HSPA

University

Technical Tutorial November 7th, 2006

Telecom Israel

Understand HSPA: High-Speed Packet Access For UMTS

Understanding HSPA

Page 1

About QUALCOMM UniversityUniversity


Telecom Israel

QUALCOMM University (QU) offers the advanced technology training solutions you need to stay on the cutting edge of wireless technology. Visit the QU website for more information about individual training products, international training centers, and distance learning opportunities, along with a complete list of classesall developed by QUALCOMM, the pioneers of CDMA.

QUALCOMM University: www.qualcommuniversity.com QUALCOMM: www.qualcomm.comUnderstanding HSPAPage 3

1

Where Can I Learn More?University


Telecom Israel

Want to learn more?QUALCOMM University offers additional indepth technical training related to this course. To learn more about this or related topics, sign up for the following courses.

WCDMA HSDPA: Protocolsand Physical Layer (1 day)

WCDMA HSUPA: Protocolsand Physical Layer (1 day)To check out the schedules for these courses and enroll, go to: www.qualcommuniversity.comUnderstanding HSPAPage 4

UMTS Courses from QUALCOMM UniversityUniversity


Telecom Israel

For the latest information on all QUALCOMM University courses, visit www.qualcommuniversity.com.Understanding HSPAPage 6

2

Tutorial ObjectivesUniversity


Telecom Israel

Provide telecommunication professionals with the basic understanding of HSPA, the high speed packet access technologies (HSDPA, HSUPA), and related applications, network architecture, and deployments. The talk will present:the market drivers for UMTS HSPA the basic enabling techniques and terminology associated with HSPA the basic operations of HSPA the HSPA implementation and performances

Understanding HSPA

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Market DriversUniversity


Telecom Israel

HSPA Motivations

Understanding HSPA

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3

3G Enables Wider Options of ServicesUniversity


Telecom Israel

EntertainmentAudio on demand Video on demand Games on demand Network Games Reservation services

Increasing Wireless Internet Traffic Demands Higher Data Rates

Business Workgroups Remote LAN access Videoconferencing

Information Database access E-mail/Fax/Web Location Based Services Emergency Call Locating Safety Credit verification

FinancialStock trading Wireless banking Financial news Interactive shopping E-commerce

and many others

EducationRemote learning Remote library access Remote language laboratoryPage 9

Understanding HSPA

3G (IMT-2000)University


Telecom Israel

Key Features: Global Roaming More Capacity, High Speed Data CDMA2000 1x Medium Speed Data Capacity/Quality Roaming Mobility AMPS 1G TDMA GSM PDC cdmaOne IS-95A cdmaOne IS-95B GPRS CDMA2000 1xEV WCDMA Multi-Mode Multi-Band Multi-Network 2G 2.5G Time 3G (IMT-2000)

Commonality Compatibility High quality Small terminals Worldwide roaming Multimedia Wide range of services

IMT-2000 aims to achieve Anywhere, Anytime CommunicationsUnderstanding HSPAPage 10

4

3G Enables Advanced Data ServicesUniversity


Telecom Israel

MM streaming MM sharing Wireless Broadband Access Interactive Gaming VoIP with AMR-WB

ve d EvolSpectral Efficiency

3GHSDPA/HSUPA HSDPA/HSUPA (Rel5 // Rel6) (Rel5 Rel6)

Rich Voice Video Telephony

WCDMA (R99) WCDMA (R99)

Voice & High Speed Data

Push-to-Talk Customized Infotainment Multimedia Messaging

EDGE EDGE

Medium Speed DataGPRS GPRS GSM GSM

Text Messaging Speech

Voice & Limited Data

Data Services Evolution Understanding HSPA

Peak Data RatePage 12

HSPA for Higher SpeedUniversity


Telecom Israel

What are the requirements for HSPA?

