LTE RF Channel Troubleshooting Guide_v1.1

(1)

HUAWEI TECHNOLOGIES CO., LTD. HUAWEI TECHNOLOGIES CO., LTD.

www.huawei.com

Huawei Confdential Huawei Confdential

Security Level: interna

LTE RF Channel

Troubleshooting Guide

(2)

Abstract



This document

This

document describes

describes the

the common

common faults

faults of

of the

the LT

LTE

E RF

RF

channels during the IF/RF maintenance, symptoms, diagnosis

methods, data reuired for diagnosis by R!"#

(3)

%ontents



Common RF Channel Faults



Uplink Channel Faults



Uplink Interference



_{eNodeB Fault Connection of}

_{eNodeB Fault Connection of ntenna}

_ntenna



(4)

%ommon RF %hannel Faults



The

The common

common faults

faults related

related to

to the

the

RF channels are uplin' channel fault,

uplin' interference, e(ode) fault

connection of antenna, do*nlin'

channel fault, do*nlin' antenna fault,

This document describes the analysis

procedure beginning from problem

symptom to conclusion#

%rossed connection+ RTP difference

bet*een main ! di-ersity

Interference+ Interference detection

cell re-erse connection+ Inter.

cell hando-er statistics

Antenna fault+

# 01R alarm

2# Passi-e intermodulation interference

$# RTP difference bet*een main !

di-ersity or lo* RTP

(5)

! channel "ailu#e mode de$c#i%tion

1ymptom and Alarm 1ymptom and Alarm

ALD !ault ALD !ault

u%lin) "ailu#e o" u%lin) "ailu#e o" ALD*antenna ALD*antenna line De+ice line De+ice

AL-/0(// ! Unit 1

AL-/0(// ! Unit 1 Channel TW&2Channel TW&2SSISSI Un3alanced

Un3alanced Ala#m li$tAla#m li$t_{SSI t#ace data}_{SSI t#ace data} M20M200000 、、 WEBWEBLMTLMT downlin) "ailu#e downlin) "ailu#e o" ALD*antenna o" ALD*antenna line De+ice line De+ice AL-/0(/4 ! Unit 5SW

AL-/0(/4 ! Unit 5SW Th#e$holdTh#e$hold C#o$$ed

C#o$$ed

Ala#m li$t Ala#m li$t

one)e6 fle lo' o" U

one)e6 fle lo' o" U M20M200000 、、 WEBWEBLMTLMT

U%lin) U%lin) Inte#"e#enc Inte#"e#enc e e inte#nal inte#nal Inte#"e#ence Inte#"e#ence Inte#modulation inte#"e#ence

Inte#modulation inte#"e#ence dec#ea$edec#ea$edd th#ou'h%ut and hando+e# $ucce$$ #ate th#ou'h%ut and hando+e# $ucce$$ #ate

SSI t#ace SSI t#ace Inte#"e#enc

Inte#"e#ence Detect e Detect -onito#in'-onito#in' 3#oad3and online "#e7uenc6 $can 3#oad3and online "#e7uenc6 $can

M20

M200000 、、 WEBWEBLMTLMT E8te#nal

E8te#nal Inte#"e#ence

Inte#"e#ence $t#on' inte#"e$t#on' inte#"e#ence w#ence will lead to a ill lead to a cell 9&Icell 9&I decline.

decline.

SSI t#ace SSI t#ace Inte#"e#enc

Inte#"e#ence Detect e Detect -onito#in'-onito#in' 3#oad3and online "#e7uenc6 $can 3#oad3and online "#e7uenc6 $can

M20 M200000 、、 WEBWEBLMTLMT !ault !ault Connection Connection o" Antenna o" Antenna e+e#$e !ault e+e#$e !ault Connection o" Connection o" Antenna Antenna

the local cell and a neighbor cell that has no the local cell and a neighbor cell that has no o-erlapping co-erage are in-ol-ed in

o-erlapping co-erage are in-ol-ed in hando-er#hando-er#

Hando+e# 9&I Hando+e# 9&I

en'inee# %a#amete#

en'inee# %a#amete# M20M200000 、、 OMSOMStatarr C#o$$ !ault C#o$$ !ault Connection o" Connection o" Antenna Antenna AL-/0(// ! Unit 1

AL-/0(// ! Unit 1 Channel TW&2Channel TW&2SSISSI Un3alanced.

Un3alanced.

the local cell and a neighbor cell that has no the local cell and a neighbor cell that has no o-erlapping co-erage are in-ol-ed in

o-erlapping co-erage are in-ol-ed in hando-er#hando-er#

Hando+e# 9&I Hando+e# 9&I

en'inee# %a#amete#

en'inee# %a#amete# M20M200000 、、 OMSOMStatarr

Channel Channel

"ault "ault

U%lin) "ault o" U%lin) "ault o" U

U

AL-/0(/: ! Unit 1

AL-/0(/: ! Unit 1 Channel TW&2Channel TW&2SSISSI T

Too Lowoo Low..

