3g Radio Parameter Ericsson

3G Ericsson Radio Parameter TELKOMSEL

Prepared by Adithya Yudha

Contents Idle Mode  Handover  Power Control  Capacity Management  Channel Switching  HSDPA 

Idle Mode and Common Channel behavior

Cell Selection 3G part Criteria for Cell Selection Squel > 0 , Squal = Qqualmeas-qQualMin (only for WCDMA cells) and Srxlev > 0 , Srxlev = Qrxlevmeas-qRxLevMin - Pcompensation (for all cells) Pcompensation = max (maxTxPowerUl - P, 0)

Qqualmeas > qQualMin (-18dB) and Qrxlevmeas > qRxLevMin (-115dBm) - max (maxTxPowerUl (24dB) - P, 0)

qQualMin : indicates the minimum required quality value in the cell. It is sent in system information, in SIB3 for the serving cell, and in SIB11 for adjacent cells qRxLevMin : indicates the minimum required signal strength in the cell. It is sent in SIB3 for the serving cell and in SIB11 for adjacent cells maxTxPowerUl : indicates the maximum allowed transmission power when the UE accesses the system on RACH. It is broadcast in SIB3

Cell Selection 3G part Squal > 0

Qqualmeas (dB) (CPICH Ec/N0)

Squal >0 AND Srxlev > 0

qQualMin (–18) Squal = Qqualmeas – qQualMin

qRxLevMin (–115) suitabl e cell?

Qrxlevmeas (dBm) CPICH RSCP

Pcompensation Pcompensation = max(maxTxPowerUl – P, 0) (dB)

Srxlev = Qrxlevmeas - qRxLevMin – Pcompensation

Srxlev > 0

Cell Reselection 3G part First according to S criteria Squal > 0 (only WCDMA cells) Srxlev > 0 The cells are ranked according to the R criteria: R(serving) = Qmeas(s) + qHyst(s) R(neighbor) = Qmeas(n) - qOffset(s,n) qHyst1 : Based on CPICH RSCP qHyst(s) qHyst2 : Based on CPICH Ec/No qOffset1sn : Based on CPICH RSCP qOffset(s,n)

qOffset2sn : Based on CPICH Ec/No (1 ) qHyst(s) and qOffset(sn) based on CPICH RSCP only

qualMeasQuantity =x

(2 ) With this setting the UE first makes qHyst(s) and qOffset(sn) based on CPICH RSCP . If a GSM cell is highest ranked, no more ranking is done. If a WCDMA neighbor is highest ranked, a second ranking takes place, this time according to CPICH Ec/No, and excluding all GSM neighbors

Cell Reselection 3G part R CRITERIA : R(serving) = Qmeas(s) + qHyst(s) R(neighbor) = Qmeas(n) - qOffset(s,n) Note that parameter qOffset1sn works identically for WCDMA-GSM and WCDMA-WCDMA neighbor relations. But the values of GSM RSSI and WCDMA CPICH RSCP are not of the same nature and therefore not directly comparable. [CPICH RSCP] = [GSM RSSI] + 7 As an example a measured RSCP on a WCDMA CPICH of -100 dBm would be comparable to a GSM broadcast channel RSSI of -93 dBm. A parameter setting of a GSM neighbor to qOffset1sn = +7 will thus make the received signal strength in the WCDMA and the GSM cell comparable.

Cell Reselection 3G part MEASUREMENT ON INTRA AND INTER-RAT NEIGHBOR The decision about when intrafrequency measurements are performed is made using the sIntraSearch parameter in relation to Squal: • If the Squal > sIntraSearch, the UE does not need to perform intrafrequency measurements. • If the Squal sRatSearch and the Srxlev > sHcsRat, the UE does not need to perform measurements on GSM cells. • If the Squal 50% and load on target less than source by a 10 % margin)  The feature is activated in an RNC by setting the parameter loadSharingRrcEnabled to TRUE f2 f2 TRUE/FALSE  The attribute loadSharingCandidate specifies whether the target cell is a load-sharing neighbor of the source cell  Triggered

f1

f1

f1

f1

Inter-Frequency Load Sharing (RRC redirection) (Extra Slide) RNC Idle Mode ”RRC Connection Request” CCCH/RACH F1 ”RRC Connection Reject” CCCH/FACH Cell selection on designated UTRA carrier ”RRC Connection Request” CCCH/RACH