Data Rate Demand for higher peak data rates

Delay Lower latency

Capacity Better capacity and throughput Better spectrum efficiency Finer resource granularity

Coverage Better coverage for higher data rate

Understanding HSPA

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5

UMTS Data Rate EvolutionUniversity


Telecom Israel

GSM GPRS EDGE W CDMA Release 99 HSDPA - Release 5 HSUPA - Release 6Understanding HSPA

Uplink Peak Data Rate (Typical Deployment) 9.6 kbps 20 kbps 60 kbps 64 kbps 384 kbps 1.4 Mbps (early deployment)

Dow nlink Peak Data Rate (Typical Deployment) 9.6 kbps 40 kbps 120 kbps 384 kbps 10 Mbps* 10 MbpsPage 14

Applications Benefiting from HSPAUniversity


Telecom Israel

Voice-over-IP (VoIP)- Low latency, Quality of Service (QoS) control, fine resource granularity and improved capacity

Delay Sensitive Error Tolerant

Video Telephony (in Packet Switched domain)- Low latency, Quality of Service (QoS) control, high data rates and improved coverage and capacity

Gaming- Low latency, fast resource allocation

Video Share / Picture ShareDelay Tolerant Error SensitiveUnderstanding HSPA

- High Uplink data rates and improved coverage and capacity

File Uploading (large files) - High Uplink data rates and improved coverageand capacityPage 15

6

University


Telecom Israel

Part I: Understanding HSDPA

Understanding HSPA

Page 18

Review - UMTS Network ArchitectureUniversity


Telecom Israel

Node B Node B Node B Node B Uu User Equipment Node B Node B Node B Node B

Iub RNC Iups SGSN GGSN Internet

USIM

Mobile Equipment

Iur Iub RNC Iucs MSC/ VLR

HLR/ AuC

GMSC

PSTN/ ISDN

Core Network UTRAN

Understanding HSPA

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7

Review - UMTS Protocol StackUniversity


Telecom Israel

Circuit Switched Connection Management (CM) NonAccess Stratum Call Control Supplementary Short Message Services (SS) Services (SMS) (CC)

Packet Switched Session Management (SM) Short Message Services (SMS)

Mobility Management (MM)

GPRS Mobility Management (GMM)

Radio Resources Control (RRC) Access Stratum Layer 2 Medium Access Control (MAC)

Radio Link Control (RLC)

Physical Layer (L1)Understanding HSPAPage 20

Review - Release 99 ChannelsUniversity


Telecom Israel

Understanding HSPA

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8

Review RRC Modes and StatesUniversity


Telecom Israel

UTRAN Connected ModeChannels: PCH, No Uplink Mobility: URA Update Calls: PS (no data transfer) DRX Mode URA_PCH CELL_PCH Channels: PCH, No Uplink Mobility: Cell Update Calls: PS (no data transfer) DRX Mode Channels: FACH, RACH Mobility: Cell Update Calls: PS Dedicated logical channels, but common transport and physical channels No DRX Mode Channels: PCH, No Uplink Mobility: Location/Routing Area Update Calls: None, PS call might be in context preserved state DRX Mode

Channels: Downlink DCH, Uplink DCH Mobility: Handover Calls: PS, CS

CELL_DCH

CELL_FACH

Release RRC Connection

Establish RRC Connection

Release RRC Connection

Establish RRC Connection

Idle Mode (Camping on a UTRAN cell)

Understanding HSPA

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Release 99 PrinciplesUniversity


Telecom Israel

How is Packet Data Managed in Release 99?

DCH (Dedicated Channel) Spreading codes assigned per user Closed loop power control Macro diversity

FACH (Common Channel) Common spreading code Header defines user No closed loop power control

DSCH (Downlink Shared Channel) not implemented for FDD Common spreading code shared by many users User assignment by Physical Layer signaling Closed loop power control with DPCH

Understanding HSPA

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9

DCH/FACH Comparison SummaryUniversity


Telecom Israel

How do we do Packet Data in Release 99Mode Channel Type Power Control DCH Dedicated Closed Inner Loop at 1500 Hz Slower Outer Loop Supported High Poor Medium Good FACH Common None or slow (based on measurement report) Not Supported Low Good Low Poor

Soft Handover Setup Time Suitability for Bursty Data Data Rate Radio Performance

Understanding HSPA

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What will HSDPA Address?University


Telecom Israel

Release 99 Downlink Limitations

Limited Peak Data Rate Maximum implemented Downlink of 384 kbps

Capacity and Throughput Modulation and codingQPSK Convolution coding (R=1/2, 1/3) or turbo coding (R=1/3)

Link adaptation due to channel conditionsFast closed inner loop power control, but Slower outer loop

Minimum TTI of 10 ms Slow Rate and Type Switching

Understanding HSPA

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HSDPA GoalsUniversity


Telecom Israel

Higher Data Rate Higher User / Cell Throughput Lower Latency

Understanding HSPA

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HSDPA Enabling TechnologiesUniversity


