03 ura update
TRANSCRIPT
RAN Feature Description Table of Contents
Table of Contents
Chapter 3 URA Update................................................................................................................3-1
3.1 Introduction...................................................................................................................... 3-1
3.1.1 Definition...............................................................................................................3-1
3.1.2 Purposes...............................................................................................................3-1
3.1.3 Terms and Abbreviations.......................................................................................3-1
3.2 Availability........................................................................................................................ 3-2
3.2.1 Network Elements Involved...................................................................................3-2
3.2.2 Software Releases................................................................................................3-3
3.2.3 Miscellaneous........................................................................................................3-3
3.3 Impact.............................................................................................................................. 3-3
3.3.1 On System Performance.......................................................................................3-3
3.3.2 On Other Features.................................................................................................3-3
3.4 Technical Description.......................................................................................................3-3
3.4.1 URA Update Configuration Model.........................................................................3-3
3.4.2 Basic Types...........................................................................................................3-4
3.4.3 Basic Signaling Procedure of URA Update...........................................................3-8
3.4.4 Signaling Procedure of URA Update with SRNS Relocation.................................3-8
3.5 Capabilities....................................................................................................................3-10
3.6 Implementation..............................................................................................................3-10
3.6.1 Enabling URA update..........................................................................................3-10
3.6.2 Reconfiguring Parameters...................................................................................3-10
3.6.3 Disabling URA update.........................................................................................3-11
3.7 Maintenance Information................................................................................................3-11
3.7.1 Alarms.................................................................................................................3-11
3.7.2 Counters..............................................................................................................3-12
3.8 References..................................................................................................................... 3-12
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RAN Feature Description List of Figures
List of Figures
Figure 3-1 URA Update Configuration Model........................................................................3-4
Figure 3-2 Basic signaling procedure for URA update..........................................................3-8
Figure 3-3 Signaling procedure for URA update with SRNS relocation.................................3-9
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RAN Feature Description List of Tables
List of Tables
Table 3-1 NEs required for URA update................................................................................3-2
Table 3-2 RAN products and related versions.......................................................................3-3
Table 3-3 Commands for the reconfiguration on the RNC side...........................................3-10
Table 3-4 URA update counters..........................................................................................3-12
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RAN Feature Description Chapter 3 URA Update
Chapter 3 URA Update
3.1 Introduction
3.1.1 Definition
The User Registration Area (URA) update is of two types:
Periodical URA update
The UE in URA_PCH state periodically performs URA update. Thus, the UTRAN
can know the position and state of the UE.
URA update triggered by URA reselection
When the UE in URA_PCH state reselects another URA, it performs URA
update with the cause "change of URA". Thus the UTRAN can know which URA
the UE is located in.
URA update procedure is initiated by the UE.
3.1.2 Purposes
URA update enables UTRAN to manage behaviors of the UE, the main benefits of
URA update are as follows:
Periodical URA update can be used as a supervision mechanism when UE in
URA_PCH state.
If the UE is in URA_PCH state, only when it moves between cells in different
URAs, will it lead to URA update triggered by URA reselection. And the UE can
retrieve a new URA identity after reselecting a cell that does not belong to the
currently assigned URA.
3.1.3 Terms and Abbreviations
I. Terms
Term Description
CELL_DCH
An RRC connected mode in which DCCH and, if configured, DTCH
are available. DCCH and DTCH are mapped to DCH. The RNC
records the cells in the active set of the UE.
CELL_FACHAn RRC connected mode in which DCCH and, if configured, DTCH
are available. DCCH and DTCH are mapped to RACH/FACH.
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RAN Feature Description Chapter 3 URA Update
Term Description
CELL_PCHAn RRC connected mode where neither DCCH nor DTCH is
available.
URA_PCHAn RRC connected mode where neither DCCH nor DTCH is
available.
II. Abbreviations
Abbreviation Full Spelling
DCCH Dedicated Control Channel
DCH Dedicated Channel
DTCH Dedicated Traffic Channel
FACH Forward Access Channel
MD Mandatory default
RACH Random Access Channel
RRC Radio Resource Control
RB Radio Bearer
SIB System Information Block
URA User Registration Area
3.2 Availability
3.2.1 Network Elements Involved
Table 3-1 describes the NEs involved with URA update.