Ala#m li$t Ala#m li$t

9&I o" acce$$ #ate 9&I o" acce$$ #ate one)e6 fle lo' o" U one)e6 fle lo' o" U

M2000 M2000 Downlin) "ault Downlin) "ault o" U o" U

AL-/0(/; ! Unit T1 Channel Gain Out o" AL-/0(/; ! Unit T1 Channel Gain Out o" an'e.

an'e.

T

T#an$mit %owe# #an$mit %owe# te$t data o" te$t data o" U<U< one)e6 fle lo' o" U

one)e6 fle lo' o" U M2000M2000

ailure mode

(6)

%ontents



Common RF Channel Faults



_{Uplink Channel Faults}



_{Uplink Interference}



_{eNodeB Fault Connection of ntenna}



(7)

4plin' %hannel Faults

When an u%lin) channel "ault occu#$, the $6m%tom$ a#e de'#aded

cell 9&I, ! Unit 1 Channel TW&2SSI Too Low ala#m, and !

Unit 1 Channel TW&2SSI Un3alanced ala#m.

I. Ha#dwa#e "ault

Choo$e

Monitor

=

Signaling Trace

=

Signaling Trace

Management

on the -/;;;

on the -/;;; o# We3 L-T

o# We3 L-T. In the

. In the na+i'ation t#ee, choo$e

na+i'ation t#ee, choo$e

Cell

Performance Monitoring

=

Interference RS

Interference RSSI Statistic

SI Statistic Detect

Detect

Monitoring

. The 1A SSI and 1> SSI a#e di$%la6ed in a ta3le,

a$ $hown in the ne8t %a'e. Chec

a$ $hown in the ne8t %a'e. Chec) whethe# the +alue$ in thi$ ta3le

) whethe# the +alue$ in thi$ ta3le

a#e le$$ than the SSI +alue$ unde# em%t6

a#e le$$ than the SSI +alue$ unde# em%t6 load. The th#e$hold "o#

load. The th#e$hold "o#

#e%o#tin' 

#e%o#tin' TW&2SSI too

TW&2SSI too low ala#m i$

low ala#m i$

–

::? d>m. The SSI unde#

em%t6 load i$ calculated a$ "ollow$@

–

:?B:;lo'>WBN!

whe#e >

whe#e >W i$ the 3andwidth in

W i$ the 3andwidth in H and N! i$

H and N! i$ the noi$e "acto# o"

the noi$e "acto# o"

the

! module and it$ +alue i$ 3etween / to /.(. A$$umin' an LU

/.0G /T/ cell o" /; -H 3andwidth, the SSI unde# em%t6 load i$

calculated a$ "ollow$@

–

(8)

4plin' %hannel Faults

(9)

II# Passi-e intermodulation

The

The #oot

#oot cau$e

cau$e o"

o" inte#modulation

inte#modulation i$

i$ nonlinea#it6

nonlinea#it6 o"

o" the

the channel$.

channel$.

An #ule to mea$u#e the nonlinea#it6 o" an antenna $6$tem i$

inte#modulation $u%%#e$$ion. !o# a linea# $6$tem, the out%ut to a /

$i'nal in%ut i$ al$o / $i'nal$. Howe+e#, "o# a nonlinea# $6$tem, a /

$i'nal in%ut 'ene#ate$ new "#e7uenc6 com%onent$ )nown a$

inte#modulation di$to#tion. The %henomenon o" 'ene#atin' new

"#e7uenc6 com%onent$ i$ called inte#modulation. I" the

inte#modulation

di$to#tion "all in the #ece%tion 3and and inc#ea$e the u%lin)

inte#"e#ence

o# 

o# TW&, inte#modulation inte#"

TW&, inte#modulation inte#"e#ence a#i$e$.

e#ence a#i$e$.

4plin' %hannel Faults

(10)

The folloing figure shos the intermodulation product of signals of

The folloing figure shos the intermodulation product of signals of )

)

band*id

band*idth after passing a

th after passing a nonlinear system#

nonlinear system#

4plin' %hannel Faults

289f.)/2:.f;f.) 289f.)/2:.f;f.) Third.order Third.order intermodulation products intermodulation products generated by central generated by central

freuency ! lo* edge

freuencies freuencies 289f<)/2:.f;f<) 289f<)/2:.f;f<) Third.order Third.order intermodulation products intermodulation products generated by central generated by central

freuency ! high edge

freuencies freuencies Third.order Third.order intermodulation products intermodulation products

generated by high ! lo*

edge freuencies edge freuencies 289f.)/2:.9f<)/2:;f. 289f.)/2:.9f<)/2:;f. $8)/2 $8)/2 289f<)/2:.9f.)/2:;f<$8)/2 289f<)/2:.9f.)/2:;f<$8)/2 Third.order intermodulation Third.order intermodulation

products generated by high

! lo* edge freuencies

%entral freuency f %entral freuency f Lo* edge Lo* edge freuencies ;f. freuencies ;f. )/2 )/2 =igh edge =igh edge freuencies ; freuencies ; f<)/2 f<)/2 IM3