Telecom Israel

How will HSDPA address the limitations of Release 99? Extension of DSCH Multi-Code operation Adaptive modulation and coding QPSK and 16-QAM Coding from R=1/3 to R=1 Fast feedback of channel condition

Improve transmission efficiency Fast retransmission and Physical Layer HARQ

Fast resource management Node B scheduling

Reduce transmission latency 2 ms TTI

Understanding HSPA

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11

Common Channel for DataUniversity


Telecom Israel

Common Channel for data transfer using the HS-PDSCH

HS-

PDS C

H

Understanding HSPA

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Multi-Code OperationUniversity


Telecom Israel

Fixed Spreading Factor SF=16 (Typical Spreading Factor for 128 kbps in Release 99)

1-15 codes can be reserved for HS-PDSCH Can be TDM or CDM between users

Up to 15 codes reserved for HS-PDSCH transmission

2 ms (3 slots)

User #1Understanding HSPA

User #2

User #3

User #4Page 41

12

Adaptive Modulation and CodingUniversity


Telecom Israel

Coding from R=1/3 to R=1 HSPDA supports 16-QAM modulation 4 bits per symbol versus 2 bits per symbol with QPSK

Understanding HSPA

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Link Adaptation versus Power ControlUniversity


Telecom Israel

Release 99 Use fast power control with fixed data rate (DCH)

HSDPA Adapt the modulation and coding to the link quality

Fast Link adaptation:Rate #3: e.g. 16-QAM, R=3/4 Rate #2: e.g. QPSK, R=3/4 Rate #1: e.g. QPSK, R=1/2

Channel quality (C/I) Switching levels

Rate #2

Rate #1 Rate #2

Rate #3 Rate #2 Rate #1

Rate #2

time

Understanding HSPA

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13

Scheduling ComparisonUniversity


Telecom Israel

RELEASE 99 Scheduling RLC ARQ Resource Allocation

RNC

RELEASE 5 (HSDPA) RLC ARQ Resource Allocation

RELEASE 5 (HSDPA) Scheduling Link Adaptation HARQ Resource AllocationUnderstanding HSPA

Node B

Page 44

HSDPA Scheduling and RetransmissionsUniversity


Telecom Israel

Scheduling Done at the Node B No interaction with the RNC Based on channel quality feedback from the UE

Retransmissions HARQ (link level retransmissions) Done at the Node B Based on UE feedback (ACK/NACK) Soft combining at the UE

Understanding HSPA

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14

Hybrid Automatic Repeat Request (HARQ)University


Telecom Israel

Scheme combining ARQ and Forward ErrorCorrection

FEC decoding based on all unsuccessfultransmissions

Stop-and-Wait (SAW) protocol Two basic schemes: Chase Combiningsame data block is sent at each retransmission

Incremental Redundancy (IR)Additional Redundant Information sent at each retransmission

Understanding HSPA

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HARQ IllustrationUniversity


Telecom Israel

NA K

l Fai

Pa

ss

AC K

NA K

Understanding HSPA

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Comparison SummaryUniversity


Telecom Israel

Mode Channel Type Pow er Control Soft Handover Suitability for Bursty Data Data Rate / Traffic Volumn

HSDPA DCH FACH Dedicated Common Common Closed Inner Loop Fixed Pow er at 1500 Hz - Slow None w ith link Outer Loop adaptation Supported Not Supported Not Supported Poor Medium Good Low Good High

Understanding HSPA

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UMTS Network Architecture with HSDPAUniversity


Telecom Israel

Node B Node B Node B Node B Uu Node B Node B Node B Node B


USIM

Mobile Equipment User Equipment

Iur Iub RNC MSC/ VLR

HLR/ AuC

Hardware and Software Changes Software Changes

Iucs

GMSC

PSTN/ ISDN

Core Network UTRAN

Understanding HSPA

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HSDPA Protocol StackUniversity


Telecom Israel

Understanding HSPA

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HSDPA ChannelsUniversity


Telecom Israel

New HSDPA ChannelsTransport Channel

High Speed Downlink Shared Channel (HS-DSCH) Downlink Transport Channel

Physical Channels

High Speed Shared Control Channel (HS-SCCH) Downlink Control Channel

High Speed Physical Downlink Shared Channel (HS-PDSCH) Downlink Data Channel

High Speed Dedicated Physical Control Channel (HS-DPCCH) Uplink Control ChannelPage 51

