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Transcript of HSPA
1 HSPA course.PPT / 08-10-2007 / AT&HH
Harri Holma, Principal EngineerAntti Toskala, Senior Manager, Standardisation
Nokia Siemens Networks, Finland
High Speed Packet Access HSDPA/HSUPA
October 8th 2007Tampere
2 HSPA course.PPT / 08-10-2007 / AT&HH
Agenda
• HSDPA in Release 5• HSUPA in Release 6• HSPA evolution in Release 7• HSPA evolution in Release 8
3 HSPA course.PPT / 08-10-2007 / AT&HH
WCDMA High Speed Downlink PacketAccess (HSDPA) of Release 5
4 HSPA course.PPT / 08-10-2007 / AT&HH
Outline• HSDPA Introduction• HSPDA Protocol Architecture• New Node B & UE functions• Modulation and coding• HSDPA & Soft Handover• HSDPA vs DCH/DSCH• HSDPA & Iub• Summary
5 HSPA course.PPT / 08-10-2007 / AT&HH
High Speed Downlink Packet Access HSDPA
• Peak data rates increased to significantly higher than 2 Mbps; Theoretically exceeding 10 Mbps
• Packet data throughput increased 50-100% compared to 3GPP release 4
• Reduced delay from retransmissions.• Solutions
• Adaptive modulation and coding QPSK and 16-QAM• Layer 1 hybrid ARQ• Short frame 2 ms
• Schedule in 3GPP• Part of Release 5• First specifications version completed 03/02
6 HSPA course.PPT / 08-10-2007 / AT&HH
HSPA Pushes Functionalities to Base Station• HSDPA = High Speed Downlink Packet Access • HSUPA = High Speed Uplink Packet Access• HSPA = HSDPA + HSUPA
HSDPA
HSUPA
Mobile Base station Radio network controller RNC
HSPA scheduling and retransmission control
in base station
HSPA scheduling and retransmission control
in base station
WCDMA R99 scheduling and retransmission
control in RNC
WCDMA R99 scheduling and retransmission
control in RNC
WCDMA R99 uplink/downlink
7 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA – General Principle
Terminal 1 (UE)
Terminal 2
L1 Feedback
L1 Feedback
Data
Data
Downlink fast schedulingdone directly by Node B (BTS) based on knowledge of:
• UE's channel quality• UE's capability• QoS demands• Power and code resource availability• Node B buffer status
Users may be time and/or code multiplexed
8 HSPA course.PPT / 08-10-2007 / AT&HH
Fast Link Adaptation in HSDPA
0 20 40 60 80 100 120 140 160-202468
10121416
Time [number of TTIs]
QPSK1/4
QPSK2/4
QPSK3/4
16QAM2/4
16QAM3/4
Inst
anta
neou
s Es
No
[dB]
C/I received by UE
Link adaptation
mode
C/I varies with fading
BTS adjusts link adaptation mode with a few ms delay based on channel quality
reports from the UE
9 HSPA course.PPT / 08-10-2007 / AT&HH
Release’99 RRM Functional Split
• Admission control on interference and power level• Initial power and SIR setting• Radio resource reservation• Air interface scheduling for common channels• DL code allocation and code tree handling• Load and overload control
• Admission control on interference and power level• Initial power and SIR setting• Radio resource reservation• Air interface scheduling for common channels• DL code allocation and code tree handling• Load and overload control
• Mapping RAB QoS Parameters into air interface L1/L2 parameters (incl. transport channel selection)• Air interface scheduling (for dedicated channels)• Handover Control• Outer loop power control and power balancing
• Mapping RAB QoS Parameters into air interface L1/L2 parameters (incl. transport channel selection)• Air interface scheduling (for dedicated channels)• Handover Control• Outer loop power control and power balancing
Radio network topology hidden to the CN
Radio network topology hidden to the CN
Node BServing
RNC SGSN
MSCDrift RNC
Iur IuIub
RRC
• Fast power control• Overload control
• Fast power control• Overload control
10 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA Protocol Architecture• New MAC entity, MAC-hs added to the Node B• Layers above, such as RLC, unchanged.
WCDMA L1
UE
Iub/Iur
SRNCNode B
Uu
MACRLC
NAS
HSDPA user plane
WCDMA L1
MAC-hs
TRANSPORT
FRAMEPROTOCOL
TRANSPORT
FRAMEPROTOCOL
MAC-dRLC
Iu
11 HSPA course.PPT / 08-10-2007 / AT&HH
Release’99 vs HSDPA Retransmissions
Terminal
BTS
RNC
Rel’99 DCH/DSCH Rel’5 HS-DSCH
Packet Retransmission
RLC ACK/NACK
Retransmission
L1 ACK/NACK
Packet
12 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA L1 Retransmissions• The L1 retransmission procedure (Hybrid ARQ, HARQ) achieves following
• L1 signaling to indicate need for retransmission -> fast round trip time facilitated between UE and BTS
• Decoder does not get rid off the received symbols when decoding fails but combines the new transmisssion with the old one in the buffer.
• There are two ways of operating:• A) Identical retransmission (soft/chase combining): where exactly same bits are
transmitted during each transmission for the packet• B) Non-identical retransmission (incremental redundancy): Channel encoder output is
used so that 1st transmission has systematic bits and less or not parity bits and in case retransmission needed then parity bits (or more of them) form the second transmission.
13 HSPA course.PPT / 08-10-2007 / AT&HH
Rate Matching• Turbo encoder coding rate = 1/3.• Rate Matching is used to adapt to the
desired coding rate.• Either puncturing or repetition.• In the example, RM punctures into
rate 3/4.• Note: The systematic bits are more
important than parity bits!
SystematicParity 1Parity 2
Turbo Encoder
Rate Matching (Puncturing)
SystematicParity 1Parity 2
Data
14 HSPA course.PPT / 08-10-2007 / AT&HH
SystematicParity 1Parity 2
Turbo Encoder
Rate Matching (Puncturing)
SystematicParity 1Parity 2
Chase Combining (at Receiver)
SystematicParity 1Parity 2
Original transmission Retransmission
Hybrid ARQ (HARQ): Chase Combining
15 HSPA course.PPT / 08-10-2007 / AT&HH
SystematicParity 1Parity 2
Turbo Encoder
Rate Matching (Puncturing)
SystematicParity 1Parity 2
Incremental Redundancy Combining
SystematicParity 1Parity 2
Original transmission Retransmission
Hybrid ARQ (HARQ): Incremental Redundancy
16 HSPA course.PPT / 08-10-2007 / AT&HH
HARQ Processes• Up to 8 processes can be configured per UE• HARQ principle used is stop-and-wait-ARQ• For continuous operation at least 6 processes is needed
HS-DSCH
1 2 3 4 5 6 1 2
…
CRC Check Result Fail Pass
NACKACK
RLC layer
1st TX 1st TX2nd TX
1st TX (new packet)
…
From scheduler buffer
17 HSPA course.PPT / 08-10-2007 / AT&HH
New Functionality in RAN/Terminals
Terminal
BTS
RNC
HSDPA Radio Resource &Mobility Management
HSDPA Iub Traffic ManagementLarger Data Volume
Data BufferingARQ Handling
Feedback DecodingFlow Control Towards RNC
Downlink Scheduling16QAM Modulation
ARQ Handling withSoft Value Buffer
Feedback Generation & Transmission
16QAM Demodulation
18 HSPA course.PPT / 08-10-2007 / AT&HH
Adaptive Modulation – QPSK and 16QAM• Release’99 uses QPSK • HSDPA uses both QPSK and 16-QAM• 16-QAM requires also amplitude estimation from CPICH for detection
QPSK 16QAM
19 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA - UE Categories• Theoretical peak bit rate up to 14 Mbps• For the market 1.8 Mbps and 3.6 Mbps capability expected initially, then 7.2 Mbps
10
9
7/8
5/6
3/4
1/2
12
11
HSDPACategory
-
-
-
3.6 Mbps
1.8 Mbps
1.2 Mbps
1.8 Mbps
0.9 Mbps
5 Codes
--36302QPSK only
--36301QPSK only
QPSK/16QAM
QPSK/16QAM
QPSK/16QAM
QPSK/16QAM
QPSK/16QAM
QPSK/16QAM
Modulation
14.0 Mbps
10.1 Mbps
-
-
-
-
15 Codes
-279521
-202511
7.2 Mbps144111
-72981
-72982
-72983
10 CodesTransportBlock sizeInter-TTI
20 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA DL Channel Structure• High speed downlink shared channel (HS-DSCH) carries the user data in the
downlink direction, with the peak rate up to 10 Mbps • High speed shared control channel (HS-SCCH) carries the necessary physical layer
control information to enable decoding of the data on HS-DSCH• Only one HS-SCCH needed if only time multiplexing is used• DCH always running in parallel
2 ms
HS-SCCHs
HS-DSCH
……
Demodulation information
User dataUser data
Control dataControl data
21 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA DL Channel Structure: HS-DSCH• HS-DSCH does not carry any physical layer control or pilot info, only user data (+
MAC layer/RLC layer headers)• Only difference in the slot formats is the use of QPSK or 16QAM modululation
Slot format #i Channel Bit Rate (kbps)
Channel Symbol Rate (ksps)
SF Bits/ HS-DSCH subframe
Bits/ Slot Ndata
0(QPSK) 480 240 16 960 320 320
1(16QAM) 960 240 16 1920 640 640
Slot #0 Slot#1 Slot #2
Tslot = 2560 chips, M*10*2 k bits (k=4)
Data Ndata1 bits
1 subframe: Tf = 2 ms
22 HSPA course.PPT / 08-10-2007 / AT&HH
HS-SCCH• The HS-SCCH is fixed data rate
channel with SF 128 (60 kbps)• First part carries
• code-set info• Modulation info
• Second Part• Transport-block size • Hybrid-ARQ process Redundancy and
constellation version• New data indicator
• Additionally UE identify informationis used target the information to correct user
• To separate which of the 4 HS-SCCHsUE needs to decode (UE specific masking)
• Decoder matrix to be observed…..
Channel coding & Rate Matching
Channel coding & Rate Matching
Channelisation codesModulation
Transport Block SizeHARQ ProcessRedundancy and Constellation VersionNew Data Indicator
UE Specific Masking
UE Specific CRC Attachment
Physical Channel Mapping
HS-SCCH
23 HSPA course.PPT / 08-10-2007 / AT&HH
HS-DSCH TX Chain
CRC Attachment
Bit Scrambling
Code Block Segmentation
Channel Coding
HARQ Functionality
Physical Channel Segmentation
Interleaving
16QAM ConstellationRe-arrangement
Interleaving
Physical Channel Mapping
HS-PDSCHs
• The HS-DSCH uses 1 to 15 codes with fixed SF 16
• Specific parts in the channelcoding chain are related to HARQ and 16QAM modulation (and somesimplifications as there is no DTX, compressed mode etc…)
• Impacted by 16QAM• Interleaving (two identical
interleavers with 16QAM TTIs)
• Constellation re-arrangement (same bits notin same constellation pointbetween retransmissions
24 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA UL Channel Structure• High Speed Dedicated Physical Control Channel (HS-DPCCH) carries the uplink
HSDPA related L1 control information to the BTS• This is parallel to the Uplink DCH• Timing from downlink packet to uplink feedback (ACK/NACK) is fixed thus
network knows for which packet the info is related to
2 ms
HS-SCCHs
HS-DSCH
7.5 slots (approx.)
