02 rn31552en10gla0 the physical layer

The Physical Layer3GRPLS (RN3155) – Module 2Part I: Channel MappingPart II: Transport Channel FormatsPart III: Cell SynchronisationPart III: Cell SynchronisationPart IV: Common Control Physical ChannelsPart V: Physical Random AccessPart VI: Dedicated Physical Channel DownlinkPart VII: Dedicated Physical Channel UplinkPart VIIII: HSDPA Physical Channel (HS-PDSCH)

1 © Nokia Siemens Networks RN31552EN10GLN0

Part VIIII: HSDPA Physical Channel (HS PDSCH) Part IX: HSUPA Physical Channels (E-DCH)

Objectives

At th d f thi d l ill b bl tAt 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 typesst d e e t code types• Name the main differences in uplink and downlink data organisation• 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• 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 HSDPAp y• Name the different HSDPA physical channel types• What kind of enhancements are implemented with HSUPA ?• Describe the E-DCH capabilities


Part I Channel Mapping


• In GSM we distinguish between logical and physical channels In UMTS there are three different

Radio Interface Channel Organisation• In GSM, we distinguish between logical and physical channels. In UMTS there are three different

types of channels: 1. Logical2. Transport 3 Physical3. 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• 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

to the next higher layer. • Consequently logical channels are in use between the mobile phone and the RNC• 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• 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.


Radio Interface Channel Organisation

• 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.e e a s o a o be ee e C a d e U , e p ys ca ed u s c a g g•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. y p y•A physical channel is defined by the UARFCN and the a spreading code in the FDD mode.


Radio Interface Channel Organisation (R99 model)

Logical Channelscontent is organised in separate channels, e.g.

System information, paging, user data, link managementy , p g g, , g

Transport ChannelsTransport 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):

Logical ChannelsThere are two types of logical channels (FDD mode):1) Control Channels (CCH):

• Broadcast Control Channel (BCCH)•System information is made available on this channelSystem 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)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. •PCCH is a downlink channel.

• Common Control Channel (CCCH)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 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.


Logical Channels

• 2) Traffic Channels (TCH):

• Dedicated Traffic Channel (DTCH)•User data has to be transferred between the UE and the networkUser 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.Dedicated user data can be transmitted point to multipoint to a group of UEs.


Logical Channels are mapped onto Transport Channels There are two types of Transport Channels

Transport Channels (TrCH)Logical Channels are mapped onto Transport Channels. There are two types of Transport Channels

(FDD mode): a) Common Transport Channels:

Broadcast Channel (BCH)• 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 changesabout 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 transmitted on this channel.

• High Speed Downlink Shared Channel (HS DSCH)• 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 theThis 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:

Transport Channels (TrCH)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 subscriberexclusively 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 anDCH is a transport channel that is subject to Node-B scheduling. The E-DCH is defined as an extension to DCH transmission.

• 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


• Note: DSCH (FDD), CPCH removed from R5 specification, 25.301 v5.6.0

Physical Channels are characterised by

Physical Channels (PhyCH)• Physical Channels are characterised by

•UARFCN,•scrambling code,channelisation code (optional)•channelisation code (optional),

•start and stop time, and•relative phase (in the uplink only, with relative phase being 0 or /2)

• Transport channels can be mapped to physical channels• 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 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


Logical Transport Physical

Channel Mapping DL (Network Point of View)

S-SCHP-SCH

LogicalChannels

TransportChannels

PhysicalChannels

P-CCPCHPCH

BCH

PCCH

BCCH CPICHS SCH

CCCHFACH

AICH

S-CCPCHPICH

CTCH

DCCH HS-

AICH

HS-PDSCHF-DPCH

DCH

DSCH

DPDCHDTCHE-AGCH

HS-SCCH


E-RGCHE-HICH

Logical Transport Physical

Channel Mapping UL (Network Point of View)Logical

ChannelsTransportChannels

PhysicalChannels

RACHRACHCCCH PRACH

DCCH

DCHDPDCHDPCCHDCH

DTCHDPCCH

E-DPCCHE-DPDCHE-DCH


E DPCCH

Channel configuration examples

AMR callThe data transferred during AMR call consists of• Speech data• Speech data• L3 signalling• L1 signallingUser data is transferred on DTCH logical channelUser data is transferred on DTCH logical channelReal time connection uses always DCH transport channelDCH transport channel is mapped on DPCH (DPDCH + DPCCH)

AMR + PS call (multirab)Additional stream of user data

NRT d t• NRT dataAlso configurations with HS-DSCH possible


NRT PS callDifferent configurations utilising DCH, FACH/RACH, HS-DSCH or HS-DSCH/E-DCH possible

Example – Channel configuration during callL i l T t Ph i lD t Logical

ChannelsTransportChannels

PhysicalChannels

Data

DCCH0-4RRC

signalling DCH1

DCH2 4

DPDCH

DTCH1 DPCCHSpeech

d t DCH2-4DTCH1 DPCCHdata

AMR speechDCH5DTCH2

NRTdata

AMR speech+

NRT data


AMR speech connection utilises multiple transport channelsRRC connection utilises multiple logical channels

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Part IITransport Channel Formats


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 unitunit. 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 Bl k b i lt l t itt d i T t Ch l i t t d t it tBlocks 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 (between the MAC layer and the physical layer) is referred to as Transport Format Set (TFS)(TFS).

Transport Blocks and Transport Block Sets are characterised by a set of attributes:• Transport Block SizeTransport 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


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

h th i

The Transfer of Transport Blocks

MAC Layer MAC Layer

UE Node B RNC

TFITBS

Transport Channel

TFITBS

PHY Layer PHY LayerFP/AAL2 FP/AAL2

PHY Layer PHY LayerL1 L1

TTI di


TTI radio frames in use

T t Bl k d T t Bl k S t h t i d b t f tt ib t ( ti d)

Transport Channel FormatsTransport 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. I th PHY l th TTI l id tifi th i t l i i d F ll i TTI i d•In the PHY layer, the TTI also identifies the interleaving period. Following TTI periods are

currently specified:- 2 ms (HS-DSCH)- 10 ms,

20- 20 ms,- 40 ms, and - 80 ms

• Error Protection SchemeWh d t i t itt d i i l li k it f l t f di t ti d th il•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:

l ti di ith t t 1/2 d 1/3•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).

Si e of CRC


• 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.

Transport Formats

DCH 2TB TB TB

TFCS

TB

TB TB TB

TTI TTI TTI

DCH 1TB TBTBS

TBTB

TB TBTBTFS

TTITTITTI

TB Transport Block TF Transport Format

TFTFC


p pTBS Transport Block Set TFS Transport Format Set

TFC Transport Format CombinationTFCS Transport Format Combination Set

The above description refers to a situation where the MAC layer hands the TBS to the PHY layer

Transport Channel Formats• 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• 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• 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).• The TF consists of two parts (FDD mode):

•Semi static part•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 forscheme, 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


dynamically. •The affected attributes are the Transport Block Size and the Transport Block Set Size.

Transport Formats

RRC Layer

Semi-Static Part

Transport Format

MAC Layer

ratio

n

Semi Static Part• TTI• Channel Coding• CRC size• Rate matching

conf

igurRate matching

Dynamic Part• Transport Block Size

T t Bl k S t Si

TrCHs

PHY Layer• Transport Block Set Size

Example: semi-static partdynamic part:p p y p- 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

Transport Channel Formats• 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 framedifferent 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-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).


