RF Drive Test Questions

RF drive test questions which can be probably ask by interviewer.

so before to face the interview you must well prepared.

Q.1: Please introduce the telecommunication/wireless system configuration.

GSM: MS-BTS-BSC-MSC WCDMA:UE-NODEB-RNC-CN

Q.2: Tell us 2G/3G(known) parameter which mostly concern in drive:

GSM:

RX Level (Received signal level):

-70dbm to 0dbm:Excellent; -70dbm to -80dbm:Good; -80dbm to -90dbm: Average ; -100 dbm -90dbm:worst 

RX Quality (Recieved signal quality):

0 to 4 :good;   4 to 6 normal; up 6 bad;

C/I: Carries power / Interface power

WCDMA:

RSCP: Recieved signal code power

-70dbm to -20dbm Excellent  ;-70dbm to -80dbm: Good;-80dbm to -90dbm: Average; -100 to -90:bad ,below -100 is worst.

Ec/Io: Chip energy / Interface of other cell:

0 to -6:good;-6 to -10: normal;-10 to -12:acceptance; below -12:bad.

Q.3: What is Swap and how many types of there?

Interchanging of feeder cables is nothing as swap.

there are 3 types of swap.

1- Sector Swap - when feeder A cables connected in B, and B cable in A.

2-Cyclic Swap- when feeder A cable connected in B, B cable connected in C, C cable connected in A.

3- Diversity Swap- When main feeder cable connected in diversity port and diversity cable connected in main port.

Q.4: Please analysis of causes of call drop?

Poor coverage:

Coverage hole, dead zone, isolated island, uplink/downlink unbalance Coverage over shooting Signal attenuation.

Interference:

Internal interference, external interference and the equipment interference ;Strong downlink/ uplink  interference.

Parameter setting not proper:

Radio link timeout counter, handover, power control, time slot busy.

Q.4: How many types of call drop there?

2 Types of call drop are there

1-SD drop- when user dial a number and without information its get disconnect.

2-TCH drop- when user dial and it shows with beep like going to connect, due to TCH busy and time slot not availble its get disconnected. shortly can say after allocation get disconnected.

Q.5: Please analysis of causes of handover failure?

1-missing neighbor or neighbor not defined.

2-when neighbor cell dont have free time slot.

3- swap in neighbor cell.

4- interference.

Q.6: Difference between handover and cell reselection?

When user moving in idle mode is nothing cell reselection and when user moving in dedicated mode nothing as handover.

Q.7: Introduce the software and test equipment you have used Software:

① TEMS product:TEMS9.1;8.14;8.03;

② Nemo

③ Probe1.5,probe1.4;probe1.3; assistant analysis

④ Mapinfo:9.0;8.5;7.0;

⑤ actix analysis

 Test mobile:

sonyerrisson: k800i; k790i; z750i; w600; w995

Nokia: 6680; N70; N80

Motorola: V3XX

Q.8: Introduce the mapinfo and googlearth?

① Check the site location from google earth or mapinfo

② check the entironment nearby the site and make a plan for the testing from google earth and mapinfo;

③ analysis the logfile from mapinfo.

Q.9: how can analysis the logfile and make report?

① actix software analysis

② Tems software analysis

③ assistant software analysis

Check coverage,quality ,handover and Throughput and so on.

Q.10: In which tool frequency plan will done?

Atoll software.