HS-DPCCH
ACK/NACK Channel Quality Information
2 ms
CRC result
25 HSPA course.PPT / 08-10-2007 / AT&HH
MAC-hs Round-Trip Loop Timing• Minimum retransmission delay 12 ms
HS-SCCH
HS-PDSCH2 slots 3 slots
A = HS-DPCCH L1, MAC-hs,HS-SCCH L1
B = HS-PDSCH L1
Retransmit
Retransmit
CQIA/N
A B
18 slots = 12 ms 2 slots
2 x Tprop + 15.5 slots
26 HSPA course.PPT / 08-10-2007 / AT&HH
HS-DPCCH
message to be transmitted
w0
w1
w2
w3
w4
w5
w6
w7
w8
w9
ACK 1 1 1 1 1 1 1 1 1 1
NACK 0 0 0 0 0 0 0 0 0 0
PRE 0 0 1 0 0 1 0 0 1 0
POST 0 1 0 0 1 0 0 1 0 0
• The HS-DPCCH is fixed data rates channel with SF 256 • As this is BPSK channel, this gives 10 bits per slot• 1 slot used for ACK/NACK code word, 2 slots for the CQI info
• For CQI one of the 0 .. 30 values transmitted (one unused value)•(20,5) code used
i Mi,0 Mi,1 Mi,2 Mi,3 Mi,4 0 1 0 0 0 1 1 0 1 0 0 1 2 1 1 0 0 1 3 0 0 1 0 1 4 1 0 1 0 1 5 0 1 1 0 1 6 1 1 1 0 1 7 0 0 0 1 1 8 1 0 0 1 1 9 0 1 0 1 1
10 1 1 0 1 1 11 0 0 1 1 1 12 1 0 1 1 1
Party omitted …
27 HSPA course.PPT / 08-10-2007 / AT&HH
HS-DPCCH Slot Format• The HS-DPCCH fields may have different power offsets• One may also repeat the ACK/NACK and/or CQI over more than one subframe
•This is needed for cell edge operation (subject to cell edge coverage level)
2560 Chips 5120 Chips
One HS-DPCCH subframe of 2 ms
ACK/NACKCQI
• HS-DPCCH is symbol aligned with the uplink DPCCH/DPDCH• BTS channel estimation done based on DPCCH (which carrier TPC, Pilot and TFCI)
Power offsetAs configured
28 HSPA course.PPT / 08-10-2007 / AT&HH
PAR Increase due HS-DPCCH• Terminal TX power is allowed to be reduced with low DCH uplink data rates, due
to the added parallel channel -> increased peak to average ratio when channels haveclose to equal power
Ratio of DPCCH/DPDCH gain factors for all values of
HS-DPCCH gain factor
Power Class 3 Power Class 4
Power(dBm)
Tol(dB)
Power(dBm)
Tol(dB)
1/15 ≤ βc/βd ≤ 12/15 +24 +1/-3 +21 +2/-2
13/15 ≤ βc/βd ≤ 15/8 +23 +2/-3 +20 +3/-2
15/7 ≤ βc/βd ≤ 15/0 +22 +3/-3 +19 +4/-2
29 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA Channel Quality Feedback
-14 -12 -10 -8 -6 -4 -2 0Tx Ec/Ior (dB)
Thr
ough
put (
kbps
)
Geometry=0dB Geometry=5dB Geometry=10dB
High Throughput
Low Throughput
• This will depend on the location in the cell, expected BTS TX power for HSDPA (parameter), channel condition & receiver etc. details
High CQI reported (close to BTS, high HSDPA power)
Low CQI reported (far from BTS, low HSDPA power)
30 HSPA course.PPT / 08-10-2007 / AT&HH
Example CQI Mapping Table
• BTS can map the receivedCQI value for the data rateto be used in the linkadaptation
• Necessary conversion to bedone depending on BTS power availability
• Reference poweradjustment used whenquality would allow higherrate than UE capability
CQI value Transport Block Size
Number of HS-PDSCH Modulation
Reference power adjustment ∆
NIR XRV
0 N/A Out of range
1 137 1 QPSK 0
2 173 1 QPSK 0
3 233 1 QPSK 0
4 317 1 QPSK 0
5 377 1 QPSK 0
6 461 1 QPSK 0
7 650 2 QPSK 0
8 792 2 QPSK 0
9 931 2 QPSK 0
10 1262 3 QPSK 0
11 1483 3 QPSK 0
12 1742 3 QPSK 0
13 2279 4 QPSK 0
14 2583 4 QPSK 0
15 3319 5 QPSK 0
16 3565 5 16-QAM 0
17 4189 5 16-QAM 0
9600 0
(continues until 31…)
31 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA & Soft Handover• In case of DCH all data is sent from all active set BTSs• In case of HSDPA, HS-DSCH sent from one BTS only, associated DCH (can be
low rate if only signaling) from all cells
Iub
Node B
RNC
Node BDCH
DCH
Iub
Node B
RNC
Node B
DCH +HS-DSCH
DCH
32 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA & Soft Handover (cont.)• The intra-frequency measurement event ID is modified• Now a measurement report will be initiated when the best serving cell changed
(parameters to have some hysteresis)• This is needed to initiate the HS-DSCH serving cell change even when active set is
unchanged• In case serving cell change, RLC layer (in the RNC) will handle unfinished ARQ
processes when Node B memory is flushed.
Iub
Node B
RNC
Node B
DCH +HS-DSCH
DCH
33 HSPA course.PPT / 08-10-2007 / AT&HH
HSPA Mobility ProcedureUE Node-B #1 Node-B #2 RNC
HS-DSCH from Node-B #2
Radio link reconfiguration and AAL2 setup to Node-B #2
“Measurement report”
“Radio bearer reconfiguration”
“RLC ACK”
“Radio bearer reconfiguration complete”
t1t2
t3
t4
HS-DSCH from Node-B #1
A
B
Radio link reconfiguration and AAL2 deletion to Node-B #1
Reroute data from Node-B #1 to Node-B #2
A = procedural delayB = gap in data flow
34 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA & Compressed mode• The inter-frequency measurement is handled by scheduling• HS-SCCH/HS-PDSCH are always trasnsmitted fully or then not at all if there is
any overlapp during the 2 ms TTI• Alternatively one can switch back to DCH for inter-frequency measurements
2 ms
HS-SCCH
HS-DSCH
DL DCH for Terminal 1
…
…
Compressed frame
Not permitted HS-DSCH TTI for Terminal 1
35 HSPA course.PPT / 08-10-2007 / AT&HH
HS-DSCH vs. DCH
Feature
Variable spreading factor
Fast power control
Adaptive modulation and coding
Fast L1 HARQ
DCH
No
Yes
No
No
HS-DSCH
No
No
Yes
Yes
BTS based scheduling No Yes
Multi-code operation Yes Yes, extended
• When compared to DCH, the key difference is the replacement of power controlwith link adaptation and L1 HARQ. Also the multicode operation has beenextended.
36 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA & DCH Resource Sharing
Common channels
DCH RT
DCH NRT
HSDPA NRT
PtxTarget
Max power
Power control head-room
Non-controllable power
Controllable power
Total transmittedcarrier power
NEW non-HSDPApower measurements
Power measurementsfrom the Node-B to
the RNC
Node-B Tx power
In addition to power also code resource
shared!
37 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA vs DCH Code Space Usage
PilotData
Slot 0.667 ms = 2/3 ms
TPC
• With Downlink DCH Time multiplexed DPCCH and DPDCH• Variable rate with DTX -> Code space not released due inactivity• Problematic for high bit rates -> Current highest DL rate 384 kbps
DPDCH DPDCH
Data
DPCCH DPCCH
TFCI
PilotData
Slot 0.667 ms = 2/3 ms
TPC
DPDCH DPDCH
Data
DPCCH DPCCH
TFCI
FULL RATE
HALF RATE
DTX
38 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA vs DCH code space usage (cont.)• With HSDPA code resource (except what is needed for DCH) shared with 2 ms
resolution -> Optimum code resource use• Also no soft handover related extra code use
C0(0) = [ 1 ]
C1(0) = [ 1 1 ]
C1(1) = [ 1 0 ]
C2(0) = [ 1 1 1 1 ]
C2(1) = [ 1 1 0 0 ]
C2(2) = [ 1 0 1 0 ]
C2(3) = [ 1 0 0 1 ]
C3(0) = [ 1 1 1 1 1 1 1 1 ]
C3(1) = [ 1 1 1 1 0 0 0 0 ]
. . .
. . .
Spreading factor:
SF = 1 SF = 2 SF = 4 SF = 8
C3(2) = [ 1 1 0 0 1 1 0 0 ]
C3(3) = [ 1 1 0 0 0 0 1 1]
. . .
. . .
C3(4) = [ 1 0 1 0 1 0 1 0 ]
C3(5) = [ 1 0 1 0 0 1 0 1 ]
. . .
. . .
C3(6) = [ 1 0 0 1 1 0 0 1 ]
C3(7) = [ 1 0 0 1 0 1 1 0 ]
. . .
. . .
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
= Allocated code
= Code which canbe allocated at the sametime as C3(1)
= Code which cannotbe allocated at the sametime as C3(1)
These codes cannotbe used at the same
time as C3(1)
39 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA Iub signaling• Parameters for Node B resource allocation , to indicate e.g. which HS-SCCH use
and which codes are available for HS-DSCH as well as how much power to use for HSDPA.
• Scheduler parameters, to control the scheduler behavior, such as scheduling priority indicator and guaranteed bit rate
• Terminal specific parameters, such a terminal capability and terminal specific HSDPA parameters (like the set of HS-SCCH codes the terminal is monitoring)
Node B RNC
Iub Iu-ps
PSCore
Data + QoSparameters (larger data rates than
Rel’99)
UE capabilityData + Scheduling
priority, discard timer, resources, CQI parameters…
40 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA Data Rate on different interfaces
QoS Parameter: Maximum Bit Rate: 1 Mbps
Node B RNC
Iu-psIub
Terminal
Uu
Iub Bit Rate: 0 - 1 Mbps
SGSN
Data fromGGSN
HS-DSCH Peak Rate: 7.2 Mbps over 2 ms
QoS Parameter: Maximum Bit Rate: 384 kbps
Node B RNC
Iu-psIub
Terminal
Uu
Iub Bit Rate: 0 - 384 kbps
SGSN
Data fromGGSN
DCH Peak Rate: 384 kbps
Release’99 DCH
Release 5 HSDPA
41 HSPA course.PPT / 08-10-2007 / AT&HH
Iub Flow Control
UE1 with high CQI
BTS
RNC
Scheduler buffer levelFor UE1
Scheduler buffer levelFor UE2
Increase Credits to UE1, Reduce
Credits to UE2
Data
UE2 with low CQI
Maximise Iubcapacity
utilisation in response to credits
Flow control is neededTo avoid buffer overflow In Node B
One unit responding to Flow control in RNC canmaximise the Iub usage
42 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA - Summary• Multi-code operation combined with lower coding rates and fast HARQ
improves link performance at cell edge (low SIR) • Multi-code operation combined with increased coding rates (e.g. 3/4) fully
utilize favorable radio environments (high SIR) without running into code shortage.