Transport Format Ranges

Transport Transport coding types CRC

Semi-static PartDynamic Part

246 bits 246 bits 20 msBCH convolutional 1/2 16

Transport Block Size

Transport Block Set Size TTI coding types

and ratesCRCsize

1...5000 bitsgranularity: 1 bit




10 ms

10, 20, 40 & 80 msFACH

PCH convolutional 1/2

convolutional 1/2& 1/3; turbo 1/3

0, 8, 12, 16 & 24

0, 8, 12, 16 & 24





10 & 20ms

10, 20, 40 & 80 ms

RACH

DCH

convolutional 1/2

convolutional 1/2& 1/3; turbo 1/3

0, 8, 12, 16 & 24

0, 8, 12, 16 & 24g y g y ;


(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-DSCHy pThe 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 g g p y

(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 b HSDPA i i d d f f l i l h lbecause HSDPA is intended for transport of logical channelsThe 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 fullThe HS DSCH FP handles the data transport from the serving RNC to the controlling RNC (ifThe 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 BIn 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

The Transfer of Transport Blocks – HS-DSCH

MAC-d MAC-d

UE Node B RNC

MAC-d

MAC-hsMAC-hs

MAC d

MAC-d PDU

ON

AL

HS-DSCH

TFI

TBS

TFI

TBS

TFI

TBS

FP/HS-DSCH FP/HS-DSCH

MAC-c/sh

OPT

IO

Flow Control

PHY Layer PHY LayerL1

FP/AAL2

L1

FP/AAL2

HS-PDSCH

Control


HS PDSCH

Transport Format for HS-DSCHAttributes of the dynamic part are:Attributes of the dynamic part are:• Transport block size (same as Transport block set size)• Redundancy version/Constellation• Modulation schemeAttributes of the semi-static part are:• no semi-static attributes are defined• no semi-static attributes are defined.Attributes of the static part are:• Transmission time interval. The Transmission time interval is

ffixed to 2ms in FDD • Error protection scheme to apply:

– Type of error protection is turbo coding; coding rate is 1/3;ype o e o p o ec o s u bo cod g; cod g a e s /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)

Transport Formats – HS-DSCH

RRC Layer

Static Part

Transport Format

MAC-d Layer

ratio

n

• TTI• Channel Coding• CRC size

conf

igurDynamic Part

• Transport block size (same asTransport block set size)

• Redundancy version/Constellation HS-DSCH

MAC-hs Layer

PHY Layer

y• Modulation scheme

Example: static part dynamic part:p p y p- 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 TFRI4TFRI; Transport Format and Resource Indicator

Transport Format for HS-DSCH

Static PartDynamic Part

1 to 200 000 bits = Transport 2 msHS DSCH turbo 1/3 24

Transport Block Size

Transport Block Set Size TTI coding types

and ratesCRCsize

Static PartDynamic Part

QPSK,

Modulation

1 to 8

Redundancyversion

granularity: 8 bit p

Block Size 2 msHS-DSCH turbo 1/3 2416-QAM 1 to 8

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• 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 l di )


16QAM, very low coding)

Transport Channel Formats – E-DCHNew MAC entities appear as follows for each network element:New MAC entities appear as follows for each network element:UE

New 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.

N d BNode BNew MAC entity (MAC-e) is added in Node B which handles:

• 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:New 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


Disassembly: Remove MAC es header,extract MAC d PDU s & deliver to MAC d

The Transfer of Transport Blocks – E-DCH

UE Node B

S RNC modifications:UE modifications:

S-RNC

S-RNC modifications:MAC-es handling:• in-sequence delivery (reordering) • SHO data combining

Node B modifications:MAC-e handling:• H-ARQ retransmission

MAC-es & MAC-e:• H-ARQ retransmission • Scheduling & MAC-e multiplexing

E DCH TFC l ti

MAC dRLC

• Scheduling & MAC-e multiplexing• E-DCH TFC selection

MAC-dRLC

MAC-es / MAC-e

MAC-d

MAC-eE-DCH FP UuPHY

MAC-esMAC d

E-DCH FPIub


PHY PHY PHY PHY

Transport Format for E-DCH & UE capability classes

E- DCH max. min. 2 & 10 ms max. #. of max. # of ReferenceCategory E-DCH

CodesSF TTI E-DCH

supportE-DCH Bits* /

10 ms TTIE-DCH Bits* /

2 ms TTIcombination

Class1 1 4 10 ms only 7110 - 0.73 Mbps2 2 4 10 & 2 ms 14484 2798 1 46 Mbps2 2 4 10 & 2 ms 14484 2798 1.46 Mbps3 2 4 10 ms only 14484 - 1.46 Mbps4 2 2 10 & 2 ms 20000 5772 2.92 Mbps5 2 2 10 ms only 20000 - 2 0 Mbps5 2 2 10 ms only 20000 - 2.0 Mbps6 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)* Maximum No. of bits / E-DCH transport block

( g p ) y ( )

•There can only be 1 transport block in each TTI, →Transport block size = Transport Block Set Size•Coding types and rates: Turbo coding 1/3Note: When 4 codes are transmitted in parallel, two codes shall be transmitted with SF2 and two with SF4


p

Transport Formats – E-DCH

RRC Layer

Static Part• TTI (2ms 10ms)

Transport Format

MAC-d Layer

ratio

n

• TTI (2ms, 10ms)• Channel Coding• CRC size• Modulation (always BPSK)

conf

igurDynamic Part

• Transport block size (same asTransport block set size)

• Redundancy version/Constellation E-DCH

MAC-es/MAC-e Layer

PHY Layer

y

Example: static part dynamic part:p p y p- 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

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 intoThe 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

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


p y p p gclass of bits as well as the size of these class of bits for the various AMR codec modes.

Example: Transport Formats in AMR callDCH 1: AMR class A DCH 2: AMR class B DCH 3: AMR class C DCH 24: RRCDCH 1: AMR class A

bits

TTI = 20 ms

DCH 2: AMR class B bits

DCH 3: AMR class C bits

Convolutional codingTTI = 20 ms

Coding type: convolutionalTTI = 20 ms

Convolutional coding

DCH 24: RRC Connection

TTI = 40 msCoding type: convolutional

Coding rate: thirdCoding rate: third

CRC size: 12 bits CRC size: 0 bits CRC size: 0 bits

Coding rate: half Coding rate: third

CRC size: 16 bits

TBS size:1

TBS i 1 TBS size: 1 TBS size = 1TB size: 148 bits

TBS size:1TB size: 81 bits

TBS size: 1TBS size: 1TB size: 39 bits

(SID)

TB size: 103 bits TB size: 148 bitsTBS size: 1TB size: 60 bits

TBS size = 0(DTX)

TBS size = 0(DTX)

TBS size = 0(DTX)

TBS size = 0(DTX)


12.2 kbit/s3.7 kbit/s

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Part IIICell Synchronisation


Cell SynchronisationWhen a UE is switched on, it starts to monitor the radio interface to find a suitable cell to camp on but it h t d t i h th th i WCDMA ll bhas 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 isInitial 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 acquireDuring 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.