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RAN Feature Description Chapter 3 URA Update
Table 3-1 NEs required for URA update
UE NodeB RNCMSC
Server
MG
WSGSN GGSN HLR
√ √ √ - - - - -
Note:
–: not required
√: required
Note:
This chapter describes only the availability of the NodeB and the RNC.
3.2.2 Software Releases
Table 3-2 describes the versions of RAN products that support URA update.
Table 3-2 RAN products and related versions
Product Version
RNC BSC6800 V100R002 and later releases
NodeB
DBS3800 V100R005 and later releases
BTS3812A V100R005 and later releases
BTS3812E V100R005 and later releases
3.2.3 Miscellaneous
None
3.3 Impact
3.3.1 On System Performance
None.
3.3.2 On Other Features
None.
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RAN Feature Description Chapter 3 URA Update
3.4 Technical Description
3.4.1 URA Update Configuration Model
The configuration model for URA update is as show in Figure 3-2.
RNC
RadioClass
GlobalParaClass CellClass
CELLURA.ClassCONNMODETIMER.Class
Timer 305
Timer 302
Constant 302
Timer 307
URA ID
Figure 3-2 URA Update Configuration Model
3.4.2 Basic Types
According to update causes, URA update can be divided into two types:
Periodic URA update
URA update triggered by URA reselection
I. Periodical URA Update
After entering URA _PCH state, the UE starts the timer T305. Upon the expiry of
timer T305, the UE initiates URA update with the cause “periodical URA update”.
Accordingly, the RNC starts another timer for the UE in URA_PCH state. The value of
this timer should be greater than that of timer T305. When receiving a URA UPDATE
message with the cause “periodical URA update”, the RNC restarts the timer T305 of
this UE.
If the UTRAN does not receive the URA UPDATE message upon expiry of the timer, it
regards that the UE is out of the network, and triggers RRC to release the network
side resource.
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RAN Feature Description Chapter 3 URA Update
Parameter Name Timer 305
Parameter ID T305
GUI Range INFINITY, D5, D10, D30, D60, D120, D360,
D720
Physical Range& Unit Infinity, 5, 10, 30, 60, 120, 360, 720 (min)
Default Value D10
Optional/Mandatory Optional
MML Command SET CONNMODETIMER
Description:
T305 is started after the UE receives CELL UPDATE CONFIRM or URA UPDATE
CONFIRM in CELL_FACH, URA_PCH or CELL_PCH state. T305 is stopped after
the UE enters another state.
When T305 expires, the UE transmit CELL UPDATE or URA UPDATE if T307 is
not activated and the UE detects "in service area". Otherwise, if T307 is not active,
start T307.
Configuration Rule and Restriction:
T305 should be set larger than T302*N302 (T305>T302*N302). UE can obtain the
value from SIB1.
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RAN Feature Description Chapter 3 URA Update
Parameter Name Timer 302
Parameter ID T302
GUI RangeD100, D200, D400, D600, D800, D1000, D1200,
D1400, D1600, D1800, D2000, D3000, D4000,
D6000, D8000
Physical Range& Unit 100, 200, 400, 600, 800, 1000, 1200, 1400, 1600,
1800, 2000, 3000, 4000, 6000, 8000(ms)
Default Value D2000
Optional/Mandatory Optional
MML Command SET CONNMODETIMER
Description:
T302 is started after the UE sends the CELL UPDATE or URA UPDATE message
and is stopped after the UE receives the CELL UPDATE CONFIRM or URA
UPDATE CONFIRM message. The CELL UPDATE or URA UPDATE message is
resent upon the expiry of the timer if V302<= N302; otherwise, the UE enters idle
mode.
Note: V302 is a counter for UE. It is reset when the procedure Cell update or URA update is
initiated and incremented upon expiry of T302. When V302 > N302, the UE enters idle
mode.
