subscriber call mobile subscr iber

PSTN GMSC MSC/VLR

HLR

MS1 6

4

32

5

1.MDN 2. MDN 3. MSC/VLR 4. HLR number

5. GMSC/VLR number 6. TLDN

Note :All these numbers are the called numbers


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3. mobile subscr iber call mobile subscr iber

6

34

52

9

78101

HLR/AUC

MSC1/VLR2 MSC2/VLR2

MS1 MS2

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Documents

01 Basic(Cdma)