• 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 toDuring 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 identificationp g– 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 cellsPhase 1 P SCH

Acquire slot synchronisation

Phase 1 – P-SCH

Phase 2 – S-SCHAcquire frame synchronisationId tif th d

Ph 3 P CPICH

Identify the code group of the cell found in the first stepDetermine the exactPhase 3 – P-CPICH Determine the exact primary scrambling code used by the found cell


cellMeasure level & quality of the found cell

Cell synchronisation is achieved with the Synchronisation Channel (SCH) This channel divides up

Cell Synchronisation• 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•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•If the UE detects the PSC, it has performed TS and chip synchronisation.


(continued on the next text slide)

Synchronisation Channel (SCH)

2560 Chips 256 Chips

Primary Synchronisation Channel (P-SCH)

CP CPCP CP CP

Secondary Synchronisation Channel (S-SCH)

Cs1 Cs2 Cs15 Cs1

10 ms Frame

Slot 0 Slot 1 Slot 14 Slot 0


Cp = Primary Synchronisation CodeCs = Secondary Synchronisation Code

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 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.


bli

SSC Allocation for S-SCHscramblingcode group

group 00 1 1 2 8 9 10 15 8 10 16 2 7 15 7 16

slot number0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

15 15

15

g pgroup 01

group 02group 03

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

11 11 15

15 15

15

15

group 03

group 05

group 041 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

1 3 4 7 4 1 5 5 3 6 2 8 7 6 8

11 1115 155

group 62

group 639 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

15 15

15 15

11 15 5

I monitor the S-SCH


With the help of the SCH the UE was capable to perform chip TS and frame synchronisation

Common Pilot Channel (CPICH)• 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 usescrambling 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)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.

•A spreading code is the product of the cell‘s scrambling code and the channelisation code.•The channelisation code is fixed: C i e the UE knows the P CPICH‘s 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)•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.


10 ms Frame

Primary Common Pilot Channel (P-CPICH)



10 ms Frame

CP

P-CPICHP-CPICH

P-CPICH

Cell scrambling code? I get it with

trial & error!applied speading code =

cell‘s primary scrambling code Cch,256,0

P CPICH


• Phase reference• Measurement reference

The UE has to perform a set of L1 measurements some of them refer to the CPICH channel:

CPICH as Measurement Reference• 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 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• UTRA carrier RSSI.

• RSSI stands for Received Signal Strength Indicator. • 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• 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• 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


measurements are based on the GSM carrier RSSI• The wideband measurements are conducted on GSM BCCH carriers.

P-CPICH as Measurement Reference

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 E /N CPICH RSCPCPICH Ec/No = CPICH RSCPUTRA carrier RSSI

CPICH Ec/No CPICH RSCP GSM carrier RSSI

0: < -241: -23.52: -233: -22 5

-5: < -120-4: -119:0: -115

0: -1101: -1092: -1083: -22.5

...47: -0.548: 049: >0

0: -1151: -114:89: -2690: -25

:71: -3972: -3873: -37


Ec/No values in dB91: ≥ -25RSCP values in dBm RSSI values in dBm

The UE knows the cell‘s primary scrambling code

Primary Common Control Physical Channel (P-CCPCH)• 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 operatorevery 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• 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. • 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 avoidedhigh 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 )document.)

• There are also no power control (TPC) bits transmitted to the UE‘s.


10 ms Frame

Primary Common Control Physical Channel (P-CCPCH)



10 ms Frame

CP

P-CCPCHP-CCPCH

P-CCPCH

Finally, I get the cell system information P CCPCH

• channelisation code: Cch,256,1• no TPC, no pilot sequence• 27 kbps (due to off period)

i d i MIB d SIB


• organised in MIBs and SIBs

• WCEL: PtxPrimaryCPICH

NSN Parameters for Cell Search• 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 primary CPICH transmission power.•[-35 dB… 15 dB], step size 0.1 dB, default: -3 dB[ ], p ,

• 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] t i 0 1 dB d f lt 5 dB•[-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.


the Cell.•[0 ... 511]

Blank Page


Synchronisation Issues in UMTS 5 different UTRAN synchronisation issues were identified:

Synchronisation Issues and Node SynchronisationSynchronisation 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• 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.

4 Transport channel synchronisation is a L2 synchronisation (for the MAC layer)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• 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


5. Time alignment handling takes place between UTRAN and the CN for adequate timing of data transfer.

Node Synchronisation

SRNCNode B

RFN: RNC Frame

Number counter0..4095 frames

3112

3113

RFN128

129

BFN

T1DL offsetBFN:

N d B F

3114130

131

T2(T4 – T1) – (T3 – T2)= Round Trip Delay(RTD) determination

Node B Frame Number counter0..4095 frames

3115

3116

131

132T3

(RTD) determinationfor DCH services

3117

3118

133

134

(T4)

T1, T2, T3

UL offset


time

3118

time

135

range: 0 .. 40959.875 msresolution: 0.125 msuser plane defined on

DCH, FACH & DSCH

A timing reference is required by the Node Synchronisation:

Cell Synchronisation and Sectorised Cells• 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)• 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 tame 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• 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• The cell s timing is identified with the counter SFN = BFN + T_cell. • (Please note, that this description only applied for the FDD mode!)


1 TST cell

Cell Synchronization and Sectorised Cells

cell1

1 TSSCH

SCH

SCH

T_cell1

T_cell2

cell2SCH

SC

SCH

SC

SCH

cell3 CH

CH

SFN = BFN + T_cell1T_cell3

BFN

SFN = BFN + T_cell2

SFN = BFN + T_cell3 cell1

SFN: Cell System Frame Number

cell3 cell2


Node B with threesectorised cells

SFN: Cell System Frame Numberrange: 0..4095 frames

T_cell: n 256 chips, n = 0..9

NSN Parameters for Sectorised Cells

• 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.


Part IVCommon Control Physical Channelsy


Secondary Common Control Physical Channel (S-CCPCH)

• The S-CCPCH can be used to transmit the transport channels

• Forward Access Channel (FACH) and Paging Channel (PCH)

( )

• 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• 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.

• 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 4S-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• Please note, that the UE must support both S-CCPCHs with and without TFCI.


Secondary Common Control Physical Channel(S-CCPCH)


10 ms Frame

( )


TFCI(optional) Data Pilot bits

S CCPCH• carries PCH and FACH• Multiplexing of PCH and FACH on one S-CCPCH• 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


(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 channelsIn 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 l SCCPCH i d i ll it ill FACH• 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.

• 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


carry PCH only and the second SCCPCH will carry FACH-u and FACH-c.


