drive test problems
DESCRIPTION
Drive Test ProblemsTRANSCRIPT
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Mohaned Yousef Ismail Yousef Telecommunication Engineer
2010
Mohaned Yousef Ismail Yousef E-mail: [email protected]
Mobile : +2 0104585755
Drive Test problems (2G,3G)
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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.
How it can be solved :
Tell the Technician to check the azimuth of the sectors to be similar to the planned azimuth.
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Mohaned Yousef Ismail Yousef Telecom engineer
3 Drive Test problems (2G & 3G)
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.
How it can be solved :
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.
How it can be solved :
down tilt the site which overshoot in that region to avoid interference.
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Mohaned Yousef Ismail Yousef Telecom engineer
4 Drive Test problems (2G & 3G)
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.
How it can be solved :
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.
How it can be solved :
Call the integrator to fix this problem.
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Mohaned Yousef Ismail Yousef Telecom engineer
5 Drive Test problems (2G & 3G)
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.
How it can be solved :
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.
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Mohaned Yousef Ismail Yousef Telecom engineer
6 Drive Test problems (2G & 3G)
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.
How it can be solved :
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.
How it can be solved :
Tell the operator to solve this problem by down tilt some sites and reduce other sites .
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Mohaned Yousef Ismail Yousef Telecom engineer
7 Drive Test problems (2G & 3G)
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,
How it can be solved :
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.
How it can be solved:
Tell technical team to solve that problem.
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Mohaned Yousef Ismail Yousef Telecom engineer
8 Drive Test problems (2G & 3G)
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.
How it can be solved :
Tell the technical team to inverse the input feeders of these antennas to solve this problem.
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Mohaned Yousef Ismail Yousef Telecom engineer
9 Drive Test problems (2G & 3G)
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.
How it can be solved :
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.
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Mohaned Yousef Ismail Yousef Telecom engineer
10 Drive Test problems (2G & 3G)
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].
How it can be solved :
Tell the technical team that there are VSWR , please check connectivity
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Mohaned Yousef Ismail Yousef Telecom engineer
11 Drive Test problems (2G & 3G)
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.
How it can be solved:
Replace the DTRU that have a problem by new one.
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Mohaned Yousef Ismail Yousef Telecom engineer
12 Drive Test problems (2G & 3G)
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.
How it can be solved :
Tell the technician that there is a disconnected DTRU on Cell E and he will solve the problem.
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Mohaned Yousef Ismail Yousef Telecom engineer
13 Drive Test problems (2G & 3G)
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.
How it can be solved :
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.
How it can be solved :
Tell the operator about that 2 frequencies and the will solve the problem.
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Mohaned Yousef Ismail Yousef Telecom engineer
14 Drive Test problems (2G & 3G)
Problem No.20
Handover intracell failure (2G)
How I can find it :
in TEMS this alert will appear in Events window
How it can be solved :
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.
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Mohaned Yousef Ismail Yousef Telecom engineer
15 Drive Test problems (2G & 3G)
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]
How it can be solved :
search for the site in the field around the wrong co-ordinates region .
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Mohaned Yousef Ismail Yousef Telecom engineer
16 Drive Test problems (2G & 3G)
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.
How it can be solved :
Tell the operator by the missing neighbors data and the problem will be solved
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Mohaned Yousef Ismail Yousef Telecom engineer
17 Drive Test problems (2G & 3G)
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.
How it can be solved :
it is a problem in hardware or in integration .
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Mohaned Yousef Ismail Yousef Telecom engineer
18 Drive Test problems (2G & 3G)
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.
How it can be solved :
I ask for the real azimuth and modify it.
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Mohaned Yousef Ismail Yousef Telecom engineer
19 Drive Test problems (2G & 3G)
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.
How it can be solved :
The integration office will solve this problem.
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Mohaned Yousef Ismail Yousef Telecom engineer
20 Drive Test problems (2G & 3G)
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.
How it can be solved :
The integration office will solve this problem.
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Mohaned Yousef Ismail Yousef Telecom engineer
21 Drive Test problems (2G & 3G)
Problem No.27
Dropped Calls .
How I can find it :
it happens due to bad level and quality .
How it can be solved :
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]
How it can be solved :
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.
How it can be solved :
Check with integration and if there are a problem there so it will be hardware problem solved by technical team.