HSDPA Parameter

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HSDPA Parameter Sonny Rafiq

description

HSDPA Parameter

Transcript of HSDPA Parameter

Page 1: HSDPA Parameter

HSDPA Parameter

Sonny Rafiq

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Overview

High Speed Downlink Packet AccessHigh Speed Downlink Packet Access In P4, 4.32 Mbps is possible and up to 14 Mbps in P5In P4, 4.32 Mbps is possible and up to 14 Mbps in P5 Best effort serviceBest effort service HSDPA P4 is time sharedHSDPA P4 is time shared HSDPA hasHSDPA has

- Link AdaptationLink Adaptation- QPSKQPSK- 16 QAM16 QAM

- Hybrid ARQHybrid ARQ- SchedulingScheduling- Short TT1 (2 msec)Short TT1 (2 msec)

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Channel Structure R5 of 3GPP standard introduces 3 new channels R5 of 3GPP standard introduces 3 new channels

that support HSDPA.that support HSDPA.- One HS-DSCH (High Speed Downlink Shared One HS-DSCH (High Speed Downlink Shared

Channel)Channel)- Mapped to up to 15 (5 in P4) HS-PDSCH Mapped to up to 15 (5 in P4) HS-PDSCH

SF 16SF 16- Dynamic allocation every 2 msecDynamic allocation every 2 msec- Time sharing only in P4. Code sharing Time sharing only in P4. Code sharing

laterlater- One HS-SCCH (High Speed Shared Control One HS-SCCH (High Speed Shared Control

Channel) in P4Channel) in P4- Control information (UE ID, HARQ, Control information (UE ID, HARQ,

TFRC) TFRC) - SF 128, 2msec, downlinkSF 128, 2msec, downlink

- One HS-DPCCH (High Speed Dedicated One HS-DPCCH (High Speed Dedicated Physical Control Channel) per UE in the uplinkPhysical Control Channel) per UE in the uplink

- HARQ UL (ACK, NACK), CQIHARQ UL (ACK, NACK), CQI

Other channels ADCH (Associated DCH)Other channels ADCH (Associated DCH)- Set of dedicated uplink (DPCCH) and Set of dedicated uplink (DPCCH) and

downlink (DPCH) for SRBdownlink (DPCH) for SRB- Uplink user data can be transmitted with a Uplink user data can be transmitted with a

DPDCHDPDCH

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MAC-hs MAC-hs is a new MAC protocol defined for HSDPAMAC-hs is a new MAC protocol defined for HSDPA

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MAC-hs HARQ UE can rapidly request retransmission of erroneously received UE can rapidly request retransmission of erroneously received

datadata Reduced roundtrip delay and increased capacity Reduced roundtrip delay and increased capacity If NACK is received Node B retransmits dataIf NACK is received Node B retransmits data UE combines the faulty block with retransmission (soft combining)UE combines the faulty block with retransmission (soft combining) MAC-hs RTT=12 msMAC-hs RTT=12 ms 6 HARQ processes needed to transmit in every TTI6 HARQ processes needed to transmit in every TTI

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Power and Spectrum Utilization

Efficient power and spectrum utilizationEfficient power and spectrum utilization No wasted transmissionNo wasted transmission

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Parameter for HSDPA: HSDPA CapabilityHSDPA Capability Power MarginPower Margin RABRAB Max HS RateMax HS Rate SchedulingScheduling Cell ChangeCell Change CoverageCoverage Link AdaptationLink Adaptation HSDPA AdmHSDPA Adm Channel SwitchingChannel Switching

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hsdpaCapability

The HSDPA capability of the cell The HSDPA capability of the cell Value : hsdpa_non_capable / hsdpa_capableValue : hsdpa_non_capable / hsdpa_capable RBS parameterRBS parameter

HSDPANON HSDPA

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Power Margin hsPowerMargin determining how much power can be allocated for hsPowerMargin determining how much power can be allocated for

HS-DSCH.HS-DSCH. Default value : 2 (0.2dB)Default value : 2 (0.2dB) Range: 2-200Range: 2-200 Resolution: 1Resolution: 1 Unit: 0.1dBUnit: 0.1dB

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hsScchMaxCodePower HS-SCCH maximum code power relative PCPICH reference HS-SCCH maximum code power relative PCPICH reference

power. power. This parameter also determines the fixed power level for HS-This parameter also determines the fixed power level for HS-

SCCH. SCCH. UNIT=0.1(dB)UNIT=0.1(dB) RESOLUTION=5RESOLUTION=5 Default: -20Default: -20

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HSDPA RABs Interactive PS 64/HS and PS 384/HS (optional)Interactive PS 64/HS and PS 384/HS (optional)

Interactive 64/HS kbps PS RAB Interactive 64/HS kbps PS RAB - UL: Interactive 64 kbps PS RB + 3.4 kbps SRBs on DPCHUL: Interactive 64 kbps PS RB + 3.4 kbps SRBs on DPCH- DL: Interactive PS RB on HS-DSCH + 3.4 kbps SRBs on DL: Interactive PS RB on HS-DSCH + 3.4 kbps SRBs on

