09-wcdma handover principal

8/16/2019 09-WCDMA Handover Principal

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Huawei Confidential. All Rights Reserved

WCDMA Handover Principal and

Analysis

ISS! ".#


2/92

2Internal se

Why mobile systems need

handover?It is decided by the characters of

mobile system:

$he %o&ility of !

$he %o&ile syste% is co%posed &y

cells which the coverage a&ility is

li%ited.

Providing the continuous service in

%o&ile syste% is the &asic ele%ent in'oS.


3/92

3Internal se

(&)ect(&)ect

Upon completion this course, you will

be able to:

The basic definitions of Handover

The alorithms of handover

decision

The handover flow

The parameters of handover


4/92

!Internal se

Chapter "Chapter " Introduction of Handover Introduction of Handover

Chapter * Measure%ent of Handover

Chapter + $he ,asic Handovers

Chapter - ,lind Handover and

Direct Retry Algorith%


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"Internal se

$he Purpose of Handover $he Purpose of Handover

#rovidin the continuous service in mobile system is the basic

element in $o%&

The load balance: sharin the resource

The hierarchy divided by speed and service: hih efficiency of usinresource


6/92

'Internal se

$he ,asic Concepts of Handover $he ,asic Concepts of Handover

(ctive %et

)onitored %et *etected set +vent reportin

+vent reportin to #eriodic reportin #eriodic reportin adio -in. /-0 adio -in. %et /-%0 1ombination way:

maimum ratio combination selection combination

The soft handover ain

1#I1H %oft handover, softer handover, hard handover lind handover


7/924Internal se

$he Categories of Handover $he Categories of Handover

(ccordin to the sinalin characters:

%oft handover /softer handover0

Hard handover

(ccordin to the properties of source cell and taret cell

Intra5fre6uency handover

Inter5fre6uency handover

Inter5mode handover /7** 859 T**0 Inter5system handover /U)T% 859 %);1*)(2


8/92>Internal se

$he Characters of Different Handovers$he Characters of Different Handovers

Item %oft Handover Hard Handover

The numbers of -in active set afterhandover

%everal =ne

Interruption durinhandover o @es

The fre6uencies ofcells

=nly happenedin Intra5fre6uency cells

1an be happened inIntra5fre6uency cells orInter5fre6uency cells

1omparison between soft handover and hard handover:


9/92AInternal se

$he Characters of Different Handovers$he Characters of Different Handovers

*urin softer handover, the uplin. sinalin are

combined in ode by maimum ratio combination, butdurin soft handover they are combined in 1 by

selection combination&

1ompare to later one, the maimum ration combination

can et more ain& %o the performance of maimum

ration combination is better&

%ince softer handover is completed in ode, it do not

consume transport resource of Iub&

1omparison between soft handover and softer handover:


10/92B


11/92BBInternal se

RNC (WFMR)

NodeB

Softer Handover Softer Handover


12/92B2Internal se

Hard Handover Hard Handover


13/92B3Internal se

$hree Steps of Handover $hree Steps of Handover

*ecision

+ecute

)easurement

)easurement )easurement control )easurement eecution and

the result processin The measurement report )ainly accomplished by U+

*ecision ased on )easurement The application and

distribution of resource )ainly accomplished by

) in 1 +ecution

The process of sinalin %upport the failure drawbac. )easurement control refresh


14/92B!Internal se

'uestions'uestions

The differences amon %oft handover,softer handover and hard handover

Typical application scenarios


15/92B"Internal se

Su%%arySu%%ary

This chapter focus on the purpose of handovers and the

cateories of handover in W1*)(&


16/92B'Internal se

Chapter " Introduction of Handover

Chapter *Chapter * Measure%ent of Handover Measure%ent of Handover

Chapter + $he ,asic HandoversChapter - ,lind Handover and



17/92B4Internal se


Section " Measure%ent control and

%easure%ent report

Section * $he &asic definitions of %easure%ent

Section + Intrafre/uency %easure%ent event

Section - Interfre/uency and

intersyste% %easure%ent event

Section 0 ! internal %easure%ent


18/92B>Internal se

Measure%ent Control and Measure%entMeasure%ent Control and Measure%ent

ReportReport

)easurement 1ontrol ：

U+ UT(

)+(%U+)+T 1=T=-

Measure%ent Control1 nor%al case


19/92BAInternal se

Measure%ent Control and Measure%entMeasure%ent Control and Measure%ent

ReportReport

)easurement report ：

U+ UT,(?

