RF PLANNING & MEASURING COVERAGE AREA USING DRIVE TOOL

GLOBALSYSTEM FOR MOBILE COMMUNICATION

BySK.ABDUL SATTAR (06J01A0403)

K.ALTAF (06J01A0415)FAHEEM NASER (06J01A0431)

AZHAR MOHAMMAD (06J01A0433)

TELECOM NETWORK

USER NETWORK

ACCESS NETWORK

CORENETWORK

MOBILE SPEED 2G GSM/CDMA =>(9.6 – 14.4)kbps 2.5G

GPRS – 115kbpsEDGE - 384kbpsCDMA – 170kbps

3GEVDOEVDV UMTSHASDPA – 14Mbps

WIRELESS INTERFACE CHALLENGES Low bandwidth Interference / Noise NLOS Environment Large Capacity Requirement Huge Demand

OBJECTIVES OF MOBILE COMMUNICATIONS Anytime Anywhere Mobility & Roaming High capacity & subs. density Seamless Network Architecture Low cost Flexibility Innovative Services Standard Interfaces Efficient use of radio spectrum

BANDWIDTH MANAGEMENT TECHNIQUES FDMA TDMA Cellular Technology & Frequency Re-use Scheme

Speech Coding Modulation

FDMA Frequency Division Multiple Access or

FDMA is a channel access method used in multiple-access protocols as a channelization protocol. FDMA gives users an individual allocation of one or several frequency bands, or channels

Uplink Frequency Band = (890 – 915) MHz Downlink Frequency Band = (935 – 960)

MHz Absolute Radio Freq Carrier Number

(ARFCN) Bandwidth = 915 – 890 or 960 – 935

= 25 MHz

Freq

Mhz. 890.2

1

890.4

2

890.6

3

890.8

4

891.0

5 6

914.8

124

• FDMA Access along Frequency axis• Each RF carrier 200khz apart

• Total 124 RF Channels available. One or more carrier assigned to each base station

……...

FDMA Access along Frequency axis

GSMFDMA

25 MHz 25 MHz

Mobile to Base

0 1 2

890.2 890.4 890.6(MHz)

Base to Mobile

0 1 2

935.2 935.4 935.6

200 kHz45MHz

Channel layout and frequency bands of operation

890 935 960915

200 kHz

TDMA

Time Division Multiple Access Scheme One Radio Frequency = Eight Time Slots One TDMA Frame = Eight Time Slots One Time Slot = One Physical Channel One Time Slot Duration = 0.577 msec

FDMA/TDMA SCHEME

890.0

890.2890.4

890.6890.8

891.0891.2 915.8

FREQ

MHz

BURSTF

R

A

M

E

BP1

BP2

BP3

BP4

BP5

BP6

BP7

BP8

BP1

BP2

TIME

8 7 6 5 4 3 2 1 FRAME OF 8 TIME SLOTS

FRAME REPETITION

PHYSICAL CHANNELS

8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1

8 7 6 5 4 3 2 1

11

1

1

1

1

2

2

2

2

2

3

3

3

3

3

4

4

4

4

4

6

6

6

6

6

7

7

7

7

7

8

8

8

8

8

5

5

5

5

5

PHYSICAL CHANNELS

12

45

67

8

3

Cell Site

CELLULAR TECHNOLOGY

CELLULAR MOBILE CONCEPTS

WHAT IS A CELL ?

A base station (transmitter) having a number of RF channels is called a cell Each cell covers a limited number of mobile subscribers

within the cell boundaries ( Coverage area)

Typical Cell Radius Approx. = 30 Km (Start up), 1 Km (Mature)

Each Cell uses a specific set of radio frequencies Each Base Station contains one or more TRXs

TYPES OF CELLS

OMNI CELLSSECTOR CELLS - Two Sector Cells - Three Sector Cells

Frequency Re-use Scheme

CELL RADIUS (KM)

COVERAGE AREA(KM2)

No. Of MOBILE SUBS.

No. of CHANNELS

REQD.

