文档名称 文 档 密 : Internal only utho r Gao Bo Staff Number 40827 Depar tment UMTS RNP Product Family: Wireless Performance & RNP & RNO Updat e Time 2010-06-01 Product Vension: RNC R10B061 ppro ver Title Analysis for Call Drop due to SRB Reset !RB Reset Pheno menon Descri ption: The problem is that there are many sites have the problem of S!" reset and T!" reset increased# Alarm Inform ation None Cause Analysi s For this problem$ %e choose the top cells of the !N& '( and !N& (' to analy)e the reason of S!" * T!" reset# From the analyses of the cell &DT and +,S$ -e can .no% that U/ %as doin0 1SDPA traffic #+t did hard handover from one cell to another cell# "ut after hard handover completed$ imminently$ U/ did hard handover bac.$ this is the pin02pon0 phenomena# +t is easy to result in radio lin. lost and the increase of T!"3S!" !eset#For the do%nlin. 4uality chan0ed so fast$ it is abnormal# And this is usually because that the &/556s parameter or cell6s covera0e is unreasonable# And the same phenomena also can find in the cells %ith +D '7789 $'7;'$ '<8(8 $'<88$'<7(= '<7;# From the trace$ %e can see that the U/ hand over from cell '7789 2014-3-1 >?@BCE 1 , G 8
Transcript
8/12/2019 Analysis for Call Drop Due to SRB Reset & TRB Reset (Gaobo40827)_1
Title Analysis for Call Drop due to SRB Reset !RB Reset
Pheno
menon
Description:
The problem is that there are many sites have the problem of S!"reset and T!" reset increased#
Alarm
Inform
ation
None
Cause
Analysi
s
For this problem$ %e choose the top cells of the !N& '( and !N& (' toanaly)e the reason of S!" * T!" reset#
From the analyses of the cell &DT and +,S$ -e can .no% that U/%as doin0 1SDPA traffic #+t did hard handover from one cell to anothercell# "ut after hard handover completed$ imminently$ U/ did hard handoverbac.$ this is the pin02pon0 phenomena# +t is easy to result in radio lin. lostand the increase of T!"3S!" !eset#For the do%nlin. 4uality chan0ed sofast$ it is abnormal# And this is usually because that the &/556sparameter or cell6s covera0e is unreasonable# And the same phenomenaalso can find in the cells %ith +D '7789 $'7;'$ '<8(8 $'<88$'<7(='<7;#
From the trace$ %e can see that the U/ hand over from cell '7789
2014-3-1 >?@ BC E 1 , G 8
8/12/2019 Analysis for Call Drop Due to SRB Reset & TRB Reset (Gaobo40827)_1
%e .no% that the U/ hand over from '7788 to'7789$ then immediately$hand over bac. to '7788#+t cost only ' or t%o seconds# This isunreasonable# +t is easy to result in radio lin. lost#
From the &DT and +,S$ %e can find the other problem caused thecall drop$ for eJample$ the bad do%nlin. 4uality and the nei0hbor cell notconfi0ured# +f in some position the do%nlin. 4uality is bad$ and the nei0hborcell has not been confi0ured$ the call drop %ill occurred easily#
'I Nei0hbor cell not confi0uredFor cell '7789$ from the +,S trace$ %e can see that it has the problem
of neighbor cell not configured. Just s the cell !!"#3 $e nl%&ed before.
'ro( the )OS* the u+lin, hs been out of s%nchroni&tion* nd fro( the
RRC-MEAS-RPR* $e cn see tht the do$nlin, of cell !//401PSCRAMBCODE=4/"2 is
bd* nd the E hs re+orted the eent of !A* but fro( the R5C configurtion file* $e
cn6t find the neighbor cell of !//40 $hose PSCRAMBCODE is 7!#. And if the cell the
E detected 1PSCRAMBCODE=7!#2 is configured s the neighbor cell of !//40* this
cll dro+ $ill not occurred. his is coerge +roble(* nd $e need to sole it.
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8/12/2019 Analysis for Call Drop Due to SRB Reset & TRB Reset (Gaobo40827)_1
-e can see that the U/ %ant to 0o to the D&1$ but From the!!&KL/ASK!P!T %e can find the /&3N, is bad no% %hich means thedo%nlin. is bad$ and the U/ %ould not receive the messa0e of!!&K!"K!/&FM# Then the &all Drop occurred# And from the!!&KL/ASK!P!T$ %e can6t see any other cells that the U/ can
detected#
And %e can see as belo%: +f the do%nlin. is 0ood$ the U/ %ill 0o to
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8/12/2019 Analysis for Call Drop Due to SRB Reset & TRB Reset (Gaobo40827)_1
