ctu ber white paper v2

8/10/2019 CTU BER White Paper v2

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White Paper:

Bit Error Rate (BER)

Abstract

The purpose of this document is to provide the local office and operator with

a method to troubleshoot and to analye BER issues on !T"#s and !T"s$

%evin &'onnell*ohnny +uo

,ersion #$-

Base Transceiver .ystems

/etwor0s

1otorola2 3nc

1ar 42 #--5


2/31

Troubleshootin6 6uide for poor BER

Revision 7istory

ate ,ersion 3ssued By !han6es

89 April #-- 8$- %$ &'onnell 3nitial Release

#5 &ct #-- 8$b %$ &'onnell Acceptable +imit updates

8 /ov #-- 8$c %$ &'onnell 3nternal Review

4 1arch #--5 #$- *ohnny +uo "pdates

References

Ref$ ,ersion 3ssued By Title

8 ,;$8$- (#--#PP E.T3 $-; =rd >eneration Partnership Pro?ect@

Technical .pecification >roup >.1E>ERadio Access /etwor0@

Radio subsystem lin0 control

(Release 8)

# >.R4 7A+uide

5 6smD6DbssD88# E1EA !ustomer 7orion macro !T"--8;-- Bit Error

.upport !entre Rate detection

4 =;DeatueDPlan avid .$ +ee Plan for rame Erase Rate eature

# =8Pa6e of


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Table of !ontents

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9

#$ escription of the Bit Error Rate

statistic $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

$$$$$$$$$$$$$$$$$$$$ =$ Possible sources for poor

BER $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ 849$ ata and information to be

6athered $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ ##9$8$ >eneral information$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$##9$#$ TE.T F8: !alibration issue$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

#=9$=$ TE.T F#: !abinet!ablin6 issue $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

#;9$9$ TE.T F=: Environment issue$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

=-$ Troubleshootin6 Process

low $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

=8

$8$ ata !ollection $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

=8$#$ ,erification$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

=8$=$ ollow


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3ntroduction8$

Bit Error Rate (BER) is usually monitored by customers to ensure optimal

performance of the networ0$ A BER measurement can be derived for the uplin0 or

the downlin0 si6nals$ This document is 6oin6 to provide customers or local offices

an analytical and systemic method to identify difference between BER and ER G

the root cause of poor BER$

"nderstandin6 the scope of the problem

!ustomers and local offices need to understand the scope of the BER issue and the

eHtent of the problem$ BER is a dynamic measurement that may indicateinterference issues and possibly fadin6 concerns and noisy channels$ &ther

statistics need to be eHamined includin6 path balance alon6 with the 3&3 statistics$

An occurrence of poor BER alon6 with another bad statistic2 will typically point to

another issue$

Also2 it is important to identify if the problem is isolated to a sin6le radio or if the

problem is present on all the radios of the site:

I 3f the problem is only on one radio2 customers can try to chan6e the

confi6uration of the site (e$6$ move the RT of the poor BER R3 to another

R3) and chec0 if the problem followed the RT or stayed on the R3$I 3f the problem is on all or multiple radios of the site then focusin6 on the

cabinet cablin62 the surf2 and the environment mi6ht shorten the investi6ation$

I B.. >ather may be used to collect BER data for whole networ0$ Assistance with

&1!ather tool is available from your local

!/R!$ Bulletin 88# has more information on how to collect it $B.. >ather

,ersion =$-$##- or later is needed to collect BER data$

Recalibration of the >!+%

Performin6 a >!+% calibration on the cabinet eHhibitin6 the problem can Juic0ly

resolve the problem since invalidinaccurate calibration may ma6nify other factors

that de6rade the BER performance of the radio$ This should always be the first

step ta0en in troubleshootin6 poor BER$

Recalibration of the cabinet for the radios eHhibitin6 hi6h BER

Performin6 a cabinet offset calibration (TKBAL !A+) on the radio eHhibitin6 the

problem can Juic0ly resolve the problem since invalidinaccurate calibration has

been identified as a recurrent issue on customers' networ0s$

Poor installationmaintenance (!ablin6)

urin6 initial installationdeployment2 it is critical that care is ta0en on the

eJuipment$ ama6ed connectors2 cables2 poor A/T ,.WR and dropped eJuipment

can lead to poor BER statistics$ A re6ular maintenance schedule is recommended

to inspect and identify faulty components before a problem becomes worse$Presence of interference in the R environment 9 =8Pa6e of