1 3.14 100 8

3 28.3 900 38

10 314 10,000 @ 360

25 1960 60,000 @ 2,000

ASSUMPTIONS Traffic /User = 30 mE , GOS = 1%

CELLULAR MOBILE CONCEPTS

• 360 * 25 KHz * 2 = 18 000 KHz = 18 MHz FOR A CELL OF 10 KM RADIUS ONLY

• THIS IS IMPOSSIBLE TO BE ALLOCATED

• HENCE FREQUENCY REUSE IS A MUST TO COVER THE TOTAL SERVICE AREA WITH A LIMITED AVAILABLE RF RESOURCES

• HENCE THE NEED FOR A CELLULAR PRINCIPLE

CELLULAR MOBILE CONCEPTS

A CLUSTER OF CELLS

4

5

6

7

2

3

1 1 2 3 4 5 6 7

GIVEN FREQ. RESOURCE

CELLULAR MOBILE CONCEPTS

CELLULAR MOBILE CONCEPTS

CO-CHL INTERFERENCE :Interference caused by another cell/mobile using the same frequency

D

R

Co Chl Interference is a Function of “Q”the re-use ratio:

Q =D / R

Lower Q Increased Co-Chl Interference

Higher Q Reduced Co-Chl Interference

Co– Channel Interference

Q = D /R = 3N

N =Cluster SizeR = Size (Radius of Cell)D = Distance between two Co- Channel Cells

Higher Q Less Interference Higher NMore Cluster SizeLess RF freq/cellLess Traffic HandlingCapacity of the system

LOWER Q Higher Interference Increased System Handling Capacity

Higher Q Less Interference Higher NMore Cluster SizeLess RF freq/cellLess Traffic HandlingCapacity of the system

Co– Channel Interference

MODULATION GMSK = GAUSSIAN MINIMUM SHIFT

KEYING The modulation method in GSM is GMSK

which facilitates the use of narrow bandwidth and coherent detection capability.

Rectangular pulses are passed through a Gaussian filter prior to their passing through a modulator.

GSMVARIOUS SUBSYSTEMS1. Network Subsystem includes the

equipments and functions related to end-to-end call.

2. Radio Subsystem includes the equipments and functions related to the management of the connections on the radio path.

3. Operations and Maintenance subsystem includes the operation and maintenance of GSM equipment for the radio and network interface.

GSMNETWORK STRUCTURE GSM Service Area: Total area served by the

combination of all member countries where a mobile can be served.

PLMN Service Area:It is one N/W area. MSC Service Area:There can many MSC/VLR

in one PLMN area.It is one Mobile Exch. Area.

GMSC: All I/C calls for PLMN N/W will be routed through GMSC. In a GSM/PLMN N/W all mobile terminated calls will be routed to a Gateway MSC. Call connections between PLMNs , or to fixed N/Ws must be routed to a GMSC.The GMSC contains the Inter working functions to make these connections.

Location Area Cells

LOCATION AREA:There are several LA in a MSC/VLR combination A LA is a part of the MSC/VLR service area in which a MS may move freely without updating location information to the MSC/VLR exchange that control the LA. Within a LA a paging message is broadcast in order to find the called mobile subs. LA can be identified by system using the LAI.

CELL.A cell is an identity served by one BTS. The MS distinguishes between cells using the BASE STATION IDENTIFICATION CODE(BSIC) that the cell site broadcast over the air.

GSMRELATION BETWEEN AREAS IN GSM

Location AreaCell

Area served by a BTS

Location Area

MSC Service Area

PLMN Service Area

GSM Service Area

NETWORK ARCHITECTURE

BTS

MSC VLR

HLR

PSTNISDN

DataNetworks

(

Air interface

OSS

BTS

BTS

MSC VLR

BSCBSC

1 MSC=16 BSC

1 BSC=1024 TRU

A Interface

A-bis interface

BSC:BASE STATION CONTROLLER, BTS: BASE TRANSRECEIVER STATION, OSS: OPERATION AND SUPPORT SUBSYSTEM.ss

CALL CONNECTIVITY

ESTABLISHMENT

How the call is connected between End to End Equipment. Irrelevant of end

equipment, it may be land phone or Mobile station

CALL & MOBILITY

MANAGEMENT

Call And Mobility Management

• RF channel overview & Modes of Mobile Station.• MS Initialization ( Network Attachment )

• Mobility Management and MM Procedures

• Connection Management (CM)

• Call Processing – MO & MT Calls

• Authentication & Location Updating Procedure

Modes Mobile Station ( MS )• MS Switched Off - can not receive incoming paging messages.