)+(%U,+)+?T ,+#=,T

Measure%ent report1 nor%al case


20/922


21/922BInternal se

$he ,asic Concepts of Measure%ent$he ,asic Concepts of Measure%ent

The measurement values of Handover

Intra5fre6uency and inter5fre6uency: 1#I1H %1# 、 1#I1H

+c;< 、 #ath loss

Inter5fre6uency ： 1#I1H %1# 、 1#I1H +c;<

Inter5system ： %) 1arrier %%I ， %I1 Identification

，

%I1 econfirmation

The reportin methods of measurement #eriodic reportin

+vent reportin

The events of reportin

Intra5fre6uency events ： B(,B,B1,B*,B7

Inter5fre6uency events ： 2*,27,2,21

Inter5system events ： 3(,31

=thers ： ','7

M t M d lM t M d l


22/9222Internal se

Measure%ent ModelMeasure%ent Model

Layer 1filtering

Layer 3filtering Evaluation

of reporting

criteria

A DB C

C'

parameters parameters


23/9223Internal se

Reporting CriterionReporting Criterion

eportin 1riterion

*ecision formula: for eample, B( event : 1.Path Loss

2.Other measurement ：

elative threshold, (bsolute threshold, Hysteresis, Time to

trier

),2/1!)11!1! 11

a Best

N

i

i New H R LogM W M Log W LogM

A

−+⋅⋅−+

⋅⋅≤⋅ ∑

=

),2/1!)11!1! 11

a Best

N

i

i New H R LogM W M Log W LogM A

−−⋅⋅−+

⋅⋅≥⋅ ∑

=


24/922!Internal se

2ey Para%eters2ey Para%eters


25/922"Internal se



%easure%ent report


Section + Intrafre/uency %easure%ent events


intersyste% %easure%ent eventsSection 0 ! Internal Measure%ent

I t f M t ! tI t f M t ! t


26/922'Internal se

Intrafre/uency Measure%ent !ventsIntrafre/uency Measure%ent !vents

(ll intra5fre6uency measurement report events are identified with

BC :

"A ， ( primary pilot channel enters the reportin rane& Whenthe active set of U+ is full, U+ stops reportin B( eventD

", ， ( primary pilot channel leaves the reportin raneD

"C ， The primary pilot channel in a non active set is better than

the primary pilot channel in an active setD

"D ， The best cell chanesD

"! ， The measurement value of a primary pilot channel eceeds

the absolute threshold

"3, The measurement value of a primary pilot channel is lower

than the absolute threshold


27/9224Internal se



%easure%ent report


Section + Intrafre/uency %easure%ent events


intersyste% %easure%ent eventsSection 0 ! Internal Measure%ent

Inter fre/uency Measure%ent !ventsInter fre/uency Measure%ent !vents


28/922>Internal se

Interfre/uency Measure%ent !ventsInterfre/uency Measure%ent !vents

Inter5fre6uency measurement events are identified with 2C *A4 The best fre6uency chanesD

*,4 The estimated 6uality value of the used fre6uency is lower than

a certain threshold, and that of the non5used fre6uency is hiher

than a certain thresholdD

*C4 The estimated 6uality value of the non5used fre6uency is hiher

than a certain thresholdD

*DThe estimated 6uality value of the used fre6uency is lower than a

certain threshold

*!4The estimated 6uality value of the non5used fre6uency is lower

than a certain threshold

*34The estimated 6uality value of the used fre6uency is hiher thana certain threshold

