- This topic has 7 replies, 1 voice, and was last updated 13 years, 6 months ago by Danish.
21st May 2007 at 11:46 #47409EEEGuest
“WHEN MS MOVES AROUND A STREET CORNER, THE SIGNAL STRENGTH REDUCES SHARPLY AND CALL DROPS BEFORE MAKING HANDOVER TO STRONGEST CELL”
What can I do for this situation? (Ericsson Systems)
thanks22nd May 2007 at 04:55 #47410AhmedGuest
dropped call happen by this state:
*you have strong interference if u want to reduce this state u must be change the frequency of the cell that u call setup.
*call dropped happen when your MS try to handover but other cell is full(no TCH empty).
Best regards22nd May 2007 at 05:25 #47411EEEGuest
thanks ahmed but
here the problem is low signal strength on serving cell after move the corner. and no handover occure to the strongest cell and finally call drops due to low signal strength altough there are strong signal strength.
help me PIX22nd May 2007 at 08:09 #47412PixGuest
It is a very typical problem, that is encountered for most micro cells in many cities. Many solutions can be used, depending on your mobile network architecture :
multiband ? (upper band, lower band, indoor band ?)
mono band ?
what kind of handovers do you perform to enter your micro, and to exit your micro ?
in alcatel, there is a special type of handovers that exist, for all cells which are defined as “MICRO” type. This handovers will provide a quick exit from micro cells to neighbours cells, as soon as the Rxlev is below a certain threshold (whether or not power control is applied), or as soon as the number of “bad decoded SACCH frames” exceed a certain amount.
Do you have such emergency HO for micro cells ?
otherwise, you can reduce HO_MARGIN and reduce the POWER BUDGET averaging window between micro cells.
And finally, you can also decrease the “emergency HO due to low signal strength in DL” threshold to exit a micro cell (for instance -85dBm instead -92 dBm)
Hope it helps,
Pix22nd May 2007 at 08:20 #47413BowieGuest
I don’t know how to solve this problem on Ericsson network, but in Nokia you can use Rapid Field Drop HO option. You need to define “chained adj cell”.22nd May 2007 at 09:14 #47414senaristGuest
I agree to PIX and in addition to
you can check OSS(Operating Support System)data for this site.You can checks power control parametre value at the same time hardware checks in the site(for example antenna tilt hight,azimuth and Tx,Rx antena cable…)this site maybe serving at the small area.24th May 2007 at 04:32 #47415TufailGuest
I think you need to decrease AWOFFSET so that HO are enabled to worst cell.
Tufail26th May 2007 at 14:31 #47416DanishGuest
In this caes kinly rule out the possibility of rapid power control if everthing at the carrier level is within limits