- can not make outgoing call.

- No dedicated channel is associated with it.

• MS Switched On - can receive incoming paging messages.

And in Idle Mode - can make outgoing call.

- No dedicated channel is associated with it.• MS in Dedicated Mode -MS is in conversation and a

dedicated traffic channel TCH is

associated with it.

RF Channels Overview

• Broadcast Control Channels - BCCH

P-MP FCCH

SCH• Common Control Channels PCH

P-P RACH

AGCH

• Dedicated Control Channels - SDCCH

P-P FACCH

SACCH

CM

CCSMS

SS

Normal Burst

3

T 57

Encrypted

1S

26

Training

1

S

57

Encrypted

3

T

8.25

GP

CM

CCSMS

SS3

T 142

Fixed Bits

3

T

8.25

GP

FCCH Burst

CM

CCSMS

SS

Possible Channel Combinations On RT in One Cell

RT 0

Timeslots

RT 1

RT 2

RT 3

BCCH CCCH CCCH

TCH

SDCCH

SDCCH TCH

0 1 2 3 4 5 6 7

TCH TCHCCCH

TCH TCH TCH TCH TCH TCH TCH

TCH TCH TCH TCH TCH TCH TCH TCH

TCH TCH TCH TCH TCH TCH TCH

CM

CCSMS

SS

Channel Combination IV :main BCCH ( GSM 05.01)

BCCHDown-link

Up-link

FCCH

SCH

0 1 2 3 4 65 7 9 118 10

CCCH

RACH

RACH

FCCH

SCH

12 13 1514 16

BCCH

5049. . .

IDLE

. . .RACH

Technical Terms Used w.r.t. MM (Mobility Management )

• IMSI – International Mobile Subscriber Identity

• IMSISDN – Mobile Subscriber ISDN number

• IMEI – International Mobile Equipment Identity

• TMSI – Temporary Mobile Subscriber Identity

• MSRN – Mobile Subscriber Roaming Number

• LAI – Location Area Identity

• A3 – Authentication Algorithm

• A5 – Ciphering Algorithm

• A8 – Kc Generation Algorithm

1. MSRN – Mobile Subscriber Roaming Number It is a temporary number used for routing the call to MS.

Format : MSRN = CC + NDC + SN

CC = Country Code

NDC = Network Destination Code

For example for Patna MSC in IMPCS network MSRN looks like 91 95330 24365.

SN = Subscriber Number

Location Related Identities

PSTN GMSC

HLR

MSCVLR

MSISDN

1

MSISDN 2

IMSI

3

IMSI MSRN 4

MSRN

5

MSRN 6MSRN

7

MSRN

Location Related Identities

• Location area consist of one or more than one cell which may be served by one or more BSC s.

• All the cells in a Location area are served by single VLR.

2. Location Area Identity (LAI ) -

• Each location area in a GSM PLMN is identified by a Location Area Identity ( LAI ).

Location Related Identities

HLRSS 7

BSC

MSC 2

VLR 1

VLR 2

BSC

BSC

BSC

LA 1

LA 2

LA 3

BTS

BTS

BTS

BTS

BTS

BTS

Location Area

MSC 1

LAI = MCC + MNC + LAC

MCC - Mobile Country Code.

MNC - Mobile Network Code.

LAC - Location Area Code .

• Maximum length of LAC is 16 bits.

• Thus there can be maximum of 65,536 Location Areas defined in one GSM PLMN.

MCC MNC LAC

3 digits 2 digits 2 octets max

LAI

( 16 bits )

Location Related Identities

MS Initialization / Network Attachment

1. MS Powered on.

- FCCH present in time slot T0 & has a fixed pattern of 142 0’s.

- MS scans entire 124 carriers and monitors RF levels. - several readings are taken to get accurate estimate

the channel power.

- MS then searches for Frequency Correction burst (FCCH) on the channel with strongest RF level.

2. Frequency Synchronization

- After tuning to FCCH MS synchronizes in time with SCH .

- SCH occurs in next frame in same time slot as FCCH.