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.ometimes poor cell plannin6 or the presence of other eJuipment near by2transmittin6 at the same freJuency of the wireless eJuipment can result in

interferences$ Tools are available to scan the R environment of the site and chec0

if poor BER is due to an abnormally noisy R environment$

The remainder of this document will describe in detail how to proceed in the BER

investi6ation and will provide tools and tips to root cause the poor BER issue$ This

document addresses possible BER issues on !T" and !T"# radios$

escription of the Bit Error Rate statistic#$

i68:ull Rate Traffic for speech bloc0

Avoidin6 transmission error in the air2 >.1 deployed codin6 G interleavin6

technolo6ies$ or full rate traffic2 per #-ms speech bloc0 of #5- bits2 can be divided

into !lass 8a2 !lass 8b2 !lass # based on their importance on speech Juality$ A = bit

!R! is applied to !lass 8a$ 3f !lass 8a bits error occurs2 the whole speech bloc0 will

be discarded for bad frame$ By encodin62 this speech bloc0 becomes 95 bits2 and

then be interleaved into ; successive halfbursts(T1A frames)$The half rate convolutional codin6 process applied to all class 8 bits provided a

si6nificant error correction capability$ 7owever2 transmission errors tend to occur in

bursts due to nature of the multipath channel fadin6$ .ince the convolutional codin6

does not operate effectively in such conditions2 an interleavin6 process has been

devised whereby each coded2 95bits lon6 bloc0 is reordered and dia6onally

interleaved over ; successive halfbursts(T1A frames)$ The interleavin6 process isfully described in ET.3 -$-=$ The de6ree of success of the channel codin6 a ndinterleavin6 operations$ 7owever2 is function of the speed of the mobile$ The =8Pa6e of


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performance of fast movin6 mobiles is usually better than slow movin6 mobiles forthe same avera6e !3$

i6#: /ormal Burst

BER per burst varies dependin6 on urban2 suburban and rural areas$ 3n same

scenario2 BER per burst is not dependin6 on the !32 but also on freJuency selective

fadin6 (Raylei6h adin6)$ And the main determinative is !3$ 3n a burst2 where the

desired si6nal is in a fadin62 it is most li0ely hi6her BER per burst than that in

nonDfadin6 condition$ The faster mobiles movin6 speed2 the less fadin6 influence on

BER per burst$

As reJuired in ET.3 -$-; MRE 8N2 BER statistic pe6s every .A!!7 multiframe(8-9

T1A frames) per timeslot$ The BER statistic trac0s the minimum2 maHimum2 and

the mean Bit Error Rate$ 1ean BER statistic is uploaded to &1! every =- or 5-

minutes dependin6 on networ0 settin6s$ The same as uplin0 BER statistic ("DBER)$

/&TE 8: BER statistics are reported per timeslot only when the channel is active$

/&TE #: >PR. timeslots do not report BER measurements$/&TE =: or the full rate channel2 BER"DBER is based on 8-9 T1A frames$

/&TE 9: or the half rate channel2 BER"DBER is based on # T1A frames$

/&TE : or the TK mode2 BER"DBER is based on 8# T1A frames$

1ean BER statistic is a statistical value based on thousands of 1. calls durin6

intervals$ Every 1. ?ust has little influence on the statistic$ or this reason2 1ean

BER statistic can only simplified into a function of !32 i6norin6 Raylei6h adin6$ The

lower !32 the hi6her 1ean BER statistic$ /ote this relation varies dependin6 on

urban2 suburban and rural areas$

5 =8Pa6e of


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i6=

BER defined as the ratio of the number of bits in error detected over the total

number of bits before deinterleavin6 and decodin6$

ER defined as the ratio of the number of bad speech frames over total speech

frames after deinterleavin6 and decodin6$ The ER will then be reported every

multiframe (9;-msec) alon6 with the Bit Error Rate statistic$ urin6 this period2 #9

speech frames are decoded and a ratio calculated$

or full rate traffic2 the #-ms speech bloc0 was interleaved into ; successive

halfbursts$ After deinterleavin6 2 reordered into one speech frame$ 3f !lass 8a bits

error occurs2 the whole speech bloc0 will be discarded for bad frame$

Residual BER defined as the ratio of the number of bits in error detected in speech

frames defined as 6ood over the total number of bits in speech frames defined as6ood$