• HSDPA is backwards compatible and can be introduced gradually in the network.
• Retransmission and scheduling into Node B• -> reduces (re-)transmission delays; Improves QoS control.
Freely configurable transmissionHSDPA is a natural capacity evolution to WCDMAand an enabler for higher speed data services
43 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA Performance
44 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA Peak Data Rates• Max Layer 1 and Layer 2 (RLC) throughput shown below• Max application layer throughput can be very close to RLC throughput
5 codes QPSK 1.8 Mbps 1.6 Mbps
# of codes Modulation Max L1 data rate
Max RLC data rate
5 codes 16-QAM 3.6 Mbps 3.36 Mbps
10 codes 16-QAM 7.2 Mbps 6.72 Mbps
15 codes 16-QAM 10.7 Mbps 9.6 Mbps
15 codes 16-QAM 14.0 Mbps 13.3 Mbps
12
UE category
5/6
7/8
9
10
Phase 1
Phase 2
45 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA Link Performance with Turbo Coding Approaches Shannon Limit
Higher bit rates can be obtained only with more antennas (MIMO) and/or wider bandwidth.
Sup
porte
d ef
fect
ive
data
rate
[Mbp
s]
0.1
1.0
10.0
-15 -10 -5 0 5 10 15 20
16QAM
0.01
Instantaneous HS-DSCH C/I before processing gain [dB]
QPSK
HSDPA linkadaptation curve
Shannon limit:3.84MHz*log (1+C/I)2
15 HS-PDSCH allocation(Rake, Pedestrian-A, 3km/h)
46 HSPA course.PPT / 08-10-2007 / AT&HH
Link Simulations in Fading Channel – Including Link Adaptation, CQI Errors and Feedback Delay
-10 -5 0 5 10 15 20 25 30 35 400
2
4
6
8
10
12
SINR(dB)
Thro
ughp
ut (M
bits
/s)
5 codes, PedA5 codes VehA5 codes fit10 codes PedA10 codes VehA10 codes fit15 codes PedA15 codes VehA15 codes fit
10 Mbps requires very high SINR >30 dB
3 Mbps requires very high SINR >24 dB
15-code
10-code
5-code
With low SINR < 5 dB, 5-code HSDPA gives similar
throughput as 10/15-code HSDPA since the throughput is interference, not code limited
47 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA SINR Definition• SF16 = HS-DSCH spreading factor = 16• PHS-DSCH = Received power of HS-DSCH channel• Pown = Own cell interference with orthogonal codes• Pother = Other cell interference• Pnoise = Receiver thermal noise• α = Own cell orthogonality
( ) noiseotherown
DSCHHS
PPPPSFSINR
++⋅−= −
α116
• SINR is increased with • Higher HS-DSCH power – network planning and dimensioning• Less own cell and other cell interference – network planning and dimensioning• Better orthogonality – multipath propagation or mobile equalizer
48 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA Data Rate vs RSCP
RLC throughput shown, 5 codes, total BTS power 20 W, Release 99 power 0-10 W
-115 -110 -105 -100 -95 -90 -85 -800
500
1000
1500
2000
2500
3000
3500
4000
CPICH RSCP [dBm]
kbps
15 W HS-DSCH10 W HS-DSCH5 W HS-DSCH
More power increases data rate
49 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA Scheduling and Cell Capacity
50 HSPA course.PPT / 08-10-2007 / AT&HH
Fast Proportional Fair Scheduling
UE2
Channel quality(CQI, Ack/Nack, TPC)
Channel quality(CQI, Ack/Nack, TPC)
Data
Data
UE1
Multi-user selection diversity(give shared channel to “best” user)
TTI 1 TTI 2 TTI 3 TTI 4
USER 1 Es/N0USER 2 Es/N0
Scheduled user
Node-B scheduling can utilize information on the
instantaneous channel conditions for each user.
51 HSPA course.PPT / 08-10-2007 / AT&HH
Proportional Fair Algorithm• Principle is to schedule the user who currently has the highest ratio of instantaneous
throughput to average throughput. The averaging time is typically a few 100 ms.• The user with the highest selection metric at a given time is selected for scheduling
in the following TTI• In practise, the gain in cell capacity is up to 30%
[ ][ ]nTnRM
k
kk ≡
Rk = instantaneous supported data rate for user k based on CQI report
Tk = average throughput for user k with 100-200 ms averaging period
Mk = selection metric where higher value gives higher probability of being scheduled
52 HSPA course.PPT / 08-10-2007 / AT&HH
3GPP HSDPA Terminal PerformanceRequirements
Performance requirements
Baseline receiver
3GPP Release
Performance gain
Minimum requirement
1-antenna Rake
Release 5 Basic receiver
Enhanced type 1
2-antenna Rake
Release 6 Better performance also against other cell interference with 2 antennas. HSDPA reference receiver for relative LTE performance evaluation.
Enhanced type 2
1-antenna Equalizer
Release 6 Improved performance against intra-cell interference
Enhanced type 3
2-antenna Equalizer
Release 7 Combines the gain mechanisms of intra-cell interference mitigation and receiver diversity
53 HSPA course.PPT / 08-10-2007 / AT&HH
0
500
1000
1500
2000
2500
3000
3500
4000
4500
Rake 1-ant Equalizer 1-ant Rake 2-ant Equalizer 2-ant
kbps
Round robin 5 codesRound robin 10 codesProportional fair 5 codesProportional fair 10 codesProportional fair 15 codes
1 Mbps
2.5 Mbps
4 Mbps
• 5-code BTS and single antenna UE Rake provides 1 Mbps• 10-code BTS and single antenna UE provides 2.5 Mbps• 15-code BTS and dual antenna UE provides 4 Mbps
HSDPA Capacity [kbps/Sector/5 MHz]
54 HSPA course.PPT / 08-10-2007 / AT&HH
Maximum HSDPA Subscribers
Cell capacity 2.5 Mbps
Convert Mbps to GBytes
Busy hour averageloading 60%
Busy hour carries 20% of daily traffic
30 days per month
3 sectors per site
From simulations
/ 8192
x 60%
/ 20%
x 30
x 3x 3
3600 seconds per hour x 3600
Total 300 subs/site
1 GB traffic per user / 1 GB (300 GB/site/month)
Cell capacity 2.5 Mbps
Required user data rate
3 sectors per site
From simulations
0.5 Mbps
x 3
Overbooking factor 20
Total 300 subs/site
Traffic volume based dimensioning Data rate based dimensioning
55 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA Measurements
56 HSPA course.PPT / 08-10-2007 / AT&HH
Stabile approx 400 kB/s = 3.28 Mbps which is max application bit rate with
3.6 Mbps L1 capability terminal
Data Rate in Elisa Network, 3xE1 Site
57 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA Round Trip Time
0
20
40
60
80
100
120
140
160
180
200
[ms]
WCDMA (128/384 kbps)HSDPA (384 kbps/1.8 Mbps)
WCDMA R99 130 ms on average (384/128 kbps)
HSDPA R5 <80 ms on average
58 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA Multiuser Capacity Sharing
Impact of 3 Users on Throughput
0
200000
400000
600000
800000
1000000
1200000
1400000
1600000
Time (s)
App
licat
ion
Thro
ughp
ut (b
ps)
1 user 1 user2 users 2 users3 users
User throughput depends directly on the number of users while the cell throughput remains constant
59 HSPA course.PPT / 08-10-2007 / AT&HH
Uplink Data Rate for HSDPA Feedback• TCP acknowledgements required approx 3% of
the downlink bandwidth in typical TCP case. • 64 kbps uplink is required to support 1.8 Mbps• 128 kbps uplink is required to support 3.6 Mbps• The uplink bandwidth may be smaller in case of
multiple TCP packets are acknowledged at once.
42 kbps application layer data rate in uplink when
1.6 Mbps in downlink
60 HSPA course.PPT / 08-10-2007 / AT&HH
0,17:13:43:779,513,1,74,QPSK,16,3,0,0,62,0,4,5,2046,0,PASS0,17:13:43:781,513,2,-,-,-,-,-,-,-,-,-,-,-,-,-0,17:13:43:783,513,3,74,QPSK,16,2,0,1,63,0,4,5,2046,0,FAIL0,17:13:43:785,513,4,-,-,-,-,-,-,-,-,-,-,-,-,-0,17:13:43:787,514,0,74,QPSK,25,0,0,0,2,0,4,5,2404,0,FAIL0,17:13:43:789,514,1,-,-,-,-,-,-,-,-,-,-,-,-,-0,17:13:43:791,514,2,-,-,-,-,-,-,-,-,-,-,-,-,-0,17:13:43:793,514,3,-,-,-,-,-,-,-,-,-,-,-,-,-0,17:13:43:795,514,4,-,-,-,-,-,-,-,-,-,-,-,-,-1,17:13:43:797,1,17:13:43:799,1,17:13:43:801,1,17:13:43:803,1,17:13:43:805,0,17:13:43:807,920,0,10,QPSK,19,0,0,0,0,0,4,1,365,0,PASS0,17:13:43:809,920,1,-,-,-,-,-,-,-,-,-,-,-,-,-0,17:13:43:811,920,2,10,QPSK,19,1,0,0,1,0,4,1,365,0,PASS
HS-DSCH Cell Change Break• L1 break is 28 ms between correctly received blocks from Cell A and Cell B• The break is short enough even for seamless VoIP voice service. For reference: the break
in GSM handovers is typically >50 ms.