Inter syste% Measure%ent !ventsInter syste% Measure%ent !vents


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2AInternal se

Intersyste% Measure%ent !ventsIntersyste% Measure%ent !vents

Inter5system measurement events are identified with

3C +A:The estimated 6uality value of the used UT( fre6uency

is lower than a certain threshold, and that of the other system

is hiher than a certain thresholdD

+,: The estimated 6uality value of the other system is lower

than a certain threshold D +C: The estimated 6uality value of the other system is hiher

than a certain threshold D

+D: The best cell in the other system chanes


30/92

3


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3BInternal se

! Internal Measure%ent! Internal Measure%ent

U+ Internal measurement events are identified with 'C

564 The time difference between downlin. receivin anduplin. transmission of the U+ is shorter than an absolute

thresholdD

534 The time difference between downlin. receivin and

uplin. transmission of the U+ is bier than an absolute

thresholdD


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32Internal se

'uestions'uestions

How many events are there in intra5fre6uency measurement?What are they?

How many events are there in U+ internal measurement?

How many events are there in inter5fre6uency measurement?

What are they?


33/92

33Internal se

Su%%arySu%%ary

This chapter covers intra5fre6uency measurement, inter5

fre6uency measurement, inter5system measurement and U+

internal measurement from their definitions and applicationscenarios&

Su%%arySu%%ary


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3!Internal se



Chapter +Chapter + $he ,asic Handovers$he ,asic HandoversChapter - ,lind Handover and



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3"Internal se

Chapter 3 The Basic HandoversChapter 3 The Basic Handovers

Section 1 Soft Handover

Section 2 Intra-frequency Hard Hando

Section 3 Inter-frequency Hard Hando

Section 4 Inter-system Hard Handove

Section 5 HS!" Handover

Section # Compressed $ode

f f S f, i f I t d ti f S ft H d


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3'Internal se

,rief Introduction of Soft Handover ,rief Introduction of Soft Handover

1haracters of %oft Handover *urin handover, U+ has several -s with different cells5555

active set& The handover amon different cells which are in same -% can

be softer handover& %oft handover:

E %election combination in uplin.

E )aimum combination in downlin. %ofter handover E )aimum combination in uplin. and downlin.

, i f I t d ti f S ft H d, i f I t d ti f S ft H d


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34Internal se

,rief Introduction of Soft Handover ,rief Introduction of Soft Handover

(dvantaes %oft handover ain: )ulti51ell ain: )ultiple irrelated soft handover branches low the re6uired

marin for fadin )acro *iversity 1ombinin ain: ain for the lin. demodulation of the soft

handover: -oad balance: *ifferent cells receive the sinals from U+ in uplin., which can

decrease the transmission power of U+& (nd U+ receive sinal from differentcells, which also can decrease the transmission power of base station&

*ecrease the possibility of call drop caused by pin5pon handover&

*isadvantaes )ore resource needed in downlin., especially for the code resource of +

service& Usually, the ain of downlin. power is neative& When the downlin. power from different cells is not balanced, it will brin

side5effect&

Measure%ent of Soft HandoverMeasure%ent of Soft Handover


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3>Internal se

Measure%ent of Soft HandoverMeasure%ent of Soft Handover

The measurement of soft handover;softer handover

)easurement value ： 1#I1H %1# 、 1#I1H

+c;o 、 #athloss #rocess of )easurement ： -ayer B filter, -ayer 2 filter

eportin way

#eriodic reportin

+vent reportin

E +vent type ： B( 、 B 、 B1 、 B* 、 B7

E U+ measures the time difference between 17 and %7

E eportin rules: trier condition, elative threshold,

(bsolute threshold, Hysteresis, Time to trier

E +vent reportin to periodic reportin

$he !vents of Soft Handover Measure%ent$he !vents of Soft Handover Measure%ent


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3AInternal se

$he !vents of Soft Handover Measure%ent$he !vents of Soft Handover Measure%ent

%oft;softer handover measurement events

Intra5fre6uency events reportin:

"A ， ( primary pilot channel enters the reportin rane&When the active set of U+ is full, U+ stops reportin B(

eventD

", ， ( primary pilot channel leaves the reportin raneD

"C ， The primary pilot channel in a non active set is better

than the primary pilot channel in an active setD

"D ， The best cell chanesD

"! ， The measurement value of a primary pilot channel

eceeds the absolute threshold

"3, The measurement value of a primary pilot channel islower than the absolute threshold

$he Decision Algorith% of Soft Handover$he Decision Algorith% of Soft Handover


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!