1ean BER statistic can only simplified into a function of !32 in nature2 it reflects the

wireless transmission Juality$ The lower !32 the hi6her 1ean BER statistic$

ER statistic can ta0e advanta6e of codin6 G interleavin6 error correctiontechnolo6ies$ When bits are in error 2 it is often still possible usin6 error correctiontechniJues to recover them$ 3n nature2 it reflects the 1. user perception of speechJuality$ 4 =8Pa6e of


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3t is also possible to report hi6h enou6h BER and hi6h ER2 when error correction

can not completely recover bits in error$ "nder this condition2 the 1. users will feel

bad speech Juality$

The Bit Error Rate (BER) statistic provides an indication of the si6nal wireless

transmission Juality received by the mobile$ The "plin0 Bit Error Rate ("DBER)

statistics provides an indication of the si6nal wireless transmission Juality received

by the BT.$ An operator can use the BER and "DBER statistic to identify a fault or

interference in the RK or TK si6nal transmission path$

The ER statistic provides an indication of the 1. user perception of speech Juality$

/ow2 &1! can only report uplin0 ER as current 1. can not report ER estimation

in measurement report$ But2 the Test 1obile can report downlin0 ER estimation$

There will be a downlin0 ER substitute feature in >.R8-

The &1! BER and &1! "DBER statistic is reported usin6 values - to 4 that are

derived from the RKC"A+ values$ The BER and "DBER statistics are

?ust O totalsample $The total value is the sum of RKC"A+ values durin6 pe6

intervals2 and the sample value is the Juantity of measure$ The statistic reports1ean RKC"A+ level durin6 pe6 intervals2 not BER ratio$ BER statistic ran6e is -


9/31


5 -$#-- -$#854 -$#84 -$===#

; -$==== -$=49

-$=4- 8$-

The &1! BER and &1! "DBER statistic only read correctly in hi6h traffic$ And there

is unreliable BER value in low traffic$

The same as ER statistic$

/ote: dealin6 with BER issue2 we should screen the unreliable BER issue due to low

traffic firstly

Below are some cases of unreliable BER value in low traffic$

Typical unreliable BER due to low traffic chart will own lar6e variations$ By its

standard deviation2 we can screen it$ Also we can screen it by PathDBalance chart$

As PathDBalance is only reported in active traffic$

9 $

9

= $

=

# $

#

8 $

8

- $

-

i69:typical hi6h "DBER due to low traffic

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4

5

9

=

#

8

-

8 # = 9 5 4 ; 8- 88 8# 8= 89 8 85 84 8; 8 #- #8 ## #=

i6: correspondin6 typical hi6h BER due to low traffic

i65 is correspondin6 PB chart2 from PB chart2 we can conclude that the voice traffic

is low$ or PB statistics only be calculated with active traffic$

89-

8#-

8--

;-

5-

9-

#-

- 8 # = 9 5 4 ; 8- 88 8# 8= 89 8 85 84 8; 8 #- #8 ## #= i65: PB chart8- =8Pa6e of


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There is a filterin6 method to screen hi6h BER due to low traffic$or each timeslot 2

8: calculate avera6e BER"DBER from -;:-- to #-:--(8# busy hours)$

#: calculate standard deviation from -;:-- to #-:--$

=: if standard deviation Qavera6e2 means low variations$ !an confirm it maybe is

true constant hi6h BER"DBER$

This filterin6 can be easily implemented by EHcel2 usin6 .tatistical unction

A,ERA>E2 A,EE,@ +o6ical unction 3$

Below table 6ives correspondin6 value for above case2 3t can be seen that standard

deviation Savera6e on all timeslots2 means should i6nore the hi6h BER issue$

T.- T.8 T.# T.= T.9 T. T.5 T.4

1ean 1ean 1ean 1ean 1ean 1ean 1ean 1ean

8$ 8$8-=;95 8$=-44 -$;#=-; -$4;=-44 8$8-45 -$45#= 8$=;#=-;

