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CONTENTS

GSM TYPES

RADIO FREQUENCY GSM 900

GSM 1800

GSM 1900 GSM OPERATORS IN PAKISTAN

PHYSICAL CHANNEL

NETWORK OVERVIEW

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GSM TYPES On the basis of frequency GSM Network has three types: GSM 900

GSM 1800 [Digital Communication System]

GSM 1900 [Primary Communication System]

Mono-band GSM networks are those which operate on one of the threeGSM frequency bands.

Dual-band networks are those which operate on any two of the three GSM

Frequency bands.

Currently, in Pakistan Four dual band networks [GSM 900 + GSM 1800] arein operation.

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RADIO SPECTRUM

30 40 50 60 70 80 90 100 120 140 160 180 200 240 300 MHz

3 4 5 6 7 8 9 10 12 14 16 18 20 24 30 GHz

0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.2 1.4 1.6 1.8 2.0 2.4

AM Marine

Short Wave - International Broadcast - Amateur

3 4 5 6 7 8 9 10 12 14 16 18 20 24 30 MHz

CB

26 28

VHF LOW Band FM VHF VHF TV 7-13

0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.2 1.4 1.6 1.8 2.0 2.4 3.0 GHz

UHF UHF TV 14-69 GPS

Cellular GSM1800, GSM1900

Broadcasting

Land-Mobile

Aeronautical

Mobile Telephony

Terrestrial Microwave

Satellite

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RADIO FREQUENCY RF Portion of Electromagnetic Spectrum in which electromagnetic waves can be

generated by alternating current [AC] fed to antenna.

GSM 900, GSM 1800 and GSM 1900 transmission takes place in UHF Band.

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Medium Medium is defined as the means by which information is sent or received between

two devices to make communication possible.

Guided Medium

Physical wire like Twisted Pair Cable (Shielded / Unshielded]

Coaxial Cable for broadband communication like Cable TV

Fiber Optic

Un-Guided Medium

Wireless Communication like GSM, AMPS

Broadcast Radio

Microwave Unidirectional transmission

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GSM 900 European Telecom authorities primarily reserved two frequency bands of

25MHZ bandwidth for GSM 900 transmission all over the world.

890MHZ --- 915MHZ [25MHZ] For Up/Reverse Link

MS to Base Station Transmission

935MHZ --- 960MHZ [25MHZ] For Down/Forward Link

Base Station to MS Transmission

The Extended GSM 900 band or E-GSM = P-GSM + 2 x [10MHZ]

The Railway GSM 900 band for Railway Companies is

R-GSM = E-GSM + 2 x [4MHZ]

Duplex Channel Spacing of 45MHZ between Uplink and DownlinkChannels.

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GSM 1800 In 1990 a newly allocated band of twice 75MHZ bandwidth was formed for

the Digital Communication System which is a version of GSM suited to the

1800MHZ frequency band and was initiated in United Kingdom.

1710MHZ --- 1785MHZ [75MHZ] For Up/Reverse Link

MS to Base Station Transmission

1805MHZ --- 1880MHZ [75MHZ] For Down/Forward Link

Base Station to MS Transmission

Duplex Channel Spacing of 95MHZ between uplink and downlink channels.

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GSM 1900 A newly allocated band of twice 60MHZ bandwidth was formed for the

transmission of GSM1900.

1850MHZ --- 1910MHZ [60MHZ] For Up/Reverse Link

MS to Base Station Transmission

1930MHZ --- 1990MHZ [60MHZ] For Down/Forward Link

Base Station to MS Transmission

Duplex Channel Spacing of 80MHZ between uplink and downlink channels.

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GSM RADIO SPECTRUMUplink

Downlink

880 890 915 1710 1785

925935

960 1805 1880

MHz

P-GSM

GSM 1800 GSM 1900

1850 1910

1930 1990

R-GSM

876

921

960

960

915

915

E-GSM

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GSM OPERATORS In Pakistan Currently there are five GSM Operators.

MOBILINK GSM [GSM 900,1800]

UFONE GSM [GSM 900,1800]

PAKTEL- GSM [E-GSM]

TELENOR [GSM 900,1800]

WARID TELECOM [GSM 900,1800]

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GSM OPERATORS GSM operators in Pakistan are allocated portion of frequency from GSM 900 and

GSM 1800 frequency bands for their Network Operation.

24 / 24890-894.8 / 935-939.8AL-WARID

24 / 24902.6-907.4 / 947.6-952.4TELENOR

50 / 50880-890 / 925-935 [E-GSM]PAKTEL

37 / 37894.9-902.5 / 939.9-947.5UFONE

37 / 37907.5-915 / 952.5-960MOBILINK

Channels[U/D]

GSM 900 [Uplink / Downlink] MHZGSM Operator

48 / 481710-1718.8 / 1805-1813.8AL-WARID

48 / 481725-1733.8 / 1820-1828.8TELENOR

Not UsedNon Dual Band OperatorPAKTEL

30 / 301718.9-1724.9 / 1813.9-1819.9UFONE

30 / 301733.9-1739.9 / 1828.9-1834.9MOBILINK

Channels[U/D]GSM 1800 [Uplink / Downlink] MHZGSM Operator

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PHYSICAL CHANNEL GSM Physical Channel bandwidth is 200KHZ.

A Physical Channel is a combination of ARFCN [Absolute Radio FrequencyChannel Number] and TS [Time Slot] and is used to carry information on Air/Um/Radio Interface between Mobile and Base Station..

GSM 900 consists of two 25MHZ frequency bands one each for uplink anddownlink transmission resulting in 124 Duplex Channels to carry traffic andsignaling information between Mobile and Base Station.

GSM 1800 consists of two 75MHZ frequency bands one each for uplink and

downlink transmission resulting in 374 Duplex Channels to carry traffic andsignaling information between Mobile and Base Station.

GSM 1900 consists of two 60MHZ frequency bands one each for uplink anddownlink transmission resulting in 299 Duplex Channels to carry traffic andsignaling information between Mobile and Base Station.

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GSM BAND ALLOCATION

GSM systems Uplink Downlink Band Duplex Duplex

Spacing channels

GSM 900 890-915 935-960 2x25 45 124

E-GSM (900) 880-915 925-960 2x35 45 174

R-GSM (900) 876-915 921-960 2x39 45 194

GSM 1800 1710-1785 1805-1880 2x75 95 374

GSM 1900 1850-1910 1930-1990 2x60 80 299

Carrier frequency = ARFCN = Absolute Radio Frequency Channel Number

Frequencies are in MHz

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NETWORK OVERVIEW A GSM system is designed as a combination of three major subsystems:

BSS [Base Station Subsystem] NSS [NetworkSwitchingSubsystem]

OSS [Operation Support Subsystem]

BSS consists of equipment and functions that are related to the managementof connection on radio path. BSS consists of following functional units:

BTS [Base Transceiver Station] BSC [Base Station Controller] TCU [Trans Coder Unit] [Optional]

NSS is built on the switch called MSC [Mobile SwitchingCenter] andincludes equipment related to end-to-end calls, mobility and interfaces withPSTN.

OSS mainly contains OMC-S [Operation and Maintenance Center-Switch]and OMC-R [Operation and Maintenance Center-Radio]. It is connected toall the equipment in switching system and to the BSC.

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NETWORK OVERVIEW

BSC MSC

BTS

OMC-R OMC-S

MS

BSSBSS NSSNSS

OSS

PSTNPSTN

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TRAFFIC / SIGNALLING

GSM Network carries two types of information:

Traffic [It concerns all user-to-user information, it can be voice or Data] Signaling [Information required by Network for its own working]

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THANK YOU!