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!BInternal se

$he !7ecution of Soft Handover $he !7ecution of Soft Handover

%oft handover eecution

The update principal of measurement control

1onfiure the neihbor cells and the parameters

accordin to best cell

-1 mode

() mode is used for measurement control

U) mode is used for measurement reportin

The compensation and restriction of soft handover

7rom event reportin to periodic reportin

E #arameters ： the time value for periodic

reportin, the number for reportin times

Soft Handover 3low 8add R9:Soft Handover 3low 8add R9:


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!2Internal se

Soft Handover 3low 8add R9:Soft Handover 3low 8add R9:

The eecution of soft handover /add -0

Soft Handover 3low 8del R9:Soft Handover 3low 8del R9:


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!3Internal se

Soft Handover 3low 8del R9:Soft Handover 3low 8del R9:

The eecution of soft handover /del -0



44/92

!!Internal se


elative threshold %et B(, B value separately B( 8 B ， which ma.es deletin - is more difficult, and it can

avoid pin5pon handover Usually B(: 3dD B: 'd

Time to trier +ach event can be set separately Usually, B9B( ， which ma.es deletin - is more difficult, and

it can avoid pin5pon handover Usually, B(: 32


45/92

!"Internal se

Chapter 3 The Basic HandoversChapter 3 The Basic HandoversSection 1 Soft Handover






$he Characters of Intrafre/uency Hard Handover$he Characters of Intrafre/uency Hard Handover


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!'Internal se

$he Characters of Intra fre/uency Hard Handover $he Characters of Intra fre/uency Hard Handover

1haracters U+ only has one - with one cell in the process of handover

*isconnect U+ with the oriinal cell, then hand it over to taretcell The wor.in fre6uency of source cell and taret cell are same

(dvantaes +nhance the usin efficiency of the =F%7 code and hardware

resource *isadvantaes

Hih call drop possibility because of the intra5fre6uencyinterference

(pplication scenarios

Without Iur interface between two 1s or the Iur interface Gam/only happened in inter51 handover0

The different strateies can be used for different conditions, such

as code resource condition, the $o% condition and so no&

$he Measure%ent1 Decision and !7ecution of$he Measure%ent1 Decision and !7ecution of


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!4Internal se

$he Measure%ent1 Decision and !7ecution of$he Measure%ent1 Decision and !7ecution of

Intrafre/uency Hard Handover Intrafre/uency Hard Handover

)easurement

%imilar to soft handover *ecision

B* event

+ecution

U+ reports 175%7 information

%ynchroniation hard handover

Use the oriinal *=77 value

1ontinuous 17

U+ does not report 175%7 information

The hard handover based on timin e5confiure *=77

1alculate 17 accordin to *=77

Intrafre/uency Hard Handover 3lowIntrafre/uency Hard Handover 3low


48/92

!>Internal se

Intra fre/uency Hard Handover 3low/ y

Intra5fre6uency hard handover flow

U+B&,(*I= -I? %+TU# ,+$U+%T

Taret

?=*+

%ource

?=*+%,?1

2& ,(*I= -I? %+TU# ,+%#=?%+

3&(-1(# establish

!& #H@%I1(- 1H(??+- ,+1=?7I:U,(TI=?

"& ,(*I= -I?

7(I-U,+ I?*I1(TI=?

'& #H@%I1(- 1H(??+- ,+1=?7I:U,(TI=? 1=)#-+T+

4& ,(*I= -I?

*+-+TI=? ,+$U+%T

>& ,(*I= -I?

*+-+TI=? ,+%#=?%+

A&(-1(# release



49/92

!AInternal se


Handover decision threshold based on + speed

U+ should do soft handover when the speed of + service is lessthan the threshold&

U+ should do intra5fre6uency hard handover when the speed of

+ service is reater than the threshold&

The parameters about B* event:

time to trier ， hysteresis

The parameters should be set accord with the $os


50/92

"


51/92

"BInternal se

/ y/ y


1haracters The wor.in fre6uency is different after handover The compressed mode needed if the U+ only has one receiver Usually, the timin re5initiation hard handover is used for hard

handover

(dvantaes 1ompare to intra5fre6uency hard handover, the success

possibility is hiher The load balance amon cells with different fre6uencies 1an realie the reasonable confiuration for hierarchy cells