- The occurrence of SCH is eight burst period ( BP’s ) later than FCCH.

3. Synchronization in Time

- After successful synchronization the MS will read the TDMA frame number and Base Station Identity Code BSIC .

- SCH contains precise timing information and current frame number to which MS is synchronized.

- BSIC consists of - PLMN colour code ( 3 bits )

- BS colour code ( 3 bits ).

MS Initialization / Network Attachment

• MS decodes information on BCCH and gets Location Area Identity ( LAI ).

• If the information stored on SIM does not match with the information MS thinks that it has moved to new location and sends LA update request to BSS.

• MS location is determined by cell identification of strongest BCCH signal received by MS.

• MS regularly measures the received signal strength of BCCH at least once every 6 sec ( Superframe Duration).

• MS stores at least six strongest BCCH and their cell identification in SIM.

MS Initialization / Network Attachment

Network Attachment Process

MS

. Cell should be of selected PLMN.

Switch -on

Measure strongest BCCH channels

PLMN Selection

Cell Selection

Location Update

Idle-Mode

. Cell should not be “ barred “.

. Radio path loss between BTS and the MS must be below a threshold set by the operator. ( Register its presence

to the network. )

Limited Service Mode

MS BTS MSCBSC

RIL3 - CM

LAPD m

Layer 1

RIL3 - MM

RIL3 - RR

Layer 1

LAPD m LAPD

Um

A bis A link BCDEFG

MTP

SCCP

BSSMAP

DTAP MM

TCAP

DTAP CM

U

PSCCP

MAP

Layer 1Layer 1

GSM Signaling Protocols Overview

LAPD MTP

I

S

SCCP

BSSMAP

BTSM

RIL 3-RR

BTSMRR

What is Mobility Management ( MM ) ?

Subscriber Data management at MSC/VLR

• Subscriber data from HLR are retrieved by MM at the time of first location up-dating of a subscriber.

• Dynamic data changes by subscriber are also managed by MM at MSC/VLR.

• Operator initiated data changes for a subscriber are also managed by MM.

Services Provided to Upper Layers

• MM sub-layer provides basic services to upper layer CM sub-layer.

• MM handover procedures provide smooth transition from one radio link to other.

What is Mobility Management ( MM ) ?

Subscriber Authentication and Confidentiality management

• MM procedures ensure authenticity of a subscriber.

• MM procedures ensure data confidentiality at radio interface.

MM Procedures

• TMSI Reallocation Procedure.

• IMSI Detach Procedure.

• Ciphering Procedure.

• Abort Procedure.

MM Common Procedures :

• Authentication Procedure.• Identification Procedure.

MM Specific Procedures :

• Location Updating Procedure.• IMSI Attach Procedure.

• During the lifetime of a MM specific procedure if a MM connection establishment is requested by a CM entity, the request will either be rejected or delayed until the running of MM specific procedure is terminated.• Any MM common procedure Procedure ( except IMSI detach) may be initiated during MM specific procedure.

• A MM specific procedure can only be started if no other MM specific procedure is running.

• The MS side should wait for release of RR connection used for a MM specific procedure before a new MM specific procedure or MM connection establishment is started.

MM Procedures

Authentication

• Authentication is used to check the validity of a mobile subscriber.

At MS At N/W

KiRAND( 128 bits )

Ki

A3 A3

SRES SRES

( 32 bits )=?

AUTHENTICATION

• RAND ( 128 bits ):Random Number

• SRES ( 32 bits) :Signed Response

• Kc ( 64 bits ) : Ciphering Key

- Ki is stored in SIM and HLR.

• Ki ( 128 bits) : Identification Key

- Purpose : Ki is used to calculate SRES and Kc.

- Ki is never transmitted over signaling network.

- Purpose : Kc is used to encrypt data over radio interface.

- Purpose : RAND is used to calculate SRES and Kc.

Ciphering

• Ciphering is used to encrypt data on radio interface.

Frame No. (22 bits )

A5

Information Bits ( 114 bits )

CIPHERING

Kc generation is done at the time of Authentication.

RAND Ki

Kc ( 64 bits)

A8

Ciphering Stream

XORCiphered Bits

1. To check identity provided by the MS.

The purpose of authentication procedure is two fold :

2. To supply n/w parameters to MS to calculate Kc.

• Authentication procedure is always initiated and controlled by the n/w.

