How to deal with uplink interference in UMTS ?

[yassanino]

hi all , i wish to get a help about some drop i have i tried tres faster but nothing in RTWP i found -85 wich means a serious uplink interference , wich action should i take to correct the cell in question

many thanks in advance

[tremalnike]

You have to identify main reason for RTWP - interference(constant in time) or load(rssi peak in BH),or wrong nodeB configuration(constant for day and night,check attenuation parameters,delay and etc.).
Which vendor you use?

[yassanino]

we rae using NSN vendor equipement

[RFHumam]

if its external interferance try to switch to another frequency, otherwise try to smallen the CPICH for this site in order to serve less pepole which means less internal interferance (consider not taking pepole out of coverage )

[vaampeere]

Hi,

Best is to use spectrum analyzer and find the source by means of triangulation. However, if equipment is not available then you can try any internal FFT analysis software tool to check overlap of any spectrum on the site by blocking the BRD.

[yassanino]

it appears that due to MHA ( not compatible and commisssioned like "other equipements" ) on some cells , untill now solution is to do a different parameters for sectores holding MHA

[dtvt2]

Pls check RTWP in non Busy hour. If it is high. there will be external interference

[yassanino]

thanks i'll check hourly the cells

[brianm]

Check if there are no missing neighbours or some subscriber with an illegal cell extender

In one town we had a building where people go for prayers and they had installed cell phone jammers to block calls during prayers. The regulatory officials ahd to ask them to switch them off as they were interfering with 3G and 2G signal

[samuraial]

If the rtwp is -85 all the time it is external interference most of the time.
In order to improve user experience you should find the source and avoid it. If not you can play with RTWPINITADJUST that can be found at nodeb level MML. Setting it to -150 will add -15dbm more and in total you will go -100dbm.
User experience will increase and throughput also.
Just be careful to monitor it as if the external interference will varnish you need to set RTWPINITADJUST 0 again.
Use automatic background noise also. Cell level.
Run dsp ucellchk command(RNC level) before and after to check the changes.


B/R