For SABFor SAB

DL common Channel configuration in case of three SCCPCH

Logical channel DTCH DCCH

CCCH

BCCH

CTCH PCCH

For SABFor SAB

Transport FACH- PCHFACH-FACH- FACH-channel u sc c

Physical channel

SCCPCH connecte

d

SCCPCH idle

SCCPCH page

SF 64 SF 128 SF 256



FACH-u FACH-c(connected)

FACH-c(idle)

0: 0x168 bitsFACH-s PCH

TFS0: 0x360 bits

(0 kbit/s)1: 1x360 bits

1: 1x168 bits

0: 0x168 bits(0 kbit/s)

1: 1x168 bits (16.8 kbit/s)


1: 1x168 bits


1: 1x168 bits


1: 1x80 bits

TTI

(36 kbit/s)

10 ms

2: 2x168 bits(33.6 kbit/s)

10 ms

(16.8 kbit/s)

10 ms

(16.8 kbit/s)

10 ms

(8 kbit/s)

10 msTTI

Channelcoding

10 ms

TC 1/3

10 ms

CC 1/2

10 ms

CC 1/3

10 ms

CC 1/3

10 ms

CC 1/2coding

CRC 16 bit 16 bit 16 bit 16 bit 16 bit



FACH-u

PCHFACH-s

FACH-c

FACH-c

SCCPCH connecte

SCCPCH idle

SCCPCH pageconnecte

didle page

TFCS0 0 kbit/s

TFCS00 0+0 = 0 kbit/s

TFCS00 0+0 = 0 kbit/s

1 8 kbit/s010210

0+16.8 = 16.8 kbit/s0+33.6 = 33.6 kbit/s

36+0 = 36 kbit/s

1001

16.8+0 = 16.8 kbit/s0+16.8 = 16.8 kbit/s

Maximum transport channel throughput = 36

Maximum transport channel

throughput = 8 kbit/s

Maximum transport channel th h t 16 8


channel throughput = 36 kbit/s

kbit/sthroughput = 16.8 kbit/s

The network has detected that there is data to be transmitted to the UE

S-CCPCH and the Paging Process• 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 messageschannel – 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• 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 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• The UE determines the S-CCPCH, where it is paged, by its IMSI and the number of PCH/S-CCPCHscarrying 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• 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 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.

UTRAN

S-CCPCH and the Paging ProcessUTRAN

P-CCPCH/BCCH (SIB 5)

commonchannel

definition,

Node B,

includinga lists of

UE

I d f S CCPCH

RNC

S-CCPCH carrying one PCH

Index of S-CCPCHs

0



1

K-1 S CCPCH carrying one PCH

S-CCPCH without PCH

K 1

UE‘s paging channel:I d IMSI d K


S-CCPCH without PCHIndex = IMSI mod Ke.g. if IMSI mod K = 1

„my pagingchannel“

Paging and Discontinuous Reception (FDD mode)

2k framesk = 3..9

Duration:Example withtwo CN domains

CN domain specificDRX cycle lengths

(option)

RRC connectedmode

UE

CS Domain PS Domain

k1 k2

UTRAN

k3stores

UEUpdate:a) derived by NAS

negotiationb) otherwise:

Update:locally with

system info

Update:a) derived by NAS

negotiationb) otherwise:b) otherwise:

system infob) otherwise:

system info

if RRC idle:UE DRX cycle length is

if RRC connected:UE DRX cycle length is


UE DRX cycle length ismin (k1, k2)

UE DRX cycle length ismin (k3, kdomain with no Iu-signalling connection)

• Paging Indicator Channel (PICH)

The Paging Process• 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 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• 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 number of paging indicator Np can be 18, 36, 72, and 144, and is set by the operator as part of the network planning processof 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 framepaging 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.

S-CCPCH and its associated PICHS-CCPCH frame,

associated with PICH framePICH

= 7680

S-CCPCH

PICH frame 7680chips

b b bbb b

for paging indication no transmission

b287 b288 b299b286b0 b1

# of pagingindicators per frameindicators per frame

(Np)1836


72144

Paging Indicator and Paging Occasion (FDD mode)

my pagingindicator (PI)

number of paging indicators18, 36, 72, 144

PI = ( IMSI div 8192) mod Np

18, 36, 72, 144

UE DRX index

When willI get paged? b f S CCPCH ith PCH

Paging Occasion = (IMSI div K) mod (DRX cycle length)

I get paged? number of S-CCPCH with PCH

FDDPaging Occasion = (IMSI div K) mod (DRX cycle length) + n * DRX cycle length

UE

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 l l th (k)• DRX cycle length (k)• Np

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)

N


• Np

Paging group size affects on how often UE has to decode paging

Example – Paging instant and group calculation

K (Number of S-CCPCH with PCH) 1k (DRX length) 6DRX cycle length 64 framesDRX cycle length 64 framesIMSI 358506452377Which S-CCPCH #? 0IMSI div K 358506452377When (Paging occation SFN)? 25 + n*DRX cycle lengthWhen (Paging occation, SFN)? 25 + n*DRX cycle length

Np 72 PIs/frameDRX Index 43762994My PI? 26

Number of subsc. In LA/RA 100000u be o subsc / 100000Number of subsc. Per S-CCPCH 100000Number of subsc. Paging occation (PICH frame) 1562.5Number of subsc Per PI 21 7


Number of subsc. Per PI 21.7

NSN Parameters for S-CCPCH and Paging

• 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•Range: [-35 dB … 15 dB] , step size 0.1 dB, default: 0 dB

• WCEL: PtxSCCPCH2 (carries PCH only)•This is the transmission power of the 2nd S-CCPCH channel, the value is relative to primary CPICH transmission powerCPICH 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•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


•Range: [-35 dB … 15 dB] , step size 0.1 dB, default: - 2 dB

WCEL: PtxPICH

NSN Parameters for S-CCPCH and Paging• 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•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•Repetition of PICH bits•[18, 36, 72, 144] with relative power [-10, -10, -8, -5] dB

• RNC: CNDRXLength•The DRX cycle length used for CN domain to count paging occasions for discontinuous•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•[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


•[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

FACH and S-CCPCH• 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• This common downlink channel is used without (fast) closed loop power control and is available all over the cell.

• 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• 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


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

FACH and S-CCPCH• 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 FACHspecified 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 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. • 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• 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


FACH and S-CCPCH

FACH Data Frame

CFN TFI TB TB

Transmit Power LevelPower offsets for TFCI and pilot bits are

defined during

Node B RNC

IubUu

defined during channel setup

Node B

max transmit

UE

max. transmitpower for S-CCPCH

0 25 5 dB

Transmit Power Level Pilot bits

0..25.5 dB,step size 0.1

PO1 PO3


Transmit Power LevelTFCI

(optional) DataPilot bits

NSN Parameters for S-CCPCH Power Setting

• 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•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 dBp [ ]; p ;


Part VPhysical Random Access


In the random access initiated by the UE two physical channels are involved:

Random Access• 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

uplinkuplink. • 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 accesstelling 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.

• 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 cellsinterference 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)• 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.


Random Access – the Working Principle

Node BUENo response

by theNode B

NNo responseby theNode B

I j d dI just detecteda PRACH preamble

OLA!


The properties of the PRACH are broadcasted (SIB5 SIB6)

Random Access Timing• 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• 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, p-a chips later

on. • If there is no response the UE sends the next preamble chips after the first one• If there is no response, the UE sends the next preamble p-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• 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


preamble-to-message distance is 4 access slots, and the preamble-to-acquisition indication is 5 timeslots.

SFN d 2 0 SFN d 2 0SFN d 2 1

Random Access TimingSFN 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 643slots 7

5120chips

UE point of view (distances depend on AICH_Transmission_Timing )UE point of view

AICHAcquisitionIndication

4096 chips

access slots

preamble-to-AIdistance p-a

AS # i

Preamble

5120 chips

Preamble

AS # i

PRACHaccess slots

Messagepart


5120 chips AS # i

preamble-to-preambledistance p-p

preamble-to-messagedistance p-m

RACH Sub channels

RACH Sub-channels and Access Service Classes• 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 (see preceding slides)• The offset is given by p-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• 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)

• 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 signaturesby 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 informationinformation.

• 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


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.