Understanding HSPA

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HSDPA Channels (continued)University


Telecom Israel

Understanding HSPA

Page 52

HSDPA Operation OverviewUniversity


Telecom Israel

HSDPA OperationHS-DPCCH HS-DSCH HS-SCCH P-CPICH

1. Each UE reports channel quality on HS-DPCCH. 2. The Node B determines which and when each UE is to be served. 3. The Node B informs the UE to be served via HS-SCCH. 4. Then deliver the data to the UE via HS-DSCH. 5. The UE sends feedback (ACK/NAK) back to Node B on HS-DPCCH.Page 53

3dTower.emf

Node BPC C H SSC HS P-D C C SC PI H C H H H

UE

Understanding HSPA

H

SD

18

HSDPA Channel Operation TimelineUniversity


Telecom Israel

Understanding HSPA

Page 54

HS-PDSCHUniversity


Telecom Israel

High Speed Physical Downlink Shared Channel (HS-PDSCH)

Carries UE data Up to 15 HS-PDSCH may be assigned simultaneously UE capability indicates maximum number of codes it supports

Uses Spreading Factor = 16Understanding HSPAPage 55

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HS-DPCCHUniversity


Telecom Israel

ACK/ NAK

CQI

HS-DPCCH Uplink Channel 2 ms 3 slots

High Speed Dedicated Physical Control Channel (HS-PDCCH) 1st slot carries ACK or NAK for received HS-DSCH blocks 2nd and 3rd slots carry Channel Quality Indicator (CQI) UE measures Downlink CPICH channel quality CQI indicates the highest data rate for error rate < 10% Frequency of CQI reports configured by UTRAN

DTX during ACK/NAK and CQI slots if nothing to send Uses Spreading Factor = 256Page 56

Understanding HSPA

HS-SCCHUniversity


Telecom Israel

High Speed Shared Control Channel (HS-SCCH)

1st part carries modulation information OVSF code assignment Modulation scheme

2nd part carries transport block size, Hybrid ARQ parameters UE Identity encoded over each part UE decodes each part independently

UE assigned up to 4 HS-SCCHs to monitor Uses Spreading Factor = 128Understanding HSPAPage 57

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Data Rate ExampleUniversity


Telecom Israel

Question:

Assuming a transport block size of 320 bits, what HSDPA data rate can be achieved by a single UE using the channel allocation timing shown above?Understanding HSPAPage 58

Data Rate Example (cont.)University


Telecom Israel

Answer: 320 bits are transmitted every 10 ms, so the maximum data rate is 32 kbps.Understanding HSPAPage 59

21

Theoretical HSDPA Maximum Data RateUniversity


Telecom Israel

How do we get from 32 kbps to 14.4 Mbps?

Multi-code transmission Consecutive assignments using multiple HybridAutomatic Repeat Request (HARQ) processes

Lower coding gain 16-QAM

Understanding HSPA

Page 60

Multi-code TransmissionUniversity


Telecom Israel

Data Rate with 15-code Multi-code32 kbps X 15 = 480 kbps

Understanding HSPA

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Consecutive AssignmentsUniversity


Telecom Israel

Data Rate with Consecutive Assignments480 kbps X 5 = 2.4 Mbps

Understanding HSPA

Page 62

Hybrid Automatic Repeat Request (HARQ)University


Telecom Israel

Hybrid Automatic Repeat Request (HARQ)

Each HSDPA assignment is handled by a HARQ process HARQ Processes run in Node B and UE Up to 8 HARQ processes per UE Number configured by Node B when HSDPA operations begin

The UE HARQ process is responsible for: Attempting to decode the data Deciding whether to send ACK or NAK Soft-combining of retransmitted data

The Node B HARQ process is responsible for: Selecting the correct bits to send according to the selected retransmission scheme and UE capability

Understanding HSPA

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Lower Coding GainUniversity


Telecom Israel

R=1/3 Turbo Coding and QPSK Modulation

Understanding HSPA

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Lower Coding Gain (continued)University


