reselect.doc

8/11/2019 reselect.doc

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ETISALAT GSM PLANNING Reselection Parameters Optimisation

RESELECTION PARAMETER OPTIMISATION

I /. C2 PARAMETER FOR PHASE 2 MOBILE STATIONS

Alcatel Telecom File Reference Date Version Page

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TA%LE O& CONTENTS

!/ RESELECTION PARAMETERS DE&INITION$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $$$$$$$$$ $$#

1.1/ C1 Parameter...........................................................................................................................................................4

1./ C Parameter...........................................................................................................................................................4

1.!/ C"##$R"%"#"CT$&'%T.....................................................................................................................................4

'/ DUAL LA(ER NET)OR* + TRA&&IC SHARING OPTIMISATION$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$,

.1/ Traffic distribution ( first traces anal)sis.................................................................................................................*

./ +m,act on t-e -andovers.........................................................................................................................................

-/ DE&AULT PARAMETERS . ALIDATION$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

!.1/ Default ,arameters..................................................................................................................................................

!./ Field tests.................................................................................................................................................................

#/ TRIAL DESCRIPTION AND PLANNING$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $$$$$$$9

,/ &IELD TRIAL &ORM$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$!,


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The aim of this document is to describe the Reselection parameters (C1 and C2) and to propose some default

parameters based on preliminary tests performed on Etisalat network. Then to propose a test plan for first C2

parameters then C1 parameters optimisation.

The main idea of tuning the reselection parameter is either for indoor sites or for the optimisation of the traffic

sharing between the micro and macro layers. n areas where the macro layer is !ery dense" the #$ will recei!e

a higher le!el from the macro layer (transmission power of the %T$ & ' d%m) than from the micro layer

(transmission power & d%m) and then reselect on the macro before handing o!er to the micro if the hando!er

criteria are met.


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1/ RESELECTION PARAMETERS DEFINITION

1.1/ C1 Parameter

C1 criterion is coming from the initial phase of $# (before microcellular). t ensures that" if a call was

attempted" it would be done with a sufficient downlink and uplink recei!ed le!el. t is based on 2

parameters" broadcasted on %CC*+

R,-E/0CCE$$/# d%m3 (minimum le!el to access to the cell)

#$/T,45R/#0,/CC* d%m3 (ma6imum #$ transmission le!el on CC* in idle mode).

C1 definition is+

C1 = (RxLev - RLE!"ACCESS"MIN # $ MA ( %& (MS"TP'R"MA"CCH - MS"TP'R"MA## %

1.2/ C2 Parameter

n 4hase 2 Reselection criterion C2 is an impro!ement" mainly for dual layer networks. t allows a better

distribution of the mobiles between the 2 layers in idle mode.

4rinciple is to discriminate mo!ing mobiles from static ones which should better be located in microcell.

C2 criterion definition is so double+

C2 = C1 ) CELL"RESELECT"OFFSET - TEMPORAR*"OFFSET + H ( PENALT*"TIME $ T #

if T 7 4E0-T8/T#E" * (PENALT*"TIME $ T # = %. This is used to a!oid to locate on

9transient cell: (fast mo!ing mobile)

CE--/RE$E-ECT/;ones.


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2/ DAL LA*ER NET'OR TRAFFIC SHARIN0 OPTIMISATION

0 good micro layer is a micro layer which grabs as much traffic as possible. Congestion aspects

are no longer taken into consideration as directed retry allows the $?CC* to TC* hando!er frommicro to umbrella layer.

2.1/ Tra3 45tr67t89 r5t tra3e5 a9a:;55

The following graph presents the distribution of the difference in recei!ed le!el from the two layers

(only samples when a micro is ser!ing or is the first neighbour ha!e been selected). The data ha!e

been collected by dri!e testing on Corniche Road" Electra Road" *amdan Road and in E1@ and

E1A blocks. The samples ha!e been gathered in dedicated mode as base station power control is

not acti!ated. Thus the number of samples is much higher than what dri!e testing can pro!ide in

idle mode.

Recei!ed le!el from macro layer B Recei!ed le!el from micro layer

The result is that when a micro is ser!ing or is the first neighbour" there is an umbrella stronger than the

micro 9 e 3a5e. f a umbrella is stronger this means that in idle mode the umbrella will be

reselected and the call will be initiated on the umbrella layer rather than on the micro one.

Then if the hando!er criteria are met (cause 1' + #acro to #icro)" we ha!e loaded the umbrella and

perform an hando!er which could ha!e been both a!oided by an optimised reselection procedure.


Mobile Communication Division Reselection.doc RNE/AMCD/AUH/9/!"! !#/!"/9 !$" ,

%.%=

1%.%=

2%.%=

,%.%=

?%.%=

@%.%=

A%.%=


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2.2/ Ima3t 89 t>e >a948ver5

0ccording to the #acro to #icro and #icro to #acro hando!ers" the reselection procedure will change

the hando!er profil between the two layers" which will lead to a decrease of the load of the umbrella and

then optimise the traffic sharing between the two layers.

The following table presents the impact of the reselection on the differents scenari of the recei!ed le!el

from both layer and the setting of the hando!ers thresholds.

Recei!ed le!el from the #acro layer

Recei!ed le!el from the #icro layer

$er!ing area after #icro to #acro *; (cause 1D 1F)

$er!ing area after #acro to #icro *; (cause 1')

?elta (#acro R,-E B #icro R,-E) & CE--/RE$E-ECT/; C2 3rtera

0 the micro layer is selected

0 call is initiated on the micro layer

0 no hando!er

Conclusion :

By using C2 criteria, the load of the umbrella has

been reduced, the number of HO has been

reduced.

't>87t C2 3rtera

0 the macro layer is selected0 call is initiated on the macro layer


Mobile Communication Division Reselection.doc RNE/AMCD/AUH/9/!"! !#/!"/9 !$" 0

Cause 1'

#acro to #icro *;

-/R,-E/#C*; (cell)

#icro should ser!e #acro should ser!e

Cause 1D" 1F

#icro to #acro *;

,/R,-E/#C*;

#acro to #icro

*;

#icro to #acro

*;


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Cell Reselection ;ffset

0 no hando!er

't> C2 3rtera



0 no hando!er

Conclusion :

In this case the call can be handled by the micro

layer as the received level is lower than the macro

to micro handover.

By using C2 criteria, the load of the umbrella has

been reduced.

Cell Reselection ;ffset

't>87t C2 3rtera

0 the macro layer is selected

0 call is initiated on the macro layer

0 no hando!er't> C2 3rtera



0 micro to macro hando!er after

0/-E/#C*;

Conclusion :

By using C1 criteria the call is iniated on the macro

and no handover is performed. By using the C2

criteria a micro to macro handover is performed.

But by setting the C!!"#$!C%"O&&$% at

a confortable value, the beginning of the call on the

micro layer will be handled in good conditions

before the handover and no degradation will be

seen by the end user.




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,/ DEFALT PARAMETERS !ALIDATION

,.1/ Dea7:t arameter5

0ccording to the distribution of the difference between the recei!ed le!el of both layers pro!ided by dri!e

tests" the following !alue should be set up as default before optimisation.

n order not to fa!our the reselection on the micro layer for fast mo!ing mobiles" the penalty time should

be set to '@s (;#C !alue G1) and CE--/RE$E-ECT/;


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?/ TRIAL DESCRIPTION AND PLANNIN0

The different steps that the trial should follow are the following +




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@/ FIELD TRIAL FORM

n order to follow the e!olution" the following forms should be filled in order to assess the impro!ement

and to follow the tests.


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