dc hspa+ qualcomm

MAY CONTAIN U.S. EXPORT CONTROLLED INFORMATION

DC-HSDPA Seminar for STC

December 8, 2010


DC-HSDPA

Describe the motivations for DC-HSDPA

Highlight the impacts / changes in Access Stratum

Examine the impacts on existing deployment

Outline the future 3GPP multi-carrier roadmap


References

3GPP Release 8 Specification References

TS 25.211 Physical Channels and mapping of Transport Channels onto

Physical Channels

TS 25.214 Physical Layer procedures

TS 25.306 UE Radio Access Capabilities specification

TS 25.331 Radio Resource Control (RRC) protocol specification

TS 25.433 UTRAN Iub interface Node B Application Part (NBAP)

signalling

TR 25.825 Dual-Cell HSDPA Operation (Withdrawn)


Outline

• Motivations

• Impacts on Access Stratum

• Impacts on Existing Deployment

• Future Multi-Carrier Roadmap


DC-HSDPA allows the use of two adjacent DL carriers for increasing the downlink data rate

More physical layer resources become available with DC-HSDPA

• Up to two transport blocks can be sent without using MIMO

• Peak data rate becomes doubled

What is DC-HSDPA?

Aggregated

Data Pipe

HS-DSCH 2

HS-DSCH 1

Up to 21Mbps with HSPA+ 64QAM

Up to 21Mbps with HSPA+ 64QAM

Up to 42Mbps


Advantages:

• Higher peak and average single user downlink data rate with 2 DL carriers (Up to 42Mbps)

• Reduced latency due to higher user throughput

• Higher cell capacity due to greater trunking efficiency and effective use of the 2 downlink carriers (increased diversity) in data scheduling

• Increased capacity for bursty applications, e.g. web applications

Motivations for DC-HSDPA


Trunking Efficiency Gain with DC-HSDPA

• Bursty traffic creates unused TTIs on each carrier which cannot be efficiently used by SC users

• Node B scheduler is able to schedule DC-HSDPA users on these TTIs

• This significantly increase the trunking efficiency and thus provides signficiant capacity gain especially for very bursty applications such as HTTP web browsing

Scheduling on F1

Scheduling on F2

Time

Time

However, these TTIs on different carriers

can be aggregated to serve more bursty traffic

Unused TTIs on each carrier may not be

sufficient to serve more bursty traffic with QoS


DC-HSDPA provides capacity gain beyond linear gain

Higher Capacity and Better User Experience

Cap

acity In

cre

ase

User Experience Boost

– Keeping the same average data burst rate (3Mbps), the capacity is increased by +200%

– Keeping the same capacity (10 users/sector), the average data burst rate is doubled

Better User Experience

– Trunking efficiency provides more than 100% capacity gain at low to intermediate loads

+100%


Outline

• Motivations





• UE DC-HSDPA Support

• Physical Layer Configuration

• Secondary cell configuration

• DC-HSDPA topology

• HS-SCCHs and HS-DPCCH

• Compatibility with other features

• MAC Layer Configuration

• MAC-ehs and HARQ

• Mobility and Measurement Reporting

• Intra-frequency

• Inter-frequency and Inter-RAT

• NBAP Signaling

Impacts on Access Stratum due to DC-HSDPA


UE DC-HSDPA Support

UE indicates its support for multi cell operation in the

RRC Connection Request message

• The presence of the “Multi cell support” IE (RRCConnectionRequest-v860ext-IE) indicates that the UE can support DC-HSDPA

UE indicates its HS-DSCH reception capability in the RRC

Connection Setup Complete message

• Apart from the legacy HS-DSCH categories, the DC-HSDPA UE also reports its support of HS-DSCH category 21 to 24 in the Release 8 physical layer category extension


Additional HS-DSCH Categories

HS-DSCH Category

Max # of Codes

Min Inter-TTI Interval

Max TB size Supported Modulation

Peak Rate

… … ….