TIME

MS N/W

Authentication Request

Authentication Response

Authentication Reject

AUTHENTICATION PROCEDURE

Authentication Procedure

Authentication Procedure

- At n/w side, authentication procedure requires authentication triplets.

Authentication Triplets :

-RAND ( 128 bits ).

- Authentication triplets contains

- SRES ( 32 bits ). - Kc ( 64 bits ). - The network can have more than one triplets. - The operator can allow reuse of triplets. - The index of currently used triplet is called CKSN ( Ciphering Key Sequence Number ).

Location Updating Procedure

• Normal Location Updating -

MS moves to new LA.

This is a general procedure which is used for following purposes -

• Periodic Location Updating -

To notify periodic availability of MS to the network.

• IMSI Attach -

MS switched on for first time in new LA or MS switched off and on.

Each time MS moves to new LA corresponding VLR is informed.

Case - I Old LA and new LA in same VLR area

• MS given new TMSI .

• Location updated in VLR memory.

Case - II Old LA and new LA in different VLR area

• HLR updates.• old VLR erases data.• new VLR records relevant parameters.

• MS is given new TMSI.

Location Update Scenario

Location Update Scenario

Phases of Location Update Scenario

• Request for service.

• Authentication

• TMSI reallocation.

• Ciphering

• HLR/ VLR updation

LOCATION UPDATE SCENARIO - I

MS BSSOld MSC/ VLR

HLR /AUC

New MSC/ VLR

1

2

Channel Request

RACH

AGCH

SDCCH Assignment

Location Update Request ( TMSI , LAI 0 )

SDCCH3

Request IMSI

Send IMSI4

Request For Service

( TMSI )

MS BSSOld MSC/ VLR

HLR/ AUC

New MSC/ VLR

5

6

Get Authentication Parameters

Authentication Response ( SRES )

SDCCH

7

( IMSI )

( RAND,Kc,SRES )

Authentication Parameters

SDCCH

Authenticate MS ( RAND )

Cipher Radio Channel

( Kc )

Cipher Up Link Channel

SDCCH

Authentication and Ciphering

LOCATION UPDATE SCENARIO - II

8

9

BSS Ciphers Down link Channel .

SDCCH

Ciphering Complete

MS BSSOld MSC/ VLR

HLR/ AUC

New MSC/ VLR

LOCATION UPDATE SCENARIO - III

Authentication and Ciphering

Up Link Ciphered

LOCATION UPDATE SCENARIO - IV

10

Update Location

Update HLR/VLR & TMSI Reallocation

De Register Mobile

Mobile De-registered11

MS BSSOld MSC/ VLR

HLR/ AUC

New MSC/ VLR

Location Updated

Location Updated Accept TMSI

SDCCH

12

13

SDCCH

Location Updated Complete

Clear Signaling Connection

Clear Complete

Release Radio Signaling Channel

SDCCH

14

16

15

MS BSSOld MSC/ VLR

HLR/ AUC

New MSC/ VLR

LOCATION UPDATE SCENARIO - V

Update HLR/VLR & TMSI Reallocation

TAX CA

TAX ND

GMSC MSC

GMSC MSC/VLR

ND Mobile moves to CA and Powers on MS

CA

ND

HLR

HLR

ND

MS

9810098111CA

ND

( Update Location/ Authentication )

De register Mobile to Old VLR

ACK from old MSC/VLR

VLR

LOCATION UPDATION

VLR

VPLMN

HPLMN

Location Update

( TMSI, LAI )

LU Accept

( New TMSI)

Update Location

Update Location

LU Accept

(Subs data)

LU Accept

Update Location

LU Accept

LU Accept

New VLR records subscriber data.