T.- ev T.8 ev T.# ev T.= ev T.9 ev T. ev T.5 ev T.4 ev

8$8#=-; -$95 8$-54# -$4;#8= -$5=485 8$88448 -$548; 8$=5#;9

T.- T.8 T.# T.= T.9 T. T.5 T.4

1ean 1ean 1ean 1ean 1ean 1ean 1ean1ean

-$= -$##-45 -$=8;58 -$84-95# -$8558 -$#=;89 -$8=; -$#4595#

Below is hi6h BER due to eHtremely low traffic on switchable PT!7$

i64: unreliable BER on .witchable PT!7 due to low traffic88 =8Pa6e of


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!onfi6urationWT.- B!!7 T.82T.# are .!!7 Wtheir BER is hi6her

T.8 (.!!7;) than T.= (T!7)Wbased on >.1 .tatistic

T.# (.!!7;) Application (5;P-#-8W5PR. traffic based on atabase settin62 commonly there is low speech traffic on

these timeslot2 possibly results in hi6h BER due to low traffic$

Presently2 PT!7 timeslot only was deployed on B!!7 carrier$

i6ure ; is correspondin6 "DBER chart$

i6;: unreliable "DBER on .witchable PT!7 due to low traffic

The BER statistic data should be eHamined on a site by site basis$ The individual

timeslots should then be analyed to find consistent readin6$ +ar6e variations due

to low traffic should be eHcluded$ .ort the site data into sectors to loo0 for site

sector problems$ >PR. timeslots do not ma0e BER measurements$ The .!!7

timeslot may be affected by phantom RA!7s$ or cells with a non


13/31


A typical plot of BER performance for a R3 is show below for a #9 hour periodini6ure $ Each line represents a different timeslot$

Typical BER Performance

;

4

5

Be r-

Be r8

Be r#

Be r=9

Be r9

Be r

Be r5=

Be r4

#

8

-

7 o u r

i6

Typically hundreds to thousands of mobiles will connect to a radio over a lon6

period of time$ .ince there is a lar6e sample of mobiles reportin6 TK and RK power

levels2 these numbers should show a normal distribution$ &ver time inaccuracies in

any one mobile will have little affect on the BER number$ EHcept wireless

interference 2this means that it ta0es an error at the BT. TK andor RK path or

power reportin6 to cause a chan6e in the BER number$ 3f there is a BER problem

then this points to a BT. TK transmit path problem$ 3f there is a "DBER problem

then this points to a BT. RK receive path problem$ 3f there is also an 3&3 issue

then there is either a problem with the RK path or interference on the RK

freJuency$ A plot for radio failin6 "DBER is shown below in i6ure 8-$ /ote

thatonly odd or even timeslots have poor BER$ This failure is on a 7orion 3 !T" with a

loose lid$ The local office should be contacted with reference to Bulletin F6smD6DbssD88# to solve this BER issue on 7orion 3 !T"s$ This fault has only been

seein6 on 7orion 3 !T"s$ This behavior is showed below in i6ure 8-$

8= =8Pa6e of


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ailin6 !T"

;

4

5

B er-

B er8

B er#

B er=9

B er9

B er

B er5=

B er4

#

8

-

8 # = 9 5 4 ; 8 - 8 8 8 # 8 = 8 9 8 85 84 8; 8 #- #8 ## #= #9

7 o u r

i68-

89 =8Pa6e of


15/31


A plot of de6raded BER performance is illustrated below in i6ure 88$ The BER maybe de6raded due to wea0 si6nals or interference into the BT. receiver$ This plot is

for a #9 hour period of the "DBER statistic$ /ote each line represents a different

timeslot$

e6raded BER

;

4

5

B er-

B er8

B er#

B er=9

B er9

B er

B er5=

B er4

#

8

-

8 # = 9 5 4 ; 8 - 8 8 8 # 8 = 8 9 8 85 84 8; 8 #- #8 ## #= #9

7 o u r

i688

8 =8Pa6e of


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A plot of poor "DBER performance is illustrated below in i6ure 8#$ The"DBERmay be de6raded due to an uplin0 path or interference problem into the BT.

