Drive Test

33
DRIVE TEST FUNDAMENTALS

Transcript of Drive Test

Page 1: Drive Test

DRIVE TEST

FUNDAMENTALS

Page 2: Drive Test

How it looks

Page 3: Drive Test

Different frequencies on

Mapinfo

Page 4: Drive Test

BSIC Planning.

• BSIC = NCC + BCC.

Base station Identity Code.

• NCC….(NETWORK Color Code).

• BCC….(Base Station Color Code).

Values Range From 0…..7.

Page 5: Drive Test

Importance of BSIC.

• Identify the BTS.

• Used to reduce DROP Calls during Co

Channel Interference.

• Mobile can’t understand co channel & identify

no difference between same frequency signal

coming from two sites & so DROP Call. BSIC

is the parameter that helps the mobile to

identify the different BTS.

Page 6: Drive Test

Current Channel

• Definitions:

1. Time: It is system time of computer.

2. Cell name: It displays the name of the sector which is serving according to the cellfile that is loaded in TEMS.

3. CGI : It stands for the Cell Global Identity which is unique for every sector of the site. It consists of MCC,MNC,LAC,CI.

MCC: Mobile Country Code 0 – 999 (e.g. 404 in India), MNC: Mobile Network Code 0 – 99 (e.g. 98 for Airtel in Gujarat) LAC : Location Area Code 0 -65535 (e.g. 5101 in Gujarat) CI: Cell Identity 0 – 65535 (e.g. 11001)

Page 7: Drive Test

Current Channel

• Cell GPRS Support: Tells sector is

having GPRS or not. Values are Yes or

No .

• Band : It tells in which Freq. Band mobile

is operating e.g. GSM 900/ 1800.

• BCCH ARFCN: It tells by which BCCH

is the mobile station getting served.

• TCH ARFCN: On which Traffic Freq.

call is going on.

• BSIC (Base Station Identity Code) : It is

combination of Network Color Code

(NCC) (0 – 7) & Base Station Color Code

(BCC) (0 – 7). e.g. 62. It is decoded by

mobile on every Sync. Channel Message.

• Mode: It is shows in which state is mobile

operating, Idle, Dedicated & Packet.

• Time slot: On which time slot of current

TCH call is going on. Viz. time slot no. of

TRX.

Page 8: Drive Test

Current Channel

• Channel Type: Type of channel mobile is getting now. Like BCCH / SDCCH/8 + SACCH/C8 or CBCH / TCH/F +FACCH/F +SACCH/F.

• Channel Mode : Shows mode of coding like Speech Full Rate of Half Rate.

• Speech Codec: It shows FR for Full Rate, HR for Half Rate & EFR for Enhanced Full Rate.

• Ciphering Algorithm : It shows ciphering algorithm used by the system to protect data for privacy. E.g. Cipher by A5/2.

• Sub Channel Number: It is displayed at a time when mobile is on dedicated mode at time of call setup when it is getting SDCCH at that time it shows which SDCCH it is getting out of 8 available. E.g. 2.

Page 9: Drive Test

Current Channel

• Hopping Channel : It shows that current

sector is having hopping feature or not.

Values are Yes or No.

• Hopping Frequencies : It displays no. of

freq. on which mobile is allowed to hop.

viz. MA List for hopping of that sector.

• Mobile Allocation Index Offset (MAIO):

It is the number which tells from which

freq. from given MA list for sector

hopping has to be started. E.g. 0 means

sector will start from first freq. to hop.

• Hopping Sequence Number (HSN) :

Indicates sequence in which frequencies

are allowed to hop from the MA List. 0-

63. 0 for Cyclic Hopping, 1 – 63 random

hopping sequences.

Page 10: Drive Test

Radio Parameters

• RxLev : Receiving level in terms of dBm that mobile is receiving from the site. Range of -30 dBm to -110dBm.

• RxQual : Quality of voice which is measured on basis of BER. Range of RxQual 0 -7.

• FER : Frame Erasure Rate it represents the percentage of frames being dropped due to high number of non-corrected bit errors in the frame. It is indication of voice quality in network.

• BER Actual : Ratio of the number of bit errors to the total number of bits transmitted in a given time interval. BER is a measure for the voice quality in network.. Depending on BER RxQual is measured. E,g, BER 0 to 0.2 % corresponds to RxQual 0. Max. BER countable and useful is up to 12.8 % which corresponds to RxQual of max. 7.

