Drive Test Problems

Mohaned Yousef Ismail Yousef Telecommunication Engineer

2010

Mohaned Yousef Ismail Yousef E-mail: [email protected]

Mobile : +2 0104585755

Drive Test problems (2G,3G)

Mohaned Yousef Ismail Yousef Telecom engineer

2 Drive Test problems (2G & 3G)

Problem No.1

Different LAC [location area code] (2G).

How I can find it :

By looking at [GSM current channel] window , I will see that my site have different LAC from its neighbors.

How it can be solved :

Tell the operator about that problem and they will change it to the right one.

Problem No.2

Shifted azimuth (2G,3G)

How I can find it :

from the coverage area of the site I find that the azimuth of that site is not logical.


Tell the Technician to check the azimuth of the sectors to be similar to the planned azimuth.



Problem No.3

Handover failure (2G)

How I can find it :

it happens when a sector in a site is not defined for the other sites around it.


report that to the operator and they will define the sectors to each other and solve the problem.

Problem No.4

Overshooting

How I can find it :

I will find in the coverage region of a site which should be serve it with good level ,that there are another site server in it

with good level and it may cause interference.


down tilt the site which overshoot in that region to avoid interference.



Problem No.5

Gaps (2G)

How I can find it :

When I test the coverage on a main road sometimes I find a gap between 2 sites because there are far away from each

other or one of them is down tilt.


by up tilting one of them to serve this gap.

Problem No.6

Hopping channels problems (2G)

How I can find it :

In 2G, sometimes the hopping channels technique doesnt work and I find that from the [hopping channel] window.


Call the integrator to fix this problem.



Problem No.7

Site down (2G,3G)

How I can find it :

when i call the front office to activate a site it may be down for 2 reasons , down for transmission [E1 down] or power

reason.


Report that to the operator to solve the problem by check E1 connection or power of the site.

Problem No.8

Connectivity problem (2G,3G)

How I can find it :

connectivity problems cause bad level , bad quality ,bad coverage area and blocked calls.

How it can be solved:

tell technician to check feeders ,connectors and jumbers.



Problem No.9

Wrong configuration (2G)

How I can find it :

I notice that from the [hopping channels] window that the real configuration different from the planed configuration.


Tell the operator to modify the TCHs to be as the planned.

Problem No.10

Ping pong handover (2G)

How I can find it :

it happens when there are a small region all sites serve it with the same level so the MS will handle between them

quickly and this may cause dropped calls.


Tell the operator to solve this problem by down tilt some sites and reduce other sites .



Problem No.11

Blocked calls (2G,3G)

How I can find it :

It happens due to RACCH error [due to high traffic] or connectivity problem,


Tell technical to check connectivity.

Problem No.12

No RRC Connection setup (3G)

How I can find it :

in this case, I cant access on that site due to hardware problem.


Tell technical team to solve that problem.



Problem No.13

Cross sector [2G, 3G] .

How I can find it :

two different sectors in the same site serve in the each other area. It happens when the 2 feeders of the TRUs of 2

antennas inversed with each other.


Tell the technical team to inverse the input feeders of these antennas to solve this problem.



Problem No.14

Cross feeder [2G]

How I can find it :

As an example in site with 2 sectors, I will find that sector A serve in its region and in Sector B region too and the Rx-

Level will be almost the same in the to regions. It happens when one feeder is inversed in the 2 antennas with each

other.


Tell the technical team to inverse the input feeder of these antennas to solve this problem and inform them that there

are a cross feeder problem.



Problem No.15

VSWR [Voltage standard wave ratio] [2G]

How I can find it :

Under the site we must see the levels of all sectors is the best, when I find Rx-Level of one of the sectors is bad so it will

be VSWR problem [connectivity problem].


Tell the technical team that there are VSWR , please check connectivity



Problem No.16

Faulty DTRU [2G]

How I can find it :

In the main beam of a sector [In dedicated mode] the TCH channels must be in good levels.. when a level of a TCH is bad

, so its a faulty DTRU.


Replace the DTRU that have a problem by new one.



Problem No.17

Disconnected DTRU [2G]

How I can find it :

Before doing any acceptance for any 2G site . I must know the configuration of that site .As an example if the

configuration of Cell E is 4 TCH 1800 Band and I found it 3 TCHs and I check with integrator and he tell me that there is

not any problem in the assigned frequencies so there is a disconnected DTRU.


Tell the technician that there is a disconnected DTRU on Cell E and he will solve the problem.



Problem No.18

Co-channel interference

How I can find it :

By looking at [hopping channel] window I can fine the C/I [carrier over interference ratio] is bad . The Co-channel

interference happens when there are two frequencies [the same] interfere with each other.


Tell the operator about that frequency and the will solve the problem.

Problem No.19

Adjacent interference

How I can find it :

By looking at [hopping channel] window I can fine the C/I [carrier over interference ratio] is bad . The Adjacent

interference happens when there are two frequencies [closed together] interfere with each other.


Tell the operator about that 2 frequencies and the will solve the problem.



Problem No.20

Handover intracell failure (2G)

How I can find it :

in TEMS this alert will appear in Events window


there is no synchronization between 900 TCHs and 1800 TCHs cabins ,So the technical will solve that problem by make

synchronization between them by help from the integration office.



Problem No.21

Wrong position ( Wrong Lat & Long)

How I can find it :

go to the given co-ordinates and I didnt find the site . [Survey team mistake]


search for the site in the field around the wrong co-ordinates region .



Problem No.22

Missing neighbor relations. [3G]

How I can find it :

in TEMS this alert will appear in Events window and it happens when 2 sites neighbors and didnt defined to each other.


Tell the operator by the missing neighbors data and the problem will be solved



Problem No.23

HSDPA failed. [3G]

How I can find it :

the average speed of HSDPA through put speed didnt reach for the acceptable range.


it is a problem in hardware or in integration .



Problem No.24

Shifted azimuth (2G,3G)

How I can find it :

It appears from the illogical coverage area of the sector which have shifted azimuth.


I ask for the real azimuth and modify it.



Problem No.25

IRAT failed ( 3G-2G)

How I can find it :

in dedicated mode , when the call have very bad RSCP and EcNo in 3G, it must go to 2G . If it wasnt happened so IRAT

failed.


The integration office will solve this problem.



Problem No.26

Reselection Failed(2G-3G)

How I can find it :

In idle mode, the priority for 3G . if we are on 2G in idle mode and it does not go to 3G so reselection failed.


The integration office will solve this problem.



Problem No.27

Dropped Calls .

How I can find it :

it happens due to bad level and quality .


Report the operator about this problem after analyzing it ,depending on its case.

Problem No.28

Bad coverage area due to wrong tilts

How I can find it :

in the field I will find poor coverage of a sector so there will be a tilts problems [ down tilt]


Tell the Technician to uptilt that sector to get the required coverage area.

Problem No.29

PS [packet switching] doesnt initiate.

How I can find it :

when I test the PS browsing of any 2G site , it doesnt initiate according to hardware problem or integration problem.


Check with integration and if there are a problem there so it will be hardware problem solved by technical team.

Drive Test Problems

Documents

g problem

drive test problems

site server

connectivity problems

hopping channels problems

bad level

coverage region

bad coverage area