*isadvantaes 1ompressed mode results in etra radio resource occupied

The timin re5initiation hard handover increase the time ofhandover and the ris. of call drop (pplication scenarios

*isconnected coverae Handover based on load Hierarchy cells

$he Interfre/uency Hard Handover Measure%ent$he Interfre/uency Hard Handover Measure%ent


52/92

"2Internal se

;alues and !vents;alues and !vents

The Inter5fre6uency hard handover measurement values )easurement values:

1#I1H %1# 、 1#I1H +c;< *ifferent handover purpose for different measurement type:

In the ede of carrier coverae: 1#I1H %1#

In the center of carrier coverae: 1#I1H +c;o

$he Measure%ent ;alues and !vents of Inter$he Measure%ent ;alues and !vents of Inter


53/92

"3Internal se

fre/uency Hard Handoverfre/uency Hard Handover

)easurement reportin #eriodic reportin

+vent reportin

2(: The best fre6uency chanesD

2: The estimated 6uality value of the used fre6uency is

lower than a certain threshold, and that of the non5used

fre6uency is hiher than a certain thresholdD

21: The estimated 6uality value of the non5used fre6uency is

hiher than a certain thresholdD

2*The estimated 6uality value of the used fre6uency is lower

than a certain threshold

2+:The estimated 6uality value of the non5used fre6uency islower than a certain threshold

27:The estimated 6uality value of the used fre6uency is

hiher than a certain threshold

Co%pressed Mode Initiation in Interfre/uencyCo%pressed Mode Initiation in Interfre/uency


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"!Internal se

p / yp / y


1onditions for measurement initiated

2* event ： can be used to enable the compressedmode to perform inter5fre6uency measurement& +nable inter5fre6uency measurement by movin speed

estimation alorithm 1onditions for )easurement stoppin

27 event (fter the best cell is chaned, the cell does not contain

inter5fre6uency neihbor cells& Inter5fre6uency measurement timer epired ecause the movin speed of U+ is chaned, the inter5

fre6uency handover measurement is stopped by cell

hierarchy alorithm&

Cells Hierarchy Algorith% ,ased on !Cells Hierarchy Algorith% ,ased on !


55/92

""Internal se

y g

Moving SpeedMoving Speed

When U+ is in one of the hierarchy cells, the movin speed

estimation alorithm is initiated Handover events in a while decides whether the speed of U+

satisfies the current cell hierarchy condition

U+ is remained in the current cell if the speed is medium&

If the speed is very hih, it will be handed over to hiher

hierarchy cell& (nd if not, hand it over to lower hierarchy cell& U+Js movin speed decided the result&

If the hierarchy is confiured by different fre6uencies, theinter5fre6uency blind handover or inter5fre6uencymeasurement handover can be initiated&

If the hierarchy is confiured by one fre6uency, the intra5fre6uency handover can be initiated&

Interfre/uency Hard Handover DecisionInterfre/uency Hard Handover Decision


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"'Internal se

y

Algorith%Algorith%

The inter5fre6uency hard handover decision

The coverae triers the handover

2 event ：

E the 6uality in the used fre6uency is lower than absolute

threshold, but the 6uality in another non5used fre6uency

is hiher than another absolute threshold&

The load triers handover

21 event ：

E the 6uality in another fre6uency is hiher than an

absolute threshold

$he !7ecution of Interfre/uency Hard Handover $he !7ecution of Interfre/uency Hard Handover


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"4Internal se

/ y/ y

The eecution of Inter5fre6uency hard handover U+ report the timin information

U+ with two receivers does not need compressed mode& %ynchroniation hard handover Usin the oriinal *=77 1ontinued 17

U+ does not report timin information U+ with a sinle receiver has to initiate compressed mode

If the ode of taret cell is not the same one which the cellsin active set belon to

E the timin re5initiation hard handover E e5confiure *=77 E 1alculate the 17 accordin to *=77

If the ode of taret cell is the same one which the cells inactive set belon to E 1alculate the taret cell timin relationship E %ynchroniation hard handover E Usin the oriinal *=77 E 1ontinued 17