DPCHDPCH Interactive 384/HS kbps PS RAB Interactive 384/HS kbps PS RAB

- UL: Interactive 384 kbps PS RB + 3.4 kbps SRBs on DPCHUL: Interactive 384 kbps PS RB + 3.4 kbps SRBs on DPCH- DL: Interactive PS RB on HS-DSCH + 3.4 kbps SRBs on DL: Interactive PS RB on HS-DSCH + 3.4 kbps SRBs on

DPCHDPCH

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RAB

allow384HsRaballow384HsRab- Switch to enable/disable the use of UL Switch to enable/disable the use of UL

384/HS kbps RAB in the RNC.384/HS kbps RAB in the RNC.- Value : True/FalseValue : True/False- RncFunctionRncFunction

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Max HS Rate Determine the maximum appropriate bit rate that can be used for Determine the maximum appropriate bit rate that can be used for

HS-DSCH over one aggregate bit pipe over Iub.HS-DSCH over one aggregate bit pipe over Iub. Default is 15 Default is 15 Unit: 0.1(Mbps)Unit: 0.1(Mbps) Range: 1-1000Range: 1-1000 RBS parameterRBS parameter

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HSDPA Scheduling HSDPA scheduler is implemented in Node BHSDPA scheduler is implemented in Node B Scheduler determines the UE to which data should be transmitted Scheduler determines the UE to which data should be transmitted

in the next 2 msec TTIin the next 2 msec TTI It considers channel conditions experienced by the UEIt considers channel conditions experienced by the UE Scheduler can assign HS-DSCH to the UE with better channel Scheduler can assign HS-DSCH to the UE with better channel

quality (CQI)quality (CQI) Short term improvements in radio conditions can mean higher Short term improvements in radio conditions can mean higher

throughputthroughput Each user gets the impression of being given a big data pipeEach user gets the impression of being given a big data pipe

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MAC-hs Scheduling Priority queue is the same as user allocated resources in 2 msec Priority queue is the same as user allocated resources in 2 msec

TTITTI MAC-hs Scheduling determines priority queueMAC-hs Scheduling determines priority queue MAC-hs functionsMAC-hs functions

- Resource EstimationResource Estimation- Queue ValidationQueue Validation- Queue SelectionQueue Selection

Scheduler

Priority Queue 1

Priority Queue 2

Priority Queue 3

Priority Queue 4

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MAC-hs SchedulingFor Queue Selection, 3 priority factors are available.For Queue Selection, 3 priority factors are available.

- f(CQI) weights downlink channel conditions. Emphasis system f(CQI) weights downlink channel conditions. Emphasis system throughputthroughput

- f(delay) weights time a user has to wait for transmission. f(delay) weights time a user has to wait for transmission. Emphasis fairness of time allocationEmphasis fairness of time allocation

- f(average rate) weights users achievable data rate. Emphasis f(average rate) weights users achievable data rate. Emphasis on fairness of throughputon fairness of throughput

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Two different algorithms available in P4 Parameter Two different algorithms available in P4 Parameter (queueSelectAlgorithm) by combination of factors(queueSelectAlgorithm) by combination of factors

Value: Value: Round_Robin / Proporsional_FairRound_Robin / Proporsional_Fair- Round_RobinRound_Robin

- Considers only f(delay). Considers only f(delay). - Fairness of time allocationFairness of time allocation

- Proportional_FairProportional_Fair- Combination of all the three factorsCombination of all the three factors- Increases system throughput by prioritizing users with good qualityIncreases system throughput by prioritizing users with good quality- Some fairness of time and rate allocation is also consideredSome fairness of time and rate allocation is also considered

MAC-hs Scheduling

high data rate

low data rateTime

#2#1 #2 #2#1 #1 #1

User 2

User 1

Scheduled user

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Sector Throughput Scheduler Type vs Sector Throughput

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

Proportional Fair Round robin

Mbps

UE

UE

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HS-DSCH Mobility (Cell Change) HS-DSCH and HS-SCCH do not support soft/softer handoverHS-DSCH and HS-SCCH do not support soft/softer handover ADCH support soft/softer handover (SRB and uplink DCH)ADCH support soft/softer handover (SRB and uplink DCH) HS-DPCCH support only softer handoverHS-DPCCH support only softer handover HS connections perform a HS cell changeHS connections perform a HS cell change HS cell change performed only with cells in the Active Set.HS cell change performed only with cells in the Active Set. Active Set Update happens first before HS Cell Change can Active Set Update happens first before HS Cell Change can

happenhappen HS Cell Change cannot be performed across RNC bordersHS Cell Change cannot be performed across RNC borders The Cell Change evaluation is triggered only if the parameter The Cell Change evaluation is triggered only if the parameter

hsCellChangeAllowed is set to TRUEhsCellChangeAllowed is set to TRUE Cell Change is performed by “RRC Physical Channel Cell Change is performed by “RRC Physical Channel