Page 11: Drive Test

Radio Parameters

• SQI : SQI is a more sophisticated measure

which is dedicated to reflecting the quality

of the speech (as opposed to radio

environment conditions). This means that

when optimizing the speech quality in

your network, SQI is the best criterion to

use. SQI is updated at 0.5 s intervals. It is

computed on basis of BER and FER. For

EFR 30, FR – 21 & HR – 17 are

respectively ideal values.

• C/I : The carrier-over-interference ratio is

the ratio between the signal strength of the

current serving cell and the signal strength

of undesired (interfering) signal

components. It should be atleast > 9 .

• MS Power Control Level : Displays

range of power control from 0 to 8

depending upon network design. E.g. 0

means no power control and 1 means

level that is defined by operator viz. 2

dBm less acc. To airtel.

Page 12: Drive Test

Radio Parameters

• DTX : Discontinuous transmission (DTX)

is a mechanism allowing the radio

transmitter to be switched off during

speech pauses. This feature reduces the

power consumption of the transmitter,

which is important for MSs, and decreases

the overall interference level on the radio

channels affecting the capacity of the

network..

• TA : Value that the base station calculates

from access bursts and sends to the mobile

station (MS) enabling the MS to advance

the timing of its transmissions to the BS so

as to compensate for propagation delay.

Value of 0 means MS in radius of 550mt.

From BS.

Page 13: Drive Test

Radio Parameters

• RL Timeout Counter (Cur) : This

parameter define the maximum value of

the radio link counter expressed in

SACCH blocks. Range of 4 – 64 in step

size of 4. it shows current value of RLT.

Decrease by 1 but increase by 2. When it

reaches zero it results in normal DROP

Call.

• RL Timeout Counter (MAX) : This

parameter define the maximum value of

the radio link counter expressed in

SACCH blocks. Range of 4 – 64 in step

size of 4. it shows current value of RLT.

Normally 16, 20, 24.

• MS Behavior Modified : This window

shows current settings for the mobile

station, for instance whether handover is

disabled or multiband reporting enabled.

Page 14: Drive Test

Serving + Neighbor

• Cell Name : Name that describes the neighboring cell as per the cellfile.

• ARFCN : Channel number mobile receives as neighbor.

• BSIC : BSIC of the neighboring cell.

• RxLev : Receiving Level in dBm of neighboring cell.

• C1 & C2 : These are the cell path loss criterion and cell reselection criteria. Valid during idle mode of mobile station.

• C31 & C32 : GPRS signal strength threshold criterion C31 and GPRS cell ranking criterion C32. Valid both in packet idle and packet dedicated mode.

Page 15: Drive Test

Other Useful Parameters.

Adjacent Channel Signal Strength.

Carrier to Interference Ratio.

• Value of C/I range from -5…..25. It should be more than 9.

Page 16: Drive Test

C/I Values

C/I Values Shown using line chart.

Page 17: Drive Test

Rx. Level, SQI, FER.

Page 18: Drive Test

SYSTEM INFO MESSAGES

• The system info messages are sent to the mobile from

the network on the BCCH in idle mode and on the

SACCH in active mode.

• System info messages (SIM) 1 to 4 are sent on the

BCCH and rotated with PCH , AGCH, SCH and FCCH,

and may be the SDCCH.

• SIM 5 and 6 are transmitted continously on the SACCH

to active mobiles on the downlink while the

measurement report is being sent on uplink.

Page 19: Drive Test
Page 20: Drive Test
Page 21: Drive Test
Page 22: Drive Test
Page 23: Drive Test
Page 24: Drive Test
Page 25: Drive Test
Page 26: Drive Test
Page 27: Drive Test
Page 28: Drive Test
Page 29: Drive Test

TEMS MENU

Page 30: Drive Test

CONTROLCOMMAND

SEQUENCE

• To Configure TEMS for Short calls.

Page 31: Drive Test

CONTROLGSM CHANNEL

VERIFICATION

• To verify GSM Channels

Page 32: Drive Test

PRESENTATION

• To make your screen as per your

requirement.

• Click on presentation menuthen on

GSMthen on menu whichever you are

looking for.

Page 33: Drive Test

THANK YOU