1
2
1 = Last correctly received transport block from Cell A
L1 log of received transport blocks
2 = First correctly received transport block from Cell B
L1 break = 43:807 – 43:779 = 28 ms
Connected to Cell A
Connected to Cell B
61 HSPA course.PPT / 08-10-2007 / AT&HH
CQI Reports in Live Network
0.00%
2.00%
4.00%
6.00%
8.00%
10.00%
12.00%
14.00%
16.00%
18.00%
CQI_DIS
T_CL_
0 (Hsd
paw)
CQI_DIS
T_CL_
1 (Hsd
paw)
CQI_DIS
T_CL_
2 (Hsd
paw)
CQI_DIS
T_CL_
3 (Hsd
paw)
CQI_DIS
T_CL_
4 (Hsd
paw)
CQI_DIS
T_CL_
5 (Hsd
paw)
CQI_DIS
T_CL_
6 (Hsd
paw)
CQI_DIS
T_CL_
7 (Hsd
paw)
CQI_DIS
T_CL_
8 (Hsd
paw)
CQI_DIS
T_CL_
9 (Hsd
paw)
CQI_DIST_C
L_10
(Hsd
paw)
CQI_DIST_C
L_11
(Hsd
paw)
CQI_DIST_C
L_12
(Hsd
paw)
CQI_DIST_C
L_13
(Hsd
paw)
CQI_DIST_C
L_14
(Hsd
paw)
CQI_DIST_C
L_15
(Hsd
paw)
CQI_DIST_C
L_16
(Hsd
paw)
CQI_DIST_C
L_17
(Hsd
paw)
CQI_DIST_C
L_18
(Hsd
paw)
CQI_DIST_C
L_19
(Hsd
paw)
CQI_DIST_C
L_20
(Hsd
paw)
CQI_DIST_C
L_21
(Hsd
paw)
CQI_DIST_C
L_22
(Hsd
paw)
CQI_DIST_C
L_23
(Hsd
paw)
CQI_DIST_C
L_24
(Hsd
paw)
CQI_DIST_C
L_25
(Hsd
paw)
CQI_DIST_C
L_26
(Hsd
paw)
CQI_DIST_C
L_27
(Hsd
paw)
CQI_DIST_C
L_28
(Hsd
paw)
CQI_DIST_C
L_29
(Hsd
paw)
CQI_DIST_C
L_30
(Hsd
paw)
0.00%
20.00%
40.00%
60.00%
80.00%
100.00%
120.00%
%CDF
70% of time CQI>15 and 16QAM would be used
QPSK 16QAM
Most typical CQI = 18 corresponds to 2.1 Mbps
with BLER=10%
Max ratewith 16QAM
62 HSPA course.PPT / 08-10-2007 / AT&HH
Example Traffic Figures• African customer
• 40 TB/week• 2130 sites ⇒ 20 GB/week/site on average• Peak cells carry >1 Mbps/cell during busy hour and up to 8 GB/day• Approx 400.000 subs ⇒ approx 0.5 GB/sub/month (not flat rate)• HSDPA carrier (two carriers)
• Asian customer• 10 TB/week• 1000 sites ⇒ 10 GB/week/site on average• Single frequency layer shared by R99 and HSDPA
• Middle East customer• 16 TB/week• 800 sites ⇒ 20 GB/week/site on average• Single frequency layer shared by R99 and HSDPA
63 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA and Iub Capacity
64 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA & Iub• HSDPA improves Iub efficiency compared to Release’99 packet data since HSDPA is a time
shared channel with a flow control in Iub• Release’99 requires dedicated resources from RNC to UE. Those resources are not fully utilized
during TCP slow start, during data rate variations or during inactivity timer• Additionally, HSDPA does not use soft handover ⇒ no need for soft handover overhead in Iub
= User 1= User 2= User 3
Iub link 1
Iub link 2
HSDPA Iubcapacity
1 2
1 = TCP slow start2 = Inactivity timer
Iub efficiently utilized by HSDPA
21
65 HSPA course.PPT / 08-10-2007 / AT&HH
Achievable Throughputs with 1-3 x E1
Iub 1*E1
• HSDPA throughput is in most cases Iub limited – not radio limited
Approx 400 kB/s = 3.28 Mbps which is max application bit rate with 3.6
Mbps L1 capability terminal
Iub 2*E1
Iub 3*E1
66 HSPA course.PPT / 08-10-2007 / AT&HH
Iub Capacity with Multiple E1s
0.01.02.03.04.05.06.07.08.09.0
10.0
1 x E1 2 x E1 3 x E1 4 x E1 5 x E1 6 x E1 7 x E1
Mbp
s
5-code QPSK UE (Cat 12)5-code 16QAM UE (Cat 6)10-code 16QAM UE (Cat 8)15-code 16QAM UE (Cat 9)Iub limit
67 HSPA course.PPT / 08-10-2007 / AT&HH
Transport Solution Must Support High Data Rates
= Very high data rate solutions beyond 100 Mbps= High data rate solutions beyond 10 Mbps= Voice and low data rate solutions
Ethernet
E1
SHDSL.bis
ADSL2+
LTE
Ethernet
GPON
DSM L3
VDSL2 LTE
PeakData rate Downstream / Downlink Upstream / Uplink
WiMAX
HSPA WiMAX
HSPA
WCDMA
GPON
10 G
1 G
100 M
10 M
1 M
0,1 M
WCDMAEDGE
evolution
EDGE
DSM L3
VDSL2
ADSL2+
ADSL
SHDSL.bis
E1
ADSL
E1
EDGEEDGE
EDGEevolution
68 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA Terminals
69 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA Terminals Initially• Data rate 1.8/3.6 Mbps downlink • Data rate 384 kbps uplink• Power class 3 = 24 dBm
Sierra wirelessNovatel Option
70 HSPA course.PPT / 08-10-2007 / AT&HH
Nokia Multimedia HSDPA Terminal N95• HSDPA 3.6 Mbps• 5-megapixel Camera• 2.6” display with 16 M colors• Integrated GPS• WLAN 802.11g• Standard 3.5 mm audio jack• Weight 120 g• Volume 90 cc
• Also E90 Communicator, 6110 Navigator, 6120, E51…
71 HSPA course.PPT / 08-10-2007 / AT&HH
WCDMA High Speed Uplink Packet Access (HSUPA) of Release 6
72 HSPA course.PPT / 08-10-2007 / AT&HH
Outline• HSUPA Introduction• HSUDA Protocol Architecture• HSUPA Retransmissions• HSUPA Peak Bit Rates• HSUPA UE Capabilites• HSUPA Channel Stuctures Uplink and Downlink• Summary
73 HSPA course.PPT / 08-10-2007 / AT&HH
High Speed Uplink Packet Access HSUPA
• Peak data rates increased to significantly higher than 2 Mbps; Theoretically reaching 5.8 Mbps
• Packet data throughput increased, though not quite highnumbers expected as with HSDPA
• Reduced delay from retransmissions.• Solutions
• Layer 1 hybrid ARQ• Node B based scheduling for uplink• Frame sizes 2ms & 10 ms
• Schedule in 3GPP• Part of Release 6• First specifications version completed 12/04
• Not fully mature version (see later 3GPP slides)• In 3GPP specs with the name Enhanced uplink DCH (E-DCH)
74 HSPA course.PPT / 08-10-2007 / AT&HH
RLC
HSUPA Protocol ArchitectureNew MAC entity, MAC-e added to the Node BIn RNC MAC-es handling packet in-sequence delivery & soft handover combiningLayers above, such as RLC, unchanged -> this required MAC-es to performreordering for packetsAdditions to physical layer (WCDMA L1)Additions to user plane Iub/Iur DCH data stream protocol (Frame Protocol)
WCDMA L1
UE
Iub/Iur
SRNCNode B
Uu
MAC
NAS
HSUPA user plane
WCDMA L1
MAC-e
TRANSPORT
FRAMEPROTOCOL
TRANSPORT
FRAMEPROTOCOL
MAC-esMAC-d
IuRLC
MAC-es/e
RLC
75 HSPA course.PPT / 08-10-2007 / AT&HH
Node B Controlled HSUPA Scheduling
• Target is to shorten the packet scheduling period ⇒ packet scheduler is able to track burstiness of source application
Data packet
+ possible retransmissions
+ control for scheduling
ACK/NAK
+ control
Node B RNC
Mac-es
Iub
Mac-e
New Node B functions:Uplink packet data schedulingHARQ control: ACK/NAKs
New Iub signalling
New L1 signalling
76 HSPA course.PPT / 08-10-2007 / AT&HH
0 1 2 3 4 5 6 7 8 9 100
0.1
0.2
0.3
0.4
0.5
0.6
0.7
NR [dB]
PDF of the NR per BTS
Mean: 4.1 (dB) StD: 1.2 (dB)
Mean: 5 (dB) StD: 0.72 (dB)
RNC sheduling Node B scheduling
Fast Scheduling Reduces Noise Variance
• Faster scheduling reduces noise rise variations
⇒ Less headroom needed⇒ Cell capacity and user data
rates are increased• With low loaded uplink, the
users may get significantly higher data rates as much more aggressive data rates can be granted to UEs
Operation point can be increased because variance is reduced.
