Date Presentation / Author
NSN 3G Network
RAN Workshop
HSDPA Overview
Date Presentation / Author
Outline
HSDPA Aktivasi HSDPA di Nokia RAN Parameter HSDPA di Nokia RNC Resource Allocation untuk HSDPA di Nokia
RAN
Date Presentation / Author
HSDPA Part of 3GPP release 5 specifications System of new physical channels for UTRAN Downlink data rates up to 14.4 Mbit/s per user It uses shared channel concept -Rather than constantly allocating and deallocating
dedicated channels to individual users, users share a high bandwidth channel - the HS-DSCH (High Speed Downlink Shared Channel).
-It allows the system to operate with a “fat pipe” Fixed SF16 multicode transmission
Date Presentation / Author
Three Keys Technical of HSDPA
Data rates are optimized dynamically during the session according to radio link quality. This ensures highest possible data rates to end-users.
To improve QoS data Packets are further compressed and BTS schedules data transmission instead of RNC. Fast interleaving(2ms).
Data retransmission is handled by BTS. UE combines correct bits from original transmission and re transmission (Hybrid ARQ). This provides fastest possible response.
HSDPA
Adaptivemodulation and
coding Fastscheduling
Fast retransmission
Date Presentation / Author
1. Adaptive Modulation and Coding (AMC)
16 QAM (Quadrature Amplitude Modulation)
QPSK (Quadrature Phase Shift Keying)
Q
1011 1001
10001010
0001 0011
00100000
0100 0110
01110101
1110 1100
11011111
I
QPSK
2 bits / symbol480 kbit/s/HS-PDSCH
10 00
0111
Q
I
16QAM
4 bits / symbol 960 kbit/s/HS-
PDSCH
Date Presentation / Author
Adaptive Modulation and Coding (AMC) 1symbol=2 bits 1 channel SF16 in QPSK = (symbol x chiprate)/16 = (2 x 3840)/16 = 480 kbps 1 fat pipe = 5 codes = 5 x 480 x (3/4) = 1.8 Mbps
1symbol=4 bits 1 channel SF16 in 16 QAM = (symbol x chiprate)/16 = (4 x 3840)/16 = 960 kbps 1 fat pipe = 5 codes = 5 x 960 x (3/4) = 3.6 Mbps
Date Presentation / Author
Adaptive Modulation and Coding
QPSK
1/4
Modulation EffectiveCode rate
2/4
3/4
16
SF
16
16
2/4
3/4
16
16
1.2 Mbit/s
Data rate(10 codes)
2.4 Mbit/s
3.6 Mbit/s
4.8 Mbit/s
7.2 Mbit/s
1.8 Mbit/s
Data rate(15 codes)
3.6 Mbit/s
5.3 Mbit/s
7.2 Mbit/s
10.7 Mbit/s
600 kbit/s
Data rate(5 codes)
1.2 Mbit/s
1.8 Mbit/s
2.4 Mbit/s
3.6 Mbit/s
4/4*16 4.8 Mbit/s 7.2 Mbit/s2.4 Mbit/s
4/4*16 9.6 Mbit/s4.8 Mbit/s
16QAM
14.4 Mbit/s
Note: * In theory
Date Presentation / Author
Node BRNC
PacketsScheduler
& Buffer
ARQ &
Coding
ACK/NACK & Feedback Decoding
Flow Control
Terminal
ARQ
Decoding
Soft Buffer
& Combining
ACK/NACK & Feedback Generation
• Fast Transmission Time Interval (TTI) reduced from 10 ms to 2 ms
2. Fast Scheduling
Date Presentation / Author
Schedulers• The scheduler schedules the information that will be sent from the
Node B to the UE.• The scheduler requires important information from the uplink HS-
DPCCH
Scheduler
QoS and Subscriber ProfileWho is the subscriber? Platinum, Gold,Silver, Normal.What type of service is the subscriber allowed? High priority, Best effort
Uplink FeedbackCQI and Ack/Nackinformation
Node B buffer statusHow much dataHow fast is the data arriving
User HistoryHow long has userbeen waiting
Available Radio ResourcesPowerCodes
Traffic ModelWhat type of traffic model shouldbe used - according to periodof the day – Peak/Off Peak
UE CapabilitySee UE categories
Users are scheduled according to theirrequirements for transmission by theNode B over the air interface
Date Presentation / Author
3. Fast Retransmission
• Retransmissions handled in BTS in layer 1
• Retransmission process Hybrid Automatic Retransmission reQuest (HARQ)
• Note: HSDPA does not support soft handover
Retransmission between
• UE and BTS by layer 1
• UE and RNC by RLC
• UE and data server by TCP
• Fast Transmission Time Interval (TTI) reduced from 10 ms to 2 ms
Date Presentation / Author
HSDPA Activation Hardware requirements HSDPA requires the following hardware: . In the base transceiver station (BTS), at least one WSPC
card is required. . In the radio network controller (RNC), all data and macro
diversity combining units (DMCUs) must be of type CDSP-C Software requirements The RNC and BTS software have to be upgraded to RAS05
level for basic HSDPA. The new features require RAS05.1.