Interfre/uency Hard Handover 3lowInterfre/uency Hard Handover 3low


58/92

">Internal se

%inalin flow

U+

B&(*I= -I %+TU# +$U+%T

Taret?=*+

%ource?=*+ %1

2& (*I= -I %+TU# +%#=%+

3&(-1(# established

!& #H@%I1(- 1H(+- +1=7IU(TI=

"& (*I= -I

7(I-U+ I*I1(TI=

'& #H@%I1(- 1H(+- +1=7IU(TI= 1=)#-+T+

4& (*I= -I

*+-+TI= +$U+%T

>& (*I= -I

*+-+TI= +%#=%+

A&(-1(# released

2ey Para%eters 8I:2ey Para%eters 8I:


59/92

"AInternal se


Inter5fre6uency coverae handover parameters:

Inter5fre6uency measurement reportin: periodic reportin or

event reportin Inter5fre6uency measurement values: 1#I1H +c;o or 1#I1H

%1#

Inter5fre6uency measurement layer 3 filter coefficient, delay

trier time and hysteresis

Inter5fre6uency initiated and stopped threshold: 1onsiderin thedifferent demands of 1#I1H +c;o and 1#I1H %1# for #%

domain and 1% domain, the different 2* and 27 parameters are

confiured&

Inter5fre6uency handover based on coverae: the 6uality

threshold of taret cell Usin fre6uency 6uality threshold in inter5fre6uency hard

handover

The minimum access threshold for inter5fre6uency handover

2ey Para%eters 8II:2ey Para%eters 8II:


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'


61/92

'BInternal se







$he ,rief Introduction of Intersyste% Hard$he ,rief Introduction of Intersyste% Hard


62/92

'2Internal se

Handover Handover

(pplication scenarios W1*)( 7** 8 ! 9%) W1*)( 7** 8 ! 9W1*)( T** W1*)( 7** 8 ! 91*)(2


63/92

'3Internal se

Co%pressed Mode InitiatedCo%pressed Mode Initiated

The inter5system measurement /%) measurement0

)easurement type: %) 1arrier %%I

%I1 Identification

%I1 econfirmation

The process of measurement: layer B filter, layer 3 filter

)easurement reportin

+vent reportin

E 2* +vent: initiate %) measurement

E 27 +vent: stop %) measurement

$he Intersyste% Hard Handover$he Intersyste% Hard Handover


64/92

'!Internal se

Decision Algorith%Decision Algorith%

The inter5system hard handover decision

Inter5system handover caused by coverae +vent reportin:

E 3( event ： The estimated 6uality value of the used

UT( fre6uency is lower than a certain threshold, and

that of the other system is hiher than a certain

threshold & #eriodic reportin:

E +valuation ： (ccordin to the periodic reported %)

%%I measurement value and the %I1 confirmin state

of taret cell of %) system, and meanwhile the U+

evaluates the %) %%I of taret cell is reater than theabsolute threshold, then consider the cell confirmed by

%I1&

$he Intersyste% Hard Handover$he Intersyste% Hard Handover

D i i Al i h


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'"Internal se

Decision Algorith%Decision Algorith%

The inter5system hard handover decision

Inter5system handover caused by non5coverae +vent reportin

E 31 event: The estimated 6uality value of the other system

is hiher than a absolute threshold&

Intersyste% Handover 3lowIntersyste% Handover 3low


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''Internal se

The eecution of inter5system handover

1" #elocation#e$uire% 2" &repare

'an%over3" 'an%over

#e$uest

(" 'an%over#e$uest Ac

12" *u #eleaseComman%

13" *u #eleaseComplete 1(" +en% En%

+ignal #esponse

" &repare'an%over-" #elocation

Comman%." DCCH 'an%over

from 0#A Comman%" 'an%over

Detect

4" 'an%over Complete

1!" 'an%overComplete

11" +en%En%

0E o%e B +#C C MSC B+C



67/92

'4Internal se

y 8 :y 8 :

Inter5system handover caused by coverae parameters Inter5system measurement initiated and stopped threshold:

