Drive@Suman Tems

8/3/2019 Drive@Suman Tems

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WHY WE NEED TO DO DRIVE TEST:

TO OPTIMISE THE NETWORK i.e1. TO RESOLVE POOR COVERAGE AREA

2. TO AVOID CALL DROPS

3. TO AVOID INTERFEARENCE

4. TO AVOID HANDOVER FAILURES


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HOPPING :

HANDOVER :

CALL DROP:

CHANNELS:

MAIO:

HSN:

BASICS REQUIRED FOR DRIVE TEST


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CURRENT CHANNEL WINDOW


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DefinitionsTime: It is system time of computer.

Cell name: It displays the name of the sector which is serving according to the

cellfile that is loaded in TEMS.

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

MCC: Mobile Country Code 0 999 (e.g. 404 in India), MNC: Mobile NetworkCode 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)

Cell GPRS Support: Tells sector is having GPRS or not. Values are Yes or NoBand : 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.


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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 timeit shows which SDCCH it is getting out of 8 available. E.g. 2.

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.


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RADIO PARAMETERS


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RxLev : . Range of -30 dBm to -110dBm.

RxQual :Range of RxQual 0 -7.

FER :Ratio of discarded speech frame to that of received speech frame

BER Actual :Ratio of no. of incorrect bits recvd to that of total bits recvd

.

SQI : SQI is a more sophisticated measure which is dedicated to reflecting the

quality of the speech (as opposed to radio environment conditions). SQI is thebest criterion to use. SQI is updated at 0.5 s intervals. It is computed on basis of

BER and FER. ( 0 to 18 ; 18 to 35)

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. .

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

PARAMATERS WE CHK DURING DRIVE TEST


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DTX : Discontinuous transmission (DTX) is a mechanism allowing the radiotransmitter 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 tothe BS so as to compensate for propagation delay. Value of 0 means MS in

radius of 550mt. From BS.

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


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SERVING+NEIGHBOUR


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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 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.


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SIGNALLING

LAYER 3:

SYS INFO 1: BCCH & TCH FREQ ALLOCATED TO THE SITE

SYS INFO 2: SHOWS THE BCCH FREQ OF DEFINED NEIGHBOURS & NCC VALUE

SYS INFO 3: SHOW MNC,NCC,LAC ,SHOWS VALUE OF T3212 TIMER ,CELLRESELECTION PARAMETER

SYS INFO 4:MS IS INFORMED WHEATHER CELL BROADCAST FUNCTION IS

USED IN THE CELL

SYS 5:SHOWS THE BA LIST ATTACHED

SYS 6: TAKE CARE OF THE CHANGE IN LAC,& CHANGE IN RLT & DTX

CONDITIONS


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TCH DROP: 3%

SD DROP : 2.1%

TCH ASSIGNMENT: 95%

HOSR : 91%

TCH BLKING : 1%

KPI


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GET SERVICE

CALL

PHASE

ESTABLISH TCH CONNECTION

ESTABLISH SD CONNECTION GET TCHGET SD

RELEASE

PHASE

CALL SET UP SUCCESS RATE

SD BLK

TCH BLKSD SUCCESS RATE

CALL SUCCESS RATE


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Network Doctor Report

ND163 : TCH DROP OF THE CELL

ND166: SD DROP OF THE CELL

ND 196: UL & DL QUALITY & INTERFEARENCE PER TRX

ND232: HOW FAR THE SECTOR IS SERVING

ND208: UL DL PATH BALANCE OF TRX

ND153: SHOWS THE DEFINED NEIGHBOURS ALONG WITH

ATTEMPTS , BLOCK & DROP

ND 111: FREQ PLAN OF THE NETWORK ALONG WITH ITS MAIO,HSN


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ALARM

CHANNEL FAILURE RATE ABOVE DEFINED THRESHOLD

LAPD failure

MEAN HOLDING TIME BELOW DEFINED THRESHOLD

EXCESSIVE TCH INTERFERENCE

BCCH IS NOT AT PREFERRED BCCH TRX

WORKING SDCCH CHANNEL RATIO BELOW THRESHOLD

BCF OPERATION DEGRADED

BTS OPERATION DEGRADED

RXLEV DIFFER BETWEEN MAIN & DIVERSITY

TRAFFIC CHANNEL ACTIVATION FAILED


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Physical Verification

Physical Verification is carried out by verifying physical parameter of the

New Site with the TSSR (Technical Site Survey Report) such as Address, Lat,

Long, Building Height, Antenna Height, Antenna Type, Orientation, Tilt.

Alarm Verification

Alarms are generated mainly due to number of reasons, and these needs to

checked before Drive is being carried out for the Site. Alarms are checked from

the NOC (Network Operating Centre) and if found needs to be verified before

drive being carried out.

Hardware Configuration Verification

Hardware verification is performed to know the Site type, BTS Type, TRX

Configuration, VSWR checking , Power measurement for each TRX.

Steps followed to perform Drive Test


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Following is the procedure and parameters that need to

checked while performing Drive Test for a New Site.

1. CPC (Cell Parameter Check)

2. MOC (Mobile Originated Calls)

3. MTC (Mobile Terminated Calls Prepaid to Postpaid)

4. SMS (Short Messaging Service)

5. GPRS

6. Handover

7. TRX Test

8. Idle Drive (Normal Drive & Frequency Lock Drive)

9. Dedicated Drive

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