PRACH Sub-channels and Access Service Classes (ASC)

SFN mod 8 of thecorresponding

P-CCPCH frame

0 0 1 2 3 4 5 6 7

Sub-channel number

1 2 3 4 5 6 7 8 9 10 110

0

1

2

0

12

1

13

2

14

3

0

4

1

5

2

6

3

7

4

8

5

9

6

10

7

11

3

4

5

9

6

10

7

11

8

12

9

13

10

14

11

0

12

1

13

2

14

3 4

8

5

5

6

7

3 4

8

5

9

6

10

7

11

8

12

9

13

10

14

11

0

12

1

13

2

14

( it d f TS 25 214 V5 11 0 h 6 1 1)(cited from TS 25.214 V5.11.0, chap. 6.1.1)

BCCH (SIB 5, SIB 7)


Node BUE• ASCs and their PRACH access resources + signatures,• AC mapping into ASCs

• In the PRACH preamble a random preamble code is used

PRACH Preamble• In the PRACH preamble, a random preamble code is used.

• This code is composed from a• Preamble Scrambling Code and a• Preamble Signature• 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• 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 sequences.

• The PRACH preamble scrambling codes are organised in 512 groups with each group holding 16• 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 accessbelonging 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)


UTRANBCCH

PRACH PreambleUTRANBCCH

available signatures forNode BUE RNC• available signatures for

random access• available preamble

scrambling codes• available spreading

factor• available sub-channels• etc.

Pi Pi Pi Pi

PRACH Preamble Scrambling Code

Preamble Signature

16 chip

256 repetitions• 512 groups à 16 preamble

scrambling codes• Cell‘s primary scrambling codes

i t d ith bl


Preamble Signature(16 different versions)

associated with preamble scrambling code group

Th l th f th PRACH t b 10 20

PRACH Message Part• 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

t itt d ith di f t 256 128 64 32transmitted 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 timeslot2 bits in the control data carry TFCI bits per timeslot.

• 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 preamblein 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• 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.


10 ms Frame

PRACH Message Part


10 ms Frame

L1 control data 8 Pilot bits (sequence depends on slot number) 2 TFCI bits

RACH data data

• SF = 256, 128, 64, or 32• channelisation code:

• SF = 256• channelisation code:

CCH 256 16*k+15, with

• CCH,SF,SF*k/16, withk = signature number

S bli d


CH,256,16 k+15,k = signature number Scrambling code =

PRACH preamble scrambling code

• When it comes to the random access two questions have to be asked:

PRACH Power Setting• 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• 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“ levelInterference level.• The UE also determines the received CPICH RSCP (variable CPICH_RSCP).• Then, it calculates the power for the first preamble:

• Preamble_Initial_Power = Primary CPICH TX power – CPICH_RSCP + UL interference + Required received C/I+ 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 UEsto 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 ß is used for the PRACH control part


The gain factor ßc is used for the PRACH control part.

Preamble_Initial_Power =Primary CPICH TX power– CPICH_RSCP

PRACH Power Setting+ UL interference + Required received C/I*

1st preamble: power setting

estimated receive levelConstant Value

attenuation in the DL

*NSN: PRACHRequiredReceivedCI

UL interferenceat Node B

Pp p1..8 dB

-5..10 dB

Pre-amble

Controlpart

Pre-amble

Pre-amble

Pp-p

Pp-p

Pp-m


amble p

# of preambles: 1..64 # of preamble cycles: 1..32

Th AICH i d t i di t t UE th t th i PRACH bl i d d th t th N d B i

Acquisition Indication Channel (AICH)• 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.

Th AICH i t itt d i 15 l t h l ti 5120 hi• 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 AI b• 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, 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 31pattern 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• 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


• 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.

20 ms Frame

Acquisition Indication Channel (AICH)

Access Slot 0 Access Slot 1 Access Slot 2 Access Slot 14

20 ms Frame

a0 a1 a2 a29 a30 a31

15AICH signature pattern (fixed)

15

0js,sj bAIa

s

Acquisition IndicatorAcquisition 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


set of available signatures

• In RAN1 Node B L1 shall be able to simultaneously scan 12 RACH sub channels with 4 signatures

NSN Parameters Related to the PRACH and AICH• 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

AICH channel.• This parameter is part of SIB 5• 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.g• [-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


• [1 ... 64]; step 1; default 8.

• WCEL: RACH tx Max

NSN Parameters Related to the PRACH and AICH• 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.g p• [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 SIB5/6part of SIB5/6.• [0 ... 15]; default 0.

• WCEL: AllowedPreambleSignatures• The preamble part in a PRACH channel carries one of 16 different orthogonal complex signatures.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: AllowedRACHSubChannelsA RACH b h l d fi b t f th t t l t f l t (12 bit fi ld)• A RACH sub-channel defines a sub-set of the total set of access slots (12 bit field).

• [0 ... 4095]; default 4095.


• WCEL: PtxAICH

NSN Parameters Related to the PRACH and AICH• 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• 0 ( Delay is 0 AS), 1 ( Delay is 1 AS) ;default 0.

• 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.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 T NB01• WCEL: RACH_Tx_NB01max• [0 ... 50]; default: 50.


Summary of RACH procedure1 Decode from BCCH

(Adopted from TS 25.214)

1- Decode from BCCH• Available RACH spreading factors• RACH scrambling code number• UE Access Service Class (ASC) infoUE Access Service Class (ASC) info• Signatures and sub-channels for each ASC• Power step, RACH C/I requirement = “Constant”, BS interference level2 – Calculate initial preamble power3 – Calculate available access slots in the next full access slot set and select randomly one of those4 – Select randomly one of the available signatures5 Transmit preamble in the selected access slot with selected signature5 – Transmit preamble in the selected access slot with selected signature6 – Monitor AICH• IF no AICH

– Increase the preamble powerp p– Select next available access slot & Go to 3

• IF negative AICH or max. number of preambles exceeded– Exit RACH procedureIF iti AICH


• IF positive AICH– Transmit RACH message with same scrambling code and channelisation code related to

signature

Part VIDedicated Physical Channel Downlinky


• The downlink DPCH is used to transmit the DCH data

Downlink Dedicated Physical Channel (DPCH)• 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 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• 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.• 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• 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• 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.

Superframe = 720 ms

Downlink Dedicated Physical Channel (DPCH)

Radio Frame0

Radio Frame1

Radio Frame2

Radio Frame71

Superframe = 720 ms

10 ms Frame


TPCbits Pilot bits

TFCIbits

(optional)Data 2 bitsData 1 bits

DPDCHDPDCH DPCCH DPCCH• 17 different slot formats

C d d l t


• Compressed mode slot format for changed SF & changed puncturing

Following features are supported in the downlink:

Downlink Dedicated Physical Channel (DPCH)• 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 transmissionincluding 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• 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.• Then, on all downlink DPCHs, the same spreading factor is used.• Also the downlink transmission of the DPCHs takes place synchronous• 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• 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).


Downlink Dedicated Physical Channel (DPCH)

maximum bit rate discontinuous transmission with lower bit rate

TS TS TS TS TS

Multicode usage:

DPCCH

Multicode usage:

DPCH 1

TS TS TS

DPCH 2

TS TS TS

DPCH 2


DPCH 3

Power offsets for the optional TFCI TPC and pilot bits have to be specified during the radio link setup

Power Offsets for the DPCH• 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 sizestep size.

• PO3: defines the power offset for the pilot bits; it ranges between 0 and 6 dB with a 0.25 step size.

• In the same message the TFCS DL DPCH slot format multiplexing position FDD TPC DL• 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.


