Very Bad Ec/No value

[ozcank]

Hi all,

I faced a problem about very bad Ec/No, when thr signal(RSCP) -72 dBm. There are 2 sites. Suddenly quality decreased.

TEMS Investigation
Type Cell Name SC UARFCN_DL CPICH_Ec/No CPICH_RSCP
SC xxxx16 14 -21.50 -72
MN yyyy28 24 -7.0 -62
MN xxxx18 34 -20.50 -73

This time, UE reads 2G neighbors of xxxx16. All cells are neighbor. Both sites has f1 and f2.

How can I solve this problem ?


Thank u so much your kindly help.

BRs,

[jan74]

Hi all,

I faced a problem about very bad Ec/No, when thr signal(RSCP) -72 dBm. There are 2 sites. Suddenly quality decreased.

TEMS Investigation
Type Cell Name SC UARFCN_DL CPICH_Ec/No CPICH_RSCP
SC xxxx16 14 -21.50 -72
MN yyyy28 24 -7.0 -62
MN xxxx18 34 -20.50 -73

This time, UE reads 2G neighbors of xxxx16. All cells are neighbor. Both sites has f1 and f2.

How can I solve this problem ?


Thank u so much your kindly help.

BRs,

Why hvae you not added SC24 to the Active Set? Thats why your EcNo is so poor??

[ozcank]

Yes, You are right.

I want to learn why this stiation occured although all cellls were neighbor.

[jan74]

Yes, You are right.

I want to learn why this stiation occured although all cellls were neighbor.

You need to read the layer 3 messages. Do you know how to do that? You need to see if you suffered from Sharp RF. Did UE suddenly become shadowed from Serving Cell? Were event1a messages sent?

[ozcank]

When the Event1a occured, all cells RSCP and Ec/No are good.

yyyy28 RAB_DropRate : less than %1
xxxx16 RAB_DropRate : aproximately %5

[jan74]

5% is very high. You need to investigate the location of that drop. Was the UE turning a corner, entering a tunnel or shadowed in another way?

[jayk]

Hi all,

I faced a problem about very bad Ec/No, when thr signal(RSCP) -72 dBm. There are 2 sites. Suddenly quality decreased.

TEMS Investigation
Type Cell Name SC UARFCN_DL CPICH_Ec/No CPICH_RSCP
SC xxxx16 14 -21.50 -72
MN yyyy28 24 -7.0 -62
MN xxxx18 34 -20.50 -73

This time, UE reads 2G neighbors of xxxx16. All cells are neighbor. Both sites has f1 and f2.

How can I solve this problem ?


Thank u so much your kindly help.

BRs,

Did you performed multiple drive tests to compare? Is that scenario repeated again? It may be a result of sharp fading..

[ozcank]

How can I solve that type drop ? ( Sharp Fading ) ?

[jan74]

How can I solve that type drop ? ( Sharp Fading ) ?

You need to improve coverage at the location of the drop to make the handover smoother. Or you could cghange handover offsets to allow handover happen earlier. However, that could cause problems elsewhere. It could also be down to speed. If the UE was very fast, a drop could occur but if slow, it might not happen. You could drive that location 20 times and not see it again.