(11)

Intermodulation products are go#erned b$ the follo"ing rules%



The magnitude of intermodulation products has

The magnitude of intermodulation products has a negati-e

a negati-e

correlation *ith the intermodulation suppression of

correlation *ith the intermodulation suppression of the antennas#

the antennas#



The magnitude of intermodulation products also depends on the

po*er of the input

po*er of the input signals# Theoretically

signals# Theoretically, for e-ery  d) increase

, for e-ery  d) increase

of the input signals, I>$ is increased by $ d)# In

of the input signals, I>$ is increased by $ d)# In practice, for

practice, for

e-ery d) increase of the input po*er, I>

e-ery d) increase of the input po*er, I>$ is increased by 2

$ is increased by 2 to $

to $

d)# In other *ords, gi-en the same intermodulation suppression,

the magnitude of intermodulation products has a positi-e

correlation ith the input poer and increases faster than the

input po*er#



The magnitude has a negati-e correlation *ith the order of

intermodulation products# I>$? I>@ ? I>3

4plin' %hannel Faults

(12)

If the folloing to conditions are met, the e(ode) is interfered by

intermodulation products+



The intermodulation signals is in

The intermodulation signals is in the recei-er band freuency#

the recei-er band freuency#



_{The intermodulation signals are strong}

_{The intermodulation signals are strong enough to affect demodulation#}

_{enough to affect demodulation#}



 __ _、_、 _{If the source signals that generate intermodulation interference include one or}_{If the source signals that generate intermodulation interference include one or}

t*o uplin' signals, the intermodulation signals are negligible due to small uplin' t*o uplin' signals, the intermodulation signals are negligible due to small uplin' signal po*er#

signal po*er#



 ₂₂ _、_、 _{Intermodulation interference that propagates through the space causes little}_{Intermodulation interference that propagates through the space causes little}

impact on other e(ode)s due to large propagation loss# impact on other e(ode)s due to large propagation loss#



 _$_$ _、_、_{Any t*o do*nlin' signals in the same}_{Any t*o do*nlin' signals in the same cell may generate interm}_{cell may generate intermodulation}_odulation

interference that is significant to the uplin' but negligible to the do*nlin'# interference that is significant to the uplin' but negligible to the do*nlin'#



 && _、_、 f great concern is the intermodulation interference generated by any t*of great concern is the intermodulation interference generated by any t*o

do*nlin' signals and falling in the uplin' band#

4plin' %hannel Faults

(13)

the passi-e intermodulation can be detected by adding do*nlin'

simulated load in off.pea' hours# If the Interference "etect >onitoring

on the >2777 sho*s that all the

on the >2777 sho*s that all the R11Is are increased, the R11I

R11Is are increased, the R11I

increase is caused by passi-e intermodulation#

(ote (ote If the

If the number number of aof acti-e ucti-e users in sers in a a cell is cell is more more than than , the , the scheduling scheduling performance performance cannotcannot be guaranteed *hen this function is enabled# Therefore, this function is

be guaranteed *hen this function is enabled# Therefore, this function is notnot recommended in such scenario#

recommended in such scenario#

4plin' %hannel Faults

(14)

The commercial intermodulation tester can only determine the magnitude of The commercial intermodulation tester can only determine the magnitude of

intermodulation of the antenna system and cannot determine the

intermodulation of the antenna system and cannot determine the location *herelocation *here the intermodulation is

the intermodulation is generated# Tgenerated# To determine the location of o determine the location of intermodulation,intermodulation, chec' the antenna system segment by segment# The follo*ing figure sho*s the chec' the antenna system segment by segment# The follo*ing figure sho*s the schematic diagram of this method#

schematic diagram of this method#

"etermine the intermodulation

The segmental inspection procedure is

The segmental inspection procedure is as follo*s+as follo*s+ "isconnect point , 2, $, or &, connect it to a "isconnect point , 2, $, or &, connect it to a lo*.lo*. intermodulation load, and add

intermodulation load, and add a do*nlin' simulateda do*nlin' simulated load# bser-e *hether the RTP and R11I are load# bser-e *hether the RTP and R11I are increased# If yes, the point is *here intermodulation increased# If yes, the point is *here intermodulation interference is introduced# An eBample is described interference is introduced# An eBample is described as follo*s+

as follo*s+

"isconnect point , connect it to a lo*. "isconnect point , connect it to a lo*. intermodulation load, add a

intermodulation load, add a do*nlin' simulated load,do*nlin' simulated load, and obser-e RTP and R11I -alues# The RTP and obser-e RTP and R11I -alues# The RTP and R11I are unchanged, indicating that the RF and R11I are unchanged, indicating that the RF module has no problem# "isconnect point 2, module has no problem# "isconnect point 2, connect it to a lo*.intermodulation load, add a connect it to a lo*.intermodulation load, add a do*nlin' simulated load, and obser-e RTP/R11I# do*nlin' simulated load, and obser-e RTP/R11I# The RTP and R11I are significantly increased, The RTP and R11I are significantly increased, indicating that the lo*er Cumper is *here

indicating that the lo*er Cumper is *here thethe intermodulation interference is introduced# intermodulation interference is introduced#