• Power offsets• TFCS• DL DPCH slot format

Power Offsets for the DPCHDL DPCH slot format

• FDD DL TPC step size

• ...

DCH Data Frame

NBAP: RADIO LINK SETUP REQUEST

Node B RNC

DCH Data Frame

IubUu

UEP0x: 0..6 dB

step size: 0 25 dB UE

PO1TPC Pilot bitsTFCI PO3PO2

step size: 0.25 dB


bits Pilot bitsbits(optional) Data 2 bitsData 1 bits

• Inner loop power control is also often called (fast) closed loop power control

Downlink Inner Loop Power ControlInner 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)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 byThe 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 step size.

• There are two downlink inner loop power control modes: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.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.


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.

Downlink Inner Loop Power Control

TPC

DPC_MODE = 0 DPC_MODE = 1

two modescell

unique TPC commandper TS

same TPC over 3 TS,then new command

TPCest per1 TS / 3 TS



UTRAN behaviour P

P Pb l

P(k) = P(k - 1) + PTPC(k) + Pbal(k),current

DL powerpower

adjustmentnew

DL powerCorrection termfor RL balancing

toward CPICH

PTPCPbal

toward CPICH

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) P (k) P (k)

P

PTPCPbal

P(k) = P(k - 1) + PTPC(k) + Pbal(k),current

DL powerpower

adjustmentnew

DL powerCorrection termfor RL balancing

toward CPICH

time

IFLimited Power Increase Used = 'used'

TPC (k) 1 > P (k) 0PTPC

Power_Raise_Limit

TPCest (k) = 1 => PTPC(k) = 0

otherwise assee preceding

slideLimit


DL_Power_Averaging_Window_Size

K-1 K time

The P CCPCH is the timing reference for all physical channels

Timing Relationship between Physical Channels• 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 S-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• The timing offset may be different for each S-CCPCH, but it is always a multiple of 256 chips, i.e. S-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 PICH = 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 DPCH,k is – similar to the S-CCPCH – a multiple of 256, i.e.

DPCH,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• 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• 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


• The AICH access slot number 0 starts simultaneously with the P-CCPCH frame, whose SFN modulo 2 is zero.

SFN d 2 0 SFN d 2 1

Timing Relationship between Physical ChannelsSFN mod 2 = 0 SFN mod 2 = 1

P-CCPCH

AICH access0 1 1282 1175 964 13103 14 0

SCH

slots 0 1 1282 1175 964 13103 14 0

0..38144 (step size 256)

nth S-CCPCH S-CCPCH,n

(s ep s e 56)

kth S-DPCH DPCH,k

0 38144


0..38144 (step size 256)

A major problem arises when the UE is connected to several cells simultaneously

Radio Interface Synchronisation• 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 = 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 sendsend.

• 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 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 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 DPCHDL 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


• The S-RNC informs also the UE about the Frame Offset.

Tm =

Radio Interface SynchronisationTm =timing differencerange: 0..38399Res.: 1 chip

Relative timingbetween DL DPCHand P-CCPCHrange: 0..38144res : 256 chips

SRNC

res.: 256 chips

Offsetbetween DL DPCHand P CCPCH

T0 =1024hi

and P-CCPCHrange: 0..38399res.: 1 chip

chips

(Frame Offset, Chip Offset)

UEcell1

cell2t t


cell1 = targetcell for HO

(Frame Offset) (TM)

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Part VIIDedicated Physical Channel Uplinky p


The uplink dedicated physical channel transmission we identify two types of physical channels:

Uplink Dedicated Physical Channels• 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• 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)and site selection diversity transmission (SSDT)• 6 different slot formats were specified for the DPCCH. Variations exist for the compressed

mode. • Dedicated Physical Data Channel (DPDCH),

• Which is used for user data transfer• 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• 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


timeslot length is 2560 chips.

Superframe = 720 ms

Uplink Dedicated Physical Channels

Radio Frame0

Radio Frame1

Radio Frame2

Radio Frame71

Superframe = 720 ms

Sl t 0 Slot 1 Sl t 2 Sl t 14

10 ms Frame


Data 1 bitsDPDCH

TPCbitsPilot bits TFCI bits

(optional)

Data 1 bitsDPDCH

DPCCH FBI bits

• 6 different slot formats• Compressed mode slot

format for changed SF & changed puncturing Feedback Indicator for


• 7 different slot formats

g p g 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

Discontinuous Transmission and Power Offsets• 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• 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 TTIDPDCH 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.

• 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• 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: c is the gain factor for the DPCCH while is the gain factor for the DPDCH The gain factors may varygain factor for the DPCCH, while d 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 d/c.

• The gain factor is calculated based on reference TFCs (The details for gain factor calculation


• 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.)

Discontinuous Transmission and Power Offsets

DPDCHDPDCH

DPCCH

DPDCH

DPCCH

DPDCH

DPCCH

TTL TTL TTLTTL TTL TTL

UL DPDCH/DPCH Power Difference:two methods to determine the gain factors:• signalled for each TFCs• calculation based on reference TFCs

DPDCH

=d

=Nominal Power Relation Aj

calculation based on reference TFCs


DPCCH=

c

=Nominal Power Relation Aj

The subscriber is mobile The distance of the UE from a Node B is changing over time

UL Inner Loop Power Control• 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• 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 controlclosed loop power control.

• 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 TheseSIR 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 UEprotocol 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: = TPC cmd stands for the


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)

UL Inner Loop Power Control

SIRest

SIRtarget

timetime

TPC TPC dTPC_cmd

in FDD mode:1500 times per second


P C t l Al ith 1

UL Inner Loop Power Control • 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

th i it d it b 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

i t t tiinterpretation.

• Power Control Algorithm 2• was specified to allow smaller step sizes in the power control in comparison to PCA1.

Thi i i l d hi h d i t• 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.F h di t th TPC d i t il d t i d Thi b i th t• 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.

UL Inner Loop Power Control

algorithms for processing power control commands TPC_cmd


PCA1

TPC cmd for each TS

PCA2

TPC cmd for 5th TSTPC_cmd for each TSTPC_cmd values: +1, -1step size TPC: 1dB or 2dB

TPC_cmd for 5th TSTPC_cmd values: +1, 0, -1step size TPC: 1dB

UL DPCCH power adjustment: DPCCH = TPC TPC_cmd

PCA2 PCA1 PCA2

km/h0 3 80


km/h0 3 80Rayleigh fading can be compensated

Power Control Algorithm 1

Example: reliable transmission

Cell 3

TPC3 = 1

TPC_cmd = -1 (D )(Down)

TPC1 = 1 TPC3 = 0

Cell 1Cell 2


Cell 2


Power Control Algorithm 2 (part 1)

TPC_temp00001

• if all TPC-values = 1 TPC_temp = +1

• if all TPC-values = 0 TPC temp = 11

000

TPC_temp = -1• otherwise TPC_temp = 0

00000000


-1Note that up to NSN RU 10 PCA 2 is not supported.

Power Control Algorithm 2 (part 2)

Example:

TPC_temp1 TPC_temp2 TPC_temp3

N

TPC temp1N = 3

i

iN 1TPC_temp

-1 -0.5 0 0.5 1

Note that up to RU 10 PCA 2 is not supported.