Telecom Israel

Data Rate with Rate 1 Turbo Coding and QPSK Modulation2.4 Mbps X 3 = 7.2 Mbps

Understanding HSPA

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16-QAMUniversity


Telecom Israel

Data Rate with 16-QAM7.2 Mbps X 2 = 14.4 Mbps

Understanding HSPA

Page 66

Theoretical HSDPA Maximum Data RateUniversity


Telecom Israel

Review: How do we get to 14.4 Mbps? Multi-code transmission Node B must allocate all 15 OVSF codes of length 16 to one UE

Consecutive assignments Node B must allocate all time slots to one UE UE must decode all transmissions correctly on the first transmission

Lower Coding Gain Effective code rate = 1 Requires very good channel conditions to decode

16-QAM Requires very good channel conditions

Understanding HSPA

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25

Inter-TTI IntervalUniversity


Telecom Israel

Inter-TTI Interval = 2CQI ACK ACK ACK

HS-DPCCH

HS-SCCH

HS-PDSCH 1

. . .HS-PDSCH N

. . .

. . .

. . .

. . .

. . .

1 2 msUnderstanding HSPA

2

3

4

5

6

7

8Page 69

RetransmissionsUniversity


Telecom Israel

NAK HS-DPCCH

ACK

ACK

ACK

ACK

ACK

ACK

HS-SCCH

HS-PDSCH 1

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

. . .

HS-PDSCH 15

1 2 ms

2

3

4

5

6

7

8

9

10

10 ms minimum retransmit intervalUnderstanding HSPAPage 70

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ACK/NAK RepetitionsUniversity


Telecom Israel

Understanding HSPA

Page 71

Node B Implementation ConsiderationsUniversity


Telecom Israel

Node B Considerations

OVSF Code Allocation Power Allocation CQI Report Processing Scheduler HSDPA Cell Re-pointing Procedure Compressed Mode

Understanding HSPA

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OVSF AllocationUniversity


Telecom Israel

HS-SCCH

SCCPCH

Understanding HSPA

Page 73

Node B Transmit Power AllocationUniversity


Telecom Israel

Total available cell power

Total available cell power

Understanding HSPA

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CQI Report ProcessingUniversity


Telecom Israel

UE measures CPICH strength Measurement reference period is 3 slots, ending 1 slot before CQI is sent

UE reports index into CQI Table Highest data rate for which UE can guarantee error rate < 10%

Node B may filter CQI reports Varying CQI means UE is in a fast changing environment Steady CQI means UE is in a stable environment

Understanding HSPA

Page 75

Node B SchedulerUniversity


Telecom Israel

Pure Time Division MultiplexingUser #1 User #2 User #2 User #3 User #1 User #4 User #4 User #2 User #1

15 codes reserved for HS-PDSCH transmission

HS -DSCH TTI (3 slots = 2 ms)

User #1 User #3

User #2 User #4

Combined Code and Time Division Multiplexing

User #1 User #3Understanding HSPA

User #2 User #4Page 76

29

HSDPA Cell Re-pointing ProcedureUniversity


Telecom Israel

Understanding HSPA

Page 77

HSUPA PerformanceUniversity


Telecom Israel

Maximum Theoretical Data Rate:

14.4 Mbps 15 codes 16QAM Consecutive assignments (Inter-TTI spacing of 1) Coding Rate of 1

Practical Peak Data Rate:

10.0 Mbps Full capability UE Good RF conditions (High Cell Geometry) Single UE

Dedicated HSDPA carrierPage 79

Understanding HSPA

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University


Telecom Israel

Part II: Understanding HSUPA

Understanding HSPA

Page 80

Release 99 Uplink Packet DataUniversity


Telecom Israel

How is Uplink Packet Data handled in Release 99?

DCH (Dedicated Channel) Variable spreading factor Closed loop power control Macro diversity (soft handover)

RACH (Common Channel) Common spreading code Fixed (negotiated) spreading factor No closed loop power control No soft handover

Understanding HSPA

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Release 99 Uplink LimitationsUniversity


Telecom Israel

Large Scheduling Delays Slow scheduling from RNC

Large Latency Transmission Time Interval (TTI) durations of 10/20/40/80 ms RNC based retransmissions in case of errors

Limited Uplink Data Rate Deployed peak data rate is 384 kbps

Limited Uplink Cell Capacity Typically about 800 kbps

Understanding HSPA

Page 82

High Speed Uplink Packet Access (HSUPA)University


Telecom Israel

Set of high speed channels is received at the Node B. Interference is shared by multiple users. Several users may be allowed to transmit at given data rateand power on a fast scheduling.Understanding HSPAPage 83

