02_RN31552EN10GLA0_The Physical Layer
Transcript of 02_RN31552EN10GLA0_The Physical Layer
The Physical Layer3GRPLS (RN3155) – Module 2
Part I: Channel Mapping
Part II: Transport Channel Formats
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Part II: Transport Channel Formats
Part III: Cell Synchronisation
Part IV: Common Control Physical Channels
Part V: Physical Random Access
Part VI: Dedicated Physical Channel Downlink
Part VII: Dedicated Physical Channel Uplink
Part VIIII: HSDPA Physical Channel (HS-PDSCH)
Part IX: HSUPA Physical Channels (E-DCH)
At the end of this module, you will be able to
• Describe the WCDMA channel structure including their mutual mapping• Explain transport channel format• List different code types
• Name the main differences in uplink and downlink data organisation
• Describe the UE cell synchronisation
Objectives
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• Describe the UE cell synchronisation• Outline the paging organisation and its impact on the UE• Characterise the random access, its power power control and code planning
• Describe the DPCHs, their power control, time organisation, and L1
synchronisation• Describe the HS-DSCH and other physical channels related to HSDPA
• Name the different HSDPA physical channel types• What kind of enhancements are implemented with HSUPA ?• Describe the E-DCH capabilities
Part I Channel Mapping
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• In GSM, we distinguish between logical and physical channels. In UMTS there are three different
types of channels:
1. Logical
2. Transport
3. Physical
• Logical Channels• Logical Channels were created to transmit a specific content.
• There are for instance logical channel to transmit the cell system information, paging information,
or user data.
• Logical channels are offered as data transfer service by the Medium Access Control (MAC) layer
Radio Interface Channel Organisation
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• Logical channels are offered as data transfer service by the Medium Access Control (MAC) layer
to the next higher layer.
• Consequently, logical channels are in use between the mobile phone and the RNC.
• Transport Channels (TrCH)• The MAC layer is using the transport service of the lower lower, the Physical layer.
• The MAC layer is responsible to organise the logical channel data on transport channels. This
process is called mapping.
• In this context, the MAC layer is also responsible to determine the used transport format.
• The transport of logical channel data takes place between the UE and the RNC.
• Physical Channels (PhyCH)•The physical layer offers the transport of data to the higher layer.
•The characteristics of the physical transport have to be described.
•When we transmit information between the RNC and the UE, the physical medium is changing.
•Between the RNC and the Node B, where we talk about the interface Iub, the transport of
information is physically organised in so-called Frames.
•Between the Node B and the UE, where we find the WCDMA radio interface Uu, the physical
transmission is described by physical channels.
•A physical channel is defined by the UARFCN and the a spreading code in the FDD mode.
Radio Interface Channel Organisation
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Logical Channelscontent is organised in separate channels, e.g.
System information, paging, user data, link management
Radio Interface Channel Organisation (R99 model)
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Transport Channelslogical channel information is organised on transport channel
resources before being physically transmitted
Physical Channels(UARFCN, spreading code)
FramesIub interface
There are two types of logical channels (FDD mode):
1) Control Channels (CCH):
• Broadcast Control Channel (BCCH)•System information is made available on this channel.
•The system information informs the UE about the serving PLMN, the serving cell, neighbourhood
lists, measurement parameters, etc.
•This information permanently broadcasted in the downlink.
• Paging Control Channel (PCCH)•Given the BCCH information the UE can determine, at what times it may be paged.
•Paging is required, when the RNC has no dedicated connection to the UE.
Logical Channels
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•Paging is required, when the RNC has no dedicated connection to the UE.
•PCCH is a downlink channel.
• Common Control Channel (CCCH)•Control information is transmitted on this channel.
•It is in use, when no RRC connection exists between the UE and the network.
•It is a bi-directional channel, i.e. it exists both uplink and downlink.
• Dedicated Control Channel (DCCH)•Dedicated resources were allocated to a UE.
•These resources require radio link management, and the control information is transmitted both
uplink and downlink on DCCHs.
• 2) Traffic Channels (TCH):
• Dedicated Traffic Channel (DTCH)•User data has to be transferred between the UE and the network.
•Therefore dedicated resources can be allocated to the UE for the uplink and downlink user data
transmission.
• Common Traffic Channel (CTCH)•Dedicated user data can be transmitted point-to-multipoint to a group of UEs.
Logical Channels
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Logical Channels are mapped onto Transport Channels. There are two types of Transport Channels
(FDD mode):
a) Common Transport Channels:
• Broadcast Channel (BCH)It carries the BCCH information.
• Paging Channel (PCH)It is in use to page a UE in the cell, thus it carries the PCCH information. It is also used to notify UEs
about cell system information changes.
• Forward Access Channel (FACH)The FACH is a downlink channel. Control information, but also small amounts of user data can be
Transport Channels (TrCH)
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The FACH is a downlink channel. Control information, but also small amounts of user data can be
transmitted on this channel.
• High Speed Downlink Shared Channel (HS-DSCH)A downlink channel shared between UEs by allocation of individual codes, from a common pool of
codes assigned for the channel or by allocating different time.
• Random Access Channel (RACH)This uplink channel is used by the UE, when it wants to transmit small amouts of data, and when the
UE has no RRC connection. It is often used to allocated dedicated signalling resources to the UE to
establish a connection or to perform higher layer signalling. It is a contention based channel, i.e.
several UE may attempt to access UTRAN simultaneously.
b) Dedicated Transport Channels:
• Dedicated Channel (DCH)Dedicated resources can be allocated both uplink and downlink to a UE. Dedicated resources are
exclusively in use for the subscriber.
• Enhanced Dedicated Channel (E-DCH)The E-DCH is a resource that exists in uplink only, when HSUPA is in use. It has only impact on the
physical and transport channel levels, it is not visible in the logical channels provided by MAC. The E-
DCH is a transport channel that is subject to Node-B scheduling. The E-DCH is defined as an
extension to DCH transmission.
Transport Channels (TrCH)
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• On the following figures. you can see the mapping of logical channels onto transport channels, as well
as the mapping of transport channels onto physical channels.
• Note: DSCH (FDD), CPCH removed from R5 specification, 25.301 v5.6.0
• Physical Channels are characterised by
•UARFCN,
•scrambling code,
•channelisation code (optional),
•start and stop time, and
•relative phase (in the uplink only, with relative phase being 0 or π/2)
• Transport channels can be mapped to physical channels.
• But there exist physical channels, which are generated at the Node B only, as can be seen on the next
Physical Channels (PhyCH)
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• But there exist physical channels, which are generated at the Node B only, as can be seen on the next
figures.
• The details of the physical channels is described in detail within this module (see following pages).
• Note: PDSCH and PCPCH removed from R5 specification, 25.301 v5.6.0
P-CCPCHPCH
BCH
PCCH
BCCH CPICH
S-SCH
P-SCH
S-CCPCH
LogicalChannels
TransportChannels
PhysicalChannels
Channel Mapping DL (Network Point of View)
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CTCH
DCCH
CCCH
DCH
FACH
HS-DSCH
AICH
HS-PDSCH
DPDCH
S-CCPCH
DTCH
PICH
E-AGCH
HS-SCCH
F-DPCH
E-RGCH
E-HICH
DCCH
LogicalChannels
TransportChannels
PhysicalChannels
RACH
CCCH PRACH
Channel Mapping UL (Network Point of View)
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DCCH
DCH
DPDCH
DTCH
DPCCH
E-DPCCH
E-DPDCHE-DCH
Channel configuration examples
AMR call
The data transferred during AMR call consists of
• Speech data
• L3 signalling
• L1 signalling
User data is transferred on DTCH logical channel
Real time connection uses always DCH transport channel
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Real time connection uses always DCH transport channel
DCH transport channel is mapped on DPCH (DPDCH + DPCCH)
AMR + PS call (multirab)
Additional stream of user data
• NRT data
Also configurations with HS-DSCH possible
NRT PS call
Different configurations utilising DCH, FACH/RACH, HS-DSCH or HS-DSCH/E-DCH possible
Example – Channel configuration during call
LogicalChannels
TransportChannels
PhysicalChannels
Data
DCCH0-4
DPDCH
RRCsignalling
DCH1
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DCH2-4DTCH1 DPCCHSpeech
data
AMR speech connection utilises multiple transport channelsRRC connection utilises multiple logical channels
DCH5DTCH2
NRT
data
AMR speech+
NRT data
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Part IITransport Channel Formats
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Transport Channel Formats
Transport Channels are used to exchange data between the MAC-layers in the UE and the RNC.
The data is hereby organised in Transport Blocks (TB). A Transport Block is the basic data unit.
The MAC layer entities use the services offered to them by the Physical layer to exchange Transport Blocks.
One Transport Block can be transmitted only over one Transport Channel. Several Transport Blocks can be simultaneously transmitted via a Transport Channel in one transport data unit to increase the transport efficiency.
The set of all Transport Blocks, transmitted at the same time on the same transport channel
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The set of all Transport Blocks, transmitted at the same time on the same transport channel (between the MAC layer and the physical layer) is referred to as Transport Format Set (TFS).
Transport Blocks and Transport Block Sets are characterised by a set of attributes:
• Transport Block Size– The transport block size specifies the numbers of bits of one Transport Block.
– If several Transport Blocks are transmitted within one TBS, then all TBs have the same size.
– Please note, that the transport block size among different TBSs – which are transmitted at different times on one transport channel - can vary.
• Transport Block Set Size– This attribute identifies the numbers of bits in one TBS.
– It must be always a multiple of the transport block size, because all TBs transmitted in one TBS have the same size.
MAC Layer MAC Layer
TBSTransport Channel
UE Node B RNC
TBS
The Transfer of Transport Blocks
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PHY Layer PHY LayerL1
FP/AAL2
L1
FP/AAL2
TFI
TBS
TTI radio frames in use
TFI
TBS
Transport Blocks and Transport Block Sets are characterised by a set of attributes (continued):
• Transmission Time Interval (TTI)•The TTI specifies the transmission time distance between two subsequent TBSs, transferred
between the MAC and the PHY layer.
•In the PHY layer, the TTI also identifies the interleaving period. Following TTI periods are
currently specified:
- 2 ms (HS-DSCH)
- 10 ms,
- 20 ms,
- 40 ms, and
- 80 ms
Transport Channel Formats
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- 80 ms
• Error Protection Scheme•When data is transmitted via a wireless link, it faces a lot of distortion and can thus easily
corrupted.
•Redundancy is added to the user data to reduce the amount of losses on air.
•In UMTS, three error protection schemes are currently specified:
•convolutionary coding with two rates: 1/2 and 1/3,
•turbo coding (rate 1/3), and
•no channel coding (this coding type is scheduled for removal from the UMTS
specifications).
• Size of CRC•CRC stands for cyclic redundancy check. Each TBS gets an CRC.
•The grade of reliability depends on the CRC size, which can be 0, 8, 12, 16, and 24 bits.
DCH 2TB TB TB
TFCS
TTI TTI TTI
TB
TB
TB
Transport Formats
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TB Transport Block TF Transport FormatTBS Transport Block Set TFS Transport Format Set
TFC Transport Format CombinationTFCS Transport Format Combination Set
DCH 1
TB
TB
TB
TB
TB
TBS
TF
TFS
TFC
TTITTITTI
TB
• The above description refers to a situation, where the MAC-layer hands the TBS to the PHY layer.
This happens in the UE. But TBSs are normally exchanged between the UE and the RNC. As a
consequence, the TBS must be transmitted over an AAL2 virtual channel between the RNC and the
Node B. The TBS is packet into a frame protocol defined for the traffic channel.
• Different TBSs can be transmitted in one Transport Channel.
• How do MAC and PHY layer know, what kind of TBS they exchanged?
• When a transport channel is setup – or modified – the allowed Transport Block Sets are specified.
• Each allowed TBS gets a unique Transport Format Indicator (TFI).• All TFIs of a Transport Channel are summarised in the Transport Format Set (TFS).
Transport Channel Formats
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• All TFIs of a Transport Channel are summarised in the Transport Format Set (TFS).• The TF consists of two parts (FDD mode):
•Semi-static part•The attributes belonging to the semi-static part are set by the RRC-layer.
•They are valid for all TBSs in the Transport Channel.
•Semi-static attributes are the Transmission Time Interval (TTI), the error correction
scheme, the CRC size, and the static rate matching parameter (used by the PHY layer for
dynamic puncturing if the TBS is too long for the radio frame).
•Dynamic part•The dynamic part comprises attributes, which can be changed by the MAC layer
dynamically.
•The affected attributes are the Transport Block Size and the Transport Block Set Size.
MAC Layer
RRC Layer
configura
tion
Semi-Static Part• TTI
• Channel Coding
• CRC size
• Rate matching
Dynamic Part
Transport Format
TrCHs
Transport Formats
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PHY Layerconfigura
tion
Dynamic Part• Transport Block Size
• Transport Block Set Size
Example: semi-static partdynamic part:- TTI = 10 ms- turbo coding - transport block size: 64 64 64 128- CRC size = 0 - transport block set size: 1 2 4 2- ...
TFI1 TFI2 TFI3 TFI4TrCH: Transport Channel
• The PHY layer can multiplex several Transport Channels in one “internal“ Transport Channel, called
Coded Composite Transport Channel (CCTrCH).
• This CCTrCH can be transmitted on one or several physical channels. Consequently, the TCSs of
different Transport Channels can be found in one radio frame.
• The Transport Format Combination Set (TFCS) lists all allowed Transport Format Combinations
(TFC).
• A Transport Format Combination Indicator (TFCI) is then used to indicate, what kind of Transport
Format Combination is found on the radio frame. You can find TFCI-fields for instance in the S-
Transport Channel Formats
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Format Combination is found on the radio frame. You can find TFCI-fields for instance in the S-
CCPCH. The TFCS is set by the RRC protocol.
• The table on the following slide lists the allowed Transport Formats for the individual Transport
Channels (FDD mode only).
1...5000 bitsgranularity: 1 bit
246 bits 246 bits
1...200000 bitsgranularity: 1 bit
20 ms
10 ms
BCH
PCH
convolutional 1/2
convolutional 1/2
16
0, 8, 12, 16 & 24
Transport Block Size
Transport Block Set Size
TTIcoding types
and ratesCRCsize
Semi-static PartDynamic Part
Transport Format Ranges
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0...5000 bitsgranularity: 1 bit
0...5000 bitsgranularity: 1 bit
0...5000 bitsgranularity: 1 bit
0...200000 bitsgranularity: 1 bit
0...200000 bitsgranularity: 1 bit
0...200000 bitsgranularity: 1 bit
10, 20, 40 & 80 ms
10 & 20ms
10, 20, 40 & 80 ms
FACH
RACH
DCH
convolutional 1/2& 1/3; turbo 1/3
convolutional 1/2
convolutional 1/2& 1/3; turbo 1/3
0, 8, 12, 16 & 24
0, 8, 12, 16 & 24
0, 8, 12, 16 & 24
(based on TS 25.302 V5.9.0)
Transport Channel Formats – HS-DSCHThe MAC layer is split to MAC-d and MAC-hs for HS-DSCH
The HS-DSCH is terminated in the BTS (so called MAC-hs)
MAC-hs layer is in charge of
• distributing the HS-DSCH resources between all the MAC-d flows according to their priority (i.e. Packet Scheduling)
• selecting the appropriate transport format for every TTI (i.e. link adaptation)
The radio interface layers above the MAC are not modified from the Release 99 architecture because HSDPA is intended for transport of logical channels
The move of the data queues to the Node B creates the need of a flow control mechanism
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The move of the data queues to the Node B creates the need of a flow control mechanism (HS-DSCH Frame Protocol) that aims at keeping the buffers full
The HS-DSCH FP handles the data transport from the serving RNC to the controlling RNC (if the Iur interface is involved) and between the controlling RNC and the Node B
In RAN side MAC-c/sh entity can be involved on HS-DSCH traffic (optional). The following functionality is covered:
• Flow control;
– flow control function also exists towards MAC-hs in case of configuration with MAC-c/sh.
• There is one MAC-c/sh entity in the UTRAN for each cell
MAC -sh is used to control the flow of all MAC-d flows of one BTS for preventing the congestion of the MAC-d data flows inside the RNC and Iub
MAC-d MAC-d
UENode B RNC
The Transfer of Transport Blocks – HS-DSCH
MAC-d PDU
MAC-d
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MAC-hsMAC-hs
PHY Layer PHY LayerL1
FP/AAL2
L1
FP/AAL2
HS-
DSCH
MAC-d PDU
TFI
TBS
TFI
TBS
TFI
TBS
FP/HS-DSCH FP/HS-DSCH
MAC-c/sh
OP
TIO
NA
L
HS-PDSCH
Flow
Control
Transport Format for HS-DSCH
Attributes of the dynamic part are:
• Transport block size (same as Transport block set size)
• Redundancy version/Constellation
• Modulation scheme
Attributes of the semi-static part are:
• no semi-static attributes are defined.
Attributes of the static part are:
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Attributes of the static part are:
• Transmission time interval. The Transmission time interval is fixed to 2ms in FDD
• Error protection scheme to apply:
– Type of error protection is turbo coding; coding rate is 1/3;
• Size of CRC is 24 bits.
BTS (LA/PS) decides then the used TBS and signals that information to the UE in HS-SCCH with 6bits (TFRI)
MAC-d Layer
RRC Layer
configura
tion
Static Part• TTI
• Channel Coding
• CRC size
Dynamic Part• Transport block size (same as
Transport Format
Transport Formats – HS-DSCH
MAC-hs Layer
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PHY Layerconfigura
tion
• Transport block size (same as
Transport block set size)
• Redundancy version/Constellation
• Modulation scheme
Example: static part dynamic part:- TTI = 2 ms- turbo coding - transport block size: 357 4420 1711 699- CRC size = 24 - modulation: QPSK 16-QAM 16-QAM QPSK
TFRI1 TFRI2 TFRI3 TFRI4
HS-DSCH
MAC-hs Layer
TFRI; Transport Format and Resource Indicator
Transport Format for HS-DSCH
1 to 200 000 bitsgranularity: 8 bit
= Transport Block Size
2 msHS-DSCH turbo 1/3 24
Transport Block Size
Transport Block Set Size
TTIcoding types
and ratesCRCsize
Static PartDynamic Part
QPSK,16-QAM
Modulation
1 to 8
Redundancyversion
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The instantaneous data rate range supported is (determined on a per-2ms interval):
• A TBS of 137 bits corresponding to 68.5 kbps (single code, QPSK, strong coding)
• A TBS of 28457 bits corresponding to 14.228 Mbps (15 codes, 16QAM, very low coding)
Transport Channel Formats – E-DCH
New MAC entities appear as follows for each network element:
UENew MAC entity (MAC-es/MAC-e) is added in the UE located below MAC-d. and is in charge of:
• H-ARQ: buffering MAC-e payloads & retransmit ting them
• Multiplexing: concatenating multiple MAC-d PDUs to MAC-es PDUs & multiplex 1 or multiple MAC-es PDUs to 1 MAC-e PDU
• E-TFC selection: Enhanced Transport Format Combination selection according to scheduling information (Relative & Absolute Grants) received from UTRAN via L1.