receiver2 commonly2 it will be accompanied with hi6h 3&3 issue$ This plot is for a #9

hour period of the "DBER statistic$

Poor BER

;

4

5

B er-

B er8

B er#

B er=9

B er9

B er

B er5=

B er4

#

8

-

8 # = 9 5 4 ; 8 - 8 8 8 # 8 = 8 9 8 85 84 8; 8 #- #8 ## #= #9

1 o n th

i68#

BER acceptable limit:

The BER statistic pe6s every 9;- ms (correspondin6 to each .A!!7 multiframe)$

This statistic can be used for trend analysis of the BER for active channels$

/ote: The avera6e BER should typically be below # for 6ood speech Juality$ This

corresponds to &1! 1eanDBER number between = and 9$

These values should have a small standard deviation durin6 busy hours$ +ar6e

variations due to low traffic should be eHcluded$ 7owever this number whensli6htly out of ran6e does not indicate a failure of the eJuipment$ The more

channels reused close to hi6h traffic sites will increase the mean BER due to

interference$ ollow the steps in section = to troubleshoot and dia6nose the BER

issue$ Typically if the number is si6nificantly above =2 then the poor bit error rate

will be accompanied by another bad statistic such as hi6h 3&32 path balance or a

hi6h number of dropped calls$/ote8: it is acceptable to have BER values varyin6 throu6hout the day since therewill most li0ely be more interferences in the natural environment durin685 =8Pa6e of


17/31


pea0 hours of the day than durin6 non


18/31


< 3nvalid or inaccurate TKBAL !A+

o 3f the radio is a new spare it comes with default !A+ data and must be TK

and RK offset calibrated within the slot it will function in

o 3f the radio was swapped from one slot to another and the preserve bay level

calibration feature is not enabled2 a recalibration of the TK and RK is

necessary

o 3f an eHpansion cabinet is added to the confi6uration it mi6ht be necessary to

recalibrate the TK and RK

o 3f eHternal combinin62 filterin6 or amplification is added to the confi6uration a

TK or RK calibration is reJuired$

< 7W!onnection problem with the cabinet slotcablin6antenna:

An element in the RHTH path mi6ht have failed 2 or mi6ht not be used or

installed correctly: bac0plane2 cablin62 bad connectors or connections2 faulty

?umpers 2faulty feed line2 fautly antenna 2loose connections$V

Remove and reinsert suspect radio from BT. cabinet$ ,erify all antenna

connections internal and eHternal to the BT.$ ,erify antenna ,.WR is within

acceptable limits$

< Base Band 7oppin6 (BB7) or R hoppin6:

7oppin6 can supply eHtra hoppin6 6ain by freJuency diversity and interference

diversity$

reJuency diversity is the capability to anti Raylei6h fadin6$ 3t is rather helpful

for stationary and low speed movin6 1.$ And no helpful for hi6h speed movin61.2 for Raylei6h fadin6 has little influence on hi6h speed movin6$

!orrect freJuency diversity plannin6 is the selection of uncorrelated freJuency

set$ The adeJuate uncorrelated freJuency 6ap is S-$5 1h$ The complete

uncorrelated freJuency 6ap is S 8 1h$

3nterference diversity can avera6e the interference impact$ The number of

hoppin6 freJuency channels is the 0ey to interference diversity$

By eHtra hoppin6 6ain2 either can improve networ0 performance2 or can enrich

networ0 capacity$ 3f hoppin6 is used to enrich networ0 capacity2 in this

condition2 lower !3 will contribute the BER issue$

3ncorrect hoppin6 plan2 will result in !oDchannel2and Ad?acent interference$/ote: 3n the hoppin6 system2 due to inherent freJuency collision2 BER will benaturally hi6her than that of nonDhoppin6 system$ 8; =8Pa6e of


19/31


< 7W problem with the R3:

