wcdma rrc states

8/17/2019 Wcdma Rrc States

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WCDMA RRC

This page covers WCDMA RRC state diagram for UE compliant to UMTS standard. It covers RR

states idle and connected.

Procedures in the UE

Procedures in Idle Mode

When UE is powered on it will e in idle mode. In this mode! UE will perform location registration

In the idle mode! UE will receive and monitor s"stem information and paging messages from the

UTRA# networ$. It does this even after camped on to the UTRA# networ$.

UTRAN Selection and Reselection

In this s"stem!non access strat%mAS' will select a s%itale UTRA# cell. Us%all" UE operates o

its (ome UTRA#. When UE goes o%t of (ome UTRA# coverage! visited UTRA# cell will e

selected.

Cell Selection and Reselection

The UE shall select the most s%itale cell ased on idle mode meas%rements and cell selection

criteria. The #AS will control the cell selection ased on list of foridden registration areas and a

list of #AS defined service areas ased on priorit" set. Even after camped on ! UE will perform


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meas%rements and alwa"s search for etter cell. )nce fo%nd it will connect with the est UTRA#

cell. This is done ased on cell selection criteria.

CONNECTED MODE

*or UE initiated calls! the higher la"ers of the UE send a re+%est to RRC la"er to estalish a

signaling connection estalishment. Upon receiving this! the RRC of the UE initiates a connectio

estalishment proced%re with the peer RRC of the UTRA# " sending an RRC connection re+%e

message thro%gh the MAC. The UE enters connected mode once the RRC connection is

estalished.

D%ring this connection estalishment proced%re! the WCDMA RRC config%res the la"ers ,a"er-

and ,a"er-/ %sing the parameters received from the UTRA# networ$. )nce the config%ration is

complete the RRC of the UE initiate the R,C signaling lin$. )nce the RRC connection

estalishment is s%ccessf%l! the signaling connection estalishment will e res%med. )nce the

signaling connection is estalished there will e higher la"er peer-to-peer signaling data

transfer.The UE enters connected mode once the WCDMA RRC connection is estalished. With

the connected mode the level of UE connection to UTRA# will e determined " the 0oS

re+%irements of the active radio accessearers and the characteristics of the traffic on those

earers.


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Procedures in Connected Mode

1 Radio Access 2earer Estalishment

1 Radio Access 2earer Release

1 Radio Access 2earer and Signaling ,in$ Config%ration

1 Transport Channel Reconfig%ration

1 Transport *ormat Comination Control

1 3h"sical Channel Reconfig%ration

1 Data Transmission

In connected mode! WCDMA UE will have cell4DC(! cell4*AC(! cell43C( and URA43C( RRC

states.

CELL_DCH state

WCDMA UE will e in the CE,,4DC( state when UE is assigned a D3C(&dedicated ph"sical

channel' either in response to RRC Connection Re+%est or thro%gh RRC controlled 2earer Re-

config proced%re. UE can e identified in this mode " three parameters vi5. fre+%enc"!scramlin

code and channeli5ation code. When UE release the RRC connection it will move to ID,E mode

CELL_ACH state

UE moves to CE,,4*AC( state when it has een assigned common channel " the UTRA#

networ$. This happens as part of RRC connection estalishment proced%re and assigned " R#

or thro%gh R2 reconfig. proced%re.

CELL_PCH state

While UE is in CE,,4*AC( or CE,,4DC( state and flow of traffic is stopped! it will move to

CE,,43C( state. (ere UE will not have an" %plin$ channel and UE monitors paging channel%sing the DR6 parameters. The p%rpose of this state is to save the power and enhance the atte

%sage for long time.


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URA_PCH state

URA is asicall" collection of cells and it is similar to 7SM ,A. This state is similar to CE,,43C(

state %t here location of the UE is $nown at URA level. This state is %sed " fast moving UEs

needing DR6 to save the atter" power.

WCDMA compliant UE will p%lish the gaps d%ring the compressed mode for meas%rement

p%rpose. This is %sed " other RATs s%ch as 7SM and ,TE to perform cell meas%rements. This

helps in cell reselection as well as handover. *ollowing are the s%mmar" of f%nctions performed

WCDMA8UMTS RRC la"er.

Su!!ar" o# UMTS RRC #unctions

1 Reception of roadcast information provided " the non-access strat%m &Core #etwor$'

1 Reception of roadcast information related to the access strat%m

1 Estalishment! maintenance and release of an RRC connection etween the UE and UTRA#

1 Estalishment! reconfig%ration and release of Radio-Access 2earers

1 Assignment! reconfig%ration and release of radio reso%rces for the RRC connection

1 RRC connection moilit" f%nctions

1 3aging8notification

1 Ro%ting of higher la"er 3DUs1 Control of re+%ested 0oS

1 Reporting and control of UE meas%rements

1 )%ter loop power control

1 Control of ciphering

wcdma rrc states

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