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Enhancements Provided by HSUPAUniversity


Telecom Israel

How will HSUPA address the limitations of Release 99? Higher Peak Data Rate in Uplink Enable new services and improve user perception

Improved Uplink Coverage for higher Data Rates Improved Uplink Cell Capacity Reduced Latency Fast Scheduling and Resource Control Increase resource utilization and efficiency

Quality of Service (QoS) support Improve QoS control and resource utilizationUnderstanding HSPAPage 84

How are Enhancements Achieved?University


Telecom Israel

Release 99 UL DCHMinimum TTI of 10 ms Slow UL rate switching (RNC based)

HSUPASmaller TTI of 2 ms Fast UL data rate control in the Node B Improved Physical Layer performance through HARQImproved Cell Capacity Higher Peak Data Rates Reduced Latency Improved QoS Support Faster Resource Control

Dedicated resource allocation that could not be used efficiently Slow mechanism to request resources Multiplexing of transport channels at Physical LayerUnderstanding HSPA

Dedicated resource allocation for latency sensitive applications Fast mechanism to request UL resources Multiplexing of logical channels at MAC layer

New Transport Channel

New Physical ChannelsPage 85

33

HSUPA vs. HSDPAUniversity


Telecom Israel

HSDPA New high-speed Channel Shared

HSUPA Dedicated Channel with Enhanced Capabilities

HARQ with Fast Retransmission at Layer 1

Rate/Modulation Adaptation Single Serving Cell Fast Node-B Scheduler One-to-ManyShared Node-B Power and CodeUnderstanding HSPA

Fast Power Control Soft Handover Fast Node-B Scheduler Many-to-OneRise-over-Thermal (RoT)Page 86

Rise-over-Thermal NoiseUniversity


Telecom Israel

Grant Received from NodeB

4

In order to decode received data correctly, a minimum SINR shall be guaranteed at the Node B receiver. Rise-over-Thermal is a measure of the Uplink load.

UE Data Rate

5UE Transmit Power

1. By increasing the number of transmitting UEs and their transmit power, the level of interference in the Uplink band increases.Interference from other UEs

1NodeB

2. This interference is perceived by the Node B receiver as noise, affecting the SINR. 3. The Node B controls the interference level by adjusting the UE grant assignments. 4. When the UE receives a new grant, it uses it in combination with available UE transmit power and the amount of data in the buffer 5. to determine the data rate and the corresponding transmit power.Page 87

2 3Determination of grant for the UE (At NodeB) UL Interference Level (RoT measure)

Understanding HSPA

34

Node B Scheduler for HSUPAUniversity


Telecom Israel

The HSUPA scheduler addresses the trade-off between: andSeveral users that want to transmit at high data rate all the time Satisfying all requested grants while preventing overloading and maximizing resource utilization

3dTower.emf

Node B

Understanding HSPA

Page 88

Rise-over-Thermal LoadingUniversity


Telecom Israel

With the introduction of HSUPA, a lower Uplink margin for preventing overload situations can be used, thanks to the fast resource allocation and control mechanisms in the Node B.RoT Overload

R6 UL margin R99 UL

Target Load

load

Possible additional load with HSUPAUnderstanding HSPAPage 89

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HSUPA Channel OperationUniversity


Telecom Israel

HSUPA Operation1. The UE sends a Transmission Request to the Node B for getting resources.3dTower.emf

EQ

R

G

R

AN

Node B

2. The Node B responds to the UE with a Grant Assignment, allocating Uplink band to the UE. 3. The UE uses the grant to select the appropriate transport format for the Data Transmission to the Node B. 4. The Node B attempts to decode the received data and send ACK/NAK to the UE. In case of NAK, data may be retransmitted.Page 90

T AT A

UE

Understanding HSPA

A C

D

K

/N

AK

HSUPA Channel Operation (continued)University


Telecom Israel

1. Transmission RequestThe UE requests data transmission by means of the Scheduling Information (SI), which is determined according the UE Power and Buffer Data availability. The scheduling information is sent in-band to the Node B.