Reconfiguration”Reconfiguration”

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Parameter for UE measurement Control

hsHysteresis1d RNC Sets the Event 1D hysteresis value specific for HS connections

Unit: 0.1 dBResolution: 5

hsQualityEstimate RNC Indicates whether it is CPICH Ec/N0 or CPICH RSCP that should be used for indicating "best cell" for HS-DSCH cell selection and HS-DSCH cell change

Value: CPICH_ECNO/CPICH_RSCP

hsTimeToTrigger1d RNC Sets the Event 1D Time to Trigger value specific for HS connections

Unit: 1 ms.Resolution: N/A

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Hs Quality Estimate

Default value is using RSCPDefault value is using RSCP

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Event 1d HS

Event 1d HS is similar to event 1dEvent 1d HS is similar to event 1d Event 1d HS occurs when the Event 1d HS occurs when the

signal level of a cell already signal level of a cell already included in the Active Set included in the Active Set becomes stronger than the becomes stronger than the current best cell in the Active Setcurrent best cell in the Active Set

Different Hysteresis, Time to Different Hysteresis, Time to trigger and qualityestimate criteria trigger and qualityestimate criteria for 1d HSfor 1d HS

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HS Coverage Relation Purpose of the coverage relation is to give the operator a Purpose of the coverage relation is to give the operator a

possibility to distribute HSDPA downlink traffic among the cells of possibility to distribute HSDPA downlink traffic among the cells of an RNC.an RNC.

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HS PATHLOSS THRESHOLD hsPathlossThresholdhsPathlossThreshold Maximum pathloss allowed for Serving HS-DSCH cell selection to Maximum pathloss allowed for Serving HS-DSCH cell selection to

validate the target cell for selection.validate the target cell for selection. Unit: 1 dBUnit: 1 dB Range: 15-170Range: 15-170 Resolution: 1Resolution: 1 Default: 170 (max)Default: 170 (max)

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HSDPA Link Adaptation There is no power control on HS-DSCHThere is no power control on HS-DSCH HS-DSCH adjusts the data rate to match the instantaneous radio HS-DSCH adjusts the data rate to match the instantaneous radio

conditions and the available transmission power in the RBSconditions and the available transmission power in the RBS The system adjusts the data rate by varying the effective code The system adjusts the data rate by varying the effective code

rate, changing the modulation scheme, and changing the number rate, changing the modulation scheme, and changing the number of codesof codes

Besides QPSK, the HS-DSCH can use 16QAM to provide higher Besides QPSK, the HS-DSCH can use 16QAM to provide higher data rates. ( parameter: supportOf16qam true/false)data rates. ( parameter: supportOf16qam true/false)

16QAM makes more efficient use of the bandwidth than QPSK but 16QAM makes more efficient use of the bandwidth than QPSK but requires greater received energy per bit.requires greater received energy per bit.

16QAM

2 bits 4 bits

QPSK

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CQI Adjustment UE sends CQI info in the UL on HS-DPCCH to aid schedulingUE sends CQI info in the UL on HS-DPCCH to aid scheduling CQI (1-30) provides the Node B with a measure of the UE's CQI (1-30) provides the Node B with a measure of the UE's

perceived channel quality and the UE receiver performanceperceived channel quality and the UE receiver performance The CQI report estimates the number of bits that can be The CQI report estimates the number of bits that can be

transmitted to the UE using a certain assumed HS-PDSCH power transmitted to the UE using a certain assumed HS-PDSCH power with a block error rate of 10%with a block error rate of 10%

UE assumes a HS- PDSCH power to calculate CQIUE assumes a HS- PDSCH power to calculate CQI The available HS-PDSCH power typically differs from the assumed The available HS-PDSCH power typically differs from the assumed

power, and the number of codes and available modulation type power, and the number of codes and available modulation type may differ from the UE's assumptions, CQI is adjusted by the Node may differ from the UE's assumptions, CQI is adjusted by the Node B with parameter cqiAdjustmentOn (true/false)B with parameter cqiAdjustmentOn (true/false)

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hsdpaUsersAdm Admission limit for the number of users assigned to the HS-Admission limit for the number of users assigned to the HS-

PDSCH/HS-SCCH in the cell. The limit is only applicable to RAB PDSCH/HS-SCCH in the cell. The limit is only applicable to RAB setup of HSDPA.setup of HSDPA.

Unit: 1 userUnit: 1 user Resolution: 1Resolution: 1 Default: 10Default: 10

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HS-DSCH Channel Switching

Uplink and downlinkactivity is monitored and the algorithm Uplink and downlinkactivity is monitored and the algorithm requests a switch to Idle mode if no uplink or downlink activity has requests a switch to Idle mode if no uplink or downlink activity has been detected been detected

hsdschInactivityTimerhsdschInactivityTimer Unit: 1 s (seconds)Unit: 1 s (seconds) Resolution: 1Resolution: 1

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Questions and discussion

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Thank you for your participation!