An alternati-e is the replacement method# Repla An alternati-e is the replacement method# Replacece

the feeder line segment by segment and chec' the the feeder line segment by segment and chec' the RTP and R11I#

(15)

%ontents



Common RF Channel Faults



_{Uplink Channel Faults}



_{Uplink Interference}



_{eNodeB Fault Connection of ntenna}



(16)

4plin' Interference

4plin'

4plin' interference interference affects affects nearly nearly all all DPIs, DPIs, including including RR% conneRR% connection ction setupsetup success rate, access success rate, call drop rate, hando-er success rate, and success rate, access success rate, call drop rate, hando-er success rate, and uplin' and do*nlin' throughput#

uplin' and do*nlin' throughput#

4plin' interference includes eBternal interference and internal interference# Internal 4plin' interference includes eBternal interference and internal interference# Internal interference common caused by intermodulation# The signal le-el of intermodulation interference common caused by intermodulation# The signal le-el of intermodulation interference at the recei-er band*idth has a ramp

interference at the recei-er band*idth has a ramp shape, the left band lo*er and rightshape, the left band lo*er and right band higher 9recei-e in

band higher 9recei-e in the lo* freuency band and tthe lo* freuency band and transmit in the high ransmit in the high freuencyfreuency,, such as 2#=, 2#=, etc#:

such as 2#=, 2#=, etc#: or the left band higher than right band 9recor the left band higher than right band 9recei-ed at highei-ed at high freuency *hile transmitting at lo* freuency such as 577>=:G if recei-e band has freuency *hile transmitting at lo* freuency such as 577>=:G if recei-e band has smaller freuency inter-al *ith the transmit band, the m

smaller freuency inter-al *ith the transmit band, the more easily intermodulationore easily intermodulation interference

interference affects affects the the uplin' uplin' reception#reception#

The

The problem problem of of eBternal eBternal interference interference cannot cannot be be eliminated eliminated from from internal internal system#system# e must find out the eBternal interference source and contact the customer to remo-e e must find out the eBternal interference source and contact the customer to remo-e the interference source#

the interference source#

hen a cell is

hen a cell is interfered by an eBternal source, both the main and di-interfered by an eBternal source, both the main and di- ersity recei-eersity recei-e the interference synchronously#

the interference synchronously# The interference can be The interference can be obtained by using theobtained by using the spectrum detection tool described in the neB

(17)

4plin' Interference

1pectrum detection tool

(18)

4plin' Interference

Tracing result indicating eBternal

(19)

4plin' Interference

Tracing result indicating an

Tracing result indicating an intermodulation interference

intermodulation interference

The

The figure figure sho*s sho*s a a broadband broadband freuency freuency scan scan *hen *hen the the net*or' net*or' intermodulation intermodulation interferenceinterference

occured# )y off.line re-ie* tool sho*s that t

(20)

4plin' Interference

Tracing result indicating no eBternal interference

(21)

%ontents



Common RF Channel Faults



_{Uplink Channel Faults}



_{Uplink Interference}



_eNodeB

_Fault

_Connection

_of

_ntenna



(22)

"ault connection

of Antenna

Ant Ant Ant Ant p poorrtt77 ppoorrtt R R R R 4 4 7 7 p poorrtt77 ppoorrtt R R R R 4 4   Re-erse Re-erse Ant Ant Ant Ant p poorrtt77 ppoorrtt R R R R 4 4 7 7 p poorrtt77 ppoorrtt R R R R 4 4   %ross %ross Ant Ant Ant Ant p poorrtt77 ppoorrtt R R R R 4 4 7 7 p poorrtt77 ppoorrtt R R R R 4 4   normal normal