Understanding HSPA

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36



Telecom Israel

2. Grant AssignmentThe Node B determines the UE Grant by monitoring Uplink interference (RoT at the receiver), and by considering the UE transmission requests and level of satisfaction. The grant is signaled to the UE by new grant channels.

Understanding HSPA

Page 92



Telecom Israel

3. Data TransmissionThe UE uses the received grant and, based on its power and data availability, selects the E-DCH Transport Format and the corresponding Transmit Power. Data are transmitted by the UE on together with the related control information.

Understanding HSPA

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37



Telecom Israel

4. Data AcknowledgmentThe Node B attempts to decode the received data and indicates to the UE with ACK/NAK if successful. If no ACK is received by the UE, the data may be retransmitted.

Understanding HSPA

Page 94

UMTS Network Architecture with HSUPAUniversity


Telecom Israel

Node B Node B Node B Node B Uu Node B Node B Node B Node B


USIM

Mobile Equipment User Equipment

Iur Iub RNC MSC/ VLR

HLR/ AuC

Hardware and Software Changes Software Changes

Iucs

GMSC

PSTN/ ISDN

Core Network UTRAN

Understanding HSPA

Page 95

38

HSUPA Protocol StackUniversity


Telecom Israel

Understanding HSPA

Page 96

HSUPA Uplink ChannelsUniversity


Telecom Israel

New HSUPA Uplink Channels:

Enhanced Uplink Dedicated Channel (E-DCH) Uplink Transport Channel

E-DCH Dedicated Physical Data Channel (E-DPDCH) Uplink Physical Channel

E-DCH Dedicated Physical Control Channel (E-DPCCH) Uplink Control Channel

Understanding HSPA

Page 99

39

HSUPA Downlink ChannelsUniversity


Telecom Israel

New HSUPA Downlink Channels:

E-DCH Hybrid ARQ Indicator Channel (E-HICH) Downlink Physical Channel

E-DCH Absolute Grant Channel (E-AGCH) Downlink Physical Channel

E-DCH Relative Grant Channel (E-RGCH) Downlink Physical Channel

Understanding HSPA

Page 100

HSUPA Channel MappingUniversity


Telecom Israel

Rel. 99 Rel. 5 Rel. 6

Understanding HSPA

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40

Uplink ChannelsUniversity


Telecom Israel

E-DPDCH Carries the payload. May include a schedulingrequest from UE to Node B.

HD

PAYLOAD

SI

TTI

E-DPCCH Carries control informationrequired to decode the payload carried by EDPDCH.

Carries an indication fromUE to indicate to the Node B whether the assigned resources are adequate.

Understanding HSPA

Page 102

Downlink ChannelsUniversity


Telecom Israel

E-AGCH

The absolute grant carries maximum allowed E-DPDCH/DPCCH ratio. Carries information that controls HARQ process.Up / Down / Hold

E-RGCH

The relative grant carries a simple command to increase (UP), Decrease (DOWN), or keep (HOLD) the current grant.

TTIACK/NAK

E-HICH

Gives feedback to the UE about previous data transmission, carrying Acknowledge (ACK) or Not Acknowledge (NAK).

TTIUnderstanding HSPAPage 103

41

HSUPA Channel TimingUniversity


Telecom Israel

Understanding HSPA

Page 104

HSUPA Features (continued)University


Telecom Israel

Shorter TTI of 2 ms In HSUPA both 10 ms and 2 ms TTI are supported A shorter TTI allows reduction of the latency and increasing the average and peak cell throughput A tighter resource control can be implemented, thus allowing for additional capacity

Higher Peak Data Rate For a 10-ms TTI UE, peak data rate is limited to 2 Mbps Higher peak data rates can be achieved with a 2-ms TTI UE 5.76 Mbps is the maximum peak data rate for HSUPAUnderstanding HSPAPage 105

42



Telecom Israel

Hybrid-ARQ N-channel Stop-and-Wait (SAW) protocol, with 4 processes for 10 ms TTI and 8 processes for 2 ms TTI3dTower.emf

E-DCH cells part of the Active Set

3dTower.emf

Separate HARQ feedback is provided per Radio-Link

AC K

DA TA

Synchronous retransmission

Node B

Node B

K NA

TA DA

Understanding HSPA

Page 106



Telecom Israel

Rate Request

The UE requests grant for data transmission The UTRAN controls the grants for transmission on Uplink Scheduled transmissions granted by the Node B for high speed data Non-Scheduled transmissions granted by the RNC for delay-sensitive applications