21 15 1 23370QPSK / 16QAM

23.4 Mbps

22 15 1 27952QPSK / 16QAM

28.0 Mbps

23 15 1 35280QPSK /

16QAM / 64QAM

35.3 Mbps

24 15 1 42192QPSK /

16QAM / 64QAM

42.2 Mbps

HS-DSCH category 21-24 support “Dual-Cell Operation”

• MIMO is not supported during Dual-Cell Operation in 3GPP R8

• Cat 21 and 22 do not support 64QAM modulation

• Cat 23 and 24 support 64QAM modulation

• Code rates for Cat 21 and 23 are limited to only 0.823

• Maximum L1 data rate in Release 8 DC-HSDPA is 42Mbps (Category 24)


Secondary Cell Configuration

• Two downlink carriers defined in RRC signaling messages

• Two “adjacent” downlink carriers – within 5MHz from each other in the same band

• “Downlink Secondary Cell Info FDD” contains the secondary cell configuration

Adjacent Frequency: A frequency whose centre is within 5 MHz of

the centre of the currently used frequency and belongs to the

same frequency band as that of the currently used frequency.

IE Notes

UARFCN downlink 0 – 16383

Primary CPICH info PSC: 0 – 511

DL Scrambling Code DL SC for HS-DSCH and HS-SCCH

(default is same as primary CPICH)

New H-RNTI For the secondary cell

HS-SCCH Channelisation Code Info and Code Number of HS-SCCHs and Code No

Downlink 64QAM configured Use 64QAM format HS-SCCH and

octet aligned TBS table

HS-DSCH TB Size Table (if Not64QAM) Use octet aligned TBS table

Measurement Power Offset (-6 .. 13) in steps of 0.5

With or without 64QAM

Diff HS-SCCH config is OK

Independent MPO

Not necessarily same PSC


Dual-Cell Topology

• The nominal radio frame timing for CPICH and timing reference are the same on the secondary serving HS-DSCH cell

• UE shall not assume the presence of any common physical channels from the secondary cell other than CPICH

HS-SCCH set 1

HS-DSCH 1

HS-SCCH set 2

HS-DSCH 2

Same Timing

CPICH 2

CPICH 1 + CCCHs

May not have other CCCHs


HS-SCCH Configuration for DC-HSDPA

• HS-SCCH Set monitored by the UE

• One set for primary and one set for secondary serving HS-DSCH cell (if active)

• Maximum size is 4 per carrier and up to 6 in total

• HS-DSCH or HS-SCCH Order

• UE can receive either data or network command on each frequency carrier• Data: Up to 1 HS-DSCH per frequency carrier, or

• Network Command: Up to 1 HS-SCCH Order per carrier

HS-SCCH set 1

Up to 4 HS-SCCHs

Up to 4 HS-SCCHs

Up to 6

HS-SCCHs

in total

HS-DSCH 1

HS-SCCH set 2

HS-DSCH 2

HSPA+ Carrier #1

(Non-Serving HS-DSCH Cell)

HS-SCCH Up to 1 HS-SCCH


Activation and Deactivation of Secondary Cell HS-DSCH Reception

Secondary Cell HS-DSCH Reception is activated if the following conditions are met:

• The UE is in Cell_DCH state

• Valid secondary cell configuration is contained in “Downlink Secondary Cell Info FDD”

• HS-DSCH reception is activated

The UE shall de-activate the Secondary Cell HS-DSCH Reception, clear the stored secondary cell configuration, flush the HARQ buffers and release the HARQ resources (associated to the secondary serving HS-DSCH cell) if any of the following conditions is met:

• The UE leaves the Cell_DCH state

• “Downlink Secondary Cell Info FDD” is empty

• HS-DSCH reception is de-activated

The network can also activate/de-activate the Secondary Cell HS-DSCH Reception using the HS-SCCH orders

• More information to follow in subsequent slide


HS-SCCH Format for DC-HSDPA

• HS-SCCH Type 1 is used during Dual Cell Operation

• MIMO (HS-SCCH Type 3) and HS-SCCH-less (HS-SCCH Type 2) are not allowed in conjunction with DC-HSDPA in 3GPP Release 8

• Secondary serving HS-DSCH cell activation / deactivation (1 bit)

• The third order bit (xord,3) is used to activate / deactivate secondary serving HS-DSCH cell

• UE behavior is unspecified if contradictory HS-SCCH orders are received

CCS

(7 bits)

(1110000)

Mod.

