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hong lim
2011-05-04, 07:31 AM
hello guys,

Can you please help me how to check if there is an interference during the drivetest and kpi test?whats are the signs and possible solutions if there is an interferrence encountered in one spot location.,thanks in advance:D

koepret
2011-05-04, 11:21 AM
hello guys,

Can you please help me how to check if there is an interference during the drivetest and kpi test?whats are the signs and possible solutions if there is an interferrence encountered in one spot location.,thanks in advance:D

Basically is CINR , and Compare with RSSI , if your RSSI is good and CINR is bad Ussually is interference .
1. Check your Frequecy Planning ( PUSC 1X3X3 or Another Else )
and Maske sure no site Face to face with Same Frequency
2. Try to Check and make Optimization for Preamble planning try Decrease Interference :)
3. Checking Antenna ( Azimuth , Mtil , Etilt ) for Decrease interference
4 . Last Option , Scan Frequency because any interference from another Network

hope will be help :)

Divisood
2011-05-05, 03:24 PM
What is reference signal recieved power in wimax? How can i calculate it?

koepret
2011-05-05, 06:04 PM
What is reference signal recieved power in wimax? How can i calculate it?

Reference signal level , Usually defend your link budget
formula of calculate also you can find in Wimax link budget
( forget that formula because theoretical base :) , but if you have link budget you can know that reference that value )

may be we can make general of legend RSSI and CINR
RSSI DL = -60dB until to - 90dB
RSSI UL = -75dB unitl to - 110dB
CINR DL and UL = 0dB until 30dB

For Calculate Link budget any parameter
- power transmitter , TDD ratio , MIMO xTxR Antenna gain and Another from BS , Antenna height ,
- power transmitter , Antenna gain , antenna height from Subscriber
in macro and Micro site will be limitation in UL ( so from subscriber )
for micro site will be limitation in DL

for RSSI 110dB and CINR 0.5 dB Basiclly still can connnect but without traffic , for good connection is with CINR 80dB and CINR 10dB .

sallywally
2011-05-05, 06:38 PM
Attached a drive test output and a macro we use to classify areas bases on RSSI and CINR relation. The macro simply states which of the coordinates are under good coverage/poor coverage/interference.

Rep plz

hong lim
2011-05-05, 10:07 PM
Attached a drive test output and a macro we use to classify areas bases on RSSI and CINR relation. The macro simply states which of the coordinates are under good coverage/poor coverage/interference.

Rep plz

thank you very much sallywally really appreciate it,can you please tell me how to use the macro in the excel,thanks:D

sallywally
2011-05-07, 12:59 AM
thank you very much sallywally really appreciate it,can you please tell me how to use the macro in the excel,thanks:D

you just paste it in the macro dialogue box and run it.

MyVi78
2011-05-13, 10:12 PM
Attached a drive test output and a macro we use to classify areas bases on RSSI and CINR relation. The macro simply states which of the coordinates are under good coverage/poor coverage/interference.

Rep plz

Hi Sally,

I'm also directly involved in WiMAX optimization. What I do is just create a simple pivot table based on cell id, RSSI and CINR. From there I just take those with higher number of sample count as the highest priority.

Could you share the attachment as an external link? I'm still new here, so not allowed to view attachments. :(

Kelvin

nirzah
2011-05-18, 08:09 PM
Attached a drive test output and a macro we use to classify areas bases on RSSI and CINR relation. The macro simply states which of the coordinates are under good coverage/poor coverage/interference.

Rep plz

what is the treshold you defined to indicate good/poor or interference?:o

adewijaya
2011-05-18, 10:46 PM
already state above, please see the common value

sorena_ir
2011-05-20, 06:54 PM
Base on my experince you should check the interference level of the network,

Consider this as the best solution for your problem,

first export all your DT result of the cluster or city into one,
then create a new parameter called interference level form:
Interference level = RSSI - CINR

e.a IL=-80 -(8)=-88dbm that sound good an there is no important interference problem in that arean

e .b IL=-65 -(4)=-69dbm that shows critical interference problem for the related area,

This can show you very cleary on MAPINFO that where you face with interference problem and need freq. replan or control the overshoots.

Hope this can solve your problem,feel free to contact with me about it.

Dont forget thanks;)
Sorena



hello guys,

Can you please help me how to check if there is an interference during the drivetest and kpi test?whats are the signs and possible solutions if there is an interferrence encountered in one spot location.,thanks in advance:D

ramsriniv
2011-06-25, 08:49 AM
Hi,

RSSI Vs CINR is the key. You plot your DT data and sites along with SC. You might find some SC that are coming too strong at your interference area.

Thanks
Ram

karim
2011-07-01, 02:08 AM
I agree with both Sorena and Ram.

/karim

miladsafa_ir
2011-07-01, 03:06 AM
Dear Friends,

Is there a training document covering interference analysis in WiMAX network design procedures?

karim
2011-07-01, 07:13 AM
Hi,

Attached Huawei RF tunning guide, perhaps it gives an idea about essentials RF paramters need to consider.


/karim

MyVi78
2011-07-01, 10:23 PM
Base on my experince you should check the interference level of the network,

Consider this as the best solution for your problem,

first export all your DT result of the cluster or city into one,
then create a new parameter called interference level form:
Interference level = RSSI - CINR

e.a IL=-80 -(8)=-88dbm that sound good an there is no important interference problem in that arean

e .b IL=-65 -(4)=-69dbm that shows critical interference problem for the related area,

This can show you very cleary on MAPINFO that where you face with interference problem and need freq. replan or control the overshoots.

Hope this can solve your problem,feel free to contact with me about it.

Dont forget thanks;)
Sorena

Interference level = RSSI - CINR is good for referencing only.

Caution should be used when depending solely on this criteria as it is not always 100% accurate..

I've seen vendor RF engineers relying on this heavily while at the same time missing out on so many other serious issues.. :(

wahaha
2011-08-13, 01:49 PM
Hi sallywally, possible to guide in details a bit how to use the macro? Noticed your explanation above, but still can't get the meaning....Appreciate it!!! :)