Rate Control

Load Control

The UTRAN monitors Rise-over-Thermal (RoT) noise at the Node B receiver. UTRAN prevents overloading by reducing scheduled grants to UEs

Understanding HSPA

Page 107

43



Telecom Israel

HSUPA Quality of Service (QoS) QoS is linked to a logical channel. Up to 15 logical channels can be multiplexed on a single MAC-e PDU. Each logical channel may have a different QOS and a different priority level.Air interface

Priority level is considered while forming a MAC-e PDU. Parameters affecting HSUPA performance are set as per the QoS requirements.

Understanding HSPA

Page 109

E-DCH Active Set and Mobility SupportUniversity


Telecom Israel

Example with an Active Set of 4 cells3dTower.emf

There are three different types of Radio Links in the UE Active Set:

Node B

Serving E-DCH cell

Serving E-DCH Cell The cell from which UE receives AGCH from scheduler. Serving (E-DCH) RLS Set of cells that contain at least the serving cell and from which the UE can receive and combine the serving RGCH. Non-Serving RL Cell that belongs to the E-DCH Active Set but does not belong to the serving RLS and from which the UE can receive a RGCH.

Non-Serving Radio Links (RL)

3dTower.emf

Node B3dTower.emf

Node B

Serving E-DCH Radio Link Set (RLS)

Understanding HSPA

Page 110

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HSUPA Serving Cell ChangeUniversity


Telecom Israel

From the 3GPP Standards: HSUPA Serving Cell is the same as HSDPA Serving CellUnderstanding HSPAPage 111

Active Set Composition with HSUPAUniversity


Telecom Israel

All cells belonging to the UE AS that handle E-DCH

All cells belonging to the UE AS

DPCH Active Set (max 6 cells) E-DCH Active Set (max 4 cells)NonServing RL

Other AS cell

E-DCH Serving Cell

Serving RL

Serving RLServing RLS

NonServing RL

Other AS cell

Send AGCHUnderstanding HSPA

UE can combine RGCH commands from these cells

Send nonserving RGCH

Is in SHOPage 112

45

Theoretical HSUPA Maximum Data RateUniversity


Telecom Israel

How do we get 5.76 Mbps? Lower Coding Gain Effective code rate = 1 Requires very good channel conditions to decode

Lower Spreading factor UE can use SF2

Multi-code transmission UE can use up to 4 codes, 2 with SF4 plus 2 with SF2 Require some power back-off at UE side

Shorter TTI Requires higher processing capabilities at terminal and Node BPage 113

Understanding HSPA

E-DPDCH with SF4 and PuncturingUniversity


Telecom Israel

Maximum payload for spreading factor of 4, TTI of 2 ms and coding rate of 1 is 1920 bits (for 960 kpbs).Understanding HSPAPage 114

46

Lower Spreading Factor SF2University


Telecom Israel

Maximum payload for spreading factor of 4, TTI of 2 ms and coding rate of 1 is 3840 bits (for 1920 kpbs).Understanding HSPAPage 115

Multi-code TransmissionUniversity


Telecom Israel

Use of multi-code transmission 2 x SF2 + 2 x SF4(2 x 1920 kbps) + (2 x 960 kbps) = 5760 kbps

Understanding HSPA

Page 116

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HSUPA UE CapabilitiesUniversity


Telecom Israel

E-DCH Category Category 1 Category 2 Category 3 Category 4 Category 5 Category 6

Max number of E-DPDCH channels 1 2 2 2 2 4

Minimum SF SF 4 SF 4 SF 4 SF 2 SF2 SF2 + SF 4

Supported TTI 10 ms 2 & 10 ms 10 ms 2 & 10 ms 10 ms 2 & 10 ms

Peak rate for TTI = 10 ms* 711 kbps 1448 kbps 1448 kbps 2000 kbps 2000 kbps 2000 kbps

Peak rate for TTI = 2 ms -1448 kbps -2886 kbps -5742 kbps

* Maximum Peak data rate for 10 ms E-DCH TTI operation is 2 Mbps in all configurationsUnderstanding HSPAPage 117

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HSPA

Documents

umts hspa

hspa peak data ratepage

high data rates

basic understanding

hspa implementation

data rate demand

high speed data cdma2000

higher peak data rates