RTWP Problem Analysis and Solution

RTWP Problem Analysis and Solution (HUWAEI) Summary High RTWP will cause low er!ormance in "SSR and ""SR#"urrently the bac$ground noise is %&'dm* i! the RTWP is higher than %+,dm thenthe load !actor will more than +'-* "A" will be o.erload congestion status#To troubleshooting a high RTWP issue* lease re!er the rocedure as below#

Analysis rocedure rocedure &# "hec$ Alarm &#&"hec$ the hardware alarm# /i$e R0 1odule R2 ranch RTWP 3i4erence Too High Alarm etc# "hec$ whether 6SWR alarm e2ists# "ommand7 3SP 6SWR I! ha.e alarm or high 6SWR (more then &#&)* 8rst escalate to SS team* then assistant themto chec$ whether it is hardware hardware roblem or inter!erence#

5# "hec$ 9ode con8guration in 9ode /1T 5#&"hec$ ulin$ R0 sensiti.ity "ommand7 3SP R03ESPARA1 R03ESPARA1 and 3SP 3ESE9S# Usually the .alue o! these t hese two arameters should be '* i! it is not '* !allbac$ to ' to chec$ whether RTWP RTWP can restore normal# 5#5"hec$ Ulin$ Attenuation 6alue "ommand7 /ST R:ATTE9# R:ATTE9# This con8guration will a4ect the R: gain# I! T1A is not used* then no need to con8gure it;and i! T1A is used then we should con8gure it as er T1A gain#The de!ault .alue is '# (Without T1A)5#< "hec$ the intermodulation inter!erence I! rimary RTWP is .ery high but secondary RTWP is normal* it may be caused by this case#1ethod7 case# 1ethod7 suggest to shut o4 the transmit ower then monitor the RTWP# I! RTWP become normal a!ter transmit ower is switched o4 and RTWP become high when transmit ower is switched on* we can susect that it may caused by !eeder =oint roblem* need SS team chec$ the !eeder connection (rimary !eeder)#"ommand !eeder)#"ommand to shut o4 the transmit ower7 SET T:SW

<# "hec$ the inter!erence !eature <#&"hec$ the RTWP trend "hec$ the RTWP counter 6S#1eanRTWP* 6S#1a2RTWP* 6S#1inRTWP# 1a$e a chart to show the inter!erence trend in one day# Trace the RTWP in 9ode /1T; trace 5>hours in one day and sa.e the result to t2t !ormatand ma$e chart to show the rimary and secondary RTWP trend in one day# Through the chart* we can $now the inter!erence !eature7 What time the inter!erence haens* in day or night; in busy hour or always?#How about the consistency between rimary and secondary RTWP trend@ Through the trend we can analye whether hea.y traBc causes the high RTWP; whether e2ternal or internal inter!erence@ <#5"hec$ the site in!ormation "hec$ it is indoor site or outdoor site#0or indoor site* need collect the in!ormation as below7 Whether 5 ndcarrier is imlemented or not@ Whether the combiner is used@ "ombiner !reCuency is match or not@ 0or outdoor site* need collect the in!ormation as below7

How many sectors e2erience high RTWP@ How about RTWP status o! nearby sites@ Is reeater located near the site@

># 0ind the inter!erence source >#&Dudge e2ternal or internal inter!erence 3isconnect the =umer (=umer at the cabinet side) !rom the 9ode* and then trace the RTWP# I! RTWP is still .ery high a!ter disconnection* that means 9ode ha.e roblem# 9eed SS team chec$ the R0 module #I! RTWP become normal a!ter disconnection* that means 9odeha.e no roblem#We canconclude that the roblem may e2ist in 0eeder system or e2ternal inter!erence# SS team can hel to do the 6SWR test !or the !eeder and  =umer to chec$ the !eeder system o$ or not# r we can change =umer to .eri!y# >#5Troubleshoot the inter!erence 3o the !reCuency scanning in 9ode /1T# 0rom the result we can chec$ whether there is strong inter!erence !rom some secial !reCuency band# I! !rom the result we 8nd the inter!erence* we need .isit the site to 8nd the inter!erence source#  We can7 I! !reCuency scanning tool a.ailable (li$e !reCuency analyer)* we can use tool to scan the inter!erence# The method to chec$ the inter!erence by scanning tool7 Switch o4 the transmit ower o! the inter!erence sector# 1a$e the test antenna o! the tool toward the direction o! the antenna o! the 9ode (!ollow the same orientation* same down tilt* also the same attitude) and scan the inter!erence# y this method we can chec$ whether e2ternal inter!erence e2ists or not# I! !reCuency scanning tool una.ailable* we can ad=ust theaimuth o! the inter!erence to chec$ !rom which direction the e2ternal inter!erence comes !rom# 

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>#<"ommon methods 9ode ha.e two sets o! RTWP* rimary and secondary RTWP; i! only one set o! RTWP is abnormal but the other set is F# We can swa the rimary !eeder with the secondary !eeder to chec$ whether high RTWP swa or not# I! two sectors are .ery near but only one sector e2erience high RTWP and the other sector is F# We can swa the !eeder o! these two sectors at the antenna side 

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