1onsiderin the different demands of 1#I1H +c;o and 1#I1H%1# for #% domain and 1% domain, the different 2* and 27parameters are confiured

Inter5system measurement values /2*, 270

1#I1H +c;o

1#I1H %1# %I1 confirmed /=ptional0 Inter5system handover caused by coverae parameters

confiure the %) %%I threshold of 1% domain and #%domain separately

Usin inter5system fre6uency 6uality handover threshold 1onfiure the delay trier time, hysteresis for each event

2ey para%eters 8II:2ey para%eters 8II:


68/92

'>Internal se

y p 8 :y p 8 :

Inter5system handover caused by non5coverae parameters The period of inter5system measurement report

The decision threshold for inter5system handover: confiure the1%, #%, sinalin separately

Time delay trier : confiure %I1 with ac.nowleded andunac.nowleded mode

Inter5fre6uency measurement layer 3 filter coefficient and

hysteresis #enalty time


69/92

'AInternal se




Section 4 Inter-system Hard Handover



$he ,rief Introduction HSDPA Handover $he ,rief Introduction HSDPA Handover


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4


71/92

4BInternal se

H%*#( handover measurement

)easurement type: 1#I1H %1# 、 1#I1H

+c;< 、 #ath loss

The process of measurement: layer B filter coefficient and

layer 3 filter coefficient

)easurement reportin

#eriodic reportin

+vent reportin

E eportin type: B(, B, B1, B*

E The event reportin converted to periodic

reportin

Service Cell Change Algorith%Service Cell Change Algorith%


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42Internal se

1hane the service cell for H%5#*%1H in active set

(ccordin to B* event to decide the best cell, and hand it over

to the cell&

(fter handover, initiate the timer to forbid the pin5pon

handover

1hane the service cell for H%5#*%1H after hard handover

+stablish the H%*#( channel in taret cell with hard handover +stablish *1H channel if the taret cell can not support H%*#(

1hane the service cell for H%5#*%1H durin soft handover

The service should be handed over to the cell which support

H%*#( when the best cell does not support H%*#( and the

oriinal service cell for H%*#( already deleted from active set&

Direct Retry for HSDPADirect Retry for HSDPA


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43Internal se

*irect retry from AA cell to " cell 1onditions

U+ in cell B re6uests to establish an +;streamin (, or U+ of 1ell57(1H state has much +;streamin data

volume to transfer /%witch channel type from 7(1H to H%5*%1H0

+istin cells: support H%*#(, with same coverae area

(dvantae: To ma.e full use of H%*#( resource

*irect retry

H%*#(

resource

"1+-- (1arrier

AA1+--2 AA 1+-- B1arrier (

Service Cell pdate 3lowService Cell pdate 3low


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4!Internal se



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4"Internal se

HSDPA handover protecting ti%er

1onfiure the T5H%*#( to avoid the influence for the dataservice caused by the pin5pon handover& *urin this period,

the service cell for H%*#( can not be chaned&

The value scope /


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4'Internal se

Chapter 3 The Basic HandoversChapter 3 The Basic Handovers

Section 1 Soft Handover



Section 4 Inter-system Hard Handover



$he Purpose of Co%pressed %ode$he Purpose of Co%pressed %ode


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44Internal se

#urpose ：

)easure the inter5fre6uency cell or inter5system cell under7** mode

1ause:

*ownlin. compressed:

%ince one receiver only can wor. in one fre6uency, the

U+ has to stop wor.in if it is oin to measure the sinalfrom another fre6uency cell& To ensure the downlin.

service unaffected, the remained data should be sent in

the limited time&

Uplin. compressed

U+ should stop the uplin. transmission when the uplin.wor.in fre6uency is very close to the measured

fre6uency, for eample %) B>


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1ompressed mode s.etch map

5ne frame

1! ms) ransmission gap availa6le for

inter7fre$uency measurements

$he reali=ation Methods of Co%pressed %ode$he reali=ation Methods of Co%pressed %ode