A 7W component of the transceiver (!T" or !T"#) can have failed which results

in abnormal noise in the transceiver or loss of output power$

ue to radio's 7W issue2 poor BER will be possibly accompanied with poor ER

(poor performance)$

As for abnormal noise2 possibly accompanied with hi6h 3&3$

As for TH power loss2 possibly accompanied with R3 TH power low alarm$

R3 8 Alarm: Power Amplifier Power +ow But unctionin6$ 3t is a ma?or alarm$

The output power of the transmit power amplifier is mar6inally below specified

limits2 but calls may continue$ The spec is #dB$

R3 ;5 Alarm: Transmitter ailure < &utput Power$ 3t is a critical alarm$

The output power of the transmit power amplifier is below the power ran6e

reJuired to sustain R transmission$ The spec is 9dB$

3f this alarm occurs three times within a 8- minute period2 the R3 is soft reset

on the first two occurrences and then be inhibited on the third occurrence$

.wap suspect radio with a different unit from a different sector$ 3f the poor

performance stays with the sector then the hardware is performin6 correctly

and you may have an interference or plannin6 issue$ 3f the poor performance

follws the radio then follow chart shown if i6ure 89$

< !ell Plannin6:

There is a relationship between !3 and networ0 capacity$ The hi6her reuse of

freJuencies 2 the lower the !3$ The lower !32 the hi6her BER$

A 6roup of cells in which each cell has a different freJuency is called a cluster$

The number of sites per cluster is O /$ .ome common reuse patterns are 4#82

98# and =$The 98# 2for eHample 2is 9 sites 2= sectors each with 8#

freJuencies used where /O9$

Radio freJuency spectrum is limited but the lar6est possible reuse pattern

should be used to have the hi6hest !3 and lowest possilbe interfernce$ A plot

of !3 vs$ / is shown in i6ure 8=$

8 =8Pa6e of


20/31


i68=: Plot of !3 vs$ sites per cluster

3n this document2 we will describe how to identify if the hi6h BER problem falls in

one of these cate6ories$ Lour investi6ation will follow the 6raph below$

#- =8Pa6e of


21/31


Poor BER

detected

Les< !ontact the networ0optimiation team andor

< 1odify the freJuencies!alibrate the radio

to be used on this sector .ection 9$8: >ather 6enericconfi6uration information on and monitor the

the radio and the site$ BER a6ain

Les TE.T F8.ection 9$#: 3s the

calibration data accurate /o

Return or fiH

the fault

eJuipment

and monitor

LesTE.T F#/o the BER a6ain.ection 9$=: 3s the problem due

to other 7W failure

Les/oTE.T F=

.ection 9$9: 3s the problem

due to the environment

< &pen an .R (provide a description of the

problem and attach the lo6s you 6athered

durin6 your investi6ation) A/

i689 ebu6 lowchart

#8 =8Pa6e of


22/31


ata and information to be 6athered9$

WAR/3/>: Throu6hout this procedure2 0eep lo6s of all 113 commands and all the

results or you tests$

>eneral information9$8$

3n this section2 we want to have a snapshoot of:

< the radios' state and confi6uration2 and

< the site's performance$

Please answer the followin6 Juestions below before you chan6e anythin6 in the

site:

< 7ow many radiossectors are affected

< What type of radio is affected (!T"2 !T"#2 both)

< or all radios affected2 6et &1! 3/TD&/D3+E statistic$

< 1onitor PB2 BER2 call drop rates and 3&3 performance2 if 7i6h 3&3 please see 3&3

white paper

< id the problem start after an up6rade2 a cell replannin62 or 7W chan6e

< Run the followin6 commands for the site at the 113


23/31


TE.T F8: !alibration issue9$#$

3n this section2 we will verify that the calibration data is valid for the antenna and

branch(es) bein6 used$ (/ote: 3t is recommended to calibrate all antennas but in

some cases2 only the antenna bein6 used is calibrated by the customer)$

,erification that the calibration data is valid9$#$8$

,erification that the calibration data is valid:

(a) !T" radio

At the EC!P 113 prompt2 enter the followin6 commands:

EC!P TE.T S calch0

EC!P TE.T S

RK Branch 8: !A+ !7E!%."1 RK Branch #: !A+ !7E!%."1

A3! LE. ---8 A3! LE. ---4

A>! LE. d=f- A>! LE. b;9

BAL LE. 4f=b BAL LE. 4f=b

BB> LE. --#a (This is for both branches$)