• ListensBCCH/FCCH

Mobile To Land Call Set-up Scenario

Phases of Mobile To Land Call

• SETUP PHASE

( Mobile Originated Call- MO Call )

• RINGING PHASE

• CONVERSATION PHASE

• RELEASE PHASE

- REQUEST FOR SERVICE ( CHANNEL ) BY MS

- CM SERVICE REQUEST

- AUTHENTICATION

- CIPHERING

- SETUP MESSAGE

- EQUIPMENT VALIDATION ( EIR CHECK )

- VALIDATION AT VLR

- ASSIGNMENT

Mobile To Land Call Set-up Scenario

• SETUP PHASE

MSMSC/VLR BSS

1

2

3

Channel Request

Request For Service

MOBILE TO LAND CALL - I

RACH

SDCCH Assignment

AGCH

CM Service Accept

SDCCH

4

CM Service Request

Mobile To Land Call Set-up Scenario

• CM SERVICE REQUEST

- The Call Control (CC) entity of MS initiates the establishment of CC connection by requesting MM sub-layer of the mobile to establish MM sub-layer connection.

- Upon establishment of MM connection CM SERVICE ACCEPT message is received from n/w.

• SETUP MESSAGE

- CC entity sends a setup message to its peer entity.

MSMSC/VLR BSS

5

6

Call Setup Request

7

SDCCH

SDCCH

Call SetupMOBILE TO LAND CALL - II

Assign Trunk and radio

Assign TCH

Radio Assignment Complete

Call Proceeding

SDCCH

SDCCH

Trunk and Radio Assignment Complete

Mobile To Land Call Set-up Scenario

MSC/VLR

Call Setup message

Is the requested basic service

provisioned for the subscriber ?

Yes

No

Release Complete

message to MS

Preliminary Digit Analysis

Is the number of digits less than the

minimum expected?

Yes

Release Complete

message to MS

No 1. Check of ODB( BAOC/BOIC/ BOIC Ex HC )

2. Subscriber call barring checks ( BAOC/BOIC etc. )

ASSIGNM ENT

Mobile To Land Call Set-up Scenario

• ASSIGNMENT

- A BSSMAP message ‘Assignment Command ’ is sent by MSC to BSS.

- The message contains a free CIC on A-Interface for terrestrial channel allocated by MSC.

- A free TCH is allocated by the BSS and MS is informed to attach to this TCH.

- On receiving a response from BSS MSC switches the speech path towards the calling MS.

Note : Mobile has not connected user connection as yet.

MSMSC/VLR BSS

8

9

10

11

Call Setup MOBILE TO LAND CALL - III

GMSC PSTN HLR

Network Setup ( Dialed Digits )

FACCH

Network Alerting

Connect

Connect Acknowledge

FACCH

Alerting

Connect

FACCH

Start Billing

MSMSC/VLR BSS

12

13

14

15

Call Release

MOBILE TO LAND CALL - IV

GMSC PSTN HLR

Disconnect

FACCH

Network Release

Release Complete

Release Complete

FACCH

Release

FACCH

Clear Command

Channel Release

Land To Mobile Call Set-up Scenario

Phases of Land To Mobile Call

• Routing Analysis

• Paging

• Authentication

• Call-Setup

• Ciphering

• Call Release

( Mobile Terminating - MT Call )

Architecture For Mobile Terminated Call

GMSC- B BSS-B

MS

VLR-B

MSC-B

VISITING PLMN

A- Interface

Air Interface

AC

K (

MS

RN

)

SR

I ( MS

ISD

N ) P

RN

AC

K ( M

SR

N )

HLR-B

IAM ( ISUP )

LAND TO MOBILE CALL - I

MSC/VLR GMSC PSTN HLR

1

2

Incoming Call

3

4

( MSISDN )Get Route

( MSISDN )Get Route

( IMSI )

Routing Information

( MSRN ) Routing Information

( MSRN )

( MSRN )

Incoming Call5

Routing Analysis

MS MSC BSS

6

7

8

Perform Page

(TMSI)Page

PCH

Channel Request

( RACH )

SDCCH

Paging Response

( TMSI, LAI )9

Access Granted

( AGCH )

Page Response

Paging

LAND TO MOBILE CALL - II

MS MSC BSS

10

11

12

Call Set Up

Call Set Up Confirm

SDCCH

Radio Channel Assigned

Assign Trunk & Radio Channel

Trunk and Radio Channel Assignment Complete

SDCCH

SDCCH

Assign Radio Channel

SDCCH

Call Set-up

LAND TO MOBILE CALL - III

MSMSC/VLR BSS

13

14

15

Connect ( off-hook )