(1 bit)

(„0‟)

Part 1

Spec. Info. type

(6 bits)

(„111101‟)

Part 2

UE CRC

(16 bits)

Spec. Info. Bits (7 bits)

Order Type

(3 bits)

(„001‟)

Order

(3 bits - first 2

bits reserved)

Reserved

(1 bit)HS-SCCH Order

xord,3 = xsecondary,1 = „1‟

xord,3 = xsecondary,1 = „0‟

DC-HSDPASC-HSDPA

HS-SCCH set 2

HS-SCCH set 1HS-SCCH set 1


HS-DPCCH – ACK/NACK

• HS-DPCCH redesign is needed to support the transmissions of two sets of ACK/NACK for the primary and secondary serving HS-DSCH cells

• ACK/NACK coding scheme is similar to the MIMO one (with10 bits data)

• 10 codewords (c.f. 8 for MIMO) to represent all combinations of ACK, NACK, and “No Transmission” for the two carriers plus 2 codewords for PRE and POST

Codeword

No

HARQ Response Type HARQ Response to the

Serving HS-DSCH Cell

HARQ Response to the Secondary


1 Single TB on the Serving HS-

DSCH Cell

ACK

2 NACK

3 Single TB on the Secondary


ACK

4 NACK

5

Single TB on each of the

Serving and Secondary Serving

HS-DSCH cells

ACK ACK

6 ACK NACK

7 NACK ACK

8 NACK NACK

9 PRE

10 POST


HS-DPCCH - CQI

• HS-DPCCH redesign is needed to support the transmissions of two sets of CQI for the primary and secondary serving HS-DSCH cells

• CQI coding scheme is also similar to the MIMO one (with10 bits data)

• 10 bits are used to carry two individual CQI reports: CQI1 and CQI2

• CQI1 corresponds to the serving HS-DSCH cell and CQI2 corresponds to the secondary serving HS-DSCH cell

• This allows 5 bits CQI for each carrier (allowing CQI values ranging from 0 to 30)

• Legacy 16QAM and 64QAM CQI tables are used as per TS25.214

• Same timing and reporting as per 3GPP Release 7

HS-DSCH

Category

CQI Mapping Table Reference

64QAM

not configured

64QAM

configured

13 C F

14 D G

21 CN/A

22 D

23 C F

24 D G

16QAM CQI Tables

64QAM CQI Tables


1.41

1.45

1.60

1.72

1.82

2.96

3.05

3.36

3.58

3.65

5.92

6.11

6.72

7.08

7.21

8.46

8.73

9.60

10.13

10.13

12.15

12.53

13.79

13.98

13.98

18.34

18.92

20.81

21.10

21.10

24.29

25.07

27.57

27.95

27.95

36.69

37.85

41.64

42.19

42.19

0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00

Cat 24 TP (Mbps)

Cat 16 TP (Mbps)

Cat 14 TP (Mbps)

Cat 10 TP (Mbps)

Cat 9 TP (Mbps)

Cat 8 TP (Mbps)

Cat 6 TP (Mbps)

Cat 12 TP (Mbps)

1. Max Throughput

3GPP layer 1

2. Max Throughput

UTRAN layer 1

3. Max RLC

Throughput

4. Consider average

10% S-BLER

5. Discount

TCP/IP headers

DC-HSDPA Throughput


Compatibility with Other Features

• CPC - DTX and DRX

• DC-HSDPA can operate simultaneously with DTX and DRX

• DRX timing and status must be the same for both carriers

• CPC - HS-SCCH-less

• HS-SCCH-less HS-DSCH transmission on the secondary serving HS-DSCH cell is not allowed in conjunction with DC-HSDPA

• MIMO

• DC-HSDPA does not support MIMO in 3GPP Release 8

• Transmit Diversity

• STTD is allowed during dual cell operation but the configuration needs to be the same for both carriers. CLTD, TSTD and MIMO are not allowed in conjunction with DC-HSDPA.


