- This topic has 19 replies, 1 voice, and was last updated 12 years, 1 month ago by Pix.
2nd December 2008 at 10:24 #54919MKTGuest
I want to know RxlevelAccessMin has got significance in case of IDLE only or
in DEDICATED also?
Our network…..after upgradation to MULTIBAND…1800/900 is showing a BAS taste for customers.
What i observed that…
Rxlevel and Rxqual are fine as long as TCH is on 900.
But on 1800 the Rxlevel goes down to -80dBm to -97 dBm on and off.
Also sometimes the situation is so worst that it reaches -106dBm or sometimes even -109dBm.
At this stage the Rxqual is normally 7….AND
It is not with any individaul site……it is common with all sites…….
Can we fix it.
MKT8th December 2008 at 14:11 #54920PixGuest
I would say that you have to define an exit strategy when the MS is in a DCS1800 cell. You have to check if a handover is possible towards another GSM900, because usually it is quite complex…11th December 2008 at 10:46 #54921BhanuGuest
Rxlevel Accmin has got significance in idle mode only.
You can ceck your MAIO plan for 1800 and also as pix mentioned,parameters for call handover to 1800 TCH.14th December 2008 at 05:20 #54922SamGuest
I understand ur problem, call drop happens when u r going away from 1800 band, but call is not handed over to 900 band; there may be two cases:
1. both band have individual BCCH
2. common BCCH for both band.
these HO causes are due to radio reasons, so if it is the case, then check hoMarginLev and hoMarginQual, u may have to adjust these parameters to initiate HO.
u have to check hoLevelUmbrella also for HO reasons.
hope this information helps you..
-Sam14th December 2008 at 17:09 #54923PixGuest
Your advice works only for one brand of equipments, but perhaps MKT is not using the same as you.15th December 2008 at 07:17 #54924mktGuest
not able to post15th December 2008 at 07:18 #54925mktGuest
Thanks for replies…….
Let me provide more inputs….
The BCCH is on 900
1800 has been used just to add capacity to the cell.15th December 2008 at 07:19 #54926mktGuest
Earlier cell was with four TRX of 900.
Now it is 4+2=6 TRX per cell. The additional two are from 180015th December 2008 at 07:19 #54927mktGuest
One more thing…
Our vendor has used 29 frequencies from the DCS1800 band for these TWO TRX of 1800.
Is there any thing wrong in using a LONG LIST in the MAL for 1800?
Any thing like RADIO LOAD???15th December 2008 at 07:20 #54928mktGuest
If power control is ON in a cell…As you don’t have to option to see uplink but certainly you have the one for downlink.
Does the RxLevel of a TCH drops/reduces by virtue of PC?15th December 2008 at 07:20 #54929mktGuest
What I observed in the drive test is that…….
Before call drop either the
Rxlevel was in the range -100 to
The RXqual was at 6 or 7.
I think these values should be sufficient enough for the Algorithms in the BSC to get triggered and handover the CALL to a SUITABLE cell—–which may be INTRA or INTER???
But that’s not happening.
So should I focus the energy on solving of Rxlevel and Rxqual…so that the need for handover doesn’t arise at all…
Should i accept the Rxlevel and Rxqual as it is and focus the energy on making the handovers as early and smooth…….?
MKT15th December 2008 at 11:38 #54930optimiserGuest
You’ve got bad quality and level at the same time. That means you have a coverage problem. You should focus on exiting the 1800 to the 900, which will normally have better radio conditions.
What are your values for the different Handover margins and priority, as well as CRO?
Since you have fewer TRX on the 1800 cell, you should limit its coverage area, by increasing the rxlevaccess min of 1800 cells.15th December 2008 at 18:33 #54931pixGuest
as far as i understand, the 1800 is not a cell : it’s the inner zone of a dualband cell. So you can’t set the CRO nor the RXLEV ACCESS MIN on the TRX1800 only.
MKT, can you tell me which vendor you’re using ? alcatel, if i remember well?
what are the values of
RXLEV DL ZONE
RXLEV UL ZONE
ZONE HO HYST DL
ZONE HO HYST UL
BS TXPWR MAX INNER
BS TXPWR MAX
L_RXLEV_DL_H and …_P
L_RXLEV_UL_H and …_P
Pix16th December 2008 at 04:41 #54932MKTGuest
The network is Ericsson…
Pix, you are right, that
1800 is used only for traffic.
Just tell me…….
if i put 29 ARFCN in the MAL for two TRX……
then, is there any DRAWBACK.16th December 2008 at 17:32 #54933PixGuest
2 / 29 = 7%, it’s very clean. (usual limit is 10% or 12%)
drawback for what ?
your have a parameter problem. Please contact your optimizer so he works on finding better settings.