FACCH

Call SetupLAND TO MOBILE CALL - IV

GMSC PSTN HLR

FACCH

Network Alerting

Mobile Alerting

Connect

Connect Acknowledge

Start Billing

MSMSC/VLR BSS

16

17

18

Disconnect

Release

19

FACCH

FACCH

Call ReleaseLAND TO MOBILE CALL - V

GMSC PSTN HLR

Network Release

FACCH Release Complete

Release Complete

Clear Command

Clear Channel

Clear CompleteFACCH

Stop Billing

TAX ND

GMSC MSC/VLR

1. ND PSTN Subscriber Dials ND Mobile Subscriber in ND.

ND

LE TANDEM

HLR

ND

MS

9810098100NDSRI

PRN to MSC/VLR

ND

ACK from MSC/VLR

ND (MSRN)

MSRN

MSISDN

MSISDNMSISDN

Page(TMSI)

TAX ND

TAX CA

GMSC MSC/VLR

GMSC MSC/VLR

2. ND PSTN Subscriber Dials CA Mobile Subscriber in CA.

ND

CA

LE

HLR

HLR

CA

MS

9881098300

ND

CA

SRI

PRN to MSC/VLR

CA

ACK from MSC/VLR CA (MSRN)

MSRN

MSISDN

Page(TMSI)

TANDEM

MSISDN

MSISDNMSISDN

TAX CA

TAX ND

GMSC MSC/VLR

GMSC MSC/VLR

3. ND PSTN Subscriber Dials ND Mobile Subscriber in CA.

CA

ND

LE TANDEM

HLR

HLR

ND

MS

9810098200CA

NDSRI

PRN to MSC/VLR

CA

ACK from MSC/VLR CA (MSRN)

MSRN

MSRN

MSRN

MSRN

MSISDN

MSISDNMSISDN

Page(TMSI)

TAX CA

TAX ND

GMSC MSC/VLR

GMSC MSC/VLR

4. CA PSTN Subscriber Dials ND Mobile Subscriber in CA.

CA

ND

LE

HLR

HLR

ND

MS

9810098400

CA

ND

SRI

PRN to MSC/VLR

CA

ACK from MSC/VLR CA (MSRN)

MSRN

MSISDN

Page(TMSI)

TANDEM

MSISDN

MSISDNMSISDN

MSRN

MSRN

MSRN

OPTIMIZATION

What is Optimization ?

- Activity of achieving and maintaining the required quality as designed

Why Optimization ?

- Deviations between plan and reality

Introduction

Optimum utilization of GSM Net work elements for providing Good Coverage and Better Speech Quality for satisfaction of Subscriber and achieving the “TRAI” bench marks of QoS

Objective OF RF OPTIMIZATION

TRAI Bench Marks for QOS 1. Call Setup Success Rate > 98%

2. Handover Success Rate > 98%

3. Co Channel Interference > 98%

4. Rx.Quality(0-5) > 95%

5. Drop Call Rate < 3%

6. TCH Blocking Rate < 2%

7. SDCCH Blocking Rate < 1%

RFOptimization identifies common problems, such as:

1.Missing neighbors

2.Antenna adjustments

3.Issues of inter system handovers, Power control

4.Interference

5.Coverage gap, overlap coverage, etc.

A. VISIT BTS SITE & COLLECT THE FOLLOWING INFO :

1. Height of Antenna

2. Antenna Azimuth – Orientation

3. Antenna tilt

4. Checking of RF connectors

5. Verification of serving area by existing Antenna orientations

6. TX Power of TRX

B. DATA FROM OMC-R :

7.Data Base – Change of cell parameters

8.Cell Wise Performance Reports

a). SDCCH congn. b). TCH congn. C). Call Volume

d). Drop Call Rate e). Handover Success Rate

f). U/L & D/L quality & Interference.

Pre Requirements for Drive Test :

DRIVE TESTING TOOL Scanning Receiver Setup - HP 7475A Receiver

Example HP 7475A Receiver

DRIVE TEST :

Tool may be setup for two mobiles –

One for Continuous call and another for short calls(2min)

Conduct the Drive Test –

covering all sectors by observing the following parameters.