(23)

e(ode) Fault

%onnection of Antenna

It

It is

is abnormal

abnormal that

that some

some no

no o-erlapping

o-erlapping co-erage

co-erage cells

cells are

are in-ol-ed

in-ol-ed in

in

hando-er# Analye these cells as follo*s+

fault conn

fault connection o

ection of antenna

f antenna has t*

has t*o type+

o type+ re-erse

re-erse antenna

antenna connection a

connection and

nd

cross antenna connection beteen to cells#

# In the case of re-erse antenna connection+

if the

if the local cell

local cell and a

and a neighbor

neighbor cell that

cell that has no

has no o-erlapping

o-erlapping co-erage are

co-erage are

in-ol-ed in hando-er, there must be another cell that has o-erlapping

co-erage *ith this neighbor cell

co-erage *ith this neighbor cell doesnHt hando-er#

doesnHt hando-er#

hen the t*o cells has re-erse connection of %PRI # there has the same phenomenon as the

re-erse connection of antenna# so it should to confirm the right %PRI connection first *hen

re-erse

connection of antenna has happened#

2# In the case of

%ross antenna connection+

if the

if the local

local cell and

cell and a n

a neighbor

eighbor cell tha

cell that has

t has no

no o-erlapping

o-erlapping co-erage

co-erage are

are

in-ol-ed in hando-er, there must be another cell that has o-erlapping

co-erage *ith this neighbor cell

(24)

E8am%le o" "ault connection

if

if ：：A: and >/ a#e in+ol+ed in hando+e#A: and >/ a#e in+ol+ed in hando+e# A: and >/ ha+e no

A: and >/ ha+e no o+e#la%%in' co+e#a'eo+e#la%%in' co+e#a'e A/

A/ and and >/ >/ ha+e ha+e o+e#la%%in' o+e#la%%in' co+e#a'eco+e#a'e A/

A/ and and C: C: a#e a#e in+ol+ed in+ol+ed in in hando+e#hando+e# A/ and C: ha+e no

A/ and C: ha+e no o+e#la%%in' co+e#a'eo+e#la%%in' co+e#a'e A:

A: and and C: C: ha+e ha+e o+e#la%%in' o+e#la%%in' co+e#a'eco+e#a'e A1 an A! "ave reverse connection of A1 an A! "ave reverse connection of antenna

antenna if

if ：： A: and >/ a#e in+ol+ed in hando+e#A: and >/ a#e in+ol+ed in hando+e# A/ and >/ a#e in+ol+ed in hando+e# A/ and >/ a#e in+ol+ed in hando+e#

A: and >/ ha+e no

A: and >/ ha+e no o+e#la%%in' co+e#a'eo+e#la%%in' co+e#a'e A/ and >/ ha+e o+e#la%%in' co+e#a'e A/ and >/ ha+e o+e#la%%in' co+e#a'e

A: and C: a#e in+ol+ed in hando+e# A: and C: a#e in+ol+ed in hando+e# A/ and C: a#e in+ol+ed in hando+e# A/ and C: a#e in+ol+ed in hando+e# A/ and C: ha+e no

A/ and C: ha+e no o+e#la%%in' co+e#a'eo+e#la%%in' co+e#a'e A: and C: ha+e o+e#la%%in' co+e#a'e A: and C: ha+e o+e#la%%in' co+e#a'e A1 an A! "ave cross connection of A1 an A! "ave cross connection of antenna antenna >/ >/ B2 B2 A: A: A/ A/ C: C:

>ecau$e the cell$ that ha+e no o+e#la%%in' co+e#a'e

a#e not

3e conf'u#

3e conf'u#ed nei'h3o# ed nei'h3o# #elation , #elation , $o two $o two "ault"ault

connection cell$

(25)

solution of

re-erse %onnection of Antenna

it i

it is common s common *ay *ay to to analye analye the handthe hando-er success o-er success rate, irate, if the f the cell ha-e cell ha-e re-ersere-erse connection of antenna, it happened in t*o cells *hich ha-e

connection of antenna, it happened in t*o cells *hich ha-e no o-erlapping co-erageno o-erlapping co-erage and configure the neighbor relation# another cell that has o-erlapping co-erage *ith and configure the neighbor relation# another cell that has o-erlapping co-erage *ith neighbor cell doesnHt

neighbor cell doesnHt hando-er#hando-er#

solution of %ross

%onnection of Antenn

a

the

the RA RA and and R) R) of of the the RR4 must RR4 must belong to belong to the the same cell, same cell, in in *hich *hich case tcase the he direction anddirection and co-erage area of RA are the same as

co-erage area of RA are the same as those of R) to ensure those of R) to ensure RTP balance# If RA and R) ofRTP balance# If RA and R) of the RR4 are

the RR4 are connected to different sectorconnected to different sectors, the problem of s, the problem of RTP unbalance occurs and theRTP unbalance occurs and the RTP unbalance alarm is

RTP unbalance alarm is reported#reported# If the RTP unbalance alarm is

If the RTP unbalance alarm is caused by incorrect connection of RA or R) to anothercaused by incorrect connection of RA or R) to another antenna, the symptoms are as follo*s+

antenna, the symptoms are as follo*s+



 _{At least t*o cells in t}_{At least t*o cells in t he same sit}_{he same site report an RT}_{e report an RT P unbalance a}_{P unbalance alarm#}_larm#



