RANDOM SIGNAL FLUCTUATIONS!!!

[Lesmana]

Dear Experts,

Right now We are using Huawei BTS in our network and earlier it was ********. Recently the swap is done. But after the swap by Huawei, we found so many problem in our network.

One Important issue is : "RANDOM SIGNAL FLUCTUATIONS" for example:

Along the road the users are getting full coverage but when they enter into any shops/office beside the road the signal drops down a lot and many times
its causes call drops. Even while sitting in a place at indoor OR Outdoor these types of random fluctuations happening.Full signal and then nothing...after that again full....like this....

Our network having huge external interference due to the adjacent CDMA band of e GSM.

Is these signal fluctuations are related with Interference ? if yes...HOW?


regards

[sabila]

first
if interference suspect u can check
at LMT right click at suspended site---->monitor channel interfernce band-->
and u can see
if
channel being interference if in band 3(yellow)-4(blue)-5(red)

second
check with your tems or celltrack or sometjhing else
at road maybe u still cover by DCS and then in shop or building u still cover by DCS

in my case the DCS still hadled MS even in indoor building
so the action is reduce power the DCS and handover to GSM

[tomrf]

try further investigatition in one spot,
-what is the dominant cell also the second or third candidat
-check the nearest cell tower, if before swap was good, so there is a problem, and as long as i found in swap process, many installation not proper during swap. make sure there is no hardware installation issue
-how about serving cell quality? if downlink quality is bad (found from drive test or trx quality measurement), probably there is BCCH co-channel or adjacent channel, if yes, do some frequencies retune
-check power control setting, try to disable it on dominant serving cell and re-drive test on same spot.

BR/
tomrf

[Lesmana]

first
if interference suspect u can check
at LMT right click at suspended site---->monitor channel interfernce band-->
and u can see
if
channel being interference if in band 3(yellow)-4(blue)-5(red)

second
check with your tems or celltrack or sometjhing else
at road maybe u still cover by DCS and then in shop or building u still cover by DCS

in my case the DCS still hadled MS even in indoor building
so the action is reduce power the DCS and handover to GSM

We already checked the IB and its 5 in many cells...so no question abt. that..and interesting thing is the IB is time variant...i.e in 1 cell the IB was high(5) for 3 days and at 4th and 5th day it showed very low..this case happening in many cells.....

@ indoor, mostly the DCS signal goes very weak...and bcch remain strong..in most of the cases problems happen when the call handed over to hopping channel...poor level & quality specially at 1800 TCH...

we are using DL P.C

[Lesmana]

try further investigatition in one spot,
-what is the dominant cell also the second or third candidat
-check the nearest cell tower, if before swap was good, so there is a problem, and as long as i found in swap process, many installation not proper during swap. make sure there is no hardware installation issue
-how about serving cell quality? if downlink quality is bad (found from drive test or trx quality measurement), probably there is BCCH co-channel or adjacent channel, if yes, do some frequencies retune
-check power control setting, try to disable it on dominant serving cell and re-drive test on same spot.

BR/
tomrf

No Hardware Issue at all...we checked in so many cells...this problem happening in many cells and its un usual to have hardware issue in so many cells at a time...we verfied it....

In almost every cases the DL quality goes very poor. we can find out interference(Co/adjacent) from here easily as if the Rx level is good but qual is Bad....But in our cases as i said...signal degrades a lot and Rx level goes very poor so the Rx qual became poor which is natural i think...why this Rx level goes very poor randomly???

while standing at the road,mobile shows full network..but after entering in any roadside shop...level drops down and come back..continuously ...happening these.

In some cases we found the Rx qual is poor though the level is good...here we can say DL interference issue and can tune the FP.

My concern is --- WHY SUCH RANDOM FLUCTUATIONS OF RX_LEVEL.

I disable the DL P.C experimentally in one cell...but no significant improvement found...

Please tell something more about adjacent channel interference..How much should be the min. gap in between the serving and adjacent channel to avoid adjacent channel interference both for egsm and dcs?

regards