TPC_cmd = -1 10

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UTRAN h ll t t th t i i f th d li k DPCCH d t t th t i i f DPDCH

Initial Uplink DCH Transmission• 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 f li k DPCCH h b i ll d t UEfor 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 ith t hi h i iti l t i iwith 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

multiplexed.The number of radio frames is set by the higher layers (RRC resp the operator)• 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?• 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


and –6 dB (step size 2 dB). CPICH_RSCP is the received signal code power on the P-CPICH, measured by the UE.

DPCCH only DPCCH & DPDCH

Initial Uplink DCH Transmission

reception


receptionat UE

trans-mission

at UE


0 to 7 frames for power control preamble

DL Synch & Activation time

0 to 7 frames ofSRB delay



DPCCH_Initial_power = – CPICH_RSCP + DPCCH_Power_offset

Part VIIIHSDPA Physical Channels


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 ratestransport 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 periods, the resources are available to other users. pHSDPA 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 carriera 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 ‘i t ti ’ d ‘b k d’ Q lit f S i (Q S) l t d di d b 3GPP


‘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.

HSDPA – General principle

• Channel quality information

L1 Feedback

•Shared DL data channel

• Error correction Ack/Nack

L1 FeedbackData

•Fast link adaptation, scheduling and L-1 error correction done in BTS

Terminal 1 (UE)L1 Feedback

Data

in BTS

•1 – 15 codes (SF=16)

•QPSK or 16QAM Datamodulation

•User may be time and/or code


Terminal 2multiplexed.

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 ) g , ( ),

than by the radio network controller (RNC).• 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 qualityperformed 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

HSDPA

Fast LinkAdaptation Fast

H-ARQ

FastPacket

scheduling

Fast Link Adaptation: Modulation and Coding is adapted every 2 ms (1 TTI) during the session to the radio link

Fast Packet Scheduling:The NodeB is responsible for resource allocation to HSDPA packet data users. Resource allocation is performed every TTI

Fast H-ARQ: Data are retransmitted by BTS. UE

acknowledges (L1) and performs quality. This ensures highest possible data rates to end-users.

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.

g ( ) psoft combination of initial

transmission & retransmissions. This provides reliable, fast and

efficient data transmission.p y


Interaction of MAC-hs and Physical Layer

HSDPA Peak Bit Rates

Coding rate Coding rate 5 codes 10 codes 15 codes

QPSK

1/4

2/4

600 kbps 1.2 Mbps 1.8 Mbps

1.2 Mbps 2.4 Mbps 3.6 Mbps

3/4 1.8 Mbps 3.6 Mbps 5.4 Mbps

2/4 2.4 Mbps 4.8 Mbps 7.2 Mbps

16QAM 3/4

4/4

3.6 Mbps 7.2 Mbps 10.7 Mbps

4.8 Mbps 9.6 Mbps 14.4 Mbpsp p p

RAS06 allows allocation of up to 15 Codes; 14.4 Mbps total;up to 3 simultaneous user; max 10 Mbps/user


up to 3 simultaneous user; max. 10 Mbps/userRU10 allows max. 14.4 Mbps/user

DL CHANNELSPhysical Channels for One HSDPA UE

BTS

HS-PDSCH: High-Speed Physical Downlink Shared Channel

HS SCCH: High Speed SharedBTS

CH

CHH

HS-SCCH: High-Speed SharedControl Channel

F-DPCH: Fractional Dedicated Ph i l Ch l

Rel99

ciat

ed D

PC

ciat

ed D

PC

15 x

HS

-P

DS

CH

x H

S-S

CC

H

S-D

PC

CH Physical Channel

Associated DPCH, DedicatedPhysical Channel.

DCH

-DP

CH

Ass

oc

Ass

oc1-1 P

1-4

x

HS

UL CHANNELSAssociated DPCH, Dedicated

Ph i l Ch l

F

UEPhysical Channel

HS-DPCCH: High-Speed Dedicated Physical Control Ch l


Channel

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• 1-15 code channels.• QPSK or 16QAM modulation.• Divided into 2ms TTIs• Fixed SF16• Fixed SF16• Doesn’t have power control

HS SCCH: High Speed Shared Control Channel

Field Number of uncoded bits

Channelisation code set information 7 bits

Modulation scheme information 1 bitHS-SCCH: High-Speed Shared Control Channel• Includes information to tell the UE how to

decode the next HS-PDSCH frame• Fixed SF128

Transport block size information 6 bits

Hybrid ARQ process information 3 bits

Redundancy and constellation version 3 bitsFixed SF128• Shares downlink power with the HS-PDSCH• More than one HS-SCCH required when code

multiplexing is used

New data indicator 1 bit

UE identity 16 bits


p g• Power can be controlled by node B

(proprietary algorithms)

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 DPCCHp• 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).• Introduced in Rel. 6 for situations where only packet services are active in the DL others

than the Signalling Radio Bearer SRBthan 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 Channelg y• 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

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.

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

multiplexing.

Picture presents U U U U U U U HS PDSCH #2

UE1

UE1

UE1

UE2

UE2

UE2

UE3

UE3

UE3

UE1 HS-PDSCH #1

Subframe #1 Subframe #2 Subframe #3 Subframe #4 Subframe #5

User data on

time multiplexing• One HS-SCCH

required per cell

E1 E1 E1 E2 E2 E2 E1 HS-PDSCH #2

UE1

UE1

UE1

UE1 HS-PDSCH #3

User data on HS-DSCH

2 slots

required per cell• Codes can be

allocated only to one user at a time

UE1

UE1

UE1

UE2

UE2

UE2

UE3

UE3

UE3

UE1 HS-SCCH

one user at a time

UE #2

UE #3 L1 feedback HS-DPCCH

3 slots

L1 feedback HS-DPCCH


UE #1

UE #2 L1 feedback HS-DPCCH

L1 feedback HS-DPCCH

Code MultiplexingWith Code Multiplexing multipleWith Code Multiplexing, multiple UEs can be scheduled during one TTI.Multiple HS SCCH channels HS PDSCH

HS-PDSCH

HS-SCCHHS-SCCH

Multiple HS-SCCH channels• One for each simultaneously

receiving UE.HS SCCH h d

HS-PDSCHHS-PDSCHHS-PDSCHHS-PDSCHHS-PDSCH• HS-SCCH power overhead.

HS-PDSCH codes divided for different transport blocks.

HS-PDSCHHS-PDSCHHS-PDSCHHS-PDSCH

HS-PDSCH

• Multiple simultaneous transport blocks to one UE not possible.

Codes can be allocated to multiple cat 6cat 6 cat 6 cat 6cat 8

users at same time• Important when cell supports more

codes than UEs do. For example 10 d ll UE 6


codes per cell, UE category 6.

Timing of HSDPA Physical Channels

HS-SCCH

P-CCPCH

HS-PDSCH

2 slots 3 slots

TTX_diff Tprop + 7.5 slots

Unit = chips2560 chips = slot3 slots = (HSDPA) subframe

Node B

_

Downlink DPCH

p p15 slots = frame

UE

Uplink DPCH

Tprop + 0.4 slots (1024 chips)

HS-DPCCH

Uplink DPCHm x 0.1 slots = TTX_diff + 10.1 slots


Downlink Code Allocation example

SF = 1

SF = 8

SF = 4

SF = 2

SF = 128

SF = 64

SF = 32

SF = 16

Codes for 5HS-PDSCH's

SF = 128

SF = 256

Codes for the cell common channels

Code for oneHS-SCCH

•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 yscheme 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 3/4between 1/4 and 3/4.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 , g(lower coding rate).