 _{The RTP change of RA is independent of that of R)#}_{The RTP change of RA is independent of that of R)#}



 _{The RTP change of different sectors is similar#}_{The RTP change of different sectors is similar#}

e(ode) Fault

(26)

%ontents



Common RF Channel Faults



_{Uplink Channel Faults}



_{Uplink Interference}



_{eNodeB Fault Connection of ntenna}



(27)

"o*nlin' %hannel Faults



_{If the}

_{If the do*nlin' channel gain is abnormal, AL>.2@2}

_{do*nlin' channel gain is abnormal, AL>.2@27 RF}

_{7 RF 4nit T %hannel}

_{4nit T %hannel}

ain ut of Range is reported#



_{Principles+ If the actual gain of the RF}

_{Principles+ If the actual gain of the RF unit T channel de-iates from the}

_{unit T channel de-iates from the}

standard gain by more than 2#@ d), this alarm is reported#



Impact+ Large gain causes c

Impact+ Large gain causes co-erage o-erlap# 1mall gain causes co-erage

o-erage o-erlap# 1mall gain causes co-erage

holes, or interruption of the ser-ices in the RF unit#

Troubleshooting

I#

I# Run

Run the

the R&T BR!'(R)FF

R&T BR!'(R)FF command to reset the RR4,

command to reset the RR4, eBcluding the

eBcluding the

possibility that the problem is caused by soft f

possibility that the problem is caused by soft failure# %hec' *hether the

ailure# %hec' *hether the

alarm is cleared#

II# If t

II# If the alarm is not cleared, replace the RR4 and return the replaced

he alarm is not cleared, replace the RR4 and return the replaced

RR4 to R!" department for further analysis#

(28)

"o*nlin' %hannel Faults

I"

I" the the 5SW 5SW +alue +alue i$ i$ a3no#mal, a3no#mal, a a 5SW 5SW ala#m ala#m i$ i$ #e%o#ted.#e%o#ted.

I" the ALD com%onent$ connection and match a#e %oo#, mo$t o" the I" the ALD com%onent$ connection and match a#e %oo#, mo$t o" the

out%ut mic#owa+e %owe# i$ not emitted 36 the antenna 3ut i$ #eected 3ac). out%ut mic#owa+e %owe# i$ not emitted 36 the antenna 3ut i$ #eected 3ac). La#'e #eection %owe# dama'e$ the module and cau$e$ #e+e#$e 3#ea)down La#'e #eection %owe# dama'e$ the module and cau$e$ #e+e#$e 3#ea)down in wo#$t ca$e$. 5SW i$ an e8%onential "unction o" the "o#wa#d  #e+e#$e in wo#$t ca$e$. 5SW i$ an e8%onential "unction o" the "o#wa#d  #e+e#$e %owe#$ and i$ inde%endent o" the in%ut $i'nal %owe#. The de"ault 5SW %owe#$ and i$ inde%endent o" the in%ut $i'nal %owe#. The de"ault 5SW

ala#m th#e$hold i$ /.; and $e+e#e 5SW ala#m th#e$hold can 3e $et 36 --L ala#m th#e$hold i$ /.; and $e+e#e 5SW ala#m th#e$hold can 3e $et 36 --L command

command -OD U-OD U. To a+oid module dama'e, i" the $e+e#e 5SW ala#m. To a+oid module dama'e, i" the $e+e#e 5SW ala#m i$ #e%o#ted, the T1 channel $witched oJ o# de'#ade Kd> out%ut %owe#.and. i$ #e%o#ted, the T1 channel $witched oJ o# de'#ade Kd> out%ut %owe#.and. The#e"o

The#e"o#e, i" t#e, i" the $e+e#he $e+e#e 5SW ala#e 5SW ala#m i$ #e%m i$ #e%o#ted, the o#ted, the cell %e#"o#cell %e#"o#mancemance dete#io#ate$ o# the cell i$

(29)

"o*nlin' %hannel Faults

If a 01R alarm

If a 01R alarm is reported, the possible causes are+is reported, the possible causes are+

# The 01R

# The 01R alarm threshold is lo*#alarm threshold is lo*# 2# The Cumper is i

2# The Cumper is incorrectly installedG the feeder line is dincorrectly installedG the feeder line is distorted, bent, damaged, orstorted, bent, damaged, or loosened#

loosened# $# The 01R

(30)

"o*nlin' %hannel Faults

Troubleshooting procedure Troubleshooting procedure

Run the

Run the L&T RRUL&T RRU command to uery the 01R command to uery the 01R alarm threshold of the RF unit and chec' the

alarm threshold of the RF unit and chec' the appropriatenes

appropriateness of the s of the 01R threshold# If the01R threshold# If the threshold is inappropriate, run the

threshold is inappropriate, run the *)! RRU*)! RRU command to modify the threshold#

command to modify the threshold#

sho*n in the right table is ratio of the reflected sho*n in the right table is ratio of the reflected po*er fo

po*er for differr different 01R# ent 01R# *hen the *hen the 01R is less01R is less than #@,the ratio of the

than #@,the ratio of the reflected po*er is relati-elyreflected po*er is relati-ely small *hich has not a significant impact on co-erage small *hich has not a significant impact on co-erage performance # *hen the 01R is more than 2#7,the performance # *hen the 01R is more than 2#7,the ratio of the reflected po*er is

ratio of the reflected po*er is relati-ely large , *hichrelati-ely large , *hich has ob-ious impact on

has ob-ious impact on co-erage performancco-erage performance#e#

The recommended configure threshold is +

01R alarm post.processing threshold 97#: ; $7 01R alarm post.processing threshold 97#: ; $7 01R alarm threshold97#7 :;27

01R alarm threshold97#7 :;27

VSWR

VSWR Reflection Reflection power power ratioratio

3 3..0 0 2255%% 2 2..0 0 1111%% 1 1..88 88%% 1 1..55 44%% 1 1..4 4 22..88%% 1 1..3 3 11..77%% 1 1..2 2 00..88%%

(31)

0ie* the 01R -alue contained in the alarm 0ie* the 01R -alue contained in the alarm ##

If the 01R is

If the 01R is greater than 77 9unit+ 7#:, the reflection po*er is large#greater than 77 9unit+ 7#:, the reflection po*er is large# Run

Run thethe !&' +&(R!&' +&(R command to uery the current 01R# Run the command to uery the current 01R# Run the &TR&TR +&(RTE&T

+&(RTE&T command to perform 01R test# command to perform 01R test#

(ote that the 1TR 01

(ote that the 1TR 01RTE1T operation interrupRTE1T operation interrupts the ser-ice# It ts the ser-ice# It is common use for is common use for off.line test#off.line test# Repeat step

Repeat step for fi-for fi-e times e times at an at an inter-al of inter-al of 2 minutes# 2 minutes# %hec' *hether %hec' *hether thethe &TR +&(RTE&T

&TR +&(RTE&T command output sho*s significant fluctuation of the 01R# command output sho*s significant fluctuation of the 01R# If y

If yes, *e es, *e can suspect can suspect that that the the AL" AL" components is components is loosely loosely connected#connected#

"o*nlin' %hannel Faults

(32)

The difference bet*een

!&' +&(R

and

&TR +&(RTE&T

+

"1P 01R+

it is online 01R, The uery does not affect the ser-ice, the

uery band ha-e difference *ith current band, so the accuracy is not high, it

*ould only as the reference#

1TR 01RTE1T+

1TR 01RTE1T+ it is offline 01R, it is it is offline 01R, it is tested at the same freuency tested at the same freuency as current %ell,as current %ell, the accuracy is much high than online 01

the accuracy is much high than online 01 R , so it is used to confirm R , so it is used to confirm *hether the RR4*hether the RR4 has 01R problem#

has 01R problem#

"o*nlin' %hannel Faults

(33)

The procedure of onsite inspection is as follo*s+

:)ased on the netor' planning data, chec' hether the band of

:)ased on the netor' planning data, chec' hether the band of RF unit is

RF unit is

consistent *ith the

consistent *ith the the AL" components such asantenna, feeder, Cumper,

the AL" components such asantenna, feeder, Cumper,

combiner, di-ider, filter, and T>A#

2: Replace one segment of the AL" at a time, and run the

2: Replace one segment of the AL" at a time, and run the &TR +&(RTE&T

&TR +&(RTE&T

command to chec' the

command to chec' the result# Incorrect connection, damaged cable, or *ater

result# Incorrect connection, damaged cable, or *ater

in the Coint can

in the Coint can cause standing *a-e#

cause standing *a-e#

$: After chec'ing the AL" connection or

$: After chec'ing the AL" connection or replacing the AL", run the

replacing the AL", run the &TR

&TR

+&(RTE&T

+&(RTE&T command to chec' the result#

command to chec' the result#



If the command output sho*s that the 01R is

If the command output sho*s that the 01R is normal, reset the RR4 to

normal, reset the RR4 to

clear the

clear the alarm# Trouble

alarm# Troubleshooting ends#

shooting ends#



If the command output sho*s that the 01R still

If the command output sho*s that the 01R still eBceeds the threshold,

eBceeds the threshold,

replace the RR4 to

replace the RR4 to chec' *hether the RR4 is

chec' *hether the RR4 is faulty#

faulty# Return the replaced

Return the replaced

RR4 to R!" department for further analysis#

"o*nlin' %hannel Faults

(34)

Common en'inee#in' $umma#6 ta3le o"

t#ou3le$hootin'

Ty#e of

fault

D

e

t

e

c

t

i

o

n

m

e

t

"

o



s

R

e

m

a

r

$

5SW o" 5SW o" antenna feeder antenna feeder Th#ou'h online

Th#ou'h online（（ DS& 5SWDS& 5SW ））detection o# oinedetection o# oine *ST 5SW

*ST 5SWTESTdetection to te$t TESTdetection to te$t 5SW5SW

Oine 5SW

detection

inte##u%t the cell

$e#+ice $e#+ice intermodulation intermodulation of antenna feeder of antenna feeder

-ethod :@In the idle $e#+ice %e#iod, $ta#t $imulated -ethod :@In the idle $e#+ice %e#iod, $ta#t $imulated load, t#ac)in'

load, t#ac)in' cell SSI cell SSI o# cell o# cell inte#"e#ence i" inte#"e#ence i" thethe SSI o" ce

SSI o" cell ha$ 3een ll ha$ 3een o3+iou$l6 chan'ed o3+iou$l6 chan'ed 3e"o#e 3e"o#e andand a"te# $imulated loaded, it i$ indicated that the cell a"te# $imulated loaded, it i$ indicated that the cell ha$ inte#modulation.

ha$ inte#modulation. -ethod /

-ethod /：： $ta#tin' 3#oad3and online "#e7uenc6$ta#tin' 3#oad3and online "#e7uenc6 $can 36 We3L-T o# -/;;; could anal6e the $can 36 We3L-T o# -/;;; could anal6e the inte#modulation.

inte#modulation. C#o$$

C#o$$ FaultFault %onnection of %onnection of Antenna Antenna inin eNode> eNode>

-ethod :@the c#o$$ "ault connection o" antenna -ethod :@the c#o$$ "ault connection o" antenna could 3e anal6ed acco#din' to en'inee#

could 3e anal6ed acco#din' to en'inee# %a#amete#$ and

%a#amete#$ and cell hando+e# cell hando+e# #ate .#ate . -ethod /@--L Command

-ethod /@--L Command ：： STST COS!EEDTST

COS!EEDTST （（ #ecommended #ecommended in in idle idle $e#+ice$e#+ice ））

ST ST COS!EEDTST COS!EEDTST inte##u%t the inte##u%t the cell $e#+ice cell $e#+ice e+e#$e

e+e#$e FaultFault %onnection of %onnection of Antenna Antenna inin eNode> eNode> -ethod /

-ethod /：： fled te$t * it i$ #ecommended in thefled te$t * it i$ #ecommended in the 3e'innin' o" the netwo#) con$t#uction 

3e'innin' o" the netwo#) con$t#uction 

-ethod /@the e+e#$e "ault connection o" antenna -ethod /@the e+e#$e "ault connection o" antenna could 3e anal6ed acco#din' to en'inee#

(35)

In"o#mation Collection o" U "ault

detail descri#tion o! detail descri#tion o! #roblem

#roblem

t$e #roblem #$enomenon must $a%e detail descri#tion t$e #roblem #$enomenon must $a%e detail descri#tion t$rou&$ te't( screens$ots or !ault)site #$oto*

t$rou&$ te't( screens$ots or !ault)site #$oto* Mandator+Mandator+

Failure site ,-.

Failure site ,-. For commercial sites( need to !eedback t$e !ault siteFor commercial sites( need to !eedback t$e !ault site

recent ,-. data

recent ,-. data O#tionalO#tional

T+#e o! RR/

T+#e o! RR/ T$e !ailure module %ersion( bands( t+#e( suc$ as t$eT$e !ailure module %ersion( bands( t+#e( suc$ as t$e

MR/( MRR/( DRF/( RR/( MRF/ etc*

MR/( MRR/( DRF/( RR/( MRF/ etc* Mandator+Mandator+

1etork o! 3LD 1etork o! 3LD eui#ment eui#ment

t$e t+#e o! 3LD netork( $et$er multi)mode base t$e t+#e o! 3LD netork( $et$er multi)mode base station( antenna surroundin&*

station( antenna surroundin&* Mandator+Mandator+

"on!i&ure !ile o! "on!i&ure !ile o! e1odeB

e1odeB ""oonn!!ii&&uurreed d !!iille e oo! ! ee11ooddeeBB MMaannddaattoorr++ One)ke+ !ile o! LM-T

One)ke+ !ile o! LM-T OOnnee))kkee+ + !!iille e oo! ! LLMM--TT MMaannddaattoorr++

One)ke+ !ile o! RR/

One)ke+ !ile o! RR/ OOnnee))kkee+ + !!iille e oo! ! RRRR// MMaannddaattoorr++

One)ke+ !ile o!

LBB-One)ke+ !ile o! LBB- OOnnee))kkee+ + !!iille e oo! ! LLBBBB- - $$iicc$ $ ccoonnnneecct t iitt$ $ RRRR// OO##ttiioonnaall