High RTWP RTWP will cause low performance in CSSR and CCSR. Currently the background noise is -!"d#m$ if the RTWP is higher than -%&d#m then the load factor will more than %!'$ C(C will be o)erload congestion status.
To troubleshooting troubleshooting a high RTWP RTWP issue$ please refer the procedure as below.
Analysis procedure
1 Check Alarm
1.1 1.1
Chec Check k the the hard hardwa ware re alar alarm. m.
*ike R+ ,odule R #ranch RTWP ifference Too High (larm etc. 1.2 1.2
Chec Check k whe wheth ther er VSWR VSWR alar alarm m exi exist sts. s.
Command/ SP 0SWR 1f ha)e alarm or high 0SWR 2more then 3$ first escalate to #SS team$ then assistant them to check whether it is hardware problem or interference.
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2 Check NodeB configuration in NodeB LMT
2.1
Check ulink R! sensiti"ity
Command/ SP R+6SP(R(, and SP 6S67S 8sually the )alue of these two parameters should be !$ if it is not !$ fallback to ! to check whether RTWP can restore normal. 2.2
Check #link Attenuation Value
Command/ *ST R9(TT67 This configuration will affect the R9 gain. 1f T,( is not used$ then no need to configure it: and if T,( is used then we should configure it as per T,( gain. The default )alue is !. 2Without T,(3 2.$
Check the intermodulation inter%erence
1f primary RTWP is )ery high but secondary RTWP is normal$ it may be caused by this case. ,ethod/ suggest to shut off the transmit power then monitor the RTWP. 1f RTWP become normal after transmit power is switched off and RTWP become high when transmit power is switched on$ we can suspect that it may caused by feeder ;oint problem$ need #SS team check the feeder connection 2primary feeder3. Command to shut off the transmit power/ S6T T9SW
3 Check the interference feature
$.1
Check the RTWP trend
Check the RTWP counter 0S.,eanRTWP$ 0S.,aRTWP$ 0S.,inRTWP. ,ake a chart to show the interference trend in one day. Trace the RTWP in 7ode# *,T: trace 45hours in one day and sa)e the result to tt format and make chart to show the primary and secondary RTWP trend in one day. Through the chart$ we can know the interference feature/ What time the interference happens$ in day or night: in busy hour or always<. How about the consistency between primary and secondary RTWP trend= Through the trend we can analy>e whether hea)y traffic causes the high RTWP: whether eternal or internal interference= $.2
Check the site in%ormation
Check it is indoor site or outdoor site. +or indoor site$ need collect the information as below/
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Whether 4nd carrier is implemented or not= 华为机密，未经许可不得扩散
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Whether the combiner is used= Combiner fre?uency is match or not=
+or outdoor site$ need collect the information as below/
How many sectors eperience high RTWP=
How about RTWP status of nearby sites=
1s repeater located near the site=
4 ind the interference source
&.1
'ud(e external or internal inter%erence
isconnect the ;umper 2;umper at the cabinet side3 from the 7ode#$ and then trace the RTWP. 1f RTWP is still )ery high after disconnection$ that means 7ode# ha)e problem. 7eed #SS team check the R+ module. 1f RTWP become normal after disconnection$ that means 7ode# ha)e no problem. We can conclude that the problem may eist in +eeder system or eternal interference. #SS team can help to do the 0SWR test for the feeder and ;umper to check the feeder system ok or not. @r we can change ;umper to )erify. &.2
Troubleshoot the inter%erence
o the fre?uency scanning in 7ode# *,T. +rom the result we can check whether there is strong interference from some special fre?uency band. 1f from the result we find the interference$ we need )isit the site to find the interference source. We can/ 1f fre?uency scanning tool a)ailable 2like fre?uency analy>er3$ we can use tool to
scan the interference. The method to check the interference by scanning tool/ Switch off the transmit power of the interference sector. ,ake the test antenna of the tool toward the direction of the antenna of the 7ode# 2follow the same orientation$ same down tilt$ also the same attitude3 and scan the interference. #y this method we can check whether eternal interference eists or not. 1f fre?uency scanning tool una)ailable$ we can ad;ust the a>imuth of the
interference to check from which direction the eternal interference comes from. &.$
Common methods
7ode# ha)e two sets of RTWP$ primary and secondary RTWP: if only one set of RTWP is abnormal but the other set is @A. We can swap the primary feeder with the secondary feeder to check whether high RTWP swap or not.
1f two sectors are )ery near but only one sector eperience high RTWP and the other sector is @A. We can swap the feeder of these two sectors at the antenna side
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to check whether high RTWP will swap from one sector to the other. #y these swap actions$ we can analy>e the interference feature and find the interference source.