Parameter Name Constant 302
Parameter ID N302
GUI Range 0–7
Physical Range& Unit -
Default Value 3
Optional/Mandatory Optional
MML Command SET CONNMODETIMER
Description:
Maximum number of retransmissions of CELL UPDATE or URA UPDATE
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RAN Feature Description Chapter 3 URA Update
Parameter Name Timer 307
Parameter ID T307
GUI Range D5, D10, D15, D20, D30, D40, D50
Physical Range& Unit 5, 10, 15, 20, 30, 40, 50(s)
Default Value 30
Optional/Mandatory Optional
MML Command SET CONNMODETIMER
Description:
T307 is started after T305 has expired and the UE detects "out of service area".
T307 is stopped after the UE detects "in service area". The UE enters idle mode
upon expiry.
II. URA Update Triggered by URA Reselection
If the UE in URA_PCH state enters a new URA, the UE performs URA update with
the cause “change of URA”.
After receiving a URA UPDATE message with the cause “change of URA”,.
Parameter Name URA ID
Parameter ID URAID
GUI Range 0–65535
Physical Range& Unit -
Default Value -
Optional/Mandatory Mandatory
MML Command ADD CELLURA
Description:
Uniquely identifying a URA. This URA ID is used for adding the UTRAN
Registration Area (URA) of a cell
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RAN Feature Description Chapter 3 URA Update
Configuration Rule and Restriction:
URA update with the cause “Change of URA” can be initiated by the UE only when
two cells are configured with different URA IDs.
URA ID can be added in advance by ADD URA command.
3.4.3 Basic Signaling Procedure of URA Update
Figure 3-3 shows the basic signaling procedure for URA update.
UE
1.URA UPDATE
2.URA UPDATE CONFIRM
RNC
Figure 3-3 Basic signaling procedure for URA update
The basic signaling procedure is described as follows:
1) The UE sends the RNC a URA UPDATE message and includes the update
cause “periodical URA update” or “change of URA” in the “URA update cause”
IE.
2) The RNC performs the corresponding processing according to the “URA update
cause” IE, and then sends a URA UPDATE CONFIRM message to the UE.
3.4.4 Signaling Procedure of URA Update with SRNS Relocation
Figure 3-1 shows the signaling procedure for the inter-RNS URA update with SRNS
relocation from RNC 1 to RNC 2.
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RAN Feature Description Chapter 3 URA Update
RNC1 RNC2CNUE
3. RELOCATION REQUIRED4. RELOCATION REQUEST
5. RELOCATION REQUEST ACK
6. RELOCATION COMMAND
9. URA UPDATE CONFIRM
8. RELOCATION DETECT
11. RELOCATION COMPLETE
2. UPLINK SIGNALLING TRANSFER INDICATION
7. RELOCATION COMMIT
10.UTRAN MOBILITY INFORMATION CONFIRM
12. IU RELEASE COMMAND
13. IU RELEASE COMPLETE
Establish RAB, in URA_PCH
1.URA UPDATE
Figure 3-1 Signaling procedure for URA update with SRNS relocation
The signaling procedure is described as follows:
The UE establishes RAB connection on RNC 1. The UE is in URA_PCH state. Here,
RNC 1 is the serving RNC (SRNC) and RNC 2 is the drift RNC (DRNC).
1) The UE in URA_PCH state sends RNC 2 a URA UPDATE message after URA
reselection.
2) RNC 2 allocates C-RNTI and D-RNTI for the UE after receiving the URA
UPDATE message from CCCH, and then sends RNC 1 an UPLINK
SIGNALLING TRANSFER INDICATION message. The message includes target
RNC-ID, allocated C-RNTI (used to identify the UE in C-RNC), and D-RNTI.
3) RNC 1 sends the CN a RELOCATION REQUIRED message, requesting SRNS
relocation.
4) The CN sends RNC 2 a RELOCATION REQUEST message
5) RNC 2 prepares L2 resources for RNC 1 relocation, and then sends the CN a
RELOCATION REQUEST ACKNOWLEDGE message.
6) The CN sends RNC 1 a RELOCATION COMMAND message, notifying RNC 1
that SRNS relocation starts.