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ealiation )ethods %7;2

%hould use the replace scramblin code

(dvantae: easy to handle for 1 *isadvantae: occupied the resource of ode, decrease the

utiliin efficiency of =F%7, influenced the coverae andincreased interference caused by the replace scramblin code&

rate matchin;puncturin

*ecrease the codin redundancy (dvantae: easy to handle for 1D the %7 ! can be usedD no

influence to utiliin efficiency of =F%7

*isadvantae: limited to the property of channel codinDdecreased the codin ain

hiher layer schedulin )(1 can restrict T71% to chane the downlin. data rate&

(dvantae: the interference is lower

*isadvantae: complicated for hiher layer, only fit for non5timin data service&

'uestions'uestions


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>


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>BInternal se

This chapter focus on the basic handovers in W1*)(: soft handover,

softer handover, intra5fre6uency hard handover, inter5fre6uency hardhandover and inter5system hard handover& It also introduced the

application scenarios for these different handovers

)eanwhile, compressed mode is introduced in this chapter


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>2Internal se



Chapter + $he ,asic Handovers

Chapter -Chapter - ,lind Handover and,lind Handover and

Direct Retry Algorith%Direct Retr y Algorith%

Application scenarios and $rigger ConditionsApplication scenarios and $rigger Conditions


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>3Internal se

1 direct retry *urin the initial sinalin establishment, the 1 connection is

refused& 1 redirection

The initial sinalin is already established, but the re6uested cellrefused and 1 direct retry is failed&

( direct retry The sinalin is established successfully, but the service

establishment is failed& lind handover

-oad balanced between inter5fre6uency cells 1 direct retry ( direct retry

RRC Direct Retry 8I:RRC Direct Retry 8I:


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>!Internal se

(pplication scenarios /I0

%ame sector covered by different fre6uencies

cellB

cell2

B 2

3

The U+ initial campin

cell

%inalin process:" RRC C(>>!C$I(> R!'!S$* RRC C(>>!C$I(> S!$P

+ RRC C(>>!$I(> S!$P C(MP9!$!

RRC Direct Retry 8II:RRC Direct Retry 8II:


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>"Internal se

(pplication scenarios /II0

The soft handover area

cellB cell2

B

2

3

UE camping

cell1 first

Soft handover

area

Signaling Process4" RRC C(>>!C$I(> R!'!S$* RRC C(>>!C$I(> S!$P+ RRC C(>>!$I(> S!$P C(MP9!$!

RRC Retry 2ey Para%etersRRC Retry 2ey Para%eters


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>'Internal se

*)aumber The maimum allowed retry times for the direct retry module

after the initial failure 1sThreshold&

When the sinal 6uality of a cell is hiher than this threshold,this cell will be included in the direct retry candidate set&

)in%inale6uired

The basic access threshold described in %ection 2&2&>,namely the minimum re6uirement of the U+ form the receivin1#I1H +c;o density durin normal demodulation&

)aelatinTime The maimum time that the (1H measurement report can

continue to be used for the direct retry candidate set&

RRC RedirectionRRC Redirection


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>4Internal se


The sinalin connection is failed, and 1 retry is also failed&

Inter5fre6 cell

cellB

B

2

BJ

! ca%ping cell"

first

%) cell

BJJSignaling process4

" RRC C(>>!C$I(> R!'!S$* RRC C(>>!C$I(> R!?!C$"@ ! initial the access processafter cell r e.selection"@@ ! initial the access processin 6SM cell after inter.syste%

cell r eselection

RRC Direct Retry and DirectionRRC Direct Retry and Direction


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>>Internal se

The trier condition should be the sinalin permittin failure

if conestion happed, the 1 connection sinalin is refused& (dvantaes and disadvantaes:

1 direct retry can ensure the time delay& 1 direction is more fleible, and can select to %) cell& ut

the time delay is loner&

RA, Direct RetryRA, Direct Retry


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>AInternal se


UT( 1+--

%) 1+--

B 3

!

Signaling process ：

" RA, Assign%ent 8fro% C>:* SR>S relocation 8to C>:

+ Handover fro% $RA> 8 Infor% !

access to 6SM syste%:

- Handover Co%plete 86SM %essage:

2

1

'uestions'uestions


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A


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This chapter focus on 1 direct retry, 1 redirection, the

application scenarios of ( direct retry and blind handover&


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09-wcdma handover principal

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