F2

”RRC Connection Setup” CCCH/FACH

Includes ‘Frequency Info’ IE

2nd will not be redirected but may be successful or rejected due to congestion

Directed retry to GSM Applicable for voice in P3 GSM

Admission Control

WCDMA

Directed retry to GSM 

Directed retry to GSM  At call set-up - RAB Establishment for voice  Triggered by Downlink Transmitted Carrier Power 

The feature is activated in an RNC by setting the parameter loadSharingDirRetryEnabled to TRUE



One GSM target can be defined for each WCDMA cell via the cell parameter directedRetryTarget



loadSharingGsmThreshold specifies the minimum load at which offloading to GSM begins: ex 80% of pwrAdm



loadSharingGsmFraction specifies the percentage of Directed Retry candidates to be diverted to GSM while the cell load is above the specified load threshold

Directed Retry to GSM UE

RBS/RNC

CN

RAB Assignment Request Directed Retry decision to send

RAB Assignment Response (failed, cause=directed retry) Relocation Required Contacts GSM cell and orders relocation

HO from UTRAN command

Relocation Command

Successful access to GSM

Iu release Command Iu release Complete

Voice calls can be relocated to GSM due to high load in WCDMA If the call is not accepted in GSM - try in WCDMA again!

Load balancing for voice between WCDMA-GSM

Features Introduction & Roadmap

When out of coverage, the WCDMA voice call is handed over to GSM

When GSM load reaches a customizable threshold, voice calls can be handed over to WCDMA

WCDMA coverage Dual Mode UE

GSM terminal

GSM coverage Load based handover to GSM during call set up, Directed Retry (P3) to GSM

Channel Switching

Channel Switching

Channel Switching Parameter Summary

Channel Switching

1. Common to Dedicated Evaluation Monitors if the UE shall be switched from a common to a dedicated transport channel due to large amount of user data buffered in the RNC or the UE.

2. Dedicated to Dedicated Up-Switch Evaluation Monitors if the throughput becomes close to the max user bandwidth and switch to the next higher bitrate radio bearer is required.

2a. Dedicated to Dedicated Coverage triggered Down-Switch Evaluation Monitors if a switch to a lower rate radio bearer is required due to coverage.

3. Dedicated to Common Evaluation Monitors if a switch from a Cell_DCH to Cell_FACH is required due to a decrease in transmitted user data.

4. Common to Idle Evaluation Monitors if a switch from Cell_FACH to Idle mode is required due to a complete lack of user data transmission.

Channel Switching

Multi-RAB Down-switch Evaluation Monitors if a release (or downswitch) of PS I/B RAB shall be initiated due to lack of PS data throughput (zero), resulting in a single speech 12.2 kbps (or speech + PS 0/0) or CS64 RAB.

Multi-RAB Up-switch Evaluation Monitors if an upswitch from multi-RAB SP0 to multi-RAB SP64 shall be initiated due to data buffered in either RNC or UE.

Channel Switching

Future releases stand-alone interactive RAB

speech + interactive RAB

HS

speech + 384/HS

384/HS

DCH

64/384 speech + 64/HS

128/128

64/HS

speech + 64/64

64/128

speech + 0/0

64/64

Low/No throughput Measurement for down Switch timer period FACH

Low/No RLC buffer load for Inactivity timer period

IDLE

PS RAB Establishment

UL throughputbased upswitch

activity/inactivity-based switching UL and/or DL

coverage-triggered downswitch (DL only)

DL throughputbased upswitch

choice based on UEand cell-capability

Capacity Management

Admission control workflow Resource request

* Current default values Yes, then block

Is admission blocked by Congestion Control?