77 HSPA course.PPT / 08-10-2007 / AT&HH
DCH vs E-DCH Retransmissions
Terminal
BTS
RNC
DCH E-DCH
Packet Retransmission
RLC ACK/NACK
Retransmission
L1 ACK/NACK
Packet(1st TX)
Combining of packetand retransmission
78 HSPA course.PPT / 08-10-2007 / AT&HH
Scheduling in soft handover• There is one serving cell• Serving cell sends either up or down command, also the absolute grant channel is
monitored from serving cell only• Other cells in the active set (assuming they also support HSUPA) send only relative
grant down commands• Those can be configured in such a way that multiple terminals listen to same
command -> overload handling
UEBTSRNC Part of activeset
Serving Cell
Hold/Down
Up/Down/Hold
E-DCH data
E-DCH data
Absolute Grant
79 HSPA course.PPT / 08-10-2007 / AT&HH
Fast Hybrid-ARQ between UE and BTS• Fast ACK/NAK from BTS• N-process Stop-And-Wait (SAW) HARQ (similar to HSDPA)• short round trip delay => lower total delay• Chase combining or Incremental Redundancy, soft buffering in BTS• In SHO, each BTS sends ACK, retransmission if no ACKs
TerminalNode BRNC Correctlyreceived packet
HARQ control and soft combining
ACK/NAK
ACK/NAK
E-DCH data
E-DCH data
PacketReordering
80 HSPA course.PPT / 08-10-2007 / AT&HH
Feedback from UE to BTSThe UE provides the BTS scheduler with (in MAC-e header)• UE buffer occupancy: how much data in RLC buffers • Information about the priority of the data in the buffer• Available transmission power resource
In physical layer (E-DPCCH) the UE provides to BTS the following• E-TFI indicating what is transmitted in the E-DPDCH• Information of the HARQ redundancy version for the packet
• Timing is known, thus BTS knows which ARQ channel to expect
• Happy bit: Is the current data rate satisfactory• UE would not be happy of the data rate if it could transmit with higher rate
due, • I.e. have enough data in its buffers and would have sufficient power resource
to transmit with a higher power than currently
E-DPCCH(L1)
MAC-e PDUon E-DPDCH
(L2)
81 HSPA course.PPT / 08-10-2007 / AT&HH
Adaptive Modulation – Why not with HSUPA?• In the downlink direction, BTS has limited power control dynamics, in the order of
10-20 dB• However in the uplink received power level is kept constant with fast closed loop
power control with more than 70 dB dynamic range• Thus there are no times when there would be “free lunch” to use higher order
modulation
• Other reasons why higher order modulation sounds interesting*…• A) To get more bits per given bandwidth - > range problem• B) To reduce the terminal peak to average ratio as having multicodes in use later ->
This would have resulted to higher average power even if the PAR would have been smallel -> less capacity
* When searching from the web HSUPA info, often one sees adaptive modulationas part of the story. This is based on the outdated stuff from the study item phase
82 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA Peak Bit Rates Initially 1.46-2 Mbps
• Theoretical peak bit rate up to 5.76 Mbps• Two SF2 and two SF4 codes in parallel• No channel coding, 0% initial transmission BLER
• Initial capability• Two SF2 codes reaches 2 Mbps (with 10 ms TTI)
• Only 10 ms TTI expected to be supported initially
2 x SF4 2 ms10 ms
# of codes TTI
2 x SF2 10 ms
2 x SF2 2 ms
2 x SF2 +2 x SF4 2 ms
1.46 Mbps
Maxdata rate
2.0 Mbps
2.9 Mbps
5.76 Mbps
Phase 1
* Devices not yet published, not 100% realiable…
83 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA Peak Data Rates• Theoretical peak bit rate up to 5.76 Mbps
• Two SF2 and two SF4 codes in parallel• No channel coding, 0% initial transmission BLER
• Initial capability Category 5 with 2 x SF2 providing 2 Mbps with 10 ms TTI• Ericsson RAN initial support only Category 3 with 2 x SF4 providing 1.46 Mbps
1 x SF4 0.73 Mbps 0.67 Mbps
# of codes 10 ms 10 ms
2 x SF4 1.46 Mbps 1.38 Mbps
1
UE category
2
3
4
5
2 x SF4 1.46 Mbps 1.38 Mbps
2 x SF2 2.0 Mbps 1.88 Mbps
2 x SF2 2.0 Mbps 1.88 Mbps
6 2 x SF2 + 2 x SF4 2.0 Mbps 1.88 Mbps
-
2 ms
-
1.46 Mbps
2.9 Mbps
-
5.76 Mbps
-
2 ms
-
1.28 Mbps
2.72 Mbps
-
5.44 Mbps
Max L1 data rate Max RLC data rate
84 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA structures in more detail
85 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA building blocks - data path• A new uplink data path below the RLC layer parallel to DCH
• E-DCH - Uplink transport channel • E-DPDCH - Dedicated physical data channel for E-DCH• E-DPCCH - Dedicated physical control channel for E-DCH• Iub Frame protocol frame for E-DCH• E-DCH is parallel to and coexisting with the uplink DCH
PHY PHY
EDCH FP EDCH FP
IubUE NodeBUu
DCCH DTCH
TNL TNL
DTCH DCCH
MAC-e
SRNC
MAC-d
MAC-e
MAC-d
MAC-es /MAC-e
MAC-es
E-DCH in E-DPDCH,Control in E-DPCCH
MAC-es PDUs
MAC-e PDUs
MAC-es PDUsin E-DCH FP
86 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA building blocks - HARQ• Uplink HARQ functionality and control
• Synchronous N-process SAW HARQ• Timing of the uplink packet defines to which HARQ process it belongs to• Timing of the downlink ACK/NACK defines which packet is
• E-DPCCH carrying HARQ information to the Node B• E-HICH carrying HARQ ACK/NACK back to the UE• MAC-es in the RNC to reorder the packets arriving in disorder due to HARQ
10 ms
E-DPCCH
E-DPDCH
30 ms between end of 1st TX and start of retransmission (14 ms with 2 ms TTI)
E-HICH
Uplink
Downlink
10 msE-DCH TTI Potential retransmission
Node Bprocessing
Corresponding ACK or NACK
UEprocessing
8 ms
87 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA UL/DL Timing• For the different TTIs, 2 ms and 10 ms, there is fixed number of ARQ subchannels
• For 2 ms TTI there are 8 ARQ sub-channels• For 10 ms TTI there are 4 ARQ sub-channels, see below
• Note the difference to HSDPA, where number of ARQ sub-channel may be configured (up to 8) + need to signal in downlink which process in used (as e.g. downlink scheduling needs to have timing freedom)
10 ms
E-DPCCH
30 ms (3 TTIs)
E-HICH
ACK/NACK
1st retransmission
E-DPCCH
E-DCHUL
DL
E-DCH
14 – 16 ms 5.5 – 7.5 ms
8 ms
Timing with 10 ms TTI
88 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA building blocks - Scheduling• Uplink Node B scheduling
• E-RGCH and E-AGCH - DL physical channels for scheduling control• Happy-bit on UL E-DPCCH to indicate Node B of the instantaneous UE status• Scheduling Info in MAC-e header to give Node B more detailed information
BTS
UE
E-DPCCH (happy bit)
E-RGCH (Relative Grant)
E-AGCH (Absolute Grant)
E-DPDCH (SI in MAC-e header)
• RG and AG control the UE’s maximum allowed E-DPDCH to DPCCH power ratio• RG carries one bit only: UP/DOWN by one step relative to currently used max E-DPDCH/DPCCH power ratio• AG carries a command informing the UE of the E-DPDCH/DPCCH power ratio to be used at maximum
• Happy-bit and SI provide the Node B with information of the UE’s status• See a separate slide
• RNC is a master that provides the Node B scheduler with limits• RNC can allocate non-scheduled transmissions for specific data flows over which the Node B has no
control over• Control over specific HARQ processes and data flows
89 HSPA course.PPT / 08-10-2007 / AT&HH
Physical channels with HSUPA, HSDPA and DCH
BTS
UE N x E-DPDCH (E-DCH)
DPCCH (Pilot, TPC, TFCI)*DPDCH (DCHs)
E-DPCCH (RSN, H-bit, E-TFCI)
DPCCH (Pilot, TPC, TFCI)DPDCH (DCHs)
HS-DPCCH (CQI, ACK/NACK)
HS-SCCH (TFRI, HARQ info)
E-RGCH (RG)E-AGCH (AG)
E-HICH (ACK/NACK)
N x HS-PDSCH (HS-DSCH)
UPLINK• DPCCH is always present• DPDCH needed for DCH• HS-DPCCH used for HSDPA feedback• E-DPCCH needed if E-DCH transmitted• E-DPDCH needed if E-DCH transmitted
DOWNLINK• DPCCH is always present*• DPDCH used for DCH• HS-SCCH needed if HSDPA transmitted• HS-PDSCHs needed if HSDPA transmitted• E-RGCH needed if RG transmitted• E-AGCH needed if AG transmitted• E-HICH needed if E-DCH received
* Downlink DPCCH could be replaced with F-DPCH (TPC only) if no DL DCH configured
90 HSPA course.PPT / 08-10-2007 / AT&HH
Uplink physical control channels with HSUPA• DPCCH is required for power control and uplink channel estimation
• Must be present even if the DPDCH is not used (and HS-DPCCH if HSDPA is used)
• E-DPCCH - (E-DCH Dedicated Physical Control Channel)• Delivers 10 information bits related to the E-DPDCH transmitted in parallel
• Retransmission Sequence Number for HARQ, 2 bits• Happy-bit for scheduling, 1 bit• E-TFCI 7 bits
• SF256 physical channel (10 channel bits per slot)• 30 channel bits result with 2 ms sub-frame
• With 10 ms E-DCH TTI the 2 ms sub-frame is repeated 5 times
Data: 10 info bits coded to 30 channel bits E-DPCCH
3 slots, 7680 chips
2 ms Sub-Frame
Slot#i Slot#14
10ms Radio Frame
Slot#0 Slot#1 Slot#2
Data: 10 info bits coded to 30 channel bits E-DPCCH
3 slots, 7680 chips
2 ms Sub-Frame
Slot#i Slot#14
10ms Radio Frame
Slot#0 Slot#1 Slot#2
91 HSPA course.PPT / 08-10-2007 / AT&HH
E-DPCCH Coding
• Control information on E-DPCCH is multiplexed: •E-TFCI information (7 bits)•Retransmission sequence number (RSN, 2 bits)•‘Happy bit’ (Rate Request, 1 bit)
• Channel Coding: a sub-code of the second order Reed-Muller Code (similar to rel’99/4/5 TFCI coding)
• Physical Channel Mapping: similar to rel’99/4/5, channel coding output bits are mapped to the allocated E-DPCCH
E-DPCCH
Physical channel mapping
Multiplexing
xh,1 xrsn,1, xrsn,2
Channel Coding
xtfci,1, xtfci,2,..., xtfci,7
x1, x2,..., x10
z0, z1,..., z29
Coding chain for E-DPCCH
92 HSPA course.PPT / 08-10-2007 / AT&HH
Uplink physical data channel with HSUPA• DPDCH is needed if uplink DCHs are configured (AMR speech etc.)• E-DPDCH (E-DCH Dedicated Physical Data Channel)
• Used to transmit the coded E-DCH transport channel• Turbo coding, 24 bit CRC, HARQ with incremental redundancy• SF 256/128/64/32/16/8/4/2 (SF 256/128 late additions!)• Two TTI lengths supported, 2 ms and 10 ms
• 10 ms TTI better from Range point of view
Data: 2560/SF bitsE-DPDCH
1 slot, 2560 chips, 2560/SF b its
2 ms Sub-Frame
Slot#i Slot#14
10ms Radio Frame
Slot#0 Slot#1 Slot#2
Data: 2560/SF bitsE-DPDCH
1 slot, 2560 chips, 2560/SF b its
2 ms Sub-Frame
Slot#i Slot#14
10ms Radio Frame
Slot#0 Slot#1 Slot#2
93 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA Physical channels in the downlinkE-HICH & E-RGCH share the same structure and the same code channel
• E-HICH transmits one ACK/NACK per received uplink E-DCH TTI• E-RGCH transmits UP/DOWN (dtx for hold) scheduling commands• A 40-bit long orthogonal sequence is QPSK modulated and sent in one slot.