MAC

Joint Queue Scheduling

• Simple design for fast implementation

One HARQ Entity per HS-DSCH

• Separate HARQs running on each carrier with no interaction (different than MIMO)

• Retransmissions sent on the same carrier only

One MAC-ehs entity

• RLC is not affected

MAC-ehs

MAC – Control

Associated Uplink Signalling

To MAC-d

Associated Downlink

Signalling

HS-DSCH

HARQ

Reordering Reordering

LCH-ID Demux LCH-ID Demux

Reassembly Reassembly

Associated

Uplink Signalling

Associated Downlink Signalling

HS-DSCH

HARQ

Re-ordering queue distribution

Disassembly


Mobility – Active Set in DC-HSDPA

• Active Set considers the Serving HS-DSCH cell frequency only

• Secondary serving HS-DSCH cell on supplementary carrier is disregarded in the active set definition

• No increase in ASET size

• Active Set Update and Serving Cell Change triggered by intra-frequency events with reference to the Serving HS-DSCH cell only

• Active Set Update: Event 1a, 1b, 1c on the primary carrier

• Serving Cell Change (SCC): Event 1d, (and potentially 1a, 1c) on the primary carrier

• Enhanced Serving Cell Change (E-SCC) is supported with DC-HSDPA configured

Active Set


Continuity of DC-HSDPA Upon Serving Cell Change

• DC-HSDPA can continue after Serving Cell Change

• Active Set Update or Reconfiguration message can specify new secondary serving HS-DSCH cell configuration in “Downlink Secondary Cell Info FDD”

• There is flexibility in controlling when to turn on /off the secondary cell HS-DSCH reception

• HS-SCCH orders can be used to de-activate / activate secondary cell HS-DSCH reception

• For example, original serving cell may de-activate DC-HSDPA upon reception of event 1d measurement report, and target serving cell may activate DC-HSDPA after successful serving cell change


Mobility – Inter-Frequency and Inter-RAT

• Inter-Frequency and Inter-RAT measurement reporting based on the Serving HS-DSCH cell frequency only

• Serving HS-DSCH cell frequency = current frequency = used frequency

• Secondary Serving HS-DSCH cell frequency = non-used frequency

• No impact on the Event 2d / 2f evaluation (triggering/de-triggering Compressed Mode measurements)

• No impact on the Event 3a evaluation (triggering Inter-RAT Handover)

• Compressed Mode measurements and Inter-RAT Handover triggered by

Event 3a: The estimated quality of the currently used UTRAN frequency is below a certain

threshold and the estimated quality of the other system is above a certain threshold.

Event 2d: The estimated quality of the currently used frequency is below a certain threshold.

Event 2f: The estimated quality of the currently used frequency is above a certain threshold.


Mobility – Moving from DC-HSDPA to SC-HSDPA

• Activation / De-activation of DC-HSDPA when moving between SC-HSDPA cell and DC-HSDPA cell

• L1: HS-SCCH order

• L3: Active Set Update, Physical Channel / Transport Channel / Radio Bearer Reconfiguration

• Blind / Measurement based DC-HSDPA reconfiguration

• DC-HSDPA reconfiguration can be based on the target serving cell configuration (without UE measurements)

• DC-HSDPA reconfiguration can also be based on UE measurements (if the coverage of the two carriers is different)

• Event 2c: The estimated quality of a non-used frequency is above a certain threshold

• Event 2e: The estimated quality of a non-used frequency is below a certain threshold


UE Measurement

• Measurement on Secondary Serving HS-DSCH cell frequency

• “Adjacent frequency index” IE extracted and stored in the variable “Adjacent frequency info” included in CELL_INFO_LIST

• UE may measure the secondary serving HS-DSCH cell frequency without Compressed Mode if the UE has such measurement capability (i.e., indicated in RRC Connection Setup Complete)

New Inter-Frequency Cells

{ CellID: 0

CellID: 1

CellID: 2

CellID: 3

…

CellID: maxCellMeas -1}

Index

CELL_INFO_LIST

Inter-Frequency Cell Info List

{ CellID: 0

CellID: 1

CellID: 2

CellID: 3

…

CellID: maxCellMeas -1

CELL_INFO_LIST

Adjacent Frequency Info

CELL_INFO_LIST

Carrier 1

Carrier 2


• DC-HSDPA needs to be signaled in the UMTS RAN and this requires changes to some NBAP and Iur messages:

