[Ers]

Hi All,

I need to discuss about engineering process needed to optimize TDR from 2% to 0.65%

Is ‘2%’ of TDR showing very very bad network performance? Or maybe any of you have experience worse than it?

Thanks in advance

[hicham]

It’s not so bad for cells with Hight TA but it’s should be under 1% for urbain cell(and less)

[mesfer]

Dear all
what do u mean TDR
thanks

[Ers]

TDR = TCH Drop Rate

hicham ..is it TIming Advance you mean for TA?

[Pix]

Hi ERS,

as said before, 2% could be OK if the cell has an extended & weak coverage (with poor rxlev in many areas)

urban cells should be better than 1.2%.

Very High TDR (>> 5%) could also be caused by poor hardware performances (abis links, board failures, etc).

[Ers]

Hi Pix,

In condition as you mentioned (..the cell has an extended & weak coverage (with poor rxlev in many areas)), is it hard to optimize TDR value from 2% to 0.65% without new site deployment?

[Pix]

Ers,

Absolutely. If you are certain that the frequencies are clean ( = no interference) and that the coverage area cannot be enhanced (with high power transmitters, or better antennas, or thicker feeders, or TMA, or remove some combiners, etc)

Keep in mind that what you need is to increase the coverage.. There is no miracle :
– increase current cell coverage (see above)
– or, add a repeater
– or, add a BTS

Now, there is a trick. It’s not “good” IMO, but it will make your stats look better. By changing some parameters, you can actually forbid the user with poor RXLEV to establish a call.
Less “low rxlev” calls = less call drops
… but also = less traffic.

the 2 parameters you can use are :
RACH TA FILTER
RXLEV ACCESS MIN

But really, if anyone asks you who told you to do that, don’t mention me. The point of my job is to increase traffic, because traffic= revenues !

Just say it’s an idea from..

Nosfera-pix

[Ers]

Pix,

If we do the tricky tweaky :)…would it possibly increase the SD blocking?

Rgrds,

Ers

[Pix]

The evil trick will actually decrease the traffic, SDCCH & TCH. Therefore, I don’t foresee an increase in SDCCH congestion.

What you are going to do is *logically* reduce the “cell best serving area”.

Yeeerk.

🙂

Pix

[Ers]

Pix,

Just to make sure..

the trick will not effect the stat param of SDSR (SD Success Rate)?

[Pix]

ERS,

The only thing I can say is that it *should* not decrease QoS, except the TCH traffic and SDCCH traffic.
Of course, there are always small chances that something unpredictable happens. But in your case, I can’t think of anything. So it is a pretty safe trick, as long as you don’t care about traffic.

(sorry to emphasize so much on traffic…)

Cheers,
pix

[hicham]

Hi and sorry to answer late,
to Reduce ur call drop in such condition (cell with important TA) u have to :

– Check 1st ur HW (in such case most important cell are in rural area and their maintenance is so hard , pylone with more than 40 HBA) : Antenna , conbiner, TRXs ect…check alarms

– check ur frequency (in general in this rural area , there is no problem)

if u don’t have any problem from these 2 u have a planification problem u have to add a new site or repeter (u have to locate the source of ur trafic)

Some astuces (not recommended becuase u reduce ur trafic):

Reduce ur RX_LEV_ACCES
Reduce the BS_POWER_MAX

with these two parameters u are sure that u will have a good KPI but with a important reduction of trafic (be carefull :))))))))

Good Luck

[Ers]

Pix & Hicham,

Thanks a lot guys,much clear for me.

Wish you both success..always 🙂

Kindly Regards,

ERS

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