Date Presentation / Author
HSDPA Activation Activation in RNC 1. Check Service Pool Information 2. Change Pool Allocation based on RNC Capacity
step 3. Execute the Pool Change (restart RNC, restart
DMPG, or Performed a controlled DMPG state change)
Activation in WBTS HSDPA support can be enabled or disabled with a cell-
specific management parameter HSDPAenabled.
Date Presentation / Author
HSDPA Activation HSDPA Activation Document
Adobe Acrobat Document
Date Presentation / Author
HSDPA Parameter in RNC
Fixed power is allocated for HSDPA transmissions (HS-DSCH). AMC is used instead of fast PC.
Associated UL HS-DPCCH is under fast PC loop. Different power levels for ACK and CQI part.
Transmit power of associated DL HS-SCCH is tuned adaptively
CCH
DCH + CCH
Variable power
Ptx Offset
Ptx Target
DCH + CCH
HSDPA power
PC headroom
Fixed power
PC headroom
Fixed power for HSDPA transmissions.
Controlled with a cell-specific parameter
CCH
R’99 DCH only R’5 DCH+HSDPA
Date Presentation / Author
Share of HSDPA and DCH bandwidth on Iub
HSDPA only pipe
Shared pipe
Shared HSDPA AAL2 Allocation Size - SHAS
Shared HSDPA Flow Control Allocation SizeSHFCAS
Date Presentation / Author
Shared HSDPA Allocation Size WBTS Parameter SharedHSDPAallocation Indicates the guaranteed bit rate in the Iub for HSDPA traffic Reservation only made when the first HSDPA user enters the cell If the DCH reservation is high so that the requested capacity is not available,
then the largest possible available capacity will be allocated If new HSDPA users arrive in the cell the reservation will be upgraded if
possible to the full value of the configured SharedHSDPAallocation size The value of the parameter depends on the priority required for the HSDPA
traffic – if HSDPA traffic is not as important as DCH traffic then assign a low value
300Kbps is the recommended minimum size 1Mbps is the recommended size for a 1+1+1 site with only 1 WSPC
Mandatory creation parameter Range 0 to 7.2 Mbps in 0.1 Mbps steps
Date Presentation / Author
Shared HSDPA Flow Control Allocation Size WBTS parameter SharedHSDPAFlowControlAllocation Indicates the maximum data rate the RNC may use to send mac-d
data on the Iub DCH traffic has strict priority except for the reserved capacity allocated
by the SharedHSDPAallocation parameter Initially this parameter could be set at 1.25 X average air interface
throughput Maximum value should be Total Iub capacity – signalling traffic
requirements Too high DCH usage and aggressive setting of SHFCAS will result in
mac-d data buffering at AAL2 level Buffer overflow will cause the RLC layer to retransmit data in Ack
mode By monitoring HOs and buffer overflows and comparing the
retransmission distributions on the mac-hs and RLC layer can provide a rough indication about the feasibility of the SHFCAS setting
Date Presentation / Author
Number Of Overbooked HSDPA Users WBTS parameter NbrOfOverbookedHSDPAUsers The parameter defines the allowed number of
MAC-d flows if the Shared HSDPA AAL2 allocation has failed.
Value 0 can be used to switch the parameter off The amount of MAC-d flows is not restricted if the
HSDPA AAL2 allocation fails and the parameter is not used
Date Presentation / Author
HSDPA Parameter Another Parameter recommended for HSDPA can be
found on below documentation
More detailed parameter can be found on NED
Adobe Acrobat Document
TN_RNC_SW_2006_078
Adobe Acrobat Document
TN_3GBTS_SW_2006_0035
Adobe Acrobat Document
HSDPA_Overview
Date Presentation / Author
HSDPA with 16 user per cell
One WSPC unit supports max. 3 HSDPA cells.
One WSPC unit supports max. 16 HSDPA users. 1)
Those 16 HSDPA users can be divided freely between three cells.
Packet Scheduler in MAC-hs schedules all users equally regardless of their cell.-> Cells get resources depending on the amount of users and traffic in each.
Max. one HSDPA WSPC in BTS-> Max. three HSDPA cells in BTS.
4 users
4 users8 users
Note 1: The actual amount of supported HSDPA users per WSPC depends heavily on the used Uplink DCH channel speed associated with HSDPA user, see dimensioning rules
HSDPA BTS Configuration in RAS05
Date Presentation / Author
HSDPA with 16 user per cell
RAS05.1 The maximum number of HSPDA users
served by a single WBTS is increased to 48 (if QPSK modulation is used).
• The maximum number of HSDPA users per cell is 16.
• HS-DSCH can be transmitted to all cells in the WBTS at the same time.
• 1 WSPC per HSDPA-capable cell is needed.
16 users
16 users16 users
One WSPC unit supports one HSDPA cell. One WSPC unit (one cell) supports max. 16
HSDPA users, i.e, there will be maximum 16 users per cell.
Packet Scheduler in MAC-hs schedules all users in a cell (RAS05.1) instead of all users in the BTS (RAS05).
Cells get resources depending on the amount of users and traffic in each.
HSDPA BTS Configuration in RAS05. 1
Date Presentation / Author
RAS05.1 HSDPA with 16 user per cellRoll out (RAS05)• Maximum number of HSDPA users per BTS:
16• HS-DSCH is transmitted to one cell at a time
from the BTS• Time multiplexed between different cells of
the BTS• Up to 3 cells per BTS can be enabled for
HSDPA
Cell specific 1.8/3.6 Mbit/s HSDPA(QPSK/16QAM)
HSDPA
AMC
Frame SizeH-ARQ
Spreading& Multip.
High capacity (RAS05.1)• Maximum number of HSDPA users per cell:
16• HS-DSCH can be transmitted to all cells in the
BTS at the same time
• HSDPA with 16 users per cell brings the HSDPA performance gains for each cell independently of the data rate in the other cells in the same BTS
• Availability of sufficient baseband processing and transport resources required
Date Presentation / Author
WBTS and HSDPA (WBTS Structure)
R-bus
DSC-BUS
Iub
WAF
WTR WSM
WPAW
SP
WS
P
WS
P
DSC-BUS
WAF
WTR WSM
WPA
WS
P
WS
P
WS
P
DSC-BUS
WAF
WTR WSM
WPA
WS
P
WS
P
R-bus
T-bus
RT-bus
RR-bus
ST-bus SR-bus
WS
P
WSP-C assigned for HSDPA use. handles L1,
MAC-hs and FP
IFUIFU
AXU
IFU
WSC
CarrierInterFace
WA
MW
AM
WA
M
R-bus
WAM unit handles
Control and AAL2
functions
Date Presentation / Author
Requirements to Enable HSDPA on a BTS WN3.0 Software installed on the BTS Due to the capacity requirements only the WSP-C supports
HSDPA At least one WSP-C need to be installed in the BTS to support
HSDPA using 5 codes A software update for the WSP-C is required to support HSDPA No changes are required to any other units for HSDPA to be taken
into operation and their dimensioning can be done according to the normal guidelines
All types of WSP units can be combined in one cabinet All BTS types that can support the WSP-C unit will be able to
support HSDPA
Date Presentation / Author
The WSP-C Unit and HSDPA• Processing power on the WSP = Channel Elements• 32 CEs are required to handle the 5 code HSDPA
implementation (HS-SDCH, HS-SCCH and HS-DPCCH)
• The 32 CEs for HSDPA will be reserved from one WSP-C only
• This leaves 32 CEs available for CCH and DCH use. Reservation of the CEs for HSDPA is static and made at BTS start up if the flag is set (HSDPAenabled=1) in the RNC
• 1 to 3 cells are supported depending on the SW release and customer parameters –For RAS05 1 WSP-C will support HSDPA for the whole BTS
Date Presentation / Author
The WSP Channel Element and Common Channels
WSP Type CEs
WSPA 32
WSPC 64
WSPD 32
WSPE 16
Bearer (Kbps) CEs required
AMR voice 1
16 1
32 2
64 4
128 4
384 16WSP Type Cells CEs required for
CCHs
WSPA 8 per cell
WSPC 1 - 3 16
WSPD CEs not reduced for CCHs
WSPE CEs not reduced for CCHs
If all types of WSP units were installed in the same BTS the CCH allocation would follow this priority:
1) All CCHs to WSPA
2) WSPC if WSPA fully loaded or does not exist
3) WSPD if WSPA/C fully loaded or does not exist
4) WSPE if WSPA/C/D fully loaded or does not exist
Date Presentation / Author
Example Baseband Calculations 1 Sectorised 1 + 1+ 1 with 1 WSPC
WSPC has 64 CEs – 32 CEs for HSDPA -16 CEs for CCHS = 16 CEs left for use by associated channels and AMR channels
Using associated channel 16/128 for HSDPA requires 4 CEs from same WSP 16/4 = 4 rem 0 so support for 4 HSDPA users + 0 AMR users Using associated channel 384 requires 16 CEs from same WSP 16/16 =1 rem 0 so support for 1 HSDPA user and 0 AMR users
Sectorised 1 + 1+ 1 with 2 WSPC WSPC 1has 64 CEs - 32CEs for HSDPA – 16 CEs for CCH s= 16 CEs left for use by associated channels and
AMR channels WSPC 2 has 64 CEs by associated channels and AMR channels Using associated channel of 64/128 for HSDPA requires 4 CEs from same WSP WSPC 1 = 16/4 = 4 r 0 WSPC 2 = 64/4 = 16 r 0 RAS05 only supports 16 HSDPA users/NodeB (WSPC 2 fulfills this) and therefore all remaining WSPC 1 CEs
must be used for AMR so support for 16 HSDPA users and 16 AMR users Using associated channel 384 requires 16 CEs from same WSP WSPC 1 = 16/16 = 1 r 0 WSPC 2 = 64/16 = 4 so support for 5 HSDPA users and 0 AMR users
Date Presentation / Author
Example Baseband Calculations 2 Sectorised 1 + 1+ 1 with 3 WSPC
WSPC 1has 64 CEs - 32CEs for HSDPA – 16 CEs for CCHs = 16 CEs left for use by associated channels and AMR channels
WSPC 2 has 64 CEs left for use by associated channels and AMR channels
WSPC 3 has 64 CEs left for use by associated channels and AMR channels
Using associated channel of 64/128 for HSDPA requires 4 CEs from same WSP
WSPC 1 = 16/4 = 4 r 0 WSPC 2 = 64/4 = 16 r 0 WSPC 3 = 64/4 = 16 r 0
RAS05 only supports 16 HSDPA users/NodeB (WSPC 2 fulfills this) and therefore WSPC 1 and WSPC 3 CEs must be used for AMR
WSPC 1 = 16 CEs and WSPC 3 = 64 CEs = 80 CEs
so support for 16 HSDPA users 80 AMR users
Using associated channel 384 requires 16 CEs from same WSP
WSPC 1 = 16/16 = 1 r 0 WSPC 2 = 64/16 = 4 r 0 WSPC 3 = 64/16 = 4 r 0
so support for 9 HSDPA users and 0 AMR users
Date Presentation / Author
HSDPA And RNCRNC196RNC196 / 48M 85M 122M 156M 196M 300M 450M
Max HSDPA peak rate per UE [Mbit/s]
3.6
HSDPA active users per cell 16
HSDPA active users per RNC 215 375 540 700 845 1080 1620
Iu-ps HSDPA net bit rate [Mbit/s] 43 94 109 140 176 270 405
HSDPA BTS 128 192 256 320 512 512 512
HSDPA carriers 384 576 768 960 1152 1152 1152
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