• Up to 40 sequences can be fitted in one SF128 code channel• E-HICH and E-RGCH meant to a UE must be in the same code channel
• 3-slot long (2 ms) sub-frame is formed by concatenating 3 sequences• E-HICH length
• 2 ms - From all cells in the E-DCH active set with 2 ms E-DCH TTI• 8 ms - (4 times repetition) from all cells in the E-DCH AS with 10 ms TTI
• E-RGCH length• 2 ms - Sent by the Serving HSUPA RLS with 2 ms E-DCH TTI• 8 ms - (4 times repetition) Sent by the Serving HSUPA RLS with 10 ms E-DCH TTI• 10 ms - (5 times repetition) Sent by cells not belonging to the Serving HSUPA RLS
Slot #14
Tslot = 2560 chip
bi,39bi,1 bi,0
Slot #0 Slot #1 Slot #2 Slot #i
1 radio frame, Tf = 10 ms
1 subframe = 2 ms E-HICH/E-RGCH(sub-)frame structure
94 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA Physical channels in the downlinkE-AGCH• SF256 channel transmitting 6 information bits and a 16-bit
UE-specific CRC• 5 bits for E-DPDCH/DPCCH power ratio• 1 bit for process applicability• 16-bit CRC used to identify to which UE the AG is for
• 1/3 convolutional coding, resulting 72 bits• 2 ms sub-frame structure, 60 channel bits per sub-frame• 12 bits from the 72 punctured away to fit in the subframe• Sub-frame is repeated 5 times when 10 ms E-DCH TTI is used
Slot #1 Slot #14Slot #2 Slot #iSlot #0
Tslot = 2560 chips
1 subframe = 2 ms
1 radio frame, Tf = 10 ms
E-AGCH 20 bits
Channel coding
xag,1, xag,2,..., xag,w
Rate matching
ID specific CRC attachment
Physical channel mapping
y1, y2,..., yw+16
z1, z2,..., z3x(w+24)
E-AGCH
r1, r2,..., r60
Coding chain for E-AGCH
E-AGCH (sub-)frame structure
95 HSPA course.PPT / 08-10-2007 / AT&HH
E-DCH (E-DPDCH) Coding• One transport block once per TTI• 24 bit CRC • Code block segmentation similar to DCH• 1/3 turbo coding (as rel’99)• Most of the blocks similar to Release’99• HARQ handling additional functionality
CRC attachment
Code block segmentation
Channel coding
Physical layerHARQ functionality/
rate matching
Physical channel segmentation
E-DPDCH#1 E-DPDCH#n
Transport block
E-DCH
Interleaving and physical channel mapping
CRC attachment
Code block segmentation
Channel coding
Physical layerHARQ functionality/
rate matching
Physical channel segmentation
E-DPDCH#1 E-DPDCH#n
Transport block
E-DCH
Interleaving and physical channel mapping
96 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA and DCH co-existance• For an existing user, E-DCH users will only show as part
of the interference variations (at BTS receiver)• -> Thus mixing DCH & E-DCH users is not a problem• The load variation caused by DCH users are not under BTS
control (but under slower RNC based method)
• Depending on the allocation, there can be allocated both E-DCH and DCH for the same terminal
• E.g. with AMR speech call active while having packet data connection on-going
• This allows smooth introduction for the network as separate carrier is not needed until single carrier capacityfully utilised
97 HSPA course.PPT / 08-10-2007 / AT&HH
HSDPA vs HSUPA Concepts
HSDPAHSDPA HSUPAHSUPA
ModulationModulation QPSK and 16-QAMQPSK and 16-QAM BPSK and Dual-BPSKBPSK and Dual-BPSK
Soft handoverSoft handover NoNo YesYes
HSUPA is like “reversed HSDPA”, except
Fast power control
Fast power control NoNo YesYes
SchedulingScheduling Point tomultipointPoint to
multipointMultipoint
to pointMultipoint
to point
Non-scheduled transmission
Non-scheduled transmission NoNo Yes, for minimum/
guaranteed bit rateYes, for minimum/guaranteed bit rate
Required for near-far avoidance
Efficient UE power amplifier
Scheduling cannot be as fast as in HSDPA
Similar to R99 DCH but with HARQ
HSUPA could be better described as Enhanced DCH in the uplink than “reversed HSDPA”
98 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA vs UL DCH
Feature
Variable spreading factor
Fast power control
Adaptive modulation
BTS based scheduling
DCH
Yes
Yes
No
No
HSUPA
Yes
Yes
No
Yes
Fast L1 HARQ No Yes
HSDPA
No
No
Yes
Yes
Yes
Multicode transmission Yes(No in practice)
Yes Yes
HSUPA (E-DCH) is an uplink DCH with Node B based HARQ and scheduling and true multicode support
Soft handover Yes Yes No(associated DCH only)
99 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA Iub signaling• Parameters for Node B resource allocation , to indicate e.g. which codes to use for
DL signaling channels, which signatures to use for which UE etc.• Scheduler parameters, to control the scheduler behavior, such as scheduling priority
and guaranteed bit rate• Terminal specific parameters, such a terminal capability and peak rate to be used
Node B RNC
Iub Iu-ps
PSCore
QoSparameters
UE capabilityScheduling
priority, resources, data
rates …
Data
Control
100 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA - Summary• Node B based uplink scheduling and HARQ for improved performance• Adaptive modulation not part of HSUPA as power control maintained• HSUPA is backwards compatible and can be introduced gradually in the
network.• Fundamental differences to DCH not big as with HSDPA
101 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA Performance
102 HSPA course.PPT / 08-10-2007 / AT&HH
Benefit of Fast Retransmissions
10−2
10−1
100
0
1
2
3
4
5
6
BLEP at 1st transmission
Eff
ectiv
e E b/N
0 [dB
]
No HARQHARQ (IR)
0.8 dB gain providing 20% higher cell
throughput
• HSUPA allows to use higher BLER because of fast retransmissions
R99
HSUPA
103 HSPA course.PPT / 08-10-2007 / AT&HH
Benefit of Node-B Based Fast Scheduling
1 2 3 4 5 6 7 80
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Noise Rise [dB]
Prob
abili
tyVA 3 km/h − 20 users/cell − 5% NR outage = 6 dB
RNC PS
Node B PS
5-10% cell throughput gain
104 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA Capacity
Uplink cell throughput [kbps]
0
200
400
600
800
1000
1200
1400
1600
WCDMA R99 HSUPA
kbps
Release’99
HSUPA
105 HSPA course.PPT / 08-10-2007 / AT&HH
-120 -115 -110 -105 -100 -95 -90 -85 -800
200
400
600
800
1000
1200
1400
1600
1800
2000
RLC
dat
a ra
te [k
bps]
RSCP [dBm]
HSUPA Coverage
High data rates if RSCP > -100 dBm
Uplink data rate limited by
UE tx power
106 HSPA course.PPT / 08-10-2007 / AT&HH
Coverage of high data-rate
Coverage gain 0.5 – 1.0 dB
UE capabilitybeyond 384 kbps
Peak data rate1.4-5.8 Mbps
Capacity gain 20-
50%
Cell throughput
gain
Latency gain<50 ms
Quality of end user
experience
HSUPAHSUPA
Lower costs in transport
Iub capacity gain
Higher add-onPS Traffic
Savings in BB capacity costs
Saves BTS sites (~10%) and adds PS traffic
Savings in transport – in Dedicated VCCsolution max 25%
Higher add-onPS traffic
HSUPA Performance Gains
107 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA Status in 3GPP
108 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA Standardisation Timeline• 03/04 Study item for 3GPP Release 6 completed and work item initiated• 12/04 First versions of HSUPA specs published• 03/05 Official work item completion date for RAN1/RAN2/RAN3• 06/05 Specifications stabilising• 09/05 Remaining open issues closed• 09/05 Performance requirement work item completion (RAN4) • 03/06 ASN.1 of RRC, NBAP and RNSAP protocols freezing
• Backwards compatibility started
2003 2004 2005 2006
3GPP study item
Study item completed
1st version in 3GPP spec
Official work item completion date
2007
Issues closed, performance
WI closed
ASN.1 frozen
109 HSPA course.PPT / 08-10-2007 / AT&HH
Key 3GPP specifications affected by HSUPA• TS25.309; FDD Enhanced Uplink; overall description; Stage 2
• 06/05 version (v. 6.3.0) is quite mature, no major open issues • TS25.211 - 25.215; Physical layer specifications
• 06/05 versions are mature and practically complete• TS25.306; UE radio access capabilities
• 06/05 version has the HSUPA UE categories,• TS25.321; MAC specification
• 06/05 version is still not fully stabile, user plane data flow is finalised, but the UE interaction with the scheduling commands requires further work
• TS25.331; RRC Protocol Specification• 06/05 version requires still further work to align with stage 2 and physical layer.
• TS25.423/25.433; RNSAP/NBAP signalling• 06/05 versions quite mature, some alignment to stage 2 and L1 still to be done
• TS25.427; Iur/Iub user plane protocols for DCH data streams• 06/05 version is mature and complete
• Performance requirement specifications TS25.101, 104, 133, 141• And others…
110 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA measurements in Lahti 10.9.2007Elisa Network, Ericsson RAN
111 HSPA course.PPT / 08-10-2007 / AT&HH
Tested card• Option GlobeTrotter GT MAX HSUPA PCMCIA modem
• Engineering sample• Drivers 5.1.0.1071• Firmware 2.7.0
112 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA Latency in the Field
• HSUPA brings network latency below 70 ms• HSUPA improves latency by 20 ms compared to HSDPA + R99
uplink
90 ms 84 ms
69 ms 65 ms
HSDPA
HSDPA + HSUPA
Ericsson Lahti live Nokia VF trialChannel
21 ms 19 msImprovement with HSUPA
113 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA Latency <45 msNSN – Nokia End-to-end Measurement
Nokia HSUPA terminal
prototypeNode-B RNC Packet core
ServerNokia Siemens networks
Minimum = 38ms, Maximum = 57ms, Average = 42msMinimum = 38ms, Maximum = 58ms, Average = 45msMinimum = 39ms, Maximum = 52ms, Average = 41msMinimum = 39ms, Maximum = 51ms, Average = 41ms
Lab measurements
05
101520253035404550
Latency
ms
RNC + coreBTS + IubAir interfaceUE
114 HSPA course.PPT / 08-10-2007 / AT&HH
HSUPA Throughput with FTP• The bit rate steps are explained by the scheduling grant resolution
840 kbps
560 kbps
710 kbps
115 HSPA course.PPT / 08-10-2007 / AT&HH
HSPA Evolution
116 HSPA course.PPT / 08-10-2007 / AT&HH
UTRAN Evolution
• Best CS + PS combined radio• Spectrum shared with current 3G• Reduced latency• Lower mobile power consumption• Flat architecture option• Simple upgrade on top of HSPA
HSPA evolution in R7/R8
HSPA evolution in R7/R8
LTE new radio access in R8
LTE new radio access in R8
HSDPA/HSUPA3GPP R6
HSDPA/HSUPA3GPP R6
• Optimized for PS only• New architecture• New modulation• Spectrum and bandwidth flexibility• Further reduced latency
Similar technical solutions applied both in HSPA evolution and in LTE
117 HSPA course.PPT / 08-10-2007 / AT&HH
3GPP Evolution in Release 5 – Release 8
HSPA R6HSPA R6 HSPA R7HSPA R7
• HSUPA 5.76 Mbps
• MBMS
• Continuous packet connectivity
• L2 optimization in downlink
• Enhanced FACH• Flat architecture• MIMO • 64QAM downlink• 16QAM uplink• MBMS evolution
HSPA R5HSPA R5
• HSDPA 14 Mbps
HSPA evolution
3GPP R83GPP R8
Long term evolution (LTE) +Further HSPA evolution
Basic HSDPA+HSUPA
• LTE: New PS only radio• L2 optimization in uplink• Enhanced RACH• Enhanced UE DRX • Flat architecture
enhancements• CS voice service over HSPA• 64QAM+MIMO • Downlink only broadcast • Synchronized E-DCH.