Fast Link Adaptation in HSDPA

121416

No [d

B]

C/I received by UE

C/I varies with fading

468

10

aneo

us E

sN

0 20 40 60 80 100 120 140 160-2024

Inst

anta

0 20 40 60 80 100 120 140 160Time [number of TTIs]

16QAM2/4

16QAM3/4 Link adaptation

mode

BTS adjusts link adaptation mode with a few ms delay based on channel quality reports from

QPSK2/4

QPSK3/4

16QAM2/4 mode on channel quality reports from the UE


QPSK1/4

Link adaptation: Modulation

1011 1001 0001 0011

QQ

10001010 00100000

I

10 00

I0100 0110

01110101

1110 1100

11011111

0111

QPSK2 bits / symbol =

16QAM4 bits / symbol =y

480 kbit/s/HS-PDSCH =max. 7.2 Mbit/s

y960 kbit/s/HS-PDSCH =

max. 14.4 Mbit/s


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 p gconfiguration:– 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.gUEs of Categories 11 and 12 support QPSK only.3GPP Rel. 7 introduces Categories 13 – 18 for 64QAM or MIMO support3GPP R l 8 i d C i 19 & 20 f 64QAM & MIMO


3GPP Rel. 8 introduces Categories 19 & 20 for 64QAM & MIMO supportSee 3GPP TS25.306

UE HS-DSCH physical layer categoriesHS DSCH M i Mi i M i b f ARQ T T l

TS 25.306

HS-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

QPSKor

16QAMCategory 5

5 1 7298 Soft 57600

Category 6

5 1 7298 IR 67200

C t 10 1 14411 S ft 115200Category 7

10 1 14411 Soft 115200

Category 8

10 1 14411 IR 134400

Category 15 1 20251 Soft 172800

QPSKonly


Category 9

15 1 20251 Soft 172800

Category 10

15 1 27952 IR 172800

Category 5 2 3630 Soft 14400

• 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 singletabulated 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 lowercorresponding to the reported or lower CQI value could be received in a 3-slot reference period ending 1 slot before the start of the first slot in which the reported pCQI value is transmitted and for which the transport block error probability would not exceed 0.1.”TS 25 214TS 25.214


Channel quality indication (CQI) from HSDPA UEUE reports the channel conditions

BTS

to the base station via the uplink channel CQI field on the HS-DPCCH

BTS

CH

CHH Rel99

UE estimates which AMC format CQI (0…30) will provide

ciat

ed D

PC

ciat

ed D

PC

15 x

HS

-P

DS

CH

x H

S-S

CC

H

S-D

PC

CH DCH

( ) ptransport block error probability < 10 % on HS-DSCH

Ass

ocA

ssoc1-

1 P

1-4

x

HS

WBTS uses CQI as one input when defining the AMC format used on the HS-PDSCH

UE • Transport Block Size• Number of HS-PDSCH (codes)

M d l ti


• 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: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 blocksThe 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 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 Th h ll b i it h dli MAC d PDU i th MAC h Th MAC h iSAP. 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


Scheduling/Priority Handling• HARQ• TFRI selection

MAC-hs

UE: RNC:

HS-DSCHHS-DPCCH


HS-SCCH

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/shMAC-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 ( g )MAC-d and MAC-hs (Configuration without MAC-c/sh) taking the 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 congestioncongestion.• 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 dataFurther 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 TSN is unique to each priority class within a HS-DSCH and isTSN 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

t i i i i ti i th RLC l ithi th TTIretransmissions 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. The UE soft memory capability shall be defined according to the needs for Chase

bi i Th ft i titi d th HARQ i i t ticombining. 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

l ti t t f t f t i i d t i iselecting 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 ofy• Forward error correction (channel coding) and• Automatic Repeat Request (retransmissions).HARQ performs retransmissions of MAC-hs PDUs from Node B to UE.Q pHARQ processes• Typically 6 per UE (depends).• Stop-and-wait ARQ per process.S op a d a Q pe p ocess• Processes operate in parallel.NACK feedback status:• “Yes” means NACK is received for this HARQ process from the UEYes 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.Transmitter chooses Redundancy Version (RV) for each transmission.Receiver performs combining of different transmission of same MAC-hs PDU.• Chase Combining.• Incremental Redundancy.


Incremental Redundancy.• Constellation Rearrangement (16QAM only).• Fast retransmissions

Retransmissions in HSDPA

Server RNC Node-BMAC-hs Layer-1retransmissions

UETCP retransmissions

RLC retransmissions


HSDPA L1 RetransmissionsThe L1 retransmission procedure (Hybrid ARQ, HARQ) achieves p ( y , )following• L1 signaling to indicate need for retransmission -> fast round trip

time facilitated between UE and BTStime 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 b ffbuffer.

There are two ways of operating: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


systematic bits and less or not parity bits and in case retransmission needed then parity bits (or more of them) form the second transmission.

T b E d

HSDPA L1 Retransmissions : Chase Combining

SystematicParity 1

Turbo Encoder

Parity 2

Rate Matching (Puncturing)

SystematicParity 1Parity 2

Original transmission Retransmission

Chase Combining (at Receiver)



T b E d

HSDPA L1 Retransmissions : Incremental Redundancy

SystematicParity 1

Turbo Encoder

Parity 2

Rate Matching (Puncturing)


Original transmission Retransmission

Incremental Redundancy Combining



Power control on HSDPA channels

Associated UL and DL DPCH utilise normal closed loop power controlDL HS-PDSCH• Fixed power or variable power e g according to load conditions• Fixed power or variable power e.g. according to load conditionsDL 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• 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– 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 signallingHS-DPCCH

ACK; NACK CQI CQI

Ack/Nack CQI report


DPCCH

Part IXHSUPA Physical ChannelsHSUPA Physical Channels


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 asoverall 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 HARQtransport 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.

HSUPA offers maximum data rates of 1920kbps in single code operation (1 code of SF=2) or p g p ( )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 d t t f d l i ll f hi h bit t l d l i fdata 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.


HSUPA – General principle

• Channel quality Information

• Error correction Ack/Nack • E-DCH

• Node B controlled

2-allocation of allowed PWR (resources)

1-Scheduling request to Node B

Node B controlled scheduling• HARQ• SF=256-2

4-L1 Feedback

3-Data tx

5 More or less

• Multi-Code operation• QPSK modulation only Dual-branch BPSK on I- & Q-

branch5-More or less

PWR is granted if needed

• Fast Link Adaptation(Adaptive Coding), no enhanced/ adaptive modulation in Rel. 6

SHO d


UE• SHO supported

HSUPA features

HSUPA enhanced data rates and spectrum efficiencyHSUPA improves system capacity and increases user data rates in the uplink direction that is transmission from the mobile terminal to the radio access networkdirection, 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 6equipment). 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 for the Node B to control, within the limits set by the RNC, the set of TFCs from , y ,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) F t HARQ t i t d t th N d B ith ft bi i i t l• 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


the RLC peers

HSUPA features

HSUPA

Fast LinkAdaptation Fast

H-ARQ

Fast PacketScheduling

Fast Link Adaptation:HSUPA (Rel. 6): The coding is adapted dynamically every TTI (2 ms / 10 ms) by the UE to radio link quality Fast Packet Scheduling:

Fast H-ARQ: UE and Node B are responsible for acknowledged PS data transmission. Data 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).

retransmission is handled by UE. NodeB performs soