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High Speed Downlink Cell FACH

Date:

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Contents

RRC States

Channel Mapping

Diferent Tasks Through RRC States.

How the eature works.

Benets o the Feature.

!ara"eters asso#iated with the eature.

Counters asso#iated with the eature.

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RRC States

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RRC States $Continued%

CELL_DCH:

&. Chara#teri'ed () the allo#ation o DCH or *+DCH and () the allo#ation o

HS+DSCH to the ,*.

-. The DCCHs are used or #ontrol signaling and DTCHs are used or user data

trans"ission..

CELL FACH:

&. ,sed or s"all data trans"ission. -. n transport la)er /RACH is "apped or ,0 and FACH is "apped or D0.

1. n logi#al la)er/ ollowing #hannels are used:

a)DCCH: Sending dedi#ated #ontrol "essage to a ,*.

b) CTCH: Co""on user data in transparent and una#knowledged "ode.

c) DTCH: Data Trans"ission.

2. A "a3i"u" o 1- k(ps is a4aila(le on FACH in D0 or user data

trans"ission.

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RRC States $Continued%

CELL_PCH:

&. the trans"ission pause is long enough/ ,* "o4es into C*005!CH or

,RA5!CH state.

-. ,* has at least one !D! #onte3t a#ti4e/ (ut does not an) ph)si#al #hannel

resour#es a4aila(le.

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Channel Mapping

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Diferent Tasks Through RRC states $Continued%

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Diferent Tasks Through RRC states $Continued%

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!ro(le"s Asso#iated with FACH State

n Release 6 7 8/ introdu#tion o HSD!A and *,0 sol4es the pro(le" o high

data rate.

This #hange applies to C*005DCH state onl) .

But other states $C*005FACH/ C*005!CH9,RA5!CH% stills operates in R "ode.

That results:

&%0ow data transer rates.

-%High laten#).

1%n e;#ient #ode usage.

2% A(sen#e o ast power #ontrol.

To o4er#o"e the pro(le"s asso#iated with other states in RRC/ .

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How the Feature ?orks

n nor"al #ase/ in C*005FACH state/. Following #hannels ha4e (een used :

?ith the introdu#tion o High Speed D0 Cell FACH/ High speed shared #hannel

will (e used instead o FACH.

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How the Feature ?orks $Continued%

This is dependent on the a#ti4ation o ollowing eatures:

a% HSD!A ntrodu#tion.

(% *nhan#ed 0a)er -.

This eature is dependant on ,* #apa(ilit). $,* Categor) &+2 and && do not

support this%.

Ater ena(ling High Speed D0 Cell FAC@H/ additional S)ste" nor"ation $S% is

trans"itted in SB 6.

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C*005DCH and C*005FACH use dedi#ated HSD!A Radio etwork Te"porar)

dentit) $H+RT% in this eature. The) will share H+RTs ro" a pool o -62H5RTs.

ne H5RT is reser4ed or BCCH trans"ission whereas another is #o""on

H5RT.

How the Feature ?orks $Continued%

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How the Feature ?orks $Continued%

For HS/ HS+D!CCH is the #hannel to report AC9AC9DT and CE $Channel

Eualit) ndi#ator%/ (ut or C*005FACH there is no su#h #hannel.

A(sen#e o HS+D!CCH o(stru#ts AMC $Adapti4e Modulation and Coding%

s#he"e in C*005FACH state.

But with this eature.AMC is done in C*005FACH state/ (ut in a slow rate.

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How the Feature ?orks $Continued%

High Speed D0 Cell FACH ensures sea"less trans"ission in C*005!CH state

and redu#es laten#). n pre release+> state/ where #ell update and #onr" is

reuired in transition.

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How the Feature ?orks $Continued% But with *nhan#ed C*00 FACH/ when data trans"ission resu"es/ ,TRA #an

dire#tl) send the data on HS+DSCH in Cell5!CH.

As soon as the ,* dete#ts the data on HS+SCCH9HS+!DSCH with the dedi#ated

H+RT the ,* will "o4e ro" Cell5!CH to Cell5FACH state and sea"lessl)

#ontinues with the data trans"ission.

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How the Feature ?orks $Continued%

n *nhan#ed Cell FACH/G BCCH/!CCH and CCCH is "apped into HS+DSCH. As a

result/ s)ste" inor"ation #an (e #on4e)ed through it or spe#i# H+RTs.

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Benets o the Feature

"pro4ed operator #apa#it) as users sta) in C*005FACH state when using

appli#ations with low to "ediu" data reuire"ents/ or e3a"ple/ so#ial "ediaappli#ations.

D0 (andwidth higher than the #urrent 1- k(ps or ,*s in C*005FACH state

$"ore than & ti"es in#rease o (andwidth is e3pe#ted%.

Slightl) aster up swit#h ro" C*005FACH state to C*005DCH state and ro"

,RA5!CH state to C*005DCH state () appro3i"atel) 6 "s in (oth #ases.

0ower laten#) in C*005FACH state/ whi#h redu#es the Round Trip Ti"e $RTT% ()

at least 2 "s or s"all ping.

*na(ler or the Batter) *;#ien#) or High Speed FACH eature/ whi#h ena(les

,*s in C*005FACH state to sa4e (atter) power () not ha4ing to de#ode the HS+

SCCH #hannel #ontinuousl).

*na(ler or the *nhan#ed ,plink or FACH eature/ whi#h uses the *+DCH

transport #hannel or the ,0 when the ,* is in dle Mode/ ,RA5!CH and

C*005FACH states.

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!ara"eters Asso#iated with the Feature RBS 0e4el !ara"eter

Parameter Name Description

licenseStateHsFach (read only)Indicates the license state for the licensed feature High SpeedDownlink for FACH.

featureStateHsFachDefines the feature state for the licensed feature High SpeedDownlink for FACH.

extraCompHsFachDefines the additional compensation applied to the converted CQIvalue used for TFC selection when data for the HS!FACH user istransmitted.

extraHsScchCompHsFachDefines the additional power compensation applied to the HS!SCCH power calculated with the converted CQI value when datafor the HS!FACH user is transmitted.

extraCompForSigHsFachDefines the additional compensation applied to the converted CQIvalue used for TFC selection when the signaling data for DCCHand CCCH for the HS!FACH user is transmitted.

extraHsScchCompForSigHsFach

Defines the additional power compensation applied to the HS!SCCH power calculated with the converted CQI value when thesignaling data for DCCH and CCCH for the HS!FACH user istransmitted.

throughputPqxHsFachDefines the throughput "andwidth set for the common priorit#$ueues for user data traffic% defined for each S&I 'the first value inthe se$uence is for S&I ( and the last one is for S&I )*+.

defaultCqiHsFachSets the CQI value used for the transmission of the ,CCH specificH!-TI.

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!ara"eters Asso#iated with Feature $Continued%

RC 0e4el !ara"eter

Parameter Name Description

hsFachEnaled na"les or disa"les the HS!FACH feature on -C level.

hsFachSupport (read only) Indicates whether or not the cell supports HS!FACH.

hsFach!os"e#el Sets the QoS!level used "# HS!FACH for this C//0DCH S&I value.

hsFach!ueueSpiDefines the S&I!values used for the common $ueues used for userdata traffic.

dl$lc%uf&ps'itchHsFach

Defines the downlink /C "uffer threshold for triggering an upswitchfrom C//0FACH to C//0DCH% for 1s that have support for HS!

FACH when the# are in a cell where Hsdsch2 2hsFachSupport34-.5hen the /C "uffer load in the downlink e6ceeds this threshold% anupswitch re$uest is issued.

racheasComp"imitHsFachDefines the total amount of compensation for the ACH 7easurementesult during the C//0FACH state% for HS!FACH.

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Counters Related with the Feature

Counters

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Ro(i etwork Condition

2&I-&2&I--

2&I-12&I-2

2&I-62&I-8

2&I->2&I-I

2&I-:2&I1H

2&I1&2&I1-

2&I112&I12

2&I162&I18

2&I1>2&I1I

2&I1:2&I2H

2&I2&2&I2-

2&I21

H.6HHJ

H.66HJ

H.8HHJ

H.86HJ

H.>HHJ

H.>6HJ

H.IHHJ

Ratio of DL FACH Volume/ Total DL Trac

Date

Percentage

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Tan! "ou