Node BNew MAC entity (MAC-e) is added in Node B which handles:
•
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• HARQ retransmissions: generating ACKs/NACKs
• E-DCH Scheduling: manages E-DCH cell re sources between UEs; implementation proprietary
• E-DCH Control: receives scheduling requests & transmits scheduling assignments.
• MAC-e PDUs de-multiplexing
S-RNCNew MAC entity (MAC-es) is added in the SRNC in order to perform:
• Reordering: reorders received MAC-es PDUs according to the received TSN
• Macro diversity selection: for SHO (Softer HO in Node-B); delivers received MAC-es PDUs from each Node B of E-DCH AS; see reordering function
• Disassembly: Remove MAC-es header,extract MAC-d PDU’s & deliver to MAC-d
UE Node B
The Transfer of Transport Blocks – E-DCH
S-RNC modifications:
MAC-es handling:
• in-sequence delivery (reordering)
Node B modifications:
MAC-e handling:
UE modifications:
MAC-es & MAC-e:
• H-ARQ retransmission
S-RNC
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PHY
MAC-es / MAC-e
MAC-d
PHY
MAC-e
PHY
E-DCH FP Uu
RLC
• in-sequence delivery (reordering)
• SHO data combining
MAC-e handling:
• H-ARQ retransmission
• Scheduling & MAC-e multiplexing
• H-ARQ retransmission
• Scheduling & MAC-e multiplexing
• E-DCH TFC selection
PHY
MAC-es
MAC-d
E-DCH FPIub
RLC
Transport Format for E-DCH & UE capability classes
E- DCH
Category
max.
E-DCH
Codes
min.
SF
2 & 10 ms
TTI E-DCH
support
max. #. of
E-DCH Bits* /
10 ms TTI
max. # of
E-DCH Bits* /
2 ms TTI
Reference
combination
Class
1 1 4 10 ms only 7110 - 0.73 Mbps
2 2 4 10 & 2 ms 14484 2798 1.46 Mbps
3 2 4 10 ms only 14484 - 1.46 Mbps
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4 2 2 10 & 2 ms 20000 5772 2.92 Mbps
5 2 2 10 ms only 20000 - 2.0 Mbps
6 4 2 10 & 2 ms 20000 11484 5.76 Mbps
• “Dual-branch BPSK” (resulting in QSPK output) is the only modulation used in HSUPA (Rel. 6)
•There can only be 1 transport block in each TTI, →Transport block size = Transport Block Set Size
•Coding types and rates: Turbo coding 1/3
Note: When 4 codes are transmitted in parallel, two codes shall be transmitted with SF2 and two with SF4
* Maximum No. of bits / E-DCH transport block
MAC-d Layer
RRC Layer
configura
tion
Static Part• TTI (2ms, 10ms)
• Channel Coding
• CRC size
• Modulation (always BPSK)
Dynamic Part• Transport block size (same as
Transport Format
Transport Formats – E-DCH
MAC-es/MAC-e Layer
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PHY Layerconfigura
tion
• Transport block size (same as
Transport block set size)
• Redundancy version/Constellation
Example: static part dynamic part:- TTI = 2 ms, 10 ms- turbo coding - transport block size: 357 2420 1711 699- CRC size = 24 BPSK BPSK BPSK BPSK
TFRI1 TFRI2 TFRI3 TFRI4
E-DCH
MAC-es/MAC-e Layer
Example: Transport Formats in AMR call
The AMR codec was originally developed and standardized by the European Telecommunications Standards Institute (ETSI) for GSM cellular systems. It has been chosen by the Third Generation Partnership Project (3GPP) as the mandatory codec for third generation (3G) cellular systems. It supports 8 encoding modes with bit rates between 4.75 and 12.2 kbps.
Feature of the AMR codec is Unequal Bit-error Detection and Protection (UED, UEP).
The UEP/UED mechanisms allow more speech over a lossy network by sorting the bits into perceptually more and less sensitive classes (A, B, C).
• A frame is only declared damaged and not delivered if there are bit errors found in the
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• A frame is only declared damaged and not delivered if there are bit errors found in the most sensitive bits (Class A).
• Acceptable speech quality results if the speech frame is delivered with bit errors in the less sensitive bits (Class B, C). Decoder uses error concealment algorithm to hide the errors.
On the radio interface, one Transport Channel is established per class of bits i.e. DCH A for class A, DCH B for class B and DCH C for class C. Each DCH has a different transport format combination set which corresponds to the necessary protection for the corresponding class of bits as well as the size of these class of bits for the various AMR codec modes.
Example: Transport Formats in AMR call
DCH 1: AMR class A bits
TTI = 20 ms
DCH 2: AMR class B bits
DCH 3: AMR class C bits
Convolutional coding
Coding rate: third
TTI = 20 ms
Coding type: convolutional
Coding rate: third
CRC size: 12 bits CRC size: 0 bits CRC size: 0 bits
TTI = 20 ms
Coding rate: half
Convolutional coding
DCH 24: RRC Connection
TTI = 40 ms
Coding type: convolutional
Coding rate: third
CRC size: 16 bits
TBS size:1TB size: 81 bits
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TBS size: 1TB size: 39 bits
(SID)
TBS size = 0(DTX)
TBS size: 1TB size: 103 bits
TBS size = 0(DTX)
TBS size = 0(DTX)
TBS size = 1TB size: 148 bitsTBS size: 1
TB size: 60 bits
TBS size = 0(DTX)
12.2 kbit/s3.7 kbit/s
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Part IIICell Synchronisation
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Cell SynchronisationWhen a UE is switched on, it starts to monitor the radio interface to find a suitable cell to camp on but it has to determine, whether there is a WCDMA cell nearby.
If a WCDMA cell is available, the UE has to be synchronised to the downlink transmission of the system information – transmitted on the physical channel P-CCPCH – before it can make a decision, in how far the available cell is suitable to camp on.
Initial cell selection is not the only reason, why a UE wants to perform cell synchronisation. This process is also required for cell re-selection and the handover procedure.
Cell synchronisation is achieved I three phases• Step 1: Slot synchronisation
– During the first step of the cell search procedure the UE uses the SCH"s primary synchronisation code to acquire slot synchronisation to a cell. This is typically done with a single matched filter (or any similar device) matched to the primary synchronisation code which is common to all cells. The slot timing of the cell can be obtained by detecting peaks in the matched filter output.
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detecting peaks in the matched filter output.
• Step 2: Frame synchronisation and code-group identification
– During the second step of the cell search procedure, the UE uses the SCH"s secondary synchronisation code to find frame synchronisation and identify the code group of the cell found in the first step. This is done by correlating the received signal with all possible secondary synchronisation code sequences, and identifying the maximum correlation value. Since the cyclic shifts of the sequences are unique the code group as well as the frame synchronisation is determined.
• Step 3: Scrambling-code identification
– During the third and last step of the cell search procedure, the UE determines the exact primary scrambling code used by the found cell. The primary scrambling code is typically identified through symbol-by-symbol correlation over the CPICH with all codes within the code group identified in the second step. After the primary scrambling code has been identified, the Primary CCPCH can be detected. And the system- and cell specific BCH information can be read.
If the UE has received information about which scrambling codes to search for, steps 2 and 3 above can be simplified.
Cell Synchronisation
Detect cells
Acquire slot synchronisation
Phase 1 – P-SCH
Phase 2 – S-SCH
Acquire frame synchronisation
40 © Nokia Siemens Networks RN31552EN10GLN0
Phase 2 – S-SCH
Phase 3 – P-CPICH
synchronisation
Identify the code group of the cell found in the first step
Determine the exact primary scrambling code used by the found cell
Measure level & quality of the found cell
• Cell synchronisation is achieved with the Synchronisation Channel (SCH). This channel divides up
into two sub-channels:
• Primary Synchronisation Channel (P-SCH)•A time slot lasts 2560 chips.
•The P-SCH only uses the first 10% of a time slot.
•A Primary Synchronisation Code (PSC) is transmitted the first 256 chips of a time slot. This is the
case in every UMTS cell.
•If the UE detects the PSC, it has performed TS and chip synchronisation.
Cell Synchronisation
41 © Nokia Siemens Networks RN31552EN10GLN0
(continued on the next text slide)
CP CP
2560 Chips 256 Chips
CP CP CP
Primary Synchronisation Channel (P-SCH)
Secondary Synchronisation Channel (S-SCH)
Synchronisation Channel (SCH)
42 © Nokia Siemens Networks RN31552EN10GLN0
Cp = Primary Synchronisation CodeCs = Secondary Synchronisation Code
10 ms Frame
Cs1 Cs2 Cs15
Slot 0 Slot 1 Slot 14
Cs1
Secondary Synchronisation Channel (S-SCH)
Slot 0
Cell Synchronisation
Secondary Synchronisation Channel (S-SCH)
The S-SCH also uses only the first 10% of a timeslot
Secondary Synchronisation Codes (SSC) are transmitted.
There are 16 different SSCs, which are organised in a 10 ms frame (15 timeslots) in such a way, that the beginning of a 10 ms frame can be
43 © Nokia Siemens Networks RN31552EN10GLN0
timeslots) in such a way, that the beginning of a 10 ms frame can be determined, and 64 different SSC combinations within a 10 ms frame are identified.
There is a total of 512 primary scrambling codes, which are grouped in 64 scrambling code families, each family holding 8 scrambling code members.
The 15 SSCs in one 10 ms frame identify the scrambling code family of the cell‘s downlink scrambling code.
15
15
scramblingcode group
group 00
group 01
group 02
group 03
group 04
1 1 2 8 9 10 15 8 10 16 2 7 15 7 16
1 1 5 16 7 3 14 16 3 10 5 12 14 12 10
1 2 1 15 5 5 12 16 6 11 2 16 11 12
1 2 3 1 8 6 5 2 5 8 4 4 6 3 7
1 2 16 6 6 11 5 12 1 15 12 16 11 2
slot number
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
11 11
11 11
15
15
15 15
15
155
SSC Allocation for S-SCH
44 © Nokia Siemens Networks RN31552EN10GLN0
group 05
group 62
group 63
1 3 4 7 4 1 5 5 3 6 2 8 7 6 8
9 11 12 15 12 9 13 13 11 14 10 16 15 14 16
9 12 10 15 13 14 9 14 15 11 11 13 12 16 10
11
11 11
11 11
15
15 15
15 15
5
I monitor the S-SCH
• With the help of the SCH, the UE was capable to perform chip, TS, and frame synchronisation.
•Even the cell‘s scrambling code group is known to the UE.
• But in the initial cell selection process, it does not yet know the cell‘s primary scrambling code.
• There is one primary scrambling code in use over the entire cell, and in neighbouring cells, different
scrambling codes are in use.
•There exists a total of 512 primary scrambling codes.
• The CPICH is used to transmit in every TS a pre-defined bit sequence with a spreading factor 256.
•The CPICH divides up into a mandatory Primary Common Pilot Channel (P-CPICH) and optional
Secondary CPICHs (S-CPICH).
• The P-CPICH is in use over the entire cell and it is the first physical channel, where a spreading code
is in use.
Common Pilot Channel (CPICH)
45 © Nokia Siemens Networks RN31552EN10GLN0
is in use.
•A spreading code is the product of the cell‘s scrambling code and the channelisation code.
•The channelisation code is fixed: Cch,256,0. i.e., the UE knows the P-CPICH‘s channelisation code,
and it uses the P-CPICH to determine the cell‘s primary scrambling code by trial and error.
• The P-CPICH is not only used to determine the primary scrambling code. It also acts as:-
•phase reference for most of the physical channels,
•measurement reference in the FDD mode (and partially in the TDD mode).
• There may be zero or several S-CPICHs. Either the cell‘s primary scrambling code or its secondary
scrambling codes can be used. In contrast to the P-CPICH, it can be broadcasted just over a part of
the cell.
CP
2560 Chips 256 Chips
Synchronisation Channel (SCH)
P-CPICH
10 ms Frame
Primary Common Pilot Channel (P-CPICH)
46 © Nokia Siemens Networks RN31552EN10GLN0
applied speading code =
cell‘s primary scrambling code ⊗⊗⊗⊗ Cch,256,0
• Phase reference• Measurement reference
P-CPICH
Cell scrambling code? I get it with
trial & error!
• The UE has to perform a set of L1 measurements, some of them refer to the CPICH channel:
• CPICH RSCP• RSCP stands for Received Signal Code Power.
• The UE measures the RSCP on the Primary-CPICH.
• The reference point for the measurement is the antenna connector of the UE.
• The CPICH RSCP is a power measurement of the CPICH.
• The received code power may be high, but it does not yet indicate the quality of the received
signal, which depends on the overall noise level.
• UTRA carrier RSSI.• RSSI stands for Received Signal Strength Indicator.
• The UE measures the received wide band power, which includes thermal noise and receiver
CPICH as Measurement Reference
47 © Nokia Siemens Networks RN31552EN10GLN0
• The UE measures the received wide band power, which includes thermal noise and receiver
generated noise.
• The reference point for the measurements is the antenna connector of the UE.
• CPICH Ec/No• The CPICH Ec/No is used to determine the “quality“ of the received signal.
• It gives the received energy per received chip divided by the band‘s power density.
• The “quality“ is the primary CPICH‘s signal strength in relation to the cell noise.
• (Please note, that transport channel quality is determined by BLER, BER, etc. )
• If the UE supports GSM, then it must be capable to make measurements in the GSM bands, too. The
measurements are based on the GSM carrier RSSI
• The wideband measurements are conducted on GSM BCCH carriers.
Received Signal Code Power (in dBm)CPICH RSCP
received energy per chip divided by the power density in the band (in dB)CPICH Ec/No
received wide band power, including thermal noise and noise generated in the
receiver
UTRA carrier RSSI
CPICH Ec/No = CPICH RSCP
UTRA carrier RSSI
P-CPICH as Measurement Reference
48 © Nokia Siemens Networks RN31552EN10GLN0
CPICH Ec/No
0: < -241: -23.52: -233: -22.5...47: -0.548: 049: >0
Ec/No values in dB
CPICH RSCP
-5: < -120-4: -119:0: -1151: -114:89: -2690: -2591: ≥ -25RSCP values in dBm
GSM carrier RSSI
0: -1101: -1092: -108:71: -3972: -3873: -37
RSSI values in dBm
• The UE knows the cell‘s primary scrambling code.
• It now wants to gain the cell system information, which is transmitted on the physical channel P-
CCPCH.
• The channelisation code of the P-CCPCH is also known to the UE, because it must be Cch,256,1 in
every cell for every operator.
• By reading the cell system information on the P-CCPCH, the UE learns everything about the
configuration of the remaining common physical channels in the cell, such as the physical channels for
paging and random access.
• As can be seen from the P-CCPCH‘s channelisation code, the data rate for cell system information is
fixed.
• The SCH is transmitted on the first 256 chips of a timeslot, thus creating here a peak load.
Primary Common Control Physical Channel (P-CCPCH)
49 © Nokia Siemens Networks RN31552EN10GLN0
• The SCH is transmitted on the first 256 chips of a timeslot, thus creating here a peak load.
• The cell system information is transmitted in the timeslot except for the first 256 chips. By doing so, a
high interference and load at the beginning of the timeslot is avoided.
• This leads to a net data rate of 27 kbps for the cell system information.
• Channel estimation is done with the CPICH, so that no pilot sequence is required in the P-CCPCH.
• (The use of the pilot sequence is explained in the context of the DPDCH later on in this
document.)
• There are also no power control (TPC) bits transmitted to the UE‘s.
CP
2560 Chips 256 Chips
Synchronisation Channel (SCH)
P-CCPCH
10 ms Frame
Primary Common Control Physical Channel (P-CCPCH)
50 © Nokia Siemens Networks RN31552EN10GLN0
P-CCPCH
Finally, I get the cell system information
• channelisation code: Cch,256,1
• no TPC, no pilot sequence• 27 kbps (due to off period)• organised in MIBs and SIBs
• WCEL: PtxPrimaryCPICH•The parameter determines the transmission power of the primary CPICH channel. •It is used as a reference for all common channels. •[-10 dBm … 50 dBm], step 0.1 dB, default: 33dBm (WPA power = 43 dBm)
• WCEL: PtxPrimarySCH•Transmission power of the primary synchronization channel, the value is relative to primary CPICH transmission power.•[-35 dB … 15 dB], step size 0.1 dB, default: -3 dB
• WCEL: PtxSecSCH•Transmission power of the secondary synchronization channel, the value is relative to
NSN Parameters for Cell Search
51 © Nokia Siemens Networks RN31552EN10GLN0
•Transmission power of the secondary synchronization channel, the value is relative to primary CPICH transmission power.•[-35 dB… 15 dB], step size 0.1 dB, default: -3 dB
• WCEL: PtxPrimaryCCPCH•This is the transmission power of the primary CCPCH channel, the value is relative to primary CPICH transmission power.•[-35 dB … 15 dB], step size 0.1 dB, default: -5 dB
• WCEL: PriScrCode•Identifies the downlink scrambling code of the Primary CPICH (Common Pilot Channel) of the Cell.•[0 ... 511]
Blank Page
52 © Nokia Siemens Networks RN31552EN10GLN0
Synchronisation Issues in UMTS. 5 different UTRAN synchronisation issues were identified:
1. Network synchronisation stands for the very accurate reference frequency, which must be
distributed to the individual UTRAN network elements.
2. Node synchronisation takes place between the Node B and the RNC.
• Node Synchronisation is used to determine the run-time difference between UTRAN nodes,
which must be estimated and then compensated.
• In the FDD mode, only RNC-Node B Node Synchronisation is in use.
3. While radio interface synchronisation is required between the UE and the Node B.
Synchronisation Issues and Node Synchronisation
53 © Nokia Siemens Networks RN31552EN10GLN0
3. While radio interface synchronisation is required between the UE and the Node B.
4. Transport channel synchronisation is a L2 synchronisation (for the MAC layer).
• It is therefore done between the UE and the RNC.
• Please note in this context, that a UE may be in a soft handover state, i.e. the UE may be
connected to several cells simultaneously.
• Transport channel synchronisation is required to guarantee, that the transport of user data
via several channels is coordinated in such a way, that the transmitted data from several
cells arrives within the UE‘s receive window.
5. Time alignment handling takes place between UTRAN and the CN for adequate timing of data
transfer.