1. Rx Level

2. Rx Quality

3. Interference

4. Handovers & Drop Calls

5. Observe whether the nearest sector is serving or not.

Route Map With Rx Qual :

Route Map With Rx Level :

No. of BTS in SSA : No. of BTS s covered in the month :

Ch.Gutta-Katedan-Attapur-

M.Patnam-TPBVN

CHRMNR-Ch.Gutta

CTO-Tarnaka-

Uppal

Shivam-VDNR-STPM-

Sec.bad Rly. Stn.-

CTO

Sanath Nagar-

Balkampet-BGMPT-

CTO

TPBVN-MSRBD-

Ramnagar-VDNR

TPBVN-Abids-Koti-

Namply-L.Pool

TPBVN-AfglGunj-CHRMNR

Uppal-AMBRPT-

Chdr.Ghat-Cachiguda-

TPBVN

1 RX LEV. Total no. Of Samples 11309 3537 7776 9586 6715 7731 7886 4961 9553>=-75dBm 11187 3534 7677 9572 6609 7495 7786 4573 9434

%Samples >=-75dBm 99 99.91 99 100 98 97 99 92 99

2 RX. Qual. Total No.Of Samples 11313 3536 7776 9586 6715 7731 7886 4961 95530 to 5 10929 3198 7366 9290 5989 7046 6837 4669 8786

0-5(>=95%) 97% 90% 95% 97% 89% 91% 87% 94% 92%

3 Hand Over H/O Attempts 74 12 39 35 37 34 20 39 39Dropped 42 0 0 0 1 1 0 2 0

H/O Success rate 56% 100% 100.00% 100% 98% 98% 100% 95% 100%

4 Aggregate C/I Total 1755 547 1096 1630 794 982 889 464 1432C/I>9 1737 513 1035 1605 773 952 847 451 1383

%Samples with C/I>9 99% 94% 94% 98% 97% 97% 95% 97% 97%

5 Call Analysis Total calls 25 10 17.00 20 14 13 17 12 22Good 24 8 16 20 14 13 16 11 19

Success Rate 96% 80% 94% 100% 100% 100% 94% 92% 86%

Blocked Calls 0 0 0 0 0 0 1 0 1Dropped 1 2 1 0 1 0 1 1 2

Call Drop rate 4% 20% 6% 0% 7% 0% 6% 8% 9%

6Service Access Delay

9 - 20Seconds (average of 100 calls <=15 Sec.)

7.2 7.3 7.12 7.2 7% 7.4 7.1 7.3 7.9

In addition the above formate Route map also submit with Rx level and Rx qual, & survey markers Like H/o ,Call drop ,H/o failure

Drive Test Results

Name of The SSA : Hyderabad

Details of Parameter Routes/Towns

Sl.No

MECHANICAL DOWNTILTING OF ANTENNA

MECHANICAL DOWNTILTING OF ANTENNA

Analysis of Drive Test Results :Observation Cause Solution

Coverage Poor (Low RX

Level)

1. Antenna Orientations & TiltPhysical check of Orientations & Tilt.

2. High VSWR Value Check RF connectors & RF cables

3. TX PowerCheck the DRX power & connectors

Poor RX Quality

1. Intereference

Check the BCCH & MAIO frequencies

Reduction of Antenna height, Orientation & Tilt

2. Low Rx levelCheck the DRX power & connectors

3. H/O failureCheck the neighbour list & definitions

Check the neghbour parameters

4. Assignment Failure RatioCheck DRX & Check VSWR & RF cable connectivity

5. Hard Ware Problem DRX problem

Analysis of Drive Test Results :Observation Cause Solution

Handover Failure

1. Not defining proper neighbours

Defining the proper neighbours.

2. Improper Neighbour Parameter values

Check the neghbour parameters

3. Due to TCH congn. Augmentation of DRIs

Call Drop

1. Not defining proper neighbours

Defining the proper neighbours.

2. Low Rx level Check the DRX power & connectors

3. Intereference

Check the BCCH & MAIO frequencies

Reduction of Antenna height, Orientation & Tilt

4. H/O failure

Check the neighbour list & definitions

Check the neghbour parameters

5. Assignment Failure RatioCheck DRX & Check VSWR & RF cable connectivity

6. Hard Ware Problem DRX problem

THANKS !

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