No, then accept

Yes, then block

No

Check if the requested + estimated # compressed mode RL > compModeAdm

15*

75*

No Yes, then block

No

Check if the requested code usage + estimated code usage > dLCodeAdm

70*

Check if the requested ASE UL + estimated ASE UL > aseUlAdm

Only checked if No BE-service requests Check if the requested Check if the requested DL SF + estimated DL SF ASE DL + estimated DL ASE > > No sfXAdm * aseDlAdm

No

Yes, then SF8adm= 8* block SF16adm= 16* SF32adm= 32*

Yes, then block

Check if the requested DL Pwr + estimated Pwr > pwrAdm

•X = 8 or X = 32 •X = 16

240*

160* Yes, then block

Yes, then block

Soft Congestion mechanism New request for ng 64/128, ng 64/64 or g access

Admission Control blocks the new request

An existing ng user of 64/384 will be switched down to 64/128 or an existing ng user of 64/128 will be switched down to 64/64

Spreading Factor (SF) limits used in Admission Control

8*

* Current default values

16* 32*

ASE release order Core Network

Iu

Iu

SRNC & DRNC

SRNC Iur

over Iu:

over Iur:

1.

Non-guaranteed service class connections

2.

Non-guaranteed service class connections

3.

CS/streaming service class connections

4.

CS /streaming service class connections

5.

Speech users

6.

Speech users

HSDPA

HSDPA Parameter Summary Parameter Name

Default Value

HSPATHLOSSTHRESHOLD

170

170

10

10

2

2

-20

-20

CQIERRORSABSENT HSPOWERMARGIN HSSCCHMAXCODEPOWER QUEUESELECTALGORITHM SUPPORTOF16QAM

Initial Setting TELKOMSEL

ROUND_ROBIN FALSE

ROUND_ROBIN TRUE

MAXHSRATE

15

30

HSONLYBESTCELL

1

1

HSHYSTERESIS1D

10

10

HSQUALITYESTIMATE HSTIMETOTRIGGER1D

CPICH_RSCP 640

CPICH_RSCP 640

MAXHSRATE



The HSDPA Iub flow control algorithm adjusts the available bit rate over Iub based mainly on the maximum possible air interface bitrate received from the scheduler, the number of users in a cell and Iub congestion indications. The RBS uses the parameter maxHsRate to determine the maximum bit rate to be used for HS-DSCH data frame traffic in one aggregated bit pipe over Iub.



The parameter maxHsRate should be configured for each RBS to represent the maximum MAC-d PDU bitrate of HS-DSCH data frames, which is available for the AAL2 path or paths carrying HSDPA traffic to the RBS in question. The parameter may be set to a MAC-d PDU bit rate of 1.5 Mbps (the default value), when one dedicated physical E1 link is used for HSDPA traffic. This maximum bitrate level is the same as the bitrate expressed by the CAPACITY ALLOCATION control frames.



As an example, the default value of this parameter has been obtained by multiplying the HSDPA available ATM bandwidth (excluding IMA overhead), e.g. 1.92 Mbps, with a factor of 0.79. This factor is dependent on the average number of MAC-d PDUs per HS-DSCH data frame. In this case, it is based on having 10 MAC-d PDUs (336 bits) per HS-DSCH data frame in average. It should be noted that assuming a lower number of PDUs per data frame gives a lower factor and vice versa.



The parameter value of maxHsRate also depends on how the transport network is configured, e.g. if ATM VC Cross Connect is used or if AAL2 switching is used. It depends on how the ATM VCs etc are configured, e.g. for HS traffic only, sharing with AAL2 class A and B, several AAL2 paths for HS etc. Therefore it is recommended to follow the guidelines given by Ericsson regarding transport network dimensioning before setting a value for this parameter.

16QAM Modulation



The RBS hardware supports both QPSK and 16QAM modulation. However, support of 16QAM is an optional feature which can be configured on cell level using the parameter supportOf16qam. The available modulation type impacts the maximum achievable bit rate in the cell,

Maximum Achievable User Bit Rate at the RLC Level As a Function of the UE HS-DSCH Category and Modulation Type