118 HSPA course.PPT / 08-10-2007 / AT&HH
HSPA Deployment Schedule
2004 2005 2006 2007 2008 2009 2010
Commercial
3GPP schedule
3GPP R6 3GPP R83GPP R7
3GPP R5 3GPP R6 3GPP R7 3GPP R8
20032002
3GPP R5
• HSUPA commercial 2007• HSPA evolution commercial 2009• LTE commercial 2010 and beyond
119 HSPA course.PPT / 08-10-2007 / AT&HH
MIMO and 64QAM
120 HSPA course.PPT / 08-10-2007 / AT&HH
HSPA Peak Data Rate Evolution• HSPA downlink data rate increases with 2x2 MIMO and 64QAM up to 42 Mbps and
uplink data rate with 16QAM up to 11 Mbps• LTE further increases the data rate beyond 100 Mbps with larger bandwidth of 20 MHz
14 Mbps
0.4 Mbps
14 Mbps
5.7 Mbps
28 Mbps1
11 Mbps
LTE: 170 MbpsHSPA: 42 Mbps2
LTE: 50 Mbps
Downlink peak rate
Uplink peak rate
3GPP R5 3GPP R6 3GPP R71 3GPP R8
1With 2x2 MIMO and 16QAM2With 2x2 MIMO and 64QAM likely for R8
121 HSPA course.PPT / 08-10-2007 / AT&HH
Category Codes Modulation MIMO Coding rate Peak bit rate 3GPP release 12 5 QPSK - ¾ 1.8 Mbps Release 5 5/6 5 16QAM - ¾ 3.6 Mbps Release 5 7/8 10 16QAM - ¾ 7.2 Mbps Release 5 9 15 16QAM - ¾ 10.1 Mbps Release 5 10 15 16QAM - Approx 1/1 14.0 Mbps Release 5 13 15 64QAM - 5/6 17.4 Mbps Release 7 14 15 64QAM - Approx 1/1 21.1 Mbps Release 7 15 15 16QAM 2x2 5/6 23.4 Mbps Release 7 16 15 16QAM 2x2 Approx 1/1 28.0 Mbps Release 7
Terminal Categories in Release 7
Category TTI Modulation Coding rate Peak bit rate 3GPP release 3 10 ms QPSK ¾ 1.4 Mbps Release 6 5 10 ms QPSK ¾ 2.0 Mbps Release 6 6 2 ms QPSK 1/1 5.7 Mbps Release 6 7 2 ms 16QAM 1/1 11.5 Mbps Release 7
HSDPA
HSUPA
122 HSPA course.PPT / 08-10-2007 / AT&HH
MIMO in HSDPA in Release 7• MIMO for HSDPA is based on D-TxAA (Double Transmit Adaptive Array) with fast L1
feedback• 2x2 MIMO peak data rate 28 Mbps with 16QAM and up to 42 Mbps with 64QAM
+
+
Coding, spreading
Coding, spreading
Demux
Base stationFeedback weights from UE Terminal
2 antennas & MIMO decoding capability
Transmitter with 2 branches per sector
123 HSPA course.PPT / 08-10-2007 / AT&HH
MIMO Modes
High CQI Multistreamtransmission
Low CQISingle stream
diversitytransmission
• Single stream transmission is similar to Release’99 closed loop transmit diversity, but with twodifferences
• The preferred antenna weights are delivered from UE to Node-B on HS-DPCCH, not on DPCCCH
• The used antenna weights in downlink are signaled on HS-SCCH while in Release 99 no explicit signaling was used. Therefore, Release 99 UE had to use antenna verification to identify the used antenna weights.
• Double data rate
• Interference resistance
124 HSPA course.PPT / 08-10-2007 / AT&HH
MIMO Multistream Usage in Macro Cells
Percentage of MIMO Multistream Usage
0 %
10 %
20 %
30 %
40 %
50 %
60 %
70 %
80 %
90 %
100 %
Vehicular A,round robin
Pedestrian A,round robin
Vehicular A,proportional fair
Pedestrian A,proportional fair
Multistream usage15% with round
robin
Multistream usage70% with
proportional fair
125 HSPA course.PPT / 08-10-2007 / AT&HH
64QAM Modulation in Release 7
QPSK 2 bits/symbol
16QAM 4 bits/symbol
64QAM 6 bits/symbol
• R5/R6 HSPA modulation• Dowlink QPSK and 16QAM• Uplink QPSK
• R7 HSPA modulation• Dowlink QPSK, 16QAM and 64QAM• Uplink QPSK and 16QAM
126 HSPA course.PPT / 08-10-2007 / AT&HH
Percentage of 64QAM usage
0 %
10 %
20 %
30 %
40 %
50 %
60 %
70 %
80 %
90 %
100 %
Vehicular A,round robin
Pedestrian A,round robin
Vehicular A,proportional fair
Pedestrian A,proportional fair
1-rx2-rx
64QAM Usage in Macro Cells
64QAM usage 20% for 2-antenna
terminals64QAM usage 10%
for 1-antenna terminals
64QAM usage 35% in favorable case
• These simulations with full loading. 64QAM usage is higher in fractional load case. • If 2x2 MIMO is used, then 64QAM usage is <<10%.
127 HSPA course.PPT / 08-10-2007 / AT&HH
Cell Capacity with Enhanced Terminals and R7 FeaturesCell throughput
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
HSPA 1-Equalizer(no 64QAM)
HSPA R7 2-Equalizer (no
MIMO, no 64QAM)
HSPA R7 withMIMO, no 64QAM
HSPA R7 withMIMO+64QAM
Mbp
s
+40%
+20%
128 HSPA course.PPT / 08-10-2007 / AT&HH
Uplink 16QAM
129 HSPA course.PPT / 08-10-2007 / AT&HH
Performance of Uplink 16QAM with Equalizer
• Up to 2x higher data rate in multipath channel with equalizer receiver compared to Rake receiver
Rake receiver BTS equalizer
Max 3.3 Mbps with Ec/N0=15 dB
Above 7 Mbps with Ec/N0=15 dB
130 HSPA course.PPT / 08-10-2007 / AT&HH
Enhanced Cell FACH (High Speed FACH)
131 HSPA course.PPT / 08-10-2007 / AT&HH
Enhanced Cell_FACH Concept
FACH HS-DSCH
S-CCPCH HS-PDSCH
HS-DSCH HS-DSCH in CELL_DCH state
HS-PDSCH
R99 solution R7 solution
• Benefits1. Seamless state transition since no physical channel reconfiguration2. Higher bit rate on CELL_FACH state (today 32 kbps for data)3. No changes to Release 5 physical channels (HS-DSCH and HS-SCCH)
32 kbps Up to 14 Mbps Up to 14 Mbps
Cell_FACH state Cell_FACH state
132 HSPA course.PPT / 08-10-2007 / AT&HH
Fast State Transitions with Enhanced FACH
PCH
FACH
DCH/HSPA
No data flow during transition >500 ms
Cell update and C-RNTI allocation takes >300 ms
RB recon-figuration
RB recon-figuration
PCH
HS-FACH
HSPA
Data flows on HS-FACH also during transition
Immediate transmission w/o cell update. No PCH required.
Release 99 – Release 6 RRC States
Release 7 RRC States
133 HSPA course.PPT / 08-10-2007 / AT&HH
Optimized Layer 2
134 HSPA course.PPT / 08-10-2007 / AT&HH
RLC
MAC-hs
…
IP packet 1500 B
UE
Node-B
RNCPDCP
RLC packet 40 B
3GPP Release 6
…
RLC
MAC-hs
IP packet 1500 BPDCP
RLC packet size flexible between 10B -1500 B
3GPP Release 7
…
Transport block size depending on scheduling
Transport block size depending on scheduling
…
MAC + RLC + PDCP MAC + RLC + PDCP
Optimized Layer 2 Concept (Flexible RLC)
• Basic RLC functions are kept: Ciphering, polling, retransmission• Smaller RLC overhead• Less packet processing required in UE and in RNC • No RLC optimization required for each service
135 HSPA course.PPT / 08-10-2007 / AT&HH
Optimized Layer 2 – RLC Header + Padding Overhead
0 %5 %
10 %15 %20 %25 %30 %35 %40 %45 %50 %
0 500 1000 1500IP packet size
Release 6 RLC (40-B RLC packet)Release 7 RLC (Flexible RLC)
Rel6: RLC PDU header 2 bytes; PDU size fixed to 336 bitRel7: RLC PDU header 2 bytes; PDU size flexible from 80 – 12000 bits
136 HSPA course.PPT / 08-10-2007 / AT&HH
Continuous Packet Connectivity
137 HSPA course.PPT / 08-10-2007 / AT&HH
Continuous Packet Connectivity in 3GPP R7
• Continuous packet connectivity includes 1. Uplink discontinuous transmission2. Downlink discontinuous reception3. HS-SCCH less HSDPA for VoIP
• Continuous packet connectivity gives• Low mobile power consumption for packet applications• Higher capacity due to less interference transmitted
DPCCHHS-DSCH
DPCCHHS-DSCH
Web page download
User reading web page
User moved to FACH/PCH
Connection goes immediately to gating mode to save mobile power when data transfer is
over
HSPA R6
HSPA R7
138 HSPA course.PPT / 08-10-2007 / AT&HH
Continuous Packet Connectivity for VoIP
• Continuous packet connectivity improves also the capacity of low data rate services, like VoIP
• Data can be transmitted in short bursts and discontinuous operation can be utilized between the bursts
HSPA with continuous packet connectivity
DPCCHDPDCHWCDMA R99 CS voice
No transmission ⇒ lesspower consumption and less
interference
20 ms
139 HSPA course.PPT / 08-10-2007 / AT&HH
UE Radio Modem Power Consumption
Power consumption relative to continuous rx/tx
0 %10 %20 %30 %40 %50 %60 %70 %80 %90 %
100 %
Tx/(Rx+Tx)=30% Tx/(Rx+Tx)=50% Tx/(Rx+Tx)=70%
VoIP call (2-ms TTI)Inactive user on Cell_DCH
VoIP assumptions - E-DCH activity 15%- DPCCH activity during E-DCH inactive 10%- DRX 60%
Inactive user- E-DCH activity 0%- DPCCH activity during E-DCH inactive 10%- DRX 80% 70% savings in
VoIP calls85% savings when inactive
140 HSPA course.PPT / 08-10-2007 / AT&HH
Uplink Gating Gain for VoIP Capacity
• Reference case: Release 6 HSUPA
• Different configurations studied for signaling
• OFF=0 means CQI sent simultaneously with data
• OFF=3 means CQI sent after data
• From simulations it can be though concluded that for 50% improvement for uplink VoIP capacity could be achieved
Gating capacity gain 50%
141 HSPA course.PPT / 08-10-2007 / AT&HH
0
20
40
60
80
100
120
140
160
WCDMA R99 CSvoice
HSPA R6 VoIP HSPA R7 VoIP
Use
rs
Downlink Uplink
VoIP Capacity• HSPA R7 VoIP can provide up to 2x higher voice capacity than CS
voice
2x
AMR12.2 kbps
142 HSPA course.PPT / 08-10-2007 / AT&HH
VoIP Optimization Features in 3GPP Release 7
Packet bundling
Packet retransmissions
L1 control overhead
Packet scheduling
Packet bundling
Retransmissions possible due to fast L1 ARQ
Low overhead due to fractional DPCH and discontinuous uplink
Advanced HSDPA scheduling
HSPA VoIP of Release 7
Single packet transmission
Retransmissions not possibledue to excessive delay
Continuous L1 control channel
No scheduling
CS voice of Release 99
Advanced terminals HSDPA equalizer No equalize
143 HSPA course.PPT / 08-10-2007 / AT&HH
0
10
20
30
40
50
60
GSMEFR
GSMAMR
GSMDFCA
WCDMACS voice
HSPA R7 LTE
Use
r per
MH
z
Voice Spectral Efficiency Evolution from GSM to LTE
• 20 x more users per MHz with 3GPP LTE than with GSM EFR!• VoIP is the way to go for future voice in mobile systems
CS voice VoIP
144 HSPA course.PPT / 08-10-2007 / AT&HH
Round Trip Time Evolution
145 HSPA course.PPT / 08-10-2007 / AT&HH
HSPA Round Trip Time
1 2 ms2 ms
1 12 ms
1.3 2 ms1
AlignHSUPA TTI
Node-B rxRNC+core
Node-B txAlign+SCCH+HSDPA TTI
Network RTT 13.3 ms
1 2 ms1.3 2 ms1
TTI align HSUPA TTI
Align+SCCH+HSDPA TTI
7.3 ms
x msUE tx
x msUE rx
Realistic RTT with HSPA evolution
3GPP limit for RTT (theory)
= UE processing time
= TTI alignment = 0..1 x TTI
= Air interface transmission time
= Network processing times
• End-to-end round trip time <30 ms expected with HSPA
146 HSPA course.PPT / 08-10-2007 / AT&HH
MBMS Release 6