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RAN Feature Description Chapter 3 URA Update
7) RNC 1 completes related preparations such as stopping signaling and traffic
RLCs, and then sends RNC 2 a RELOCATION COMMIT message.
8) RNC 2 sends the CN a RELOCATION DETECT message, notifying the CN that
the relocation starts. Then RNC 2 performs related operations such as L2
configuration.
9) RNC 2 sends the UE a URA UPDATE CONFIRM message in the new cell,
including the old S-RNTI and SRNC ID as well as the new S-RNTI, SRNC-ID,
and C-RNTI.
10) The UE sends RNC 2 an RRC message, UTRAN MOBILITY INFORMATION
CONFIRM.
11) RNC 2 sends the CN a RELOCATION COMPLETE message.
12) The CN sends RNC 1 an IU RELEASE COMMAND message, requesting RNC 1
to release the Iu interface resource related to this UE.
13) RNC 1 sends the CN an IU RELEASE COMPLETE message.
3.5 Capabilities
None
3.6 Implementation
3.6.1 Enabling URA update
This feature does not need extra hardware or initialization. It takes effect
automatically.
For the network planning or optimization, the data can be adjusted on the RNC LMT
as required. The default values of the related parameters are recommended to be
used.
3.6.2 Reconfiguring Parameters
I. Parameter Reconfiguration on the RNC Side
Table 3-1 describes the commands used for the reconfiguration on the RNC side.
Table 3-1 Commands for the reconfiguration on the RNC side
Function Command
To query the UE timers and
constants in connected modeLST CONNMODETIMER
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RAN Feature Description Chapter 3 URA Update
Function Command
About UE timers
and constants in
connected mode
To set the UE timers and
constants in connected modeSET CONNMODETIMER
About the UE
state-transition
algorithms
To query the UE state-transition
algorithmsLST UESTATETRANS
To set the UE state-transition
algorithmsSET UESTATETRANS
About the URATo query the URA of a cell LST CELLURA
To add the URA of a cell. ADD CELLURA
II. Parameter Reconfiguration on the NodeB Side
None.
III. Examples
Before data configuration on RNC LMT, use the related LST command to check
related information. Only after recording the original data can you modify the
parameters.
//Set the period of URA update initiated by the UE in URA_PCH state to 5
minutes.
SET CONNMODETIMER: T305=D5;
//Set the Min quality level to a smaller value, such as –21, to make it
easier to reselect cell 3, for URA update with the cause “URA
reselection”.
MOD CELLSELRESEL: CELLID=3, QUALMEAS=CPICH_RSCP, QQUALMIN=-21;
//Add two URAs, and add cell 1 and cell 2 to URA 1 and URA 2.
ADD URA: URAID=1;
ADD CELLURA: CELLID=1, URAID=1;
ADD URA: URAID=2;
ADD CELLURA: CELLID=2, URAID=2;
//If the UE in CELL_PCH state initiates cell updates due to cell
reselection more than three times within 60 seconds, enable the UE to
transit to URA_PCH state if it initiates cell update again.
SET DCCC: CELLRESELECTTIMER=60, CELLRESELECTCOUNTER=3;
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RAN Feature Description Chapter 3 URA Update
3.6.3 Disabling URA update
URA update can be set and reconfigured, but not disabled.
3.7 Maintenance Information
3.7.1 Alarms
None.
3.7.2 Counters
URA update counters belong to CELL->URAUPDATE.Cell, where CELL is
measurement object type, and URAUPDATE.Cell is measurement unit.
Table 3-2 lists the URA update counters.
Table 3-2 URA update counters
Item Description
VS.URAUpd.Prd Number of URA updates due to periodic URA update
VS.URAUpd.CHG Number of URA updates due to change of URA
VS.URAUpd.Succ.PrdNumber of successful URA updates due to periodic URA
update
VS.URAUpd.Succ.CHGNumber of successful URA updates due to change of
URA
3.8 References
3GPP TS 25.331 "Radio Resource Control (RRC); protocol specification"
3GPP TS 25.931 “UTRAN Functions, Examples on Signaling Procedures"
3GPP TS 25.413 "UTRAN Iu interface RANAP signaling"
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