!& LE. =ef- !& LE. 85b

REC LE. ffe= REC LE. fe#8

3> LE. ---5 3> LE. ---

R..3 LE. a8a R..3 LE. a-ce

TK !A+ !7E!%."1

ET LE. ;5

PWR LE. -9a#

TK LE. ----

,,A LE. a=c4

,erify that the Y!A+Y value for the row titled ZBAL is YLE.Y$

3f there is a /&2 then the result for TE.T F8 is /& and you should recalibrate the

radio and monitor the BER a6ain$ 3f 3&3 is also occurrin6 then please reference the

3&3 white paper and perform specific tas0s$

&therwise if calibration data is o0 6o to (9$#$#) below

(b) !T"# radioAt the .P 113 prompt2 run the followin6 commands:

#= =8Pa6e of


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!T"#$carA$tsD-Sch6

Enter Password: pia

Access +evel = >ranted

!T"#$carA$tsD-ScalDstatus tall

!al !a Br .tatus Result ,alid !hec0sum ,er .7!


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1anual verification9$#$#$

WAR/3/>: Be sure to ta0e the radios connected to this dupleHer out of service so

that the TK power is off$

(8) A si6nal 6enerator is reJuired to in?ect an R si6nal into the antenna (A/T) port

of the dupleHer$

At the R.. 113 prompt:113: The EC!P is now in test mode$

EC!P TE.T S ts a chan 8#

EC!P TE.T S

The data for all timeslots has been chan6ed$

EC!P TE.T S

EC!P TE.T S self cal rHDlev

EC!P TE.T S

Power into radio: (A3! is assumed out$)

B8 RH +ev:


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Power into cabinet:

B8 RH +ev:


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ecimal EJuivalent

&,R 8# 8# 8# 8# 8# 8# 8#

8#

rt = = = = = = =

=

reJ$ 8;-$# 8;-$# 8;-$# 8;-$# 8;-$# 8;-$# 8;-$#

8;-$#

!T"#$carA$tsD-S

!T"#$carA$tsD-SrHlev

T. -


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,erify that the new calibration offsets are not too different from the initial ones you6ot in .ection 9$8 for this radio$ To do that2 use the eHcel spreadsheet that can be

found at http:compass$mot$com6o8948==5-$

(8) .elect the freJuency you are 6oin6 to use

(#) !opy and paste the initial and new values into the spreadsheet

(=) +oo0 at the differences between the initial and new data$ 3f the difference for

the antenna bein6 used is more than # dB for most of the offsets2 the result for

TE.T F8 is /& and you should monitor the PB a6ain with the new RK

calibrationoffset values$

&therwise continue to section (9$=) below

TE.T F#: !abinet!ablin6 issue9$=$

3n this section we will discuss the various items that could be bro0en or dama6ed

on the cabinet$ 3n many situations all that is reJuired is a close inspection of the

cabinet loo0in6 for dama6ed connectors and cables$ There are three places to loo0

to identify this type of failure: TK path2 RK path and the combined TKRK path$There are two other possibilities2 thou6h less li0ely2 in which interference can be

6enerated$ These are after the dupleHer combinin6 and a bad ."R."R#$

TK Path

< +oc0 the radio and power down$

< 3nspect the short TK cable that 6oes from the !T"!T"# to the dupleHer$ 1a0e

sure there are no cuts or frays or places where it loo0s li0e the cable is comin6

apart$ 3f there is dama6e replace the cable$

< 3f the short TK cable loo0s o02 remove the cable connectin6 the !T"!T"# to the

dupleHer$ 3nspect the center conductor on the cable2 the !T"#2 and the

dupleHer$ 3f there is dama6e to the cable or the cable's center conductor is

bent2 replace the cable$ 3f it loo0s li0e the !T"!T"# connector is dama6ed or

loose2 return the !T"!T"# for repair and note the dama6ed connector on the

R1A$ 3nspect the dupleHer center conductor and return if there is dama6e or if

the connector is bent$

< 3nspect any other cables that mi6ht be used in the TK path such as cables

connected to combiners2 add


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< Remove the RK cable2 for the desired path2 from the dupleHer and ."R$3nspect the cable for dama6e and cuts$ 3f it loo0s li0e the cable is brea0in6 near

the connector2 it is bad$ Replace this cable as necessary$ Also inspect the /

ctu ber white paper v2

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