MBMS Release 7
Same scrambling code in all cellsDifferent cells = multipath propagation
Different scrambling codes Different cells = inter-cell interference
Single Frequency MBMS
Carrier can be shared with unicast
Dedicated MBMS carrier required
147 HSPA course.PPT / 08-10-2007 / AT&HH
HSPA+ Architecture Evolution
148 HSPA course.PPT / 08-10-2007 / AT&HH
Architecture EvolutionPacket Domain User Plane
HSPA (3GPP R6)
I-HSPA (3GPP R7)
LTE (3GPP R8) WiMAX
Node-B
RNC
SGSN
GGSN
Node-B with RNC functions
GGSN
eNode-B
SAE GW ASN GW
Base station
• Flat architecture = single network element in user plane in radio network and in core network
• Same architecture in I-HSPA, LTE and in WiMAX
Ciphering and header compression
149 HSPA course.PPT / 08-10-2007 / AT&HH
I-HSPA Specified as Part of 3GPP Release 7
• 3GPP Release 7 has specified flat architecture for HSPA • A change to RANAP specification to extend the RNC-ID to allow it
to be longer than 4096 values• “Introduction of an Extended RNC-ID IE”• TS25.331, TS25.413, TS25.423, TS25.433, TS25.453, TS48.008, TS48.018
• A clarifying description how existing 3GPP functionalities can be used to allow UE mobile-originated and mobile-terminated CS call re-direction
• TR25.999, Section 7.1.4.4 CS Service in stand-alone scenario: “Evolved HSPA system focuses on PS services. Due to the PS optimized architecture in the stand-alone scenario, the HSPA UE should be served in the evolved HSPAwhen it requests a PS service only, and in the legacy architecture (WCDMA or GSM) when it requests a CS service…”
• Carrier sharing solution between RNC based architecture and flatarchitecture accepted using UE involved SRNS relocation procedure
• Soft handover optimization for Signalling Radio Bearers was included to Iur specifications
150 HSPA course.PPT / 08-10-2007 / AT&HH
HSPA Evolution in Release 8
151 HSPA course.PPT / 08-10-2007 / AT&HH
New Release 8 Items for HSPA Evolution Approved in 3GPP RAN September 2007
Work item Nokia/NSNWork item Nokia/NSN
Enhanced Uplink for CELL_FACH State in FDDEnhanced UE DRX
Work or study item RaporteurTitle
Work item Nokia/NSNSRNS Relocation Enhancement
05/0809/08
Target completion
03/08Work item Nokia/NSNEnhancement for HSPA Architecture 06/08Work item EricssonImproved L2 for uplink 03/08Work item Nokia/NSNCS voice service over HSPA 03/08Work item VodafoneHSDPA demodulation requirements for
16QAM and QPSK with 15-codes 06/08
Work item Ericsson64QAM+MIMO 03/08Work item EricssonDownlink only broadcast 06/08
Study item Nokia/NSNSynchronized E-DCH 03/08
Note: 6 out of 8 new items have Nokia/NSN as raporteur
New items in Release 8
Continuation from Release 7
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3. UL data transmission4. MAC-e header with UE-id for
contention resolution
5. Collision resolution:UE id is returned on E-AGCH
#0 #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #12#13#14#11DPCCHE-DPCCHE-DPDCH
#0 #1 #2 #3 #4 #5 AICHE-AGCH
E-HICH E-HICH E-HICH
#0 #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #12#13#14#11 #0 #1 #2 #3 #4 #5DPCCH DPCCH DPCCHE-DPCCHE-DPDCH
1. PRACH preamble ramp-up phase with PRACH sub-channels and/or PRACH signaturesequences reserved for enhanced RACH
2. Acquisition indication and E-DCHresource allocation, extended AICH
6. E-DCH with a new data rate after reception of E-AGCH
F-DPCH
E-DPCCH
E-DPDCH
E-DPCCH
E-DPDCH
Enhanced RACH Item (One Proposal Below)• Fast access to high data rates also in uplink to complement R7 Enhanced FACH
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Enhanced UE DRX Item• UE must decode all FACH frames in Release 7 ⇒ receiver is running continuously
eating batteries• The target in Release 8 is to enable Discontinuous reception (DRX) on FACH• Example keep alive transmission below, where FACH DRX can lead to
considerable battery savings• The work item also explores the state transition to PCH without any RRC signalling
RACH
FACH in R7
= Keep alive transmission
= No data coming to UE, but UE must still decode all FACH frames
FACH in R8 = UE uses discontinuous reception when no data coming
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HS-DSCH
E-DCH
Cell_DCH Cell_FACH Cell_PCH
PCH
Direct mapping to HS-SCCH
DRX in Release 7 DRX in Release 8 Long DRX periods (>500 ms)
DTX in Release 7 Transmission only when needed
RRC States in 3GPP Release 7/8• The RRC states remain in Release 7/8 (DCH, FACH, PCH, idle), but the states will
have more similarities and the state transitions will be faster• Similar transport channels in DCH and FACH• DRX can be used in all states
• DRX period longer in PCH state than in DCH or FACH
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Improved L2 in Uplink
• Follows the same principle that was applied in downlink in Release 7• The benefits
• Reduced L2 overhead MAC + RLC• Lower processing power requirements in UE and in RNC• No RLC optimization required per service
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CS Voice over HSPA Concept• The target to use HSPA transport channels for carrying CS voice service to get end
user and operator performance benefits• No difference from service point of view compared to current CS voice : CS core is
not aware of radio mapping and roaming and charing remains the same• No changes to HSPA Layer 1 required
DCH
CS core
HS-DSCH + E-DCH
PS core
Transport channel
Layer 2 TM RLC UM RLC
PDCP1
1IP header compression2TM=transparent mode3UM=unacknowledged mode
Under discussion
Dejitter bufferApplication layer
Current CS voice VoIPCS voice
over HSPA
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CS Voice over HSPA Benefits Compared to CS Voice over Release 99 Channels
• Improved talk-time• Uplink gating and downlink DRX can be used according to Release 7
Continuous packet connectivity (CPC)• Talk time improvement expected clearly more than 50%
• Faster call setup time• Core signalling runs fast on HSPA• HSPA allows asynchronous RAB Setup without slow DCH reconfiguration
procedures• UE-UE call setup time could ideally be below 1 s
• Higher capacity• Equaliser, L1 retransmissions, uplink gating, HS-SCCHless features.• No VoIP related overhead required : no IP, RTP headers
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CS Voice over HSPA – Dejitter Buffer
• L1 retransmissions and downlink scheduling will cause delay fluctuations. The order of the packets may also change in L1 processes
• Dejitter buffer is required in RNC in uplink and internally in UE in downlink to hide the delay variations
• Dejitter buffers are not specified in 3GPP. The requirements for UE VoIPdejitter developed in 3GPP (memory, etc) can be reused for CS-HSPA
RNC12 3 4 1 2 3 4 CS core
Dejitter buffer in RNC
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Synchronized E-DCH – Motivation • HSPA uplink cell throughput is low compared to traffic requirements and compared to
LTE• Expected traffic asymmetry DL:UL 2:1• HSPA downlink is 72% x LTE while uplink is 45% x LTE
• ⇒ Preferably 50% uplink cell throughput gain required in HSUPA
Cell throughput 5 MHz
0
1
2
3
4
5
6
7
8
9
10
Downlink Uplink
Mbp
s HSPALTE
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Synchronized E-DCH Concept• Orthogonal uplink transmission by using the same scrambling code for all intra-cell
users with synchronous transmission. • Expected uplink capacity gain up to 70% in macro cells
• Simple upgrade to terminal transmission and BTS reception since existing channels are used
• Soft handover less important than in HSUPA R6 ⇒ well suited for I-HSPA • Required changes to 3GPP specifications and implementations
• new downlink scheduling channels• slow timing advance adjustment • updated scheduling algorithm
• Node-B based scheduling in HSUPA makes synchronous transmission more feasible compared to 3GPP USTS 2001
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Synchronized E-DCH Code Allocation• Uplink code tree allocation given with HS-SCCH like channel (CRC for reliability) with 2 ms x
N duration (range for N to be defined) based in happy bit/HSUPA MAC header info
C1(0) = [ 1 1 ]
C1(1) = [ 1 0 ]
C2(0) = [ 1 1 1 1 ]
C2(1) = [ 1 1 0 0 ]
C2(2) = [ 1 0 1 0 ]
C2(3) = [ 1 0 0 1 ]
C3(0) = [ 1 1 1 1 1 1 1 1 ]
C3(1) = [ 1 1 1 1 0 0 0 0 ]
. . .
. . .
SF = 2 SF = 4 SF = 8
C3(2) = [ 1 1 0 0 1 1 0 0 ]
C3(3) = [ 1 1 0 0 0 0 1 1]
. . .
. . .
C3(4) = [ 1 0 1 0 1 0 1 0 ]
C3(5) = [ 1 0 1 0 0 1 0 1 ]
. . .
. . .
C3(6) = [ 1 0 0 1 1 0 0 1 ]
C3(7) = [ 1 0 0 1 0 1 1 0 ]
. . .
. . .
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
Code allocated with “HS-CACH”
These codes cannotbe used at the same
time as C3(1)
Codes at SF 256 allocated each users DPCCH and E-DPCCH
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Synchronized E-DCH Timing Control and Soft Handover
• No soft handover intended for data (as other Node B would have to detect the code allocation blindly (not desirable to signal all the time, keeping E-DPCCH unchanged expect spreading/scrambling code different that usually)
• F-DPCH+ provides now both power control and uplink timing control (latter e.g. by puncturing some of the power control commands
• Timing adjustment resolution e.g. 1/6 to ¼ chips in order not to mandate a particular sampling rate
• Timing advance command rate max. 40 Hz (investigated in 2001 with USTS)
Node B
Node B
F-DPCH
F-DPCH+, O-HSUPA, HSDPA
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Architecture Work Items• SRNS Relocation Enhancement
• Approved as the continuation of the HSPA Architecture Evolution work, aiming at optimizing the relocation procedures. The results may be applicable for both “legacy”and “flat” UTRAN architectures.
• Enhancement for HSPA Architecture• Continuing the HSPA architecture evolution work on the topics of e.g., optimizing the
RRM and introducing MBMS for a flat architecture.