Extract From Huawei Gsm Fundamentals

EXTRACT FROM HUAWEI GSM Fundamentals

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GSM 900

Duplex Separation: 45MHzChannel Bandwidth: 200KHz

EGSM

880 890 915 925 935 960MHz

GSM EGSM GSM

The Frequency Spectrum




Duplex Separation: 95MHzChannel Bandwidth: 200KHz

Base Station Receive

1710 1785 1805 1880MHz

Base Station Transmit

DCS 1800

The Frequency Spectrum




Frequency Re-Use

Because frequency resource of mobile system is very limited,

The different Subscribers must use the same frequency in different place.

Of course, the quality of communication must be ensured.

What is Frequency Re-Use?




Frequency Re-UseHow can we reuse frequency?

7(Site)X 1(Cell) Re-use 2

1

2

3

4

5

6

7




Frequency Re-Use

4(Site)X 3(Cell)

Re-use5

19 6

102

73

115

91

10

212

84

11

73

9

51

6




CELL

Omni

1

120degree

12

3

Omni-Directional Cells

120 Degree Sectors




AUC

MESIM

OMC

HLR

MSC/VLR

BTS BSC

PSTN

OSS

MS

NSS

BSS

EIR

GSM Network Components




Mobile Station—MS

International Mobile Equipment Identity (IMEI)

– Mobile Equipment

MS=ME+SIM

International Mobile Subscriber Identity (IMSI)

– Subscriber Identity Module




Subscriber Identity Module – SIM

International Mobile Subscriber Identity (IMSI)

Temporary Mobile Subscriber Identity (TMSI)

Location Area Identity (LAI) Subscriber Authentication Key (Ki) Mobile Station International Standard

Data Network (MSISDN), it is optional.

GSM




The Base Station Controller – BSC

The Base Transceiver Station – BTS

The Trans-coder – TC and Sub multiplexer (SM)

BTS

BSC

TC/SMBSS

MSC

Base Station Subsystem – BSS




Mobile Switching Center – MSC Home Location Register – HLR Visitor Location Register – VLR Equipment Identity Register – EIR Authentication Center – AUC Inter-Working Function – IWFEcho Cancellor – EC

AUCHLR

MSC/VLR

PSTN

NSSEIROMC

BSS

EC

IWF

The Network Switching System




Mobile Service Switching Center – MSC

Call Processing Operations and Maintenance

Support Inter-network & Inter-working Billing




Home Location Register – HLR

Subscriber ID (IMSI and MSISDN) Current subscriber VLR (current location) Supplementary service information Subscriber status (registered/deregistered) Authentication key and AuC functionality




Visitor Location Register – VLR

Mobile Status(IMSI detached/ attached)

Location Area Identity(LAI)

Temporary Mobile Subscriber Identity(TMSI)

Mobile Station Roaming Number(MSRN)




IMEIIs Checked against White List

IMEIIs Checked against Black/Grey List

If NOT found, checked against Grey/Black List

If NOT found, checked against White List indications

If found, returns a Black or Grey List indicator

•White List•Black List•Grey List

Equipment Identity Register – EIR




• Rate Conversion• Protocol Adaptation

PSTN

MSC

EC IWF

Inter-Working Function – IWF




Echo takes place by GSM system delay caused by call processing,speech encoding and decoding etc.An Echo Canceller is used on the PSTN side of the MSC for all voice circuits

2-wire4-wire

2- wire

Hybrid Hybrid

Generation of Echo at 2-wire to 4-wire Interface

Echo Canceller － EC




OSS(NMC)

OMCOMC

OMC

Region2

Region 1Region 3

Operation and Maintenance Sub System




Operation and Maintenance Center – OMC

OMC – R: OMC assigned specifically to the Base Station Subsystem

OMC – S: OMC assigned specifically to the Network Switching Subsystem




OMC Functional Architecture

OSMMI

DB

Event/AlarmManagement

SecurityManagement

ConfigurationManagement

Performance Management

Fault Management




HLRVLR

MSC

EIR

AUC

EC IWF

TC

VLR

MSC

IWF EC

BTS BSCMS

B

H

F

G

A

E

C

D

Um Abis

GSM Interface




Call Setup FlowMS BTS BSC MSCChannel_req Channel_Required

Channel_ActiveChannel_Active_Ack

IMMEDIATE ASSIGN COMMANDEstablish_IND(CM Service Req)First SABM

CM Service Accepted

CR(Complete_L3_information)CC

SetupCall Processing

ASSIGNMENT COMMANDFirst SABM Establish_IND

Channel_ActiveChannel_Active_Ack

Assignment_Req

Assignment_CMPASSIGNMENT CMPAlertingConnect

Connect Ack

DisconnectRelease

Release CompleteClear_CMDClear_CMP

Conversation

SABM: Set asynchronous balanced mode command--Initial access frameUA: Unnumbered acknowledgement response




1999 2000 2001

57.6 kbps

115 kbps

384 kbps

2 Mbps

GSM

HSCSD

GPRS

EDGE

IMT-2000

9.6 kbps

2G

2.5G

3G

GSM Develop Path

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Extract From Huawei Gsm Fundamentals