• AUDIT RESPONSE

• RESOURCE STATUS INDICATION

• RADIO LINK SETUP REQUEST / RESPONSE / FAILURE

• RADIO LINK ADDITION REQUEST / RESPONSE / FAILURE

• RADIO LINK RECONFIGURATION PREPARE / READY / REQUEST / RESPONSE

• RADIO LINK PARAMTER UPDATE INDICATION

NBAP Signaling


Outline

• Motivations





Co-existence with Legacy UEs

• Legacy UEs and DC-HSDPA capable UEs can be mixed on the same carriers

• Separate HS-SCCH sets on the two carriers

• No need to set aside dedicated spectrum for DC-HSDPA


Effective Use of the Under-Utilized Carrier

• High traffic sector would require one voice carrier and two HSPA+ carriers

• Low traffic sector may not justify deployment of three frequency carriers

• Under-utilized voice carrier capacity can be utilized with DC-HSDPA

• Voice and other real-time applications should be prioritized by network QoS mechanism

• Smaller TBS assigned on F1 if resources are running low


Outline

• Motivations





DC-HSDPA and MIMO

• In 3GPP Release 9, DC-HSDPA can be combined with MIMO

• Upto 84Mbps in 10MHz

• Potentially higher spectral efficiency than Release 8 DC-HSDPA

• MIMO beamforming can improve cell-edge users

• Cell-edge users cannot benefit from 64QAM


Multicarrier Roadmap – 4 DL Carriers

• In 3GPP Release 9, aggregation of up to four DL carriers provides increased capacity due to greater trunking efficiency

• Improved user experience by bundling mutiple carriers

• Up to 84Mbps with 4x carriers (no MIMO)

• Efficient resource utilization by dynamic load balancing

• Load balancing also improves performance for legacy UEs

• DC-HSUPA can provide significant uplink throughput and capacity gain

• Uplink peak rate doubled to 23Mbps in 10MHz

• Greater trunking effciency and better user experiences


Multicarrier Roadmap – Multi-Band Support

• Aggregation across bands leverages operator’s complete spectrum assets

• Facilitates possiblity of aggregating more than two carriers

• Lower band coverage benefits for all MC UEs


DC-HSUPA

• In 3GPP Release 9, DC-HSUPA can provide significant uplink throughput and capacity gain

• Uplink peak rate doubled to 23Mbps in 10MHz

• Greater trunking effciency and better user experiences


DC-HSDPA –What Did We Learn?

Why was DC-HSDPA introduced?

What would be the impacts of DC-HSDPA on Access Statum?

What would be the impacts of DC-HSDPA on existing R7 deployment?

How does the future roadmap of multicarrier support look like?


Exercises

1. What are the improvements of multi-carrier HSDPA?

2. What are the limitations of 3GPP Release 8 DC-HSDPA?

3. How can the network activate / de-activate DC-HSDPA?

4. List the features that are not compatible with DC-HSDPA.

5. What enhancements does 3GPP Release 9 introduce in multi-carrier HSPA?


Exercises – Answers

1. What are the improvements of multi-carrier HSDPA?

Answer: Higher peak rate, increased capacity and better user experiences

2. What are the limitations of 3GPP Release 8 DC-HSDPA?

Answer: Only two adjacent carriers max (in the same band), 64QAM only

3. How can the network activate / de-activate DC-HSDPA?

Answer: L1: HS-SCCH orders, L3: Active Set Update, Reconfiguration messages, etc.

4. List the features that are not compatible with DC-HSDPA.

Answer: MIMO, CLTD, TSTD, HS-SCCH-less

5. What enhancements does 3GPP Release 9 introduce in multi-carrier HSPA?

Answer: 4 carriers HSDPA (64QAM), DC-HSDPA with MIMO, DC-HSUPA


Comments/Notes

dc hspa+ qualcomm

Documents

dchsdpa users

dchsdpa bursty traffic

signficiant capacity

access stratum impacts

average data burst rate

impacts changes

bursty applications

linear gainhigher capacity