SRNCNode B
3112
3113
3114
RFN128
129
130
BFN
T1
T2
DL offsetBFN: Node B Frame
Number counter0..4095 frames
RFN: RNC Frame
Number counter0..4095 frames
Node Synchronisation
54 © Nokia Siemens Networks RN31552EN10GLN0
tim
e
3114
3115
3116
3117
3118
tim
e
131
132
133
134
135
(T4)
T2
T3
(T4 – T1) – (T3 – T2)= Round Trip Delay(RTD) determinationfor DCH services
T1, T2, T3range: 0 .. 40959.875 ms
resolution: 0.125 ms
UL offset
user plane defined onDCH, FACH & DSCH
0..4095 frames
• A timing reference is required by the Node Synchronisation:
• Node B Frame Number (BFN)• The BFN is a counter at the Node B, based on the 10 ms framing structure of WCDMA.
• RNC Frame Number (RFN)• The RFN is a counter at the RNC, based on the 10 ms framing structure of WCDMA.
• Cell System Frame Number (SFN)• This is a counter for each cell, and is broadcasted on the P-CCPCH.
• With one Node B, several (sector) cells can be deployed. These cells overlap.
• If the SCH is transmitted at the same time in all the sector cells of the Node B, and when a UE is in
Cell Synchronisation and Sectorised Cells
55 © Nokia Siemens Networks RN31552EN10GLN0
• If the SCH is transmitted at the same time in all the sector cells of the Node B, and when a UE is in
the overlapping coverage area of two of these cells, it will have difficulties to synchronise to one cell.
• As a consequence, an offset can be used for neighbouring cells of one Node B: T_cell. • T_cell is a timing delay for the starting time of the physical channels SCH, CPICH, BCCH relative
to the Node B‘s timer BFN.
• The timing delay is a multiple (0..9) of 256 chips due to of the length of a SCH burst.
• The cell‘s timing is identified with the counter SFN = BFN + T_cell.
• (Please note, that this description only applied for the FDD mode!)
cell1
cell2
cell3
1 TS
SCH
SCH
SCH
SCH
SCH
SCH
SCH
T_cell
T_cell1
T_cell2SCH
Cell Synchronization and Sectorised Cells
56 © Nokia Siemens Networks RN31552EN10GLN0
Node B with threesectorised cells
BFN
SFN = BFN + T_cell1
SFN = BFN + T_cell2
SFN = BFN + T_cell3
T_cell3
SFN: Cell System Frame Numberrange: 0..4095 frames
T_cell: n ∗∗∗∗ 256 chips, n = 0..9
cell3 cell2
cell1
• WCEL: Tcell•Timing delay is used for defining the start of SCH, P-CPICH, Primary CCPCH and DL
Scrambling Code(s) in a cell relative to BFN.
•[0 ... 2304] chips, step 256 chips, no default value.
NSN Parameters for Sectorised Cells
57 © Nokia Siemens Networks RN31552EN10GLN0
Part IVCommon Control Physical Channels
58 © Nokia Siemens Networks RN31552EN10GLN0
• The S-CCPCH can be used to transmit the transport channels
• Forward Access Channel (FACH) and
• Paging Channel (PCH).
• More than one S-CCPCH can be deployed.
• The FACH and PCH information can multiplexed on one S-CCPCH – even on the same 10 ms frame -
, or they can be carried on different S-CCPCH.
Secondary Common Control Physical Channel (S-CCPCH)
59 © Nokia Siemens Networks RN31552EN10GLN0
• The first S-CCPCH must have a spreading factor of 256, while the spreading factor of the remaining
S-CCPCHs can range between 256 and 4.
• UTRAN determines, whether a S-CCPCH has the TFCI (Transport Format Combination Indicator)
included.
• Please note, that the UE must support both S-CCPCHs with and without TFCI.
Slot 0 Slot 1 Slot 2 Slot 14
10 ms Frame
TFCI(optional)
Data Pilot bits
Secondary Common Control Physical Channel(S-CCPCH)
60 © Nokia Siemens Networks RN31552EN10GLN0
S-CCPCH
(optional)Data Pilot bits
• carries PCH and FACH
• Multiplexing of PCH and FACH on one
S-CCPCH, even one frame possible
• with and without TFCI (UTRAN set)
• SF = 4..256
• (18 different slot formats
• no inner loop power control
Secondary CCPCH in NSN RAN
The Secondary CCPCH (Common Control Physical Channel) carries FACH and PCH transport channels
In RAN’04, number of SCCPCHs increase from two to three. The three SCCPCH channel configuration is needed only if SAB – Service area Broadcast is used.
Parameter NbrOfSCCPCHs (Number of SCCPCHs) tells how many SCCPCHs will be configured for the cell. (1, 2 or 3)
• If only one SCCPCH is used in a cell, it will carry FACH-c (Containing DCCH/CCCH /BCCH), FACH-u (containing DTCH) and PCH. FACH and PCH multiplexed onto the same SCCPCH.
61 © Nokia Siemens Networks RN31552EN10GLN0
same SCCPCH.
• If two SCCPCHs are used in a cell, the first SCCPCH will always carry PCH only and the second SCCPCH will carry FACH-u and FACH-c.
• If three SCCPCHs are used in a cell, the third SCCPCH will carry FACH-s (containing CTCH) and FACH-c idle (containing CCCH and BCCH ) . The third SCCPCH is only
needed when Service Area Broadcast (SAB) is active in a cell.
Logical channel DTCH DCCH CCCH BCCH CTCH PCCH
For SABFor SAB
DL common Channel configuration in case of three SCCPCH
Secondary CCPCH in NSN RAN
62 © Nokia Siemens Networks RN31552EN10GLN0
Transport channel
Physical channel
FACH-u PCHFACH-s
SCCPCH connected
SCCPCH idle
FACH-c FACH-c
SCCPCH page
SF 64 SF 128 SF 256
FACH-u FACH-c(connected)
FACH-c(idle)
TFS
0: 0x360 bits(0 kbit/s)
1: 1x360 bits(36 kbit/s)
1: 1x168 bits
0: 0x168 bits(0 kbit/s)
1: 1x168 bits (16.8 kbit/s)
2: 2x168 bits(33.6 kbit/s)
0: 0x168 bits(0 kbit/s)
1: 1x168 bits(16.8 kbit/s)
FACH-s
0: 0x168 bits(0 kbit/s)
1: 1x168 bits(16.8 kbit/s)
PCH
0: 0x80 bits(0 kbit/s)
1: 1x80 bits(8 kbit/s)
Secondary CCPCH in NSN RAN
63 © Nokia Siemens Networks RN31552EN10GLN0
TTI
Channelcoding
CRC
10 ms
TC 1/3
16 bit
(33.6 kbit/s)
10 ms
CC 1/2
16 bit
10 ms
CC 1/3
16 bit
10 ms
CC 1/3
16 bit
10 ms
CC 1/2
16 bit
FACH-u PCHFACH-s
SCCPCH connected
SCCPCH idle
FACH-c FACH-c
SCCPCH page
TFCSTFCS TFCS
Secondary CCPCH in NSN RAN
64 © Nokia Siemens Networks RN31552EN10GLN0
TFCS01
0 kbit/s8 kbit/s
TFCS00010210
0+0 = 0 kbit/s0+16.8 = 16.8 kbit/s0+33.6 = 33.6 kbit/s
36+0 = 36 kbit/s
TFCS001001
0+0 = 0 kbit/s16.8+0 = 16.8 kbit/s0+16.8 = 16.8 kbit/s
Maximum transport channel throughput = 36
kbit/s
Maximum transport channel
throughput = 8 kbit/s
Maximum transport channel throughput = 16.8
kbit/s
• The network has detected, that there is data to be transmitted to the UE.
• Both in the RRC idle mode and in the RRC connected mode (e.g. in the sub-state CELL_PCH) a UE
may get paged. But how does the mobile know, when it was paged?
• And in order to save battery power, we don‘t want the UE to listen permanently to paging
channel – instead, we want to have discontinuous reception (DRX) of paging messages.
• But when and where does the UE listen to the paging messages?
• Cell system information is broadcasted via the P-CCPCH.
• The cell system information is organised in System Information Blocks (SIB).
• SIB5 informs the mobile phones about the common channel configuration, including a list of
S-CCPCH descriptions.
• The first 1 to K entries transmit the (transport channel) PCH, while the remaining S-CCPCH
S-CCPCH and the Paging Process
65 © Nokia Siemens Networks RN31552EN10GLN0
• The first 1 to K entries transmit the (transport channel) PCH, while the remaining S-CCPCH
in the list hold no paging information.
• The UE determines the S-CCPCH, where it is paged, by its IMSI and the number of PCH/S-CCPCHs
carrying S-CCPCHs K.
• When paging the UE, the RNC knows the UE‘s IMSI, too, so that it can put the paging message on
the correct PCH transport channel.
• Discontinuous Reception (DRX) of paging messages is supported.
• A DRX cycle length k has to be set in the network planning process for the cs domain, ps
domain, and UTRAN.
• k ranges between 3 and 9. If for instance k=6, then the UE is paged every 2k = 640 ms.
• If the UE is in the idle mode, it takes the smaller k-value of either the cs- or ps-domain.
• If the UE is in the connected mode, it has to select the smallest k-value of UTRAN and the
CN, it is not connected to.
Node B
UTRANP-CCPCH/BCCH (SIB 5)
commonchannel
definition,including
a lists ofUE
Index of S-CCPCHs
RNC
S-CCPCH and the Paging Process
66 © Nokia Siemens Networks RN31552EN10GLN0
S-CCPCH carrying one PCH
S-CCPCH carrying one PCH
S-CCPCH carrying one PCH
S-CCPCH without PCH
S-CCPCH without PCH
0
1
K-1
UE‘s paging channel:
Index = IMSI mod K
e.g. if IMSI mod K = 1
„my pagingchannel“
2k framesk = 3..9
Duration:
CN domain specificDRX cycle lengths
(option)
CS Domain PS Domain UTRAN
RRC connectedmode
Example withtwo CN domains
Paging and Discontinuous Reception (FDD mode)
67 © Nokia Siemens Networks RN31552EN10GLN0
UEUpdate:a) derived by NAS
negotiationb) otherwise:
system info
Update:locally with
system info
k1 k2
Update:a) derived by NAS
negotiationb) otherwise:
system info
k3stores
if RRC idle:UE DRX cycle length is
min (k1, k2)
if RRC connected:UE DRX cycle length is
min (k3, kdomain with no Iu-signalling connection)
• Paging Indicator Channel (PICH)• UMTS provides the terminals with an efficient sleep mode operation. The UEs do not have to read and
process the content, transmitted during their paging occasion on their S-CCPCH.
• Each S-CCPCH, which is used for paging, has an associated Paging Indicator Channel (PICH).
• A PICH is a physical channel, which carries paging indicators.
• A set of (paging indicator) bits within the PICH indicate to a UE, whether there is a paging occasion for
it. Only then, the UE listens to the S-CCPCH frame, which is transmitted 7680 chips after the PICH
frame in order to see, whether there is indeed a paging message for it.
• The PICH is used with spreading factor 256.
• 300 bits are transmitted in a 10 ms frame, and 288 of them are used for paging indication.
• The UE was informed by the BCCH, how many paging indicators exist on a 10 ms frame.
The Paging Process
68 © Nokia Siemens Networks RN31552EN10GLN0
• The UE was informed by the BCCH, how many paging indicators exist on a 10 ms frame.
• The number of paging indicator Np can be 18, 36, 72, and 144, and is set by the operator as part
of the network planning process.
• The higher Np, the more paging indicators exist, the more paging groups exist, among which UEs
can be distributed on.
• Consequently, the lower the probability, that a UE reacts on a paging indicator, while there is no
paging message in the associated S-CCPCH frame.
• But a high number of paging indicators results in a comparatively high output power for the PICH,
because less bits exists within a paging indicator to indicate the paging event.
• The operator then also has to consider, if he has to increase the number of paging attempts.
• How does the UE and UTRAN determine the paging indicator (PI) and the Paging Occasion?
• This is shown in one of the next slides.
PICH frame
S-CCPCH frame, associated with PICH frame
ττττPICH
= 7680chips
for paging indication no transmission
ττττS-CCPCH
S-CCPCH and its associated PICH
69 © Nokia Siemens Networks RN31552EN10GLN0
b287 b288 b299b286b0 b1
for paging indication no transmission
# of pagingindicators per frame
(Np)
18
36
72
144
UE
my pagingindicator (PI)
PI = ( IMSI div 8192) mod Np
DRX index
number of paging indicators18, 36, 72, 144
Paging Indicator and Paging Occasion (FDD mode)
70 © Nokia Siemens Networks RN31552EN10GLN0
Paging Occasion = (IMSI div K) mod (DRX cycle length) + n * DRX cycle length
UE
When willI get paged? number of S-CCPCH with PCH
FDDmode
Example – Paging instant and group calculation
UE calculates paging instant based on following information as presented before
• IMSI
• Number of S-CCPCH (K)
• DRX cycle length (k)
• Np
User are distributed to different paging groups based on their IMSI. Paging group
71 © Nokia Siemens Networks RN31552EN10GLN0
User are distributed to different paging groups based on their IMSI. Paging group size can be calculated based on
• Number of S-CCPCH (K)
• DRX cycle length (k)
• Np
Paging group size affects on how often UE has to decode paging message from S-CCPCH � Power consumption
Example – Paging instant and group calculation
K (Number of S-CCPCH with PCH) 1
k (DRX length) 6
DRX cycle length 64 frames
IMSI 358506452377
Which S-CCPCH #? 0
IMSI div K 358506452377
When (Paging occation, SFN)? 25 + n*DRX cycle length
Np 72 PIs/frame
72 © Nokia Siemens Networks RN31552EN10GLN0
Np 72 PIs/frame
DRX Index 43762994
My PI? 26
Number of subsc. In LA/RA 100000
Number of subsc. Per S-CCPCH 100000
Number of subsc. Paging occation (PICH
frame) 1562.5
Number of subsc. Per PI 21.7
• WCEL: NbrOfSCCPCHs•The parameter defines how many S-CCPCH are configured for the given cell.
•Range: [1 … 3], step: 1; default = 1
• WCEL: PtxSCCPCH1 (carries FACH & PCH)
•This is the transmission power of the 1st S-CCPCH channel, the value is relative to primary
CPICH transmission power.
•Range: [-35 dB … 15 dB] , step size 0.1 dB, default: 0 dB
• WCEL: PtxSCCPCH2 (carries PCH only)
NSN Parameters for S-CCPCH and Paging
73 © Nokia Siemens Networks RN31552EN10GLN0
• WCEL: PtxSCCPCH2 (carries PCH only)
•This is the transmission power of the 2nd S-CCPCH channel, the value is relative to primary
CPICH transmission power.
•Range: [-35 dB … 15 dB] , step size 0.1 dB, default: - 5 dB
• WCEL: PtxSCCPCH3 (carries FACH only)
•This is the transmission power of the SCCPCH channel which carries only a FACH
(containing CCCH) and a FACH (containing CTCH).
•This parameter is only needed when Service Area Broadcast(SAB)is activated in a cell(three
S-CCPCH channel configuration).
•Range: [-35 dB … 15 dB] , step size 0.1 dB, default: - 2 dB
• WCEL: PtxPICH•This is the transmission power of the PICH channel.
•It carries the paging indicators which tell the UE to read the paging message from the
associated secondary CCPCH.
•This parameter is part of SIB 5.
•[-10 dB..5 dB]; step 1 dB; default: -8 dB (with Np =72)
•NP•Repetition of PICH bits
•[18, 36, 72, 144] with relative power [-10, -10, -8, -5] dB
NSN Parameters for S-CCPCH and Paging
74 © Nokia Siemens Networks RN31552EN10GLN0
• RNC: CNDRXLength•The DRX cycle length used for CN domain to count paging occasions for discontinuous
reception.
•This parameter is given for CS domain and PS domain separately.
•This parameter is part of SIB 1.
•[640, 1280, 2560, 5120] ms; default = 640 ms.
• WCEL: UTRAN_DRX_length•The DRX cycle length used by UTRAN to count paging occasions for discontinuous
reception.
•[80, 160, 320, 640, 1280, 2560, 5120] ms; default = 320 ms
• The transport channel Forward Access Channel (FACH) is used, when relatively small amounts of
data have to be transmitted from the network to the UE.
• The FACH is only transmitted downlink.
• In-band signalling is used to indicate, which UE is the recipient of the transmitted data (see MAC PDU
with UE-ID type).
• This common downlink channel is used without (fast) closed loop power control and is available all
over the cell.
FACH and S-CCPCH
75 © Nokia Siemens Networks RN31552EN10GLN0
• FACH data is transmitted in one or several S-CCPCHs.
• FACH and PCH data can be multiplexed on one S-CCPCH, but they can also be be transmitted on
different S-CCPCHs.
• The FACH is organised in FACH Data Frames via the Iub-interface.
• Each FACH Data Frames holds the Transmission Blocks for one TFS.
• The used TFS is identified by the TFI.
• A TFI is associated with one Transmission Time Interval (TTI), which can be either 10, 20, 40 or 80
ms.
• The TTI identifies the interleaving time on the radio interface.
• FACH Data Frame has header fields, which identify the CFN, TFI, and the Transmit Power Level.
• The Transmit Power Level gives the preferred transmission power level for the FACH and for the TTI
time.
• The values specified here range between 0 and 25.5 dB, with a step size of 0.1 dB.
• The value is taken as a negative offset to the maximum power configured for the S-CCPCHs,
specified for the FACH.
• The pilot bits and the TFCI-field may have a relative power offset to the power of the data field, which
may vary in time.
• (The offset is determined by the network.)
• The power offsets are set by the NBAP message COMMON TRANSPORT CHANNEL SETUP
REQUEST, which is sent from the RNC to the Node B.
FACH and S-CCPCH
76 © Nokia Siemens Networks RN31552EN10GLN0
REQUEST, which is sent from the RNC to the Node B.
• There are two power offset information included:
• PO1: defines the power offset for the TFCI bits; it ranges between 0 and 6 dB with a 0.25 step
size.
• PO3: defines the power offset for the pilot bits; it ranges between 0 and 6 dB with a 0.25 step
size.
• Another important parameter is the maximum allowed power on the FACH: MAX FACH Power.
Blank Page
77 © Nokia Siemens Networks RN31552EN10GLN0
Node B RNC
FACH Data Frame
CFN TFI TB TB
Iub
Uu
Transmit Power Level
Power offsets for TFCI and pilot bits are
defined during channel setup
FACH and S-CCPCH
78 © Nokia Siemens Networks RN31552EN10GLN0
Transmit Power Level
UE
TFCI(optional)
Data
Pilot bits
max. transmitpower for S-CCPCH
0..25.5 dB,step size 0.1
PO1 PO3
• WCEL: PowerOffsetSCCPCHTFCI•Defines the power offset for the TFCI symbols relative to the downlink transmission power of a Secondary CCPCH.•This parameter is part of SIB 5.
•P01_15/30/60•15 kbps: [0..6 dB]; step 0.25 dB; default: 2 dB•30 kbps: [0..6 dB]; step 0.25 dB; default: 3 dB•60 kbps: [0..6 dB]; step 0.25 dB; default: 4 dB
NSN Parameters for S-CCPCH Power Setting
79 © Nokia Siemens Networks RN31552EN10GLN0
Part VPhysical Random Access
80 © Nokia Siemens Networks RN31552EN10GLN0
• In the random access, initiated by the UE, two physical channels are involved:
• Physical Random Access Channel (PRACH)• The physical random access is decomposed into the transmission of preambles in the
uplink.
• Each preamble is transmitted with a higher output power as the preceding one.
• After the transmission of a preamble, the UE waits for a response by the Node B.
• This response is sent with the physical channel Acquisition Indication Channel (AICH),telling the UE, that the Node B as acquired the preamble transmission of the random access.
• Thereafter, the UE sends the message itself, which is the RACH/CCCH of the higher layers.
• The preambles are used to allow the UE to start the access with a very low output power.
Random Access
81 © Nokia Siemens Networks RN31552EN10GLN0
• The preambles are used to allow the UE to start the access with a very low output power.
• If it had started with a too high transmission output power, it would have caused
interference to the ongoing transmissions in the serving and neighbouring cells.
• Please note, that the PRACH is not only used to establish a signalling connection to
UTRAN, it can be also used to transmit very small amounts of user data.
• Acquisition Indication Channel (AICH)• This physical channel indicates to the UE, that it has received the PRACH preamble and is
now waiting for the PRACH message part.
Node BUENo response
by theNode B
No responseby theNode B
Random Access – the Working Principle
82 © Nokia Siemens Networks RN31552EN10GLN0
Node B
I just detecteda PRACH preamble
OLA!
• The properties of the PRACH are broadcasted (SIB5, SIB6).
• The candidate PRACH is randomly selected (if there are several PRACH advertised in the cell) as well
as the access slots within the PRACH.
• 15 access slots are given in a PRACH, each access slot lasting two timeslots or 5120 chips.
• In other words, the access slots stretch over two 10 ms frames.
• A PRACH preamble, which is transmitted in an access slot, has a length of 4096 chips.
• Also the AICH is organised in (AICH) access slots, which stretch over two timeslots.
• AICH access slots are time aligned with the P-CCPCH.
• The UE sends one preamble in uplink access slot n.
• It expects to receive a response from the Node B in the downlink (AICH) access slot n, ττττ chips later
Random Access Timing
83 © Nokia Siemens Networks RN31552EN10GLN0
• It expects to receive a response from the Node B in the downlink (AICH) access slot n, ττττp-a chips later
on.
• If there is no response, the UE sends the next preamble ττττp-p chips after the first one.
• The maximum numbers of preambles in one preamble access attempt can be set between 1 and 64.
• The number of PRACH preamble cycles can be set between 1 and 32.
• If the AICH_Transmission_Timing parameter in the SIB is set to BCCH SIB5 & SIB6 to
• 0 = then, the minimum preamble-to-preamble distance is 3 access slots, the minimum
preamble-to-message distance is 3 access slots, and the preamble-to-acquisition indication
is 3 timeslots.
• 1 = then, the minimum preamble-to-preamble distance is 4 access slots, the minimum
preamble-to-message distance is 4 access slots, and the preamble-to-acquisition indication
is 5 timeslots.
SFN mod 2 = 0 SFN mod 2 = 0SFN mod 2 = 1
P-CCPCH
AICH accessslots 0 1 1282 1175 964 13103 14 0 1 2 75 643
5120chips
UE point of view
Acquisition
(distances depend on AICH_Transmission_Timing )
Random Access Timing
84 © Nokia Siemens Networks RN31552EN10GLN0
Preamble
5120 chips
Preamble
AS # i
4096 chips
preamble-to-preamble
distance ττττp-p
PRACHaccess slots
AICHaccess slots
Messagepart
preamble-to-message
distance ττττp-m
AcquisitionIndication
preamble-to-AI
distance ττττp-a
AS # i
• RACH Sub-channels• RACH sub-channels were introduced to define a sub-set of uplink access slots.
• A total number of 12 RACH sub-channels exist, numbered from 0 to 11.
• The PRACH access slots are numbered relative to the AICH assess slot.
• The offset is given by ττττp-a (see preceding slides).
• The AICH is transmitted synchronised to the P-CCPCH.
• An access slot of sub-channel #i is using access slot #i, when SFN mod 8 = 0 or 1. It is then
using every 12th access slot following access slot #i.
• You can see in the figure on the right hand side all existing sub-channels and the timeslots,
they are using.
• Access Classes (AS) and Access Service Classes (ASC)
RACH Sub-channels and Access Service Classes
85 © Nokia Siemens Networks RN31552EN10GLN0
• Access Classes (AS) and Access Service Classes (ASC)• Access Service Classes were introduced to allow priority access to the PRACH resources,
by associating ASCs to specific access slot spaces (RACH sub-channels) and signatures.
• 8 ASC can be specified by the operator; The UE determines the ASC and its associated
resources from SIB5 and SIB7.
• The mapping of the subscribers access classes (1..15) is part of the SIB5 cell system
information.
• RACH Access Slot Sets• Two access slot set were specified:
• Access slot set 1 holds PRACH access slots 1 to 7, i.e. the PRACH access slots, whose
corresponding AICH access slots begin in a P-CCPCH with a SFN modulo 2 = 0.
• Access slot set 2 holds PRACH access slots 8 to 15, i.e. the PRACH access slots, whose
corresponding AICH access slots begin in a P-CCPCH with a SFN modulo 2 = 1.
SFN mod 8 of the
corresponding
P-CCPCH frame
0
1
2
3
4
0
12
9
6
1
13
10
7
2
14
11
3
0
12
4
1
13
5
2
14
6
3
0
7
4
1
8
5
2
9
6
3
10
7
4
Sub-channel number
1 2 3 4 5 6 7 8 9 10 11
11
8
5
0
PRACH Sub-channels and Access Service Classes (ASC)
86 © Nokia Siemens Networks RN31552EN10GLN0
4
5
6
7
6
3
7
4
8
5
9
6
10
7
11
8
0
12
9
1
13
10
2
14
11
3
0
12
4
1
13
5
2
14
(cited from TS 25.214 V5.11.0, chap. 6.1.1)
Node B
BCCH (SIB 5, SIB 7)
UE• ASCs and their PRACH access resources + signatures,• AC mapping into ASCs
• In the PRACH preamble, a random preamble code is used.
• This code is composed from a
• Preamble Scrambling Code and a
• Preamble Signature
• There is a total of 16 preamble signatures of 16 bit length, which is repeated 256 times within one
preamble.
• When monitoring the cell system information, the UE gets the information, which of the signatures are
available for use in the cell. (see IE PRACH info)
• There are 8192 preamble scrambling codes, which are constructed from the long scrambling code
PRACH Preamble
87 © Nokia Siemens Networks RN31552EN10GLN0
• There are 8192 preamble scrambling codes, which are constructed from the long scrambling code
sequences.
• The PRACH preamble scrambling codes are organised in 512 groups, with each group holding 16
members.
• There are also 512 primary scrambling codes available in UMTS, and one of them is in use in the cell.
• If the primary scrambling code s is in use in the cell, then only the PRACH preamble scrambling codes
belonging to PRACH preamble scrambling code group s can be used for random access.
• Consequently, 16 PRACH preamble scrambling codes are left, and the BCCH is used to inform the
UE, which PRACH preamble scrambling codes can be used. (see IE PRACH info)
Node B
UTRANBCCH
UE RNC• available signatures for
random access• available preamble
scrambling codes• available spreading
factor• available sub-channels• etc.
PRACH Preamble
88 © Nokia Siemens Networks RN31552EN10GLN0
Pi Pi Pi Pi
Preamble Signature
(16 different versions)
16 chip
256 repetitions
⊗
PRACH Preamble Scrambling Code
• 512 groups à 16 preamble scrambling codes
• Cell‘s primary scrambling codes associated with preamble scrambling code group
• etc.
• The length of the PRACH message part can be 10 ms or 20 ms.
• Its length is set as Transmission Time Interval (TTI) value by the higher layers.
• Uplink, we apply code multiplexing.
• Control data (L1 data) is transmitted with spreading factor 256, while message data can be
transmitted with spreading factors 256, 128, 64 or 32.
• The message data contains the information, given by the RACH.
• The control data contains 8 known pilot bits per timeslot. 15 different pilot bit sequences exist – they
are associated with the timeslot, where the transmission takes place within the 10 ms message frame.
2 bits in the control data carry TFCI bits per timeslot.
• Which spreading code is allocated to the message part?
PRACH Message Part
89 © Nokia Siemens Networks RN31552EN10GLN0
• Which spreading code is allocated to the message part?
• The message part‘s channelisation code is determined from the signature, which was used by the UE
in the preamble.
• 16 different signatures exist, and each can be correlated to a channelisation code in the
channelisation code tree with spreading factor 16.
• The channelisation codes are calculated like this:
• Each signature has a number k, with 0 ≤ k ≤ 15.
• For the control data, the channelisation code CCH,256,n is used, with n = 16*k + 15.
• For the message data, the channelisation code CCH,SF,m is used, with m = SF*k/16.
• The scrambling code is the same, which was used for the PRACH preamble.
Slot 0 Slot 1 Slot 2 Slot 14
10 ms Frame
RACH data
L1 control data 8 Pilot bits (sequence depends on slot number) 2 TFCI bits
data
PRACH Message Part
90 © Nokia Siemens Networks RN31552EN10GLN0
• SF = 256• channelisation code:
CCH,256,16*k+15, withk = signature number
• SF = 256, 128, 64, or 32• channelisation code:
• CCH,SF,SF*k/16, with
k = signature number
Scrambling code =
PRACH preamble scrambling code
• When it comes to the random access, two questions have to be asked:
• What kind of output power does the UE select for the first preamble?
• And how does the output power change with the subsequent preambles and the message part?
• Open Loop Power Control• The output power for the first PRACH preamble is based in parts on broadcasted parameters (SIB6, if
missing, from SIB5; and SIB7).
• The UE acquires the Node B‘s “Primary CPICH TX Power“, a “Constant Value“, and the “UL
Interference“ level.
• The UE also determines the received CPICH RSCP (variable CPICH_RSCP).
• Then, it calculates the power for the first preamble:
PRACH Power Setting
91 © Nokia Siemens Networks RN31552EN10GLN0
• Then, it calculates the power for the first preamble:
• Preamble_Initial_Power = Primary CPICH TX power – CPICH_RSCP + UL interference + Required received C/I
• The “Required received C/I“ is an UTRAN parameter (NSN: PRACHRequiredReceivedCI;
range: -35 ... -10 dB, step 1 dB default: -25dB).
• The “UL Interference“ is measured by the Node B and broadcasted via SIB 7 on P-CCPCH
to the UEs.
• The power ramp steps from one preamble to the next can be set between 1 and 8 dB (step size 1dB).
• The power offset between the last PRACH and the PRACH control message can be set between –5
and 10 dB (step size 1dB).
• The gain factor ßc is used for the PRACH control part.
Preamble_Initial_Power =Primary CPICH TX power– CPICH_RSCP+ UL interference + Required received C/I*
UL interference
1st preamble: power setting
attenuation in the DL
estimated receive levelConstant Value
PRACH Power Setting
*NSN: PRACHRequiredReceivedCI
92 © Nokia Siemens Networks RN31552EN10GLN0
at Node B
Pre-amble
Controlpart
Pre-amble
Pre-amble
Pp-p
Pp-p
Pp-m
1..8 dB-5..10 dB
# of preambles: 1..64 # of preamble cycles: 1..32
• The AICH is used to indicate to UEs, that their PRACH preamble was received, and that the Node B is
expecting to receive the PRACH message part next.
• The AICH returns an indicator of signature s, which was used in the PRACH preamble.
• Spreading factor is fixed to 256 for the AICH.
• The AICH is transmitted via 15 access slots, each lasting 5120 chips.
• Consequently, the AICH access slots are distributed over two consecutive 10 ms frames.
• Similar to the PRACH preamble, only 4096 chips are used to transmit the Acquisition Indicator part.
• 32 real value symbols are transmitted.
• Each real value is calculated by a sum of AIsbs,j.
• AI is an acquisition indicator for signature s.
• If signature s is positively confirmed, Ai is set to +1; a negative confirmation results in –1; if
Acquisition Indication Channel (AICH)
93 © Nokia Siemens Networks RN31552EN10GLN0
• If signature s is positively confirmed, Ais is set to +1; a negative confirmation results in –1; if
signature s is not part of the active signature set, then Ais is set to 0. bs,j stands for signature
pattern j, with j = 0..31.
• If more than one PRACH preamble signatures within one PRACH access slot is detected correctly,
the Node B sends the AIs of all the detected signatures simultaneously in the 1st or 2nd AICH
access slot after the PRACH access slot.
• If the number of correctly detected signatures is higher than the Node B's capability to
simultaneously decode the PRACH message parts, a negative AIs is used for generating the AIs
for those PRACH messages, which can not be decoded within the default message part
transmission timing.
• A negative AI indicates to the MS that it shall exit the random access procedure.• The Node B 's capability to decode the PRACH message parts is determined in the RNC and
transmitted to the Node B.
Access Slot 0 Access Slot 1 Access Slot 2 Access Slot 14
20 ms Frame
a0 a1 a2 a29 a30 a31
Acquisition Indication Channel (AICH)
94 © Nokia Siemens Networks RN31552EN10GLN0
∑=
=15
0
js,sj bAIas
AICH signature pattern (fixed)
Acquisition Indicator
• +1 if signature s is positively confirmed
• -1 if signature s is negatively confirmed
• 0 if signature s is not included in the
set of available signatures
• In RAN1, Node B L1 shall be able to simultaneously scan 12 RACH sub-channels with 4 signatures
per sub-channel from UEs situating up to 'Cell radius' distance from the Node B site.
• 'Cell radius' is the maximum radius of the cell and it is given from the RNC to the Node B. In RAN1,
the maximum value for the 'Cell radius' is 20 km.
• WCEL: PRACHRequiredReceivedCI• This UL required received C/I value is used by the UE to calculate the initial output power on
PRACH according to the Open loop power control procedure.• This parameter is part of SIB 5.• [-35 dB..-10 dB]; step 1 dB; default -25 dB
• WCEL: PowerRampStepPRACHPreamble• UE increases the preamble transmission power when no acquisition indicator is received by UE in
NSN Parameters Related to the PRACH and AICH
95 © Nokia Siemens Networks RN31552EN10GLN0
• UE increases the preamble transmission power when no acquisition indicator is received by UE in AICH channel.
• This parameter is part of SIB 5.• [1dB..8dB]; step 1 dB; default: 2 dB
• WCEL: PowerOffsetLastPreamblePrachMessage• The power offset between the last transmitted preamble and the control part of the PRACH
message.• [-5 dB..10 dB]; step 1 dB; default 2dB
• WCEL: PRACH_preamble_retrans• The maximum number of preambles allowed in one preamble ramping cycle, which is part of
SIB5/6.• [1 ... 64]; step 1; default 8.
• WCEL: RACH_tx_Max• Maximum number of RACH preamble cycles defines how many times the PRACH pre-amble
ramping procedure can be repeated before UE MAC reports a failure on RACH transmission to higher layers.
• This message is part of SIB5/6.• [1 ... 32]; default 8.
• WCEL: PRACHScramblingCode• The scrambling code for the preamble part and the message part of a PRACH Channel, which is
part of SIB5/6.• [0 ... 15]; default 0.
NSN Parameters Related to the PRACH and AICH
96 © Nokia Siemens Networks RN31552EN10GLN0
• WCEL: AllowedPreambleSignatures• The preamble part in a PRACH channel carries one of 16 different orthogonal complex signatures.
NSN Node B restrictions: A maximum of four signatures can be allowed (16 bit field).• [0 ... 61440]; default 15.
• WCEL: AllowedRACHSubChannels• A RACH sub-channel defines a sub-set of the total set of access slots (12 bit field).• [0 ... 4095]; default 4095.
• WCEL: PtxAICH• This is the transmission power of one Acquisition Indicator (AI) compared to CPICH power. • This parameter is part of SIB 5.• [-22 ... 5] dB, step 1 dB; default: -8 dB.
• WCEL: AICHTraTime• AICH transmission timing defines the delay between the reception of a PRACH access slot
including a correctly detected preamble and the transmission of the Acquisition Indicator in the AICH.
• 0 ( Delay is 0 AS), 1 ( Delay is 1 AS) ;default 0.
• WCEL: RACH_Tx_NB01min
NSN Parameters Related to the PRACH and AICH
97 © Nokia Siemens Networks RN31552EN10GLN0
• WCEL: RACH_Tx_NB01min• In case that a negative acknowledgement has been received by UE on AICH a backoff timer TBO1
is started to determine when the next RACH transmission attempt will be started.• The backoff timer TBO1 is set to an integer number NBO1 of 10 ms time intervals, randomly
drawn within an Interval 0 ≤ NB01min ≤ NBO1 ≤ NB01max (with uniform distribution).• [0 ... 50]; default: 0.
• WCEL: RACH_Tx_NB01max• [0 ... 50]; default: 50.
Summary of RACH procedure
1- Decode from BCCH
• Available RACH spreading factors
• RACH scrambling code number
• UE Access Service Class (ASC) info
• Signatures and sub-channels for each ASC
• Power step, RACH C/I requirement = “Constant”, BS interference level
2 – Calculate initial preamble power
3 – Calculate available access slots in the next full access slot set and select randomly one of those
(Adopted from TS 25.214)
98 © Nokia Siemens Networks RN31552EN10GLN0
of those
4 – Select randomly one of the available signatures
5 – Transmit preamble in the selected access slot with selected signature
6 – Monitor AICH
• IF no AICH– Increase the preamble power
– Select next available access slot & Go to 3
• IF negative AICH or max. number of preambles exceeded– Exit RACH procedure
• IF positive AICH
– Transmit RACH message with same scrambling code and channelisation code related to signature
Part VIDedicated Physical Channel Downlink
99 © Nokia Siemens Networks RN31552EN10GLN0
• The downlink DPCH is used to transmit the DCH data.
• Control information and user data are time multiplexed.
• The control data is associated with the Dedicated Physical Control Channel (DPCCH), while the user
data is associated with the Dedicated Physical Data Channel (DPDCH).
• The transmission is organised in 10 ms radio frames, which are divided into 15 timeslots.
• The timeslot length is 2560 chips. Within each timeslot, following fields can be found:
• Data field 1 and data field 2, which carry DPDCH information
• Transmission Power Control (TPC) bit field
• Transport Format Combination Indicator (TFCI) field, which is optional
• Pilot bits
• The exact length of the fields depends on the slot format, which is determined by higher layers.
Downlink Dedicated Physical Channel (DPCH)
100 © Nokia Siemens Networks RN31552EN10GLN0
• The exact length of the fields depends on the slot format, which is determined by higher layers.
• The TFCI is optional, because it is not required for services with fixed data rates.
• Slot format are also defined for the compressed mode; hereby different slot formats are in used, when
compression is achieved by a changed spreading factor or a changed puncturing scheme.
• The pilot sequence is used for channel estimation as well as for the SIR ratio determination within the
inner loop power control.
• The number of the pilot bits can be 2, 4, 8 and 16 – it is adjusted with the spreading factor.
• A similar adjustment is done for the TPC value; its bit numbers range between 2, 4 and 8.
• The spreading factor for a DPCH can range between 4 and 512. The spreading factor can be changed
every TTI period.
• Superframes last 720 ms and were introduced for GSM-UMTS handover support.
Slot 0 Slot 1 Slot 2 Slot 14
10 ms Frame
Radio Frame0
Radio Frame1
Radio Frame2
Radio Frame71
Superframe = 720 ms
Downlink Dedicated Physical Channel (DPCH)
101 © Nokia Siemens Networks RN31552EN10GLN0
Slot 0 Slot 1 Slot 2 Slot 14
TPCbits
Pilot bitsTFCIbits
(optional)
Data 2 bitsData 1 bits
DPDCHDPDCH DPCCH DPCCH
• 17 different slot formats• Compressed mode slot
format for changed SF & changed puncturing
• Following features are supported in the downlink:
• Blind rate detection, and
• Discontinuous transmission.
• Rate matching is done to the maximum bit rate of the connection. Lower bit rates are possible,
including the option of discontinuous transmission.
• Please note, that audible interference imposes no problem in the downlink.
• Multicode usage:• Several physical channels can be allocated in the downlink to one UE.
• This can occur, when several DPCH are combined in one CCTrCH in the PHY layer, and the data
rate of the CCTrCH exceeds the maximum data rates allowed for the physical channels.
Downlink Dedicated Physical Channel (DPCH)
102 © Nokia Siemens Networks RN31552EN10GLN0
rate of the CCTrCH exceeds the maximum data rates allowed for the physical channels.
• Then, on all downlink DPCHs, the same spreading factor is used.
• Also the downlink transmission of the DPCHs takes place synchronous.
• One DPCH carries DPDCH and DPCCH information, while on the remaining DPCHs, no DPCCH
information is transmitted.
• But also in the case, when several DPCHs with different spreading factors are in use, the first DPCH
carries the DPCCH information, while in the remaining DPCHs, this information is omitted
(discontinuous transmission).
TS TS
maximum bit rate
TS TS TS
discontinuous transmission with lower bit rate
Multicode usage:
Downlink Dedicated Physical Channel (DPCH)
DPCCH
103 © Nokia Siemens Networks RN31552EN10GLN0
TS TS TS
TS TS TS
DPCH 1
DPCH 2
DPCH 3
• Power offsets for the optional TFCI, TPC and pilot bits have to be specified during the radio link setup.
• This is done with the NBAP message RADIO LINK SETUP REQUEST message, where following
parameters are set:
• PO1: defines the power offset for the TFCI bits; it ranges between 0 and 6 dB with a 0.25
step size.
• PO2: defines the power offset for the TPC bits; it ranges between 0 and 6 dB with a 0.25
step size.
• PO3: defines the power offset for the pilot bits; it ranges between 0 and 6 dB with a 0.25
step size.
Power Offsets for the DPCH
104 © Nokia Siemens Networks RN31552EN10GLN0
step size.
• In the same message, the TFCS, DL DPCH slot format, multiplexing position, FDD TPC DL
step size increase, etc. are defined.
• The FDD TPC DL step size is used for the DL inner loop power control.
DCH Data Frame
Iub
NBAP: RADIO LINK SETUP REQUEST
• Power offsets• TFCS• DL DPCH slot format• FDD DL TPC step
size• ...
Power Offsets for the DPCH
105 © Nokia Siemens Networks RN31552EN10GLN0
Node B RNC
Iub
UE
Uu
PO1TPCbits
Pilot bitsTFCIbits
(optional) Data 2 bitsData 1 bits
PO3PO2
P0x: 0..6 dBstep size: 0.25 dB
• Inner loop power control is also often called (fast) closed loop power control.
• It takes place between the UE and the Node B.
• We talk about UL inner loop power control, when the Node B returns immediately after the reception of
a UE‘s signal a power control command to the UE. By doing so, the UE‘s SIR ratio is kept at a certain
level (the details will be discussed later on in the course).
• DL inner loop power control control is more complex. When the UE receives the transmission of the
Node B, the UE returns immediately a transmission power control command to the Node B, telling the
Node B either to increase or decrease its output power for the UE‘s DPCH.
• The Node B‘s transmission power can be changed by 0.5, 1, 1.5 or 2 dB. 1 dB must be supported by
the equipment. If other step sizes are supported or selected, depends on manufacturer or operator.
• The transmission output power for a DPCH has to be balanced for the PICH, which adds to the power
Downlink Inner Loop Power Control
106 © Nokia Siemens Networks RN31552EN10GLN0
• The transmission output power for a DPCH has to be balanced for the PICH, which adds to the power
step size.
• There are two downlink inner loop power control modes:
• DPC_MODE = 0: Each timeslot, a unique TPC command is send uplink.
• DPC_MODE = 1: Three consecutive timeslots, the same TPC command is transmitted.
• One reason for the UE to request a higher output power is given, when the QoS target has not been
met.
• It requests the Node B to transmit with a higher output power, hoping to increase the quality
of the connection due to an increased SIR at the UE‘s receiver.
• But this also increases the interference level for other phones in the cell and neighbouring
cells.
• The operator can decide, whether to set the parameter Limited Power Increase Used.
• If used, the operator can limit the output power raise within a time period.
two modescell
TPC
Downlink Inner Loop Power Control
107 © Nokia Siemens Networks RN31552EN10GLN0
DPC_MODE = 0
unique TPC commandper TS
DPC_MODE = 1
same TPC over 3 TS,then new command
TPCest per1 TS / 3 TS
UTRAN behaviour
P(k) = P(k - 1) + PTPC(k) + Pbal(k),
currentDL power
poweradjustment
newDL power
Correction termfor RL balancing
toward CPICH
P
PTPCPbal
IF
Downlink Inner Loop Power Control
108 © Nokia Siemens Networks RN31552EN10GLN0
time
IFLimited Power Increase Used = 'Not used'
PTPC(k) =
+ ∆∆∆∆ TPC, if TPCest (k) = 1
- ∆∆∆∆ TPC, if TPCest (k) = 0
∆∆∆∆ TPC step size: 0.5, 1, 1.5 or 2 dB
mandatory
UTRAN behaviour
P(k) = P(k - 1) + PTPC(k) + Pbal(k),
currentDL power
poweradjustment
newDL power
Correction termfor RL balancing
toward CPICH
P
time
PTPCPbal
IF
Downlink Inner Loop Power Control
109 © Nokia Siemens Networks RN31552EN10GLN0
IFLimited Power Increase Used = 'used'
DL_Power_Averaging_Window_Size
PTPC
Power_Raise_Limit
K-1
TPCest (k) = 1 => PTPC(k) = 0
otherwise assee preceding
slide
K time
• The P-CCPCH is the timing reference for all physical channels.
• As can be seen in the figure on the right hand side, following timing relationships exist:
• The SCH, CPICH, P-CCPCH and DSCH have an identical timing.
• S-CCPCHs can be transmitted with a timing offset ττττS-CCPCH,n. (n stands for the nth S-CCPCH.)
• The timing offset may be different for each S-CCPCH, but it is always a multiple of 256 chips,
i.e. ττττS-CCPCH,n = Tn * 256 chips, with Tn ∈ {0,..,149}.
• We have already seen, that some S-CCPCHs transmit paging information.
• The associated PICH frame ends ττττPICH = 7680 chips before the associated S-CCPCH frame.
• DPCHs are also transmitted with a timing offset, which may be different for different DPCHs.
• The timing offset ττττ is – similar to the S-CCPCH – a multiple of 256, i.e.
Timing Relationship between Physical Channels
110 © Nokia Siemens Networks RN31552EN10GLN0
• The timing offset ττττDPCH,k is – similar to the S-CCPCH – a multiple of 256, i.e.
ττττDPCH,k = Tk * 256 chips, with Tk ∈ {0,..,149}.
• The timing of a DSCH, which is allociated with a DPCH, is explained later on in the course
documentation.
• AICH access slots for the RACH and CPCH also require a time organisation.
• As we have seen e.g. with the RACH, an access slot combines two timeslots.
• How can the timing to the P-CCPCH be identified?
• The P-CCPCH transmits the cell system frame number (SFN), which increases by one with
each radio frame.
• The AICH access slot number 0 starts simultaneously with the P-CCPCH frame, whose SFN
modulo 2 is zero.
SFN mod 2 = 0 SFN mod 2 = 1
P-CCPCH
AICH accessslots 0 1 1282 1175 964 13103 14 0
SCH
Timing Relationship between Physical Channels
111 © Nokia Siemens Networks RN31552EN10GLN0
nth S-CCPCHττττS-CCPCH,n
kth S-DPCHττττDPCH,k
0..38144
(step size 256)
0..38144
(step size 256)
• A major problem arises, when the UE is connected to several cells simultaneously.
• The active set cells must transmit the downlink DPCH in a way that their arrival time is within a receive
window at the UE.
• DLnom is the nominal receive time of a radio frame with a specific CFN at the UE.
• To = 4 TS later, the UE starts to transmit the a radio frame with the same CFN.
• To is always calculated relative to the UE transmission start point.
• Of course, due to multipath propagation and handover situations, the reception of the
beginning of a downlink radio frame is often not exactly at To times before the UE starts to
send.
• When the UE is in a soft handover, and moving from one cell to another, the radio frames arriving from
one cell may arrive later and later, while the radio frames of another cell arrive earlier. I.e., the
Radio Interface Synchronisation
112 © Nokia Siemens Networks RN31552EN10GLN0
one cell may arrive later and later, while the radio frames of another cell arrive earlier. I.e., the
reception from the two neighbouring cells drifts apart.
• The picture on the right hand side is only valid, if the UE is in the macro-diversity state. In this case,
the parameter Tm is the time difference between the nominal downlink received signal DLnom and the
appearance of the first P-CCPCH of the neighbouring cell.
• The serving RNC determines the required offset between P-CCPCH of the neighbouring cell and the
DL DPCH.
• This information is sent as Frame Offset and Chip Offset to the target Node B.
• The target Node B can change the transmission of the DL DPCH only with a step size of 256
chips, in order to be synchronised to the SCH and P-CCPCH structure.
• The S-RNC informs also the UE about the Frame Offset.
T =
Tm =timing differencerange: 0..38399Res.: 1 chip
SRNC
Relative timingbetween DL DPCHand P-CCPCHrange: 0..38144res.: 256 chips
Offsetbetween DL DPCHand P-CCPCHrange: 0..38399res.: 1 chip
Radio Interface Synchronisation
113 © Nokia Siemens Networks RN31552EN10GLN0
UEcell1
T0 =1024chips
cell2= target
cell for HO
(Frame Offset, Chip Offset)
res.: 1 chip
(Frame Offset)(TM)
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114 © Nokia Siemens Networks RN31552EN10GLN0
Part VIIDedicated Physical Channel Uplink
115 © Nokia Siemens Networks RN31552EN10GLN0
• The uplink dedicated physical channel transmission, we identify two types of physical channels:
• Dedicated Physical Control Channel (DPCCH),• Which is always transmitted with spreading factor 256.
• Following fields are defined on the DPCCH:
• pilot bits for channel estimation. Their number can be 3, 4, 5, 6, 7 or 8.
• Transmitter Power Control (TPC), with either one or two bits
• Transport Format Combination Indicator (TFCI), which is optional, and a
• Feedback Indicator (FBI). Bits can be set for the closed loop mode transmit diversity
and site selection diversity transmission (SSDT)
• 6 different slot formats were specified for the DPCCH. Variations exist for the compressed
mode.
Uplink Dedicated Physical Channels
116 © Nokia Siemens Networks RN31552EN10GLN0
mode.
• Dedicated Physical Data Channel (DPDCH),• Which is used for user data transfer.
• Its spreading factor ranges between 4 and 256.
• 7 different solt formats are defined, which are set by the higher layers.
• The DPCCH and DPDCH are combined by I/Q code multiplexing with each multiframe.
• Multicode usage is possible. If applied, additional DPDCH are added to the uplink transmission, but no
additional DPCCHs! The maximum number of DPDCH is 6.
• The transmission itself is organised in 10 ms radio frames, which are divided into 15 timeslots. The
timeslot length is 2560 chips.
Slot 0 Slot 1 Slot 2 Slot 14
10 ms Frame
Radio Frame0
Radio Frame1
Radio Frame2
Radio Frame71
Superframe = 720 ms
Uplink Dedicated Physical Channels
117 © Nokia Siemens Networks RN31552EN10GLN0
TPCbits
Pilot bitsTFCI bits(optional)
Data 1 bitsDPDCH
DPCCH FBI bits
• 7 different slot formats
• 6 different slot formats• Compressed mode slot
format for changed SF & changed puncturing
Feedback Indicator for• Closed loop mode transmit diversity, &• Site selection diversity transmission (SSDT)
• Discontinuous transmission (DTX) is supported for the DCH both uplink and downlink.
• If DTX is applied in the downlink – as it is done with speech – then 3000 bursts are generated in one
second. (1500 times the pilot sequence, 1500 times the TPC bits)
• This causes two problems:
• Inter-frequency interference, caused by the burst generation.
• At the Node B, the problem can be overcome with exquisite filter equipment. This filter
equipment is expensive and heavy. Therefore it cannot be applied in the UE.
• The UE‘s solution is I/Q code multiplexing, with a continuous transmission for the DPCCH.
DPDCH changes can still occur, but they are limited to the TTI period. The minimum TTI
period is 10 ms. The same effects can be observed, then the DPDCH data rate and with it its
output power is changing.
Discontinuous Transmission and Power Offsets
118 © Nokia Siemens Networks RN31552EN10GLN0
output power is changing.
• 3000 bursts causes audible interference with other equipment – just see for example GSM.
• By reducing the changes to the TTI period, the audible interference is reduced, too.
• Determination of the power difference between the DPCCH and DPDCH• I/Q code multiplexing is done in the uplink, i.e. the DPCCH and DPDCH are transmitted with
different codes (and possible with different spreading factors). Gain factors are specified: ββββc is the
gain factor for the DPCCH, while ββββd is the gain factor for the DPDCH. The gain factors may vary
for each TFC. There are two ways, how the UE may learn about the gain factors:
• The gain factors are signalled for each TFC. If so, the nominal power relation Aj between
the DPDCH and DPCCH is ββββd/ββββc.
• The gain factor is calculated based on reference TFCs. (The details for gain factor calculation
based on reference TFCs are not discussed in this course.)
DPCCH
DPDCH
DPCCH
DPDCH
DPCCH
DPDCH
TTL TTL TTL
Discontinuous Transmission and Power Offsets
119 © Nokia Siemens Networks RN31552EN10GLN0
UL DPDCH/DPCH Power Difference:
DPCCH
DPDCH
=ββββd
ββββc
=Nominal Power Relation Aj
two methods to determine the gain factors:
• signalled for each TFCs
• calculation based on reference TFCs
• The subscriber is mobile. The distance of the UE from a Node B is changing over time.
• With growing distance and a fixed output power at the UE, the received signals at the Node B
become weaker.
• UE output power adjustment is required.
• But the UE‘s received signal strength can change fast – Rayleigh fading in one phenomena,
which causes this event.
• As a consequence, a fast UL power control is required.
• This power control is called UL inner loop power control, though many experts also call it (fast)
closed loop power control.
• At each active set cell, a target SIR (SIR ) is set for each UE. The active set cells estimate SIRest
UL Inner Loop Power Control
120 © Nokia Siemens Networks RN31552EN10GLN0
• At each active set cell, a target SIR (SIRtarget) is set for each UE. The active set cells estimate SIRest
on the UE‘s receiving uplink DPCH. Each active set cell determines the TPC value. If the estimated
SIR is larger than the UE‘s target SIR, then the determined TPC value is 0. Otherwise it is 1. These
values are determined on timeslot basis and returned on timeslot basis.
• The UE has to determine the power control command (TPC_cmd). The higher layer control
protocol RRC is used to inform the UE, which power control algorithm to apply. This informs the UE
also how to generate a power control command from the incoming TPC-values.
There are power control algorithm 1 (PCA1) and 2 (PCA2), which are described in the figure
following the next one. Given the power control algorithm and the TPC-values, the UE determines,
how to modify the transmit power for the DPCCH: ∆∆∆∆DPCCH = ∆∆∆∆ TPC ×××× TPC_cmd. ∆∆∆∆ TPC stands for the
transmission power step size.
(continued on the next text slide)
SIRest
SIRtarget
UL Inner Loop Power Control
121 © Nokia Siemens Networks RN31552EN10GLN0
time
TPC ⇒⇒⇒⇒TPC_cmd
in FDD mode:1500 times per second
• Power Control Algorithm 1• is applied in medium speed environments.
• Here, the UE is commanded to modify its transmit power every timeslot.
• If the received TPC value is 1, the UE increases the transmission output at the DPCCH by
∆∆∆∆DPCCH, otherwise it decreases it by ∆∆∆∆DPCCH. • The ∆∆∆∆DPCCH is either 1 or 2 dB, as set by the higher layer protocols.
• TPC values from the same radio link set represent one TLC_cmd.
• TPC_cmds from different radio link sets have to be weighted, if there is no reliable
interpretation.
• Power Control Algorithm 2
UL Inner Loop Power Control
122 © Nokia Siemens Networks RN31552EN10GLN0
• Power Control Algorithm 2• was specified to allow smaller step sizes in the power control in comparison to PCA1.
• This is necessary in very low and high speed environments.
• In these environments, PCA1 may result in oscillating around the target SIR.
• PCA2 changes only with every 5th timeslot, i.e. the TPC_cmd is set to 0 the first 4 timeslots.
In timeslot 5, the TPC_cmd is –1, 0, or 1.
• For each radio set, the TPC_cmd is temporarily determined. This can be seen in the next
figure.
• The temporary transmission power commands (TPC_temp) are combined as can be seen in
the figure after the next one. Here you can see, how the final TPC_cmd is determined.
Note that up to NSN RU 10 only PCA 1 is supported.
algorithms for processing power control commands TPC_cmd
PCA1
TPC_cmd for each TSTPC_cmd values: +1, -1step size ∆∆∆∆ : 1dB or 2dB
PCA2
TPC_cmd for 5th TSTPC_cmd values: +1, 0, -1step size ∆∆∆∆ : 1dB
UL Inner Loop Power Control
Note that up to NSN RU 10
only PCA 1 is supported.
123 © Nokia Siemens Networks RN31552EN10GLN0
PCA2 PCA1 PCA2
step size ∆∆∆∆ TPC: 1dB or 2dB step size ∆∆∆∆ TPC: 1dB
UL DPCCH power adjustment: ∆∆∆∆DPCCH = ∆∆∆∆ TPC ×××× TPC_cmd
km/h0 ≈≈≈≈ 3 ≈≈≈≈ 80Rayleigh fading can be compensated
Example: reliable transmission
Cell 3
TPC3 = 1⇒⇒⇒⇒
TPC_cmd = -1 (Down)
Power Control Algorithm 1
124 © Nokia Siemens Networks RN31552EN10GLN0
Cell 1Cell 2
TPC1 = 1 TPC3 = 0
Note that up to NSN RU 10 only PCA 1 is supported.
TPC_temp
0
0
0
0
1
0
• if all TPC-values = 1
⇒ TPC_temp = +1
• if all TPC-values = 0
⇒ TPC_temp = -1
• otherwise
⇒ TPC_temp = 0
Power Control Algorithm 2 (part 1)
125 © Nokia Siemens Networks RN31552EN10GLN0
0
0
0
0
0
0
0
0
0
-1
⇒ TPC_temp = 0
Note that up to NSN RU 10 PCA 2 is not supported.
TPC_temp1 TPC_temp2 TPC_temp3
Example:
N = 3
Power Control Algorithm 2 (part 2)
126 © Nokia Siemens Networks RN31552EN10GLN0
∑=
N
i
i
N 1
TPC_temp1
-1 -0.5 0 0.5 1
TPC_cmd = -1 10
Note that up to
RU 10 PCA 2 is
not supported.
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127 © Nokia Siemens Networks RN31552EN10GLN0
• UTRAN shall start the transmission of the downlink DPCCH and may start the transmission of DPDCH
if any data is to be transmitted.
• The UE uplink DPCCH transmission shall start
• When higher layers consider the downlink physical channel established, if no activation time
for uplink DPCCH has been signalled to UE
• If an activation time has been given, uplink DPCCH transmission shall not start before the
downlink physical channel has been established and the activation time has been reached.
• When we look to the PRACH, we can see, that preambles were used to avoid UEs to access UTRAN
with a too high initial transmission power.
• The same principle is applied for the DPCH.
• The UE transmits between 0 to 7 radio frames only the DPCCH uplink, before the DPDCH is code
Initial Uplink DCH Transmission
128 © Nokia Siemens Networks RN31552EN10GLN0
• The UE transmits between 0 to 7 radio frames only the DPCCH uplink, before the DPDCH is code
multiplexed.
• The number of radio frames is set by the higher layers (RRC resp. the operator).
• Also for this period of time, only DPCCH can be found in the downlink.
• The UE can be also informed about a delay regarding RRC signalling – this is called SRB delay,
which can also last 0 to 7 radio frames. The SRB delay follows after the DPCCH preamble.
• How to set the transmission power of the first UL DPCCH preamble?
• Its power level is
• DPCCH_Initial_power = – CPICH_RSCP + DPCCH_Power_offset• The DPCCH Power Offset is retrieved from RRC messages. It’s value ranges between –164
and –6 dB (step size 2 dB). CPICH_RSCP is the received signal code power on the P-
CPICH, measured by the UE.
receptionat UE
DPCCH only DPCCH & DPDCH
Initial Uplink DCH Transmission
129 © Nokia Siemens Networks RN31552EN10GLN0
trans-mission
at UE
DPCCH only DPCCH & DPDCH
0 to 7 frames for power control preamble
DPCCH_Initial_power = – CPICH_RSCP + DPCCH_Power_offset
DL Synch & Activation time
0 to 7 frames ofSRB delay
Part VIIIHSDPA Physical Channels
130 © Nokia Siemens Networks RN31552EN10GLN0
High Speed Physical Downlink Shared Channel(HS-PDSCH)The WCDMA system normally carries user data over dedicated transport channels, or DCHs, which brings maximum system performance with continuous user data. The DCHs are code multiplexed onto one RF carrier. In the future, user applications are likely to involve the transport of large volumes of data that will be burst in nature and require high bit rates.
HSDPA introduces a new transport channel type, High Speed Downlink Shared Channel (HS-DSCH) that makes efficient use of valuable radio frequency resources and takes into account bursty packet data. This new transport channel shares multiple access codes, transmission power and use of infrastructure hardware between several users. The radio network resources can be used efficiently to serve a large number of users who are accessing to the resources and so forth. In other words, several users can be time multiplexed so that during silent
131 © Nokia Siemens Networks RN31552EN10GLN0
can be used efficiently to serve a large number of users who are accessing to the resources and so forth. In other words, several users can be time multiplexed so that during silent periods, the resources are available to other users.
HSDPA offers maximum peak rates of up to 14.4 Mbps in a 5 MHz channel. However, more important than the peak rate is the packet data throughput capacity, which is improved significantly. This increases the number of users that can be supported at higher data rates on a single radio carrier.
Another important characteristic of HSDPA is the reduced variance in downlink transmission delay. A guaranteed short delay time is important for many applications such as interactive games. In general, HSDPA’s enhancements can be used to implement efficiently the ‘interactive’ and ‘background’ Quality of Service (QoS) classes standardized by 3GPP. HSDPA’s high data rates also improve the use of streaming applications on shared packet channels, while the shortened roundtrip time will benefit web-browsing applications.
L1 Feedback
Data
•Shared DL data channel
•Fast link adaptation, scheduling and L-1
• Channel quality information
• Error correction Ack/Nack
HSDPA – General principle
132 © Nokia Siemens Networks RN31552EN10GLN0
Terminal 1 (UE)
Terminal 2
L1 Feedback
Data
Data
scheduling and L-1 error correction done in BTS
•1 – 15 codes (SF=16)
•QPSK or 16QAM modulation
•User may be time and/or code multiplexed.
HSDPA features
HSDPA enhanced data rates and spectrum efficiency HSDPA improves system capacity and increases user data rates in the downlink direction, that is, transmission from the radio access network to the mobile terminal. This improved performance is based on:
• 1) adaptive modulation and coding
• 2) a fast scheduling function, which is controlled in the base station (BTS), rather than by the radio network controller (RNC).
• 3) fast retransmissions with soft combining and incremental redundancy
133 © Nokia Siemens Networks RN31552EN10GLN0
• 3) fast retransmissions with soft combining and incremental redundancy
Fast scheduling
• Scheduling of the transmission of data packets over the air interface is performed in the base station based on information about the channel quality, terminal capability, QoS class and power/code availability. Scheduling is fast because it is performed as close to the air interface as possible and because a short frame length is used.
HSDPA features
Fast Link Adaptation: Modulation and Coding is
Fast Packet Scheduling:The NodeB is responsible for resource allocation to HSDPA Fast H-ARQ:
HSDPA
Fast LinkAdaptation
FastH-ARQ
FastPacket
scheduling
134 © Nokia Siemens Networks RN31552EN10GLN0
Modulation and Coding is adapted every 2 ms (1 TTI) during the session to the radio link quality. This ensures highest possible data rates to end-users.
resource allocation to HSDPA packet data users. Resource allocation is performed every TTI = 2 ms. For resource allocation, the users radio link quality may be taken into account.Fast Packet Scheduling improves the spectrum efficiency.
Fast H-ARQ: Data are retransmitted by BTS. UE
acknowledges (L1) and performs soft combination of initial
transmission & retransmissions. This provides reliable, fast and
efficient data transmission.
Interaction of MAC-hs and Physical Layer
HSDPA Peak Bit Rates
Coding rate
QPSK
Coding rate
1/4
2/4
3/4
5 codes 10 codes 15 codes
600 kbps 1.2 Mbps 1.8 Mbps
1.2 Mbps 2.4 Mbps 3.6 Mbps
1.8 Mbps 3.6 Mbps 5.4 Mbps
135 © Nokia Siemens Networks RN31552EN10GLN0
16QAM
2/4
3/4
4/4
2.4 Mbps 4.8 Mbps 7.2 Mbps
3.6 Mbps 7.2 Mbps 10.7 Mbps
4.8 Mbps 9.6 Mbps 14.4 Mbps
RAS06 allows allocation of up to 15 Codes; 14.4 Mbps total;
up to 3 simultaneous user; max. 10 Mbps/user
RU10 allows max. 14.4 Mbps/user
BTS
Associa
ted D
PC
H
Associa
ted D
PC
H
15 x
HS
-P
DS
CH SC
CH
DP
CC
H
DL CHANNELS
HS-PDSCH: High-Speed Physical Downlink Shared Channel
HS-SCCH: High-Speed SharedControl Channel
F-DPCH: Fractional Dedicated Physical Channel
Associated DPCH, Dedicated
Rel99 DCH
Physical Channels for One HSDPA UE
DP
CH
136 © Nokia Siemens Networks RN31552EN10GLN0
UE
Associa
ted D
PC
H
Associa
ted D
PC
H
1-1
5 x
HS
PD
SC
H
1-4
x H
S-S
CC
H
HS
-DP
CC
H
Associated DPCH, DedicatedPhysical Channel.
UL CHANNELS
Associated DPCH, DedicatedPhysical Channel
HS-DPCCH: High-Speed Dedicated Physical Control Channel
F-D
PC
H
HSDPA DL physical channels
HS-PDSCH: High-Speed Physical Downlink Shared Channel
• Transfers actual HSDPA data of HS-DSCH transport channel.
• 1-15 code channels.
• QPSK or 16QAM modulation.
• Divided into 2ms TTIs
• Fixed SF16
• Doesn’t have power controlField Number of
137 © Nokia Siemens Networks RN31552EN10GLN0
HS-SCCH: High-Speed Shared Control Channel
• Includes information to tell the UE how todecode the next HS-PDSCH frame
• Fixed SF128
• Shares downlink power with the HS-PDSCH
• More than one HS-SCCH required when codemultiplexing is used
• Power can be controlled by node B(proprietary algorithms)
Field Number of
uncoded bits
Channelisation code set information 7 bits
Modulation scheme information 1 bit
Transport block size information 6 bits
Hybrid ARQ process information 3 bits
Redundancy and constellation version 3 bits
New data indicator 1 bit
UE identity 16 bits
HSDPA DL physical channels
F-DPCH: Fractional Dedicated Physical Channel
• The F-DPCH carries control information generated at layer 1 (TPC commands).
• It is a special case of DL DPCCH
• fixed SF = 256
• Frame structure of the F-DPCH: each 10 ms frame is split into 15 slots (each of 2/3 ms), corresponding to 1 power-control period
• Up to 10 users can share the same F-DPCH to receive power control information (per user: 2 F-DPCH bits/slot = 1.5 ksymb/s).
138 © Nokia Siemens Networks RN31552EN10GLN0
user: 2 F-DPCH bits/slot = 1.5 ksymb/s).
• Introduced in Rel. 6 for situations where only packet services are active in the DL others than the Signalling Radio Bearer SRB
• Should be used in case of low data rate packet services handled by HSDPA & HSUPA, where the associated DPCH causes to much (power) overhead and code consumption
Associated DPCH, Dedicated Physical Channel
• Transfers L3 signalling (Signalling Radio Bearer (SRB)) information e.g. RRC measurement control messages
• Power control commands for associated UL DCH
• DPCH needed for each HSDPA UE.
HSDPA UL physical channelsHS-DPCCH: High-Speed Dedicated Physical Control Channel
• MAC-hs Ack/Nack information (send when data received).
• Channel Quality Information, CQI reports (send in every 4ms)
• SF 256
• Power control relative to DPCH
• No SHO
139 © Nokia Siemens Networks RN31552EN10GLN0
Associated DPCH, Dedicated Physical Channel
• DPCH needed for each HSDPA UE.
• Transfers signalling
• Also transfers uplink data 64, 128, 384kbps, e.g. TCP acks and UL data transmission
Physical channel structure – Time multiplexing
3GPP enables time and code multiplexing.
Picture presents time multiplexing
• One HS-SCCH
UE1
UE1
UE1
UE2
UE2
UE2
UE1
HS-PDSCH #2
UE1
UE1
UE1
UE2
UE2
UE2
UE3
UE3
UE3
UE1
HS-PDSCH #1
UE1
UE1
UE1
UE1
HS-PDSCH #3
1 radio frame (15 slots, total 10 ms)
2 ms
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Subframe #1 Subframe #2 Subframe #3 Subframe #4 Subframe #5
User data on HS-DSCH
2 slots
140 © Nokia Siemens Networks RN31552EN10GLN0
• One HS-SCCH required per cell
• Codes can be allocated only to one user at a time
E1 E1 E1 E1HS-PDSCH #3
UE #1
UE #2
UE #3
UE1
UE1
UE1
UE2
UE2
UE2
UE3
UE3
UE3
UE1
HS-SCCH
L1 feedback HS-DPCCH
3 slots
L1 feedback HS-DPCCH
L1 feedback HS-DPCCH
Code Multiplexing
With Code Multiplexing, multiple UEs can be scheduled during one TTI.
Multiple HS-SCCH channels
• One for each simultaneously receiving UE.
• HS-SCCH power overhead.
HS-PDSCH codes divided for
HS-PDSCH
HS-PDSCH
HS-PDSCH
HS-PDSCH
HS-PDSCH
HS-PDSCH
HS-PDSCH
HS-PDSCH
HS-SCCH
HS-SCCH
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HS-PDSCH codes divided for different transport blocks.
• Multiple simultaneous transport blocks to one UE not possible.
Codes can be allocated to multiple users at same time
• Important when cell supports more codes than UEs do. For example 10 codes per cell, UE category 6.
cat 6
HS-PDSCH
HS-PDSCH
HS-PDSCH
cat 6 cat 6 cat 6cat 8
HS-SCCH
HS-PDSCH
2 slots 3 slots
P-CCPCH
TTX_diff
Downlink DPCH
Tprop + 7.5 slots
Unit = chips2560 chips = slot3 slots = (HSDPA) subframe15 slots = frame
Timing of HSDPA Physical Channels
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HS-DPCCH
Node B
UE
Uplink DPCH
Downlink DPCH
Tprop + 0.4 slots (1024 chips)
m x 0.1 slots = TTX_diff + 10.1 slots
SF = 32
SF = 8
SF = 16
SF = 4
SF = 2
SF = 1
Codes for 5
Downlink Code Allocation example
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SF = 128
SF = 256
SF = 64
Codes for the cell common channels
Code for one
HS-SCCH
Codes for 5
HS-PDSCH's
•166 codes @ SF=256 available for the associated DCHs and non-HSDPA uses
Adaptive Modulation and Coding
Link adaptation in HSDPA is the ability to adapt the modulation scheme and coding according to the quality of the radio link.
The spreading factor remains fixed, but the coding rate can vary between 1/4 and 3/4.
The HSDPA specification supports the use of 5, 10 or 15 multi-
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The HSDPA specification supports the use of 5, 10 or 15 multi-codes.
Link adaptation ensures the highest possible data rate is achieved both for users with good signal quality (higher coding rate), typically close to the base station, and for more distant users at the cell edge (lower coding rate).
Fast Link Adaptation in HSDPA
02468
10121416
stan
taneo
us
EsN
o [d
B] C/I received by
UEC/I varies
with fading
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0 20 40 60 80 100 120 140 160-2
0
Time [number of TTIs]
QPSK1/4
QPSK2/4
QPSK3/4
16QAM2/4
16QAM3/4
Ins
Link adaptation
mode
BTS adjusts link adaptation mode with a few ms delay based on channel quality reports from
the UE
1011 1001
10001010
0001 0011
00100000
0100 01101110 1100
Q
I
10 00
0111
Q
I
Link adaptation: Modulation
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QPSK
2 bits / symbol =480 kbit/s/HS-PDSCH =
max. 7.2 Mbit/s
16QAM
4 bits / symbol =960 kbit/s/HS-PDSCH =
max. 14.4 Mbit/s
0111010111011111
3GPP Rel. 7 introduces DL 64QAM support for HS-PDSCH
UE HS-DSCH physical layer categoriesMaximum number of HS-DSCH codes received
• Defines the maximum number of HS-DSCH codes the UE is capable of receiving.
Total number of soft channel bits in HS-DSCH
• Defines the maximum number of soft channel bits over all HARQ processes
• When explicit signalling is used UTRAN configures Process Memory Size for each HARQ process so that the following criterion must be fulfilled in the configuration:
– Total number of soft channel bits in HS-DSCH ≥ sum of Process Memory Size
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– Total number of soft channel bits in HS-DSCH ≥ sum of Process Memory Size of all the HARQ processes.
Minimum inter-TTI interval in HS-DSCH
• Defines the distance from the beginning of a TTI to the beginning of the next TTI that can be assigned to the UE.
UEs of Categories 11 and 12 support QPSK only.
3GPP Rel. 7 introduces Categories 13 – 18 for 64QAM or MIMO support
3GPP Rel. 8 introduces Categories 19 & 20 for 64QAM & MIMO support
See 3GPP TS25.306
UE HS-DSCH physical layer categoriesHS-DSCH category
Maximum number of HS-DSCH codes
received
Minimum inter-TTI interval
Maximum number of bits of an HS-DSCH transport
block received within an HS-DSCH TTI
ARQ Type at maximum data rate
Total number of soft
channel bits
Category 1 5 3 7298 Soft 19200
Category 2 5 3 7298 IR 28800
Category 3 5 2 7298 Soft 28800
Category 4 5 2 7298 IR 38400
Category 5 5 1 7298 Soft 57600
Category 6 5 1 7298 IR 67200
TS 25.306
QPSKor
16QAM
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Category 6 5 1 7298 IR 67200
Category 7 10 1 14411 Soft 115200
Category 8 10 1 14411 IR 134400
Category 9 15 1 20251 Soft 172800
Category 10 15 1 27952 IR 172800
Category 11 5 2 3630 Soft 14400
Category 12 5 1 3630 Soft 28800
QPSKonly
16QAM
• 3GPP Rel. 7 introduces Categories 13 – 18 for 64QAM or MIMO support
• 3GPP Rel. 8 introduces Categories 19 & 20 for 64QAM & MIMO support
CQI mapping – UE Category 1-6
“Based on an unrestricted observation interval, the UE shall report the highest tabulated CQI value for which a single HS-DSCH sub-frame formatted with the transport block size, number of HS-PDSCH codes and modulation corresponding to the reported or lower CQI value could be received in a 3-slot reference period ending 1 slot before the
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reference period ending 1 slot before the start of the first slot in which the reported CQI value is transmitted and for which the transport block error probability would not exceed 0.1.”
TS 25.214
BTS
Associa
ted D
PC
H
Associa
ted D
PC
H
15 x
HS
-P
DS
CH SC
CH
DP
CC
H
Rel99 DCH
Channel quality indication (CQI) from HSDPA UEUE reports the channel conditions to the base station via the uplink channel CQI field on the HS-DPCCH
UE estimates which AMC format � CQI (0…30) will provide transport block error probability < 10 % on HS-DSCH
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UE
Associa
ted D
PC
H
Associa
ted D
PC
H
1-1
5 x
HS
PD
SC
H
1-4
x H
S-S
CC
H
HS
-DP
CC
H
10 % on HS-DSCH
WBTS uses CQI as one input when defining the AMC format used on the HS-PDSCH
• Transport Block Size
• Number of HS-PDSCH (codes)
• Modulation
• Incremental redundancy
MAC-hsUE: The MAC-hs handles the HS-DSCH specific functions. In the model below the MAC-hs comprises the following entity:
• HARQ:
– The HARQ entity is responsible for handling the HARQ protocol. There shall be one HARQ process per HSDSCH per TTI. The HARQ functional entity handles all the tasks that are required for hybrid ARQ. It is for example responsible for generating ACKs or NACKs. The detailed configuration of the hybrid ARQ protocol is provided by RRC over the MAC-Control SAP.
• Reordering:
– The reordering entity organises received data blocks according to the received TSN. Data blocks with consecutive TSNs are delivered to higher layers upon reception. A timer mechanism determines delivery of nonconsecutive data blocks to higher layers. There is one reordering entity
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determines delivery of nonconsecutive data blocks to higher layers. There is one reordering entity for each priority class.
RNC: The MAC-hs is responsible for handling the data transmitted on the HS-DSCH. Furthermore it is responsible for the management of the physical resources allocated to HS-DSCH. MAC-hs receives configuration parameters from the RRC layer via the MAC-Control SAP. There shall be priority handling per MAC-d PDU in the MAC-hs. The MAC-hs is comprised of four different functional entities:
• Flow Control
• Scheduling/Priority Handling
• HARQ
• TFRI selection
MAC-hs
UE: RNC:
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HS-SCCH
HS-DSCH
HS-DPCCH
Flow control
This is the companion flow control function to the flow control function in the MAC-c/sh in case of Configuration with MAC-c/sh and MAC-d in case of Configuration without MAC-c/sh.
Both entities together provide a controlled data flow between the MAC-c/sh and the MAC-hs (Configuration with MAC-c/sh) or the MAC-d and MAC-hs (Configuration without MAC-c/sh) taking the transmission capabilities of the air interface into account in a dynamic
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transmission capabilities of the air interface into account in a dynamic manner.
This function is intended to limit layer 2 signalling latency and reduce discarded and retransmitted data as a result of HS-DSCH congestion.
• Iub congestion
• MAC-d buffer overflow in MAC-hs
Flow control is provided independently per priority class for each MAC-d flow.
Scheduling/Priority Handling
This function manages HS-DSCH resources between HARQ entities and data flows according to their priority class.
Based on status reports from associated uplink signalling either new transmission or retransmission is determined.
Further it sets the priority class identifier and TSN for each new data block being serviced. To maintain proper transmission priority a new transmission can be initiated on a HARQ process at any time. The
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transmission can be initiated on a HARQ process at any time. The TSN is unique to each priority class within a HS-DSCH, and is incremented for each new data block.
It is not permitted to schedule new transmissions, including retransmissions originating in the RLC layer, within the same TTI, along with retransmissions originating from the HARQ layer.
HARQ and TFRI selectionHARQ:
• One HARQ entity handles the hybrid ARQ functionality for one user.
• One HARQ entity is capable of supporting multiple instances (HARQ process) of stop and wait HARQ protocols.
• There shall be one HARQ process per TTI.
• The HARQ protocol is based on an asynchronous downlink and synchronous uplink scheme.
• The ARQ combining scheme is based on Incremental redundancy.
– Chase Combining is considered to be a particular case of Incremental Redundancy.
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– Chase Combining is considered to be a particular case of Incremental Redundancy. The UE soft memory capability shall be defined according to the needs for Chase combining. The soft memory is partitioned across the HARQ processes in a semi-static fashion through upper layer signalling. The UTRAN should take into account the UE soft memory capability when configuring the different transport formats (including possibly multiple redundancy versions for the same effective code rate) and when selecting transport formats for transmission and retransmission.
TFRI selection:
• Selection of an appropriate transport format and resource combination for the data to be transmitted on HSDSCH.
L1 error correction – HARQHybrid ARQ is a combination of
• Forward error correction (channel coding) and
• Automatic Repeat Request (retransmissions).
HARQ performs retransmissions of MAC-hs PDUs from Node B to UE.
HARQ processes
• Typically 6 per UE (depends).
• Stop-and-wait ARQ per process.
• Processes operate in parallel.
NACK feedback status:
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NACK feedback status:
• “Yes” means NACK is received for this HARQ process from the UE
• “No” means ACK/NACK has not received yet
• “DTX” means ACK/NACK was not received in predefined time period.
Transmitter chooses Redundancy Version (RV) for each transmission.
Receiver performs combining of different transmission of same MAC-hs PDU.
• Chase Combining.
• Incremental Redundancy.
• Constellation Rearrangement (16QAM only).
• Fast retransmissions
Server RNC Node-BMAC-hs Layer-1
retransmissions
Retransmissions in HSDPA
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UE
RLC retransmissions
TCP retransmissions
HSDPA L1 RetransmissionsThe 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.
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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.
Systematic
Parity 1
Parity 2
Turbo Encoder
Rate Matching (Puncturing)
Systematic
Original transmission Retransmission
HSDPA L1 Retransmissions : Chase Combining
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Parity 1
Parity 2
Chase Combining (at Receiver)
Systematic
Parity 1
Parity 2
Systematic
Parity 1
Parity 2
Turbo Encoder
Rate Matching (Puncturing)
Systematic
Original transmission Retransmission
HSDPA L1 Retransmissions : Incremental Redundancy
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Parity 1
Parity 2
Incremental Redundancy Combining
Systematic
Parity 1
Parity 2
Power control on HSDPA channels
Associated UL and DL DPCH utilise normal closed loop power control
DL HS-PDSCH
• Fixed power or variable power e.g. according to load conditions
DL HS-SCCH
• 3GPP specifications do not explicitly specify any closed loop PC modes for the HS-SCCH
• The Node-B must rely on feedback information from the UE related to the reception quality of other channel types, such as:
– Power control commands for the associated DPCH
– CQI reports for HS-DSCH
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– CQI reports for HS-DSCH
– ACK/NACK feedback or DTX in uplink HS-DPCCH
UL HS-DPCCH
• Based on associated DPCH power control with power offsets
• The power offset parameters [∆ACK; ∆NACK; ∆CQI] are controlled by the RNC and reported to the UE using higher layer signalling
HS-DPCCH
DPCCH
∆ACK; ∆NACK ∆CQI ∆CQI
Ack/Nack CQI report
Part IXHSUPA Physical Channels
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High Speed Uplink Packet Access (HSUPA)
HSUPA or High Speed Uplink Packet Access is used for the UMTS Rel. 6 counterpart and in analogy to Rel. 5 HSDPA. Nevertheless, HSUPA has been specified by 3GPP under the term „FDD Enhanced Uplink“. The scope of HSUPA is identical to that of HSDPA: to improve the overall radio resource efficiency, leading to higher capacity respectively throughput per cell as well as higher peak data rates per user / connection.
HSUPA introduces a new transport channel type, Enhance Dedicated Channel (E-DCH), a transport channel that is dedicated to only 1 UE and subject to Node-B scheduling and HARQ. The E-DCH is defined as an extension to DCH transmission.
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HSUPA offers maximum data rates of 1920kbps in single code operation (1 code of SF=2) or up to 5.76Mbps by allowing multicode operation (2 codes of SF=2 + 2 codes of SF=4).
HSUPA brings benefits for both the operators and the end users. In practice, it means higher data rates for end users, larger coverage especially for high bit rates, lower delay in case of transmission failures, larger capacity in the radio network and the opportunity for the operator to deliver services (the existing ones and the new ones) at a lower cost of bit.
2-allocation of
• Channel quality Information
• Error correction Ack/Nack
HSUPA – General principle
1-Scheduling request
to Node B
• E-DCH
• Node B controlled scheduling
• HARQ
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UE
4-L1 Feedback
2-allocation of
allowed PWR (resources)
3-Data tx
5-More or less PWR is granted if
needed
• HARQ
• SF=256-2
• Multi-Code operation
• QPSK modulation only Dual-branch BPSK on I- & Q-
branch
• Fast Link Adaptation(Adaptive Coding), no enhanced/ adaptive modulation in Rel. 6
• SHO supported
HSUPA features
HSUPA enhanced data rates and spectrum efficiency
HSUPA improves system capacity and increases user data rates in the uplink direction, that is, transmission from the mobile terminal to the radio access network. This improved performance is based on:
• 1) Fast Link Adaptation using adaptive coding (1/4 -3/4, 4/4 with high level equipment). In HSUPA, no adaptive modulation takes part in UMTS Rel. 6.
• 2) Fast Node B UL scheduling function: This is controlled in the base station (BTS), rather than by the radio network controller (RNC). It gives the possibility
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(BTS), rather than by the radio network controller (RNC). It gives the possibility for the Node B to control, within the limits set by the RNC, the set of TFCs from which the UE may choose a suitable TFC (Transport Format Combination). Is fast because it is performed as close to the air interface as possible and because a short frame length is used.
• 3) Fast HARQ: terminated at the Node B, with soft combining or incremental redundancy. It allows lower retransmission delay in case of transmission failure, since re-transmission is performed between the UE and the BTS, not between the RLC peers
HSUPA features
Fast Link Adaptation:HSUPA (Rel. 6): The coding is Fast H-ARQ: UE and Node B are
HSUPA
Fast LinkAdaptation Fast
H-ARQ
Fast PacketScheduling
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HSUPA (Rel. 6): The coding is adapted dynamically every TTI (2 ms / 10 ms) by the UE to radio link quality. Modulation is fixed to QPSK in Rel. 6. Rel. 7 offers adaptation of the modulation (QPSK/16QAM), too.Fast Link Adaptation improves the spectrum efficiency significant.
Fast Packet Scheduling:NodeB schedules UL resource allocation (every TTI = 2/10ms).
Fast H-ARQ: UE and Node B are responsible for acknowledged PS data transmission. Data retransmission is handled by UE. NodeB performs soft combining of original and Re-transmissions to enhance efficiency. This provides fast & efficient error correction.
Physical Layer in Interaction with MAC-e
HSUPA Peak Bit Rates
Coding rate
1/4
1code x SF4 2codes x SF4 2codes x SF22codes x SF2
+ 2codes x SF4
480 kbps 960 kbps 1.92 Mbps 2.88 Mbps
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3/4
4/4
720 kbps 1.46 Mbps 2.88 Mbps 4.32 Mbps
960 kbps 1.92 Mbps 3.84 Mbps 5.76 Mbps
NSN RU10 (WBTS5.0) gives support to UE categories 1-7 up to 1.92 (about 2) Mbps (2 x SF2)
per UE (only 10 ms TTI, ¼ coding)
BTS
Associa
ted D
PC
H
Associa
ted D
PC
H
DP
DC
H
DP
CC
H
RG
CH
DL CHANNELS
E-AGCH: E-DCH Absolute Grant Channel
E-RGCH: E-DCH Relative Grant Channel
E-HICH: E-DCH Hybrid ARQ Indicator Channel
Associated DPCH, Dedicated Physical
Rel99 DCH
Physical Channels for One HSUPA UE
HIC
H
AG
CH
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UE
Associa
ted D
PC
H
Associa
ted D
PC
H
1-4
x E
-DP
DC
H
E-D
PC
CH
E-R
GC
H
Associated DPCH, Dedicated Physical Channel.
UL CHANNELS
E-DPDCH: Enhanced Dedicated Physical Data Channel
E-DPCCH: Enhanced Dedicated Physical Control Channel
Associated DPCH, Dedicated Physical Channel
E-H
ICH
E-A
GC
H
HSUPA UL physical channels
E-DPDCH: Enhanced Dedicated Physical Data Channel
• carries UL packet data (E-DCH)
• up to 4 E-DPDCHs for 1 Radio Link
• SF = 256 – 2 (BPSK)
• pure user data & CRC
• CRC size: 24 bit (1 CRC/TTI)
• TTI = 2 / 10 ms
• UE receives resource allocation via Grant Channels
• managed by MAC-e/-es
• Error Protection: Turbo Coding 1/3
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• Error Protection: Turbo Coding 1/3
• Soft/Softer Handover support
E-DPCCH: Enhanced Dedicated Physical Control Channel
• transmits control information associated with the E-DCH
• 0 or 1 E-DPCCH for 1 Radio Link
• SF = 256
Associated DPCH, Dedicated Physical Data Channel
• DPCH needed for each HSUPA UE.
• Transfers signalling
• Also transfers uplink data 64, 128, 384kbps, e.g. TCP acks and UL data transmission
E-DCH: E-DPDCH & E-DPCCH
I
Σ
cd,1 βd
I+jQ
DPDCH1
cd,3 βd
DPDCH3
cd,5 βd
DPDCH5
Rel. `99 New in Rel. 6 for HSUPA:E-DPDCH & E-DPCCH
E-DPDCH:used to carry the E-DCH transport channel.
There may be 0, 1, 2 or 4 E-DPDCH on each radio link.
E-DPCCH:used to transmit control information associated
170 © Nokia Siemens Networks RN31552EN10GLN0
j
Q
cd,2 βd
DPDCH2
cd,4 βd
cc βc
DPCCH
Σ
Sdpch
DPDCH4
cd,6 βd
DPDCH6
used to transmit control information associated with the E-DCH.
Configuration #
DPDCH HS-DPCCH
E-DPDCH
E-DPCCH
1 6 1 - -
2 1 1 2 1
3 - 1 4 1
Maximum number of simultaneous UL DCHs
E-DPDCH : SF-Variation & Multi-Code Operation
CC1,0 = (1)
CC2,0 = (1,1)
CC4,0 = (1,1,1,1)
CC4,1 = (1,1,-1,-1)
CC4,2 = (1,-1,1,-1)
CC64,0
CC64,1
CC64,2
•• •
• • •
SF = 1 SF = 2 SF = 4 SF = 64SF = 8
NDPDC
H
E-
DPDCHk
CCSF,k
0
E-DPDCH1
CCSF,SF/4 if SF
≥ 4
CC2,1 if SF = 2
CC if SF = 4
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CC2,1 = (1,-1)
CC4,3 = (1,-1,-1,1) CC64,63
CC64,62
0E-DPDCH2
CC4,1 if SF = 4
CC2,1 if SF = 2
E-DPDCH3
E-DPDCH4
CC4,1
1
E-DPDCH1 CCSF,SF/2
E-DPDCH2
CC4,2 if SF = 4
CC2,1 if SF = 2
E-DPDCH: SF = 256 - 2
SF = 2 ⇒⇒⇒⇒ 1920 kbit/s
Multi-Code operation:up to 2 x SF2 + 2 x SF4
⇒⇒⇒⇒ up to 5.76 Mbps
E-DPDCH & E-DPCCH frame structure and content
E-DPDCH: Data only (+ 1 CRC/TTI);SF = 256 – 2; Rchannel = 15 – 1920 kbps
Ndata = 10 x 2k+2 bit (K = 0..5)
E-DPCCH: L1 control data; SF = 256; 10 bit
1 Slot = 2560 chip = 2/3 ms
Slot #0 Slot #1 Slot #2 Slot #i Slot #14
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1 subframe = 2 ms
1 radio frame, Tframe = 10 ms
k SFChannel Bit Rate[kbps]
Bit/ Fram
e
Bit/ Subfram
e
Bit/Slot
Ndata
0 64 60 600 120 40
1 32 120 1200 240 80
2 16 240 2400 480 160
3 8 480 4800 960 320
4 4 960 9600 1920 640
5 2 19201920
03840 1280
E-DPCCH content:• E-TFCI information (7 bit)
indicates E-DCH Transport Block Size; i.e. at given TTI (TS 25.321; Annex B)• Retransmission Sequence Number RSN (2 bit)
Value = 0 / 1 / 2 / 3 for:Initial Transmission, 1st / 2nd / further Retransmission
• „Happy" bit (1 bit)indicating if UE could use more resources or not
Happy 1
Not happy 0
The E-DPDCH is used for user data transmission. The Spreading Factor can be varied between 256 and 2. Multi-Code operation using up to 2 SF = 2 Codes and 2 SF=4 codes enables L1 data rates up to 5.76 Mbps.
The E-DPCCH Spreading Factor is fixed to 256; One sub-frame contains 10 information bit
The E-DPDCH and E-DPCCH frame & slot format can be found in TS 25.211(-670); 5.2.1.3.The content and mapping of the E-DPCCH information fields can be found in TS 25.212(-670); 4.9.2.
The information field consists of 3 different segments:
E-DPDCH & E-DPCCH frame structure and content
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E-DCH Transport Format Combination Indicator (E-TFCI): 7 bit indicating the transport format being transmitted simultaneously on the E-DPDCHs. Via this information the receiver will be informed how many E-DPDCHs are transmitted in parallel and which Spreading Factor(s) are used (see TS 25.321 Annex B: E-DCH Transport Block Size Tables for FDD).
Retransmission Sequence Number (RSN): 2 bit informing the H-ARQ sequence number of the transport block currently being sent on E-DPDCHs. Value = 0 / 1 / 2 / 3 for Initial Transmission, 1st / 2nd / further Retransmission
Happy Bit: 1 bit indicating whether the UE needs more resources or not (TS 25.321(-670); 9.2.5.3.1 & 11.8.1.5).
HSUPA DL physical channels
E-AGCHE-DCH Absolute Grant Channel
carries DL absolute grants for UL E-DCH
contains: UE-Identity (E-RNTI) & max. UE power ratio
E-DCH absolute grant transmitted over 1 TTI (2/10 ms)
SF = 256 (30 kbps; 20 bit/Slot)
NodeB
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E-RGCHE-DCH Relative Grant Channel
carries DL relative grants for UL E-DCH;
complementary to E-AGCH
contains: relative Grants („UP“, „HOLD“, „DOWN“) & UE-Identity
E-DCH relative grant transmitted 1 TTI (2/10 ms)
SF = 128 (60 kbps; 40 bit/Slot)
UE
E-DCH Radio Network Temporary Identifier:
allocated by S-RNC for E-DCH user per Cell
E-DCH transmission:after E-AGCHafter E-RGCHNon-scheduled transmission
HSUPA DL physical channels
UENodeB
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UE
E-HICHE-DCH Hybrid ARQ Indicator Channel
carries H-ARQ acknowledgement indicator for UL E-DCH
contains ACK/NACK (+1; -1) & UE-Identity
E-DCH relative grant transmitted 1 TTI (2/10 ms)
SF = 128 (60 kbps; 40 bit/Slot)
NodeB
HSUPA DL physical channels
E-AGCH: E-DCH Absolute Grant Channel
• carries DL absolute grants for UL E-DCH
• contains: UE-Identity (E-RNTI) & max. UE power ratio
• E-DCH absolute grant transmitted over 1 TTI (2/10 ms)
• SF = 256 (30 kbps; 20 bit/Slot)
E-RGCH: E-DCH Relative Grant Channel
• carries DL relative grants for UL E-DCH;
• complementary to E-AGCH
• contains: relative Grants („UP“, „HOLD“, „DOWN“) & UE-Identity
• E-DCH relative grant transmitted 1 TTI (2/10 ms)
• SF = 128 (60 kbps; 40 bit/Slot)
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• SF = 128 (60 kbps; 40 bit/Slot)
E-HICH: E-DCH Hybrid ARQ Indicator Channel
• carries H-ARQ acknowledgement indicator for UL E-DCH
• contains ACK/NACK (+1; -1) & UE-Identity
• E-DCH relative grant transmitted 1 TTI (2/10 ms)
• SF = 128 (60 kbps; 40 bit/Slot)
Associated DPCH, Dedicated Physical Channel
• Transfers L3 signalling (Signalling Radio Bearer (SRB)) information e.g. RRC measurement control messages
• Power control commands for associated UL DCH
• DPCH needed for each HSUPA UE.
Adaptive Coding in HSUPAIn the same way as for HSDPA, in HSUPA Turbo Coding with a code rate of 1/3 is applied. In the following rate matching according to the radio interface conditions is performed. Puncturing in case of good radio conditions, repetition in case of bad radio conditions. Similar to HSDPA the effective coding will range between 1/4 and 3/4. High level equipment will support 4/4 coding as well.
Link adaptation in HSUPA is the ability to adapt only the coding according to the quality of the radio link.
The HSUPA specification supports the use of SF 256-2 and 1-4 codes for E-DPDCH. In order to achieve the max data rates, following configurations are supported:
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supported:
• 1code x SF4
• 2codes x SF4
• 2codes x SF2 (max imum supported in NSN RU 10)
• 2codes x SF2 + 2codes x SF4
Link adaptation ensures the highest possible data rate is achieved both for users with good signal quality (higher coding rate), typically close to the base station, and for more distant users at the cell edge (lower coding rate).
Adaptive Coding in HSUPA
• HSUPA adapts the Coding to the current Radio Link Quality
• HSUPA varies the effective Coding between 1/4 – 1(4/4)
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NodeB
UE
1/42/43/44/4 UE
Note that support for 4/4 coding is optionally given by UE and not supported in NSN RU 10!
Modulation in HSUPA
“Dual-Branch BPSK
1-Bit Keying
• Rel. 6 defines only QPSK (“Dual-branch BPSK“) as modulation method for HSUPA.
• 16QAM Modulation (“Dual-branch QPSK”) has been regarded as to complex for initial HSUPA
• (16 QAM = Dual-branch QPSK is defined in Release 7)
• no Adaptive Modulation takes place in Rel. 6; Adaptive Modulation with QPSK/16QAM in Rel. 7
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-1 1
(Q)
I
QPSK:
2-Bit Keying
16 QAM
64QAM
on both Code Trees in the UE
FDD E-DCH physical layer categories
For HSUPA 6 new UE capability classes have been defined (TS 25.306-680; Tab 5.1g).They are described in the table FDD E-DCH physical layer categories (3GPP TS25.306 UE Radio Access capabilities).
The key differences between the different classes are related to:- the UE‘s multi-code capability - the support of the 2 ms TTI. All UEs are supporting the 10 ms TTI.- the minimum Spreading Factor (minimum SF = 4 or 2).
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- the minimum Spreading Factor (minimum SF = 4 or 2).
Maximum # of E-DCH codes
• Defines the maximum number of E-DCH codes the UE is capable to use for tx in UL.
FDD E-DCH physical layer categories
E- DCH
Category
max.
E-DCH
Codes
min.
SF
2 & 10 ms
TTI E-DCH
support
max. #. of
E-DCH Bits*
/ 10 ms TTI
max. # of
E-DCH Bits*
/ 2 ms TTI
Reference
combination
Class
1 1 4 10 ms only 7110 - 0.73 Mbps
2 2 4 10 & 2 ms 14484 2798 1.46 Mbps
3 2 4 10 ms only 14484 - 1.46 Mbps
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4 2 2 10 & 2 ms 20000 5772 2.92 Mbps
5 2 2 10 ms only 20000 - 2.0 Mbps
6 4 2 10 & 2 ms 20000 11484 5.76 Mbps
7* 4 2 10 & 2 ms 20000 22996 11.52 Mbps
Extracted from TS 25.306: UE Radio Access Capabilities
7* category 7 is defined in 3GPP Rel 7 and supports QPSK and 16 QAM in Uplink
NSN RU10 (WBTS5.0) gives support to UE categories 1-7 up to 2 Mbps per UE (only 10 ms TTI)
MAC Architecture
UE: MAC-es / MAC-e are handling E-DCH specific functions; split between MAC-es & MAC-e in the UE is not detailed; MAC-es/MAC-e comprises following entities:
• H-ARQ: buffering MAC-e payloads & retransmit ting them
• Multiplexing: concatenating multiple MAC-d PDUs to MAC-es PDUs & multiplex 1 or multiple MAC-es PDUs to 1 MAC-e PDU
• E-TFC selection: Enhanced Transport Format Combination selection according to scheduling information (Relative & Absolute Grants) received from UTRAN via L1
UTRAN side
Node B: 1 MAC-e entity in Node B for each UE & 1 E-DCH scheduler function handle HSUPA specific functions in Node B:
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functions in Node B:
• E-DCH Scheduling: manages E-DCH cell re- sources between UEs; implementation proprietary
• E-DCH Control: receives scheduling requests & transmits scheduling assignments.
• De-multiplexing: de-multiplexing MAC-e PDUs
• H-ARQ: generating ACKs/NACKs
S-RNC: 1 MAC-es entity for each UE in S-RNC, performing the following functions
• Reordering: reorders received MAC-es PDUs according to the received TSN
• Macro diversity selection: for SHO (Softer HO in Node-B); delivers received MAC-es PDUs from each Node B of E-DCH AS; see reordering function
• Disassembly: Remove MAC-es header,extract MAC-d PDU’s & deliver to MAC-d
MAC Architecture: UE Side
MAC-es/MAC-e are handling E-DCH specific functions
• Split between MAC-es & MAC-e in the UE is not detailed
• comprises following entities:
• H-ARQ: buffering MAC-e payloads & re-transmitting them
• Multiplexing: concatenating multiple MAC-d PDUs → MAC-es PDUs & multiplex 1 / multiple MAC-es PDUs → 1 MAC-e PDU • E-TFC selection: Enhanced Transport Format Combination selection according to scheduling information (Relative & Absolute Grants) received from UTRAN via L1
DCCH DTCHDTCHMAC ControlCTCHBCCH CCCHPCCH
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FACH RACH DSCH DCH DCHCPCH PCH FACH DSCHHS-DSCH
associated
DL Signalling
E-DCHassociated
UL Signallingassociated
DL Signalling
associated
UL Signalling
MAC-d
MAC-c/shMAC-hsMAC-es/MAC-e
MAC Architecture: UTRAN side
1 MAC-e entity in Node B for each UE &
1 E-DCH scheduler function handle HSUPA specific functions in Node B
• E-DCH Scheduling: manages E-DCH cell re-sources between UEs; implementation proprietary
• E-DCH Control: receives scheduling requests &transmits scheduling assignments.
• De-multiplexing: de-multiplexing MAC-e PDUs
• H-ARQ: generating ACKs/NACKs
DCCH DTCHDTCHMAC Control
MAC ControlCCCH CTCHBCCHPCCHMAC ControlMAC Control
MAC Control
NodeB
• 1 MAC-es entity for each UE in S-RNC
• Reordering: reorders received MAC-es PDUs according to the received TSN
• Macro diversity selection: for SHO(Softer HO in Node-B).
delivers received MAC-es PDUs from each Node B of E-DCH AS → reordering function
• Disassembly: Remove MAC-es header, extract MAC-d PDU’s & deliver → MAC-d
RNC
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FACH RACH DSCHIur or
localDCH DCH
CPCHPCH
Configuration
with MAC-c/sh
associated
DL Signalling
MAC-e MAC-hs MAC-c/sh
MAC-d
MAC-es
associated
UL Signalling
E-DCHassociated
DL Signallingassociated
UL Signalling
HS-DSCH Iub
Configuration
without MAC-c/sh
Configuration
with MAC-c/sh
HSUPA Fast Packet Scheduling
HSUPA (Rel. 6) Fast Packet Scheduling:
• Node B controlled
• resources allocated on Scheduling Request
• short TTI = 2 / 10 ms
• Scheduling Decision on basis of actual physical layer load (available in Node B)
☺ up-to date / Fast scheduling decision ⇒ high UL resource efficiency
☺ higher Load Target (closer to Overload Threshold) possible ⇒high UL resource efficiency
� L1 signalling overhead
HSUPA (Rel. 6) Fast Packet Scheduling:
• Node B controlled
• resources allocated on Scheduling Request
• short TTI = 2 / 10 ms
• Scheduling Decision on basis of actual physical layer load (available in Node B)
☺ up-to date / Fast scheduling decision ⇒ high UL resource efficiency
☺ higher Load Target (closer to Overload Threshold) possible ⇒high UL resource efficiency
� L1 signalling overhead
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Scheduling Request
(buffer occupation,...)
UE
IubNode
B
Scheduling Grants
(max. amount ofUL resources to be used)
E-DCHdata transmission
E-DCHdata transmission
S-RNC
HSUPA Link Adaptation
Scheduling
Request
Node
Scheduling
Grants
MAC-e (UE) decides E-DCH Link Adaptation (TFC; effective Coding)
on basis of:
• Channel quality estimates (CPICH Ec/Io)
• Every TTI (2/10 ms)
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UENode
B
Rel. 99:
Fixed
Turbo Coding 1/3
Rel. 99:
Fixed
Turbo Coding 1/3
Rel. 6 HSUPA:
dynamic Link Adaptation
⇒ effective Coding 1/4 - 4/4
⇒
☺ higher UL data rates
☺ higher resource efficiency
Rel. 6 HSUPA:
dynamic Link Adaptation
⇒ effective Coding 1/4 - 4/4
⇒
☺ higher UL data rates
☺ higher resource efficiency
HSUPA Fast H-ARQ
HSUPA: Fast H-ARQ with UL E-DCH
• Node B (MAC-e) controlled
• SAW* H-ARQ protocol • based on synchronous DL (L1) ACK/NACK• Retransmission strategies:
Incremental Redundancy & Chase Combining
• 1st Retransmission ≈≈≈≈ 40 / 16 ms (TTI = 10 / 2 ms)• limited number of Retransmissions*
• lower probability for RLC Retransmission
• Support of Soft & Softer Handover
HSUPA: Fast H-ARQ with UL E-DCH
• Node B (MAC-e) controlled
• SAW* H-ARQ protocol • based on synchronous DL (L1) ACK/NACK• Retransmission strategies:
Incremental Redundancy & Chase Combining
• 1st Retransmission ≈≈≈≈ 40 / 16 ms (TTI = 10 / 2 ms)• limited number of Retransmissions*
• lower probability for RLC Retransmission
• Support of Soft & Softer Handover
☺ Short delay times(support of QoS services)
☺ less Iub/Iur traffic
☺ Short delay times(support of QoS services)
☺ less Iub/Iur traffic
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UE
Iub
NodeB
E-DCH PacketsE-DCH Packets
L1 ACK/NACKL1 ACK/NACK
RetransmissionRetransmission
MAC-e controls L1 H-ARQ:• storing & retransmitting payload• packet combining (IR & CC)
MAC-e controls L1 H-ARQ:• storing & retransmitting payload• packet combining (IR & CC)
correctly receivedpackets
correctly receivedpackets
IR: Incremental Redundancy
CC: Chase Combining
HARQ: Hybrid Automatic Repeat Request
SAW: Stop-and-Wait
* HARQ profile - max. number of
transmissions attribute
RNC
HSUPA Fast HARQHARQ protocol characteristics
• Stop- & wait-HARQ is used (SAW);
• HARQ based on synchronous DL ACK/NACKs
• HARQ based on synchr. UL retransmissions:
• There will be an upper limit to the number of retransmissions (maximum number of transmissions attribute; 11.1.1)
• Pre-emption will not be supported by E-DCH (ongoing re-transmissions will not be pre-empted by higher priority data for a particular process);
• Intra Node B macro-diversity and Inter Node B macro-diversity should be supported for
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• Intra Node B macro-diversity and Inter Node B macro-diversity should be supported for the E-DCH with HARQ
• Incremental redundancy shall be supported by the specifications with Chase combining as a subcase
HSUPA HARQ Error Handling:• The most frequent error cases to be handled are the following:• NACK is detected as an ACK: the UE starts a fresh with new data in the HARQ process.
The previously transmitted data block is discarded in the UE and lost. Retransmission is left up to higher layers;
• ACK is detected as a NACK: if the UE retransmits the data block, the NW will re-send an ACK to the UE. If in this case the transmitter at the UE sends the RSN set to zero, the receiver at the NW will continue to process the data block as in the normal case
HSUPA Soft Handover
Sectorcells
Softer Handover: • UE connected to cells of same
Node B (same MAC-e entity)• combining Node B internal• no extra Iub capacity needed
Softer Handover: • UE connected to cells of same
Node B (same MAC-e entity)• combining Node B internal• no extra Iub capacity needed
Iub
Soft Handover:
UE connected to UTRAN
via different Node Bs
Soft Handover:
UE connected to UTRAN
via different Node Bs
Node B
Node B
UE
SHO Gains:
full Coverage
for HSUPA
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CN
S-RNC:select E-DCHdata (MAC-es)& deliver to CN
S-RNC:select E-DCHdata (MAC-es)& deliver to CN
E-DCH Active Set:• set of cells carrying the
E-DCH for 1 UE.• can be identical / a
subset of DCH AS• is decided by the S-RNC
E-DCH Active Set:• set of cells carrying the
E-DCH for 1 UE.• can be identical / a
subset of DCH AS• is decided by the S-RNC
Iu
IubIub
Node B
RNC
Node B
Iub
RNC
E-DCH
AS
E-DCH
AS
HSUPA Soft Handover
HSUPA: Support of Soft(er) Handover
• Macro diversity is used in HSUPA, i.e. the UL data packets can be received by more than one cell. This is important for Radio Network Planning to maximise cell ranges (SHO gains); TS 25.309: 5: The coverage is an important aspect of the user experience and that it is desirable to allow an operator to provide for consistency of performance across the whole cell area..
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across the whole cell area..Intra Node B macro-diversity (Softer Handover) and Inter Node B macro-diversity (SHO) should be supported for the E-DCH with HARQ.
• E-DCH active set: The set of cells which carry the E-DCH for one UE. It can be identical or a subset of the DCH active set. The E-DCH active set is decided by the S-RNC
HSUPA Power Control
TS 25.14;5.1.2
NodeB
DPCCH
• Always transmitted
• Inner-Loop Power Control!
• Setting of E-DPCCH & E-DPDCHpower relative to DPCCH power
• PtxUE < min [Ptx,maxUE; max
Ptx,cell*]
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Configuration #i
DPDCH
HS-DPCCH
E-DPDCH E-DPCCH
1 6 1 - -
2 1 1 2 1
3 - 1 4 1
B
UE
UL DCH max configurations for Rel 99, HSDPA & HSUPA
Taken from specification TS 25.213;4.2.1
• Power Management/Control for E-DCHNo special power management/control mechanism is needed for E-DCH.
• Power Control: DPDCH & DPCCHThe initial UL DPCCH transmit power is set by higher layers. Subsequently the UL transmit power
control procedure simultaneously controls the power of a DPCCH & its corresponding DPDCHs (if
present). The relative transmit power offset between DPCCH & DPDCHs is determined by the network
and is computed using the gain factors signalled to the UE using higher layer signalling.
The operation of the inner power control loop, adjusts the power of the DPCCH & DPDCHs by the
same amount, provided there are no changes in gain factors. ...
Power Control
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same amount, provided there are no changes in gain factors. ...
• Setting of the UL E-DPCCH and E-DPDCH powers relative to DPCCH power.
The power of the E-DPCCH and the E-DPDCH(s) is set in relation to the DPCCH. For this purpose,
gain factors are used for scaling the UL channels relative to each other.
During the operation of the UL power control procedure the UE transmit power shall not exceed a
max. allowed value which is the lower out of the max. output power of the terminal power class and a
value which may be set by higher layer signalling.
UL power control shall be performed while the UE transmit power is below the max. allowed output
power.
For this course module, following 3GPP specifications were used:
• TS 25.211 V6, Physical channels & mapping of transport channels onto physical channels
• TS 25.212 V6, Multiplexing and channel coding (FDD) • TS 25.213 V6, Spreading and modulation (FDD) • TS 25.214 V6, Physical layer procedures (FDD)
• TS 25.215 V6, Physical layer; Measurements (FDD) • TS 25.301 V6, Radio interface protocol architecture
• TS 25.302 V6, Services provided by the physical layer
• TS 25.306 V5 – V8: UE Radio Access capabilities
References
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• TS 25.306 V5 – V8: UE Radio Access capabilities• TS 25.308 V6, High Speed Downlink Packet Access (HSDPA); Overall description• TS 25.309 V6, FDD Enhanced UL (HUSPA); Overall description
• TS 25.321 V6, Medium Access Control (MAC) protocol specification• TS 25.331 V6, Radio Resource Control (RRC) protocol specification
• TS 25.402 V6, Synchronization in UTRAN Stage 2
• TS 25.433 V6, UTRAN Iub interface Node B Application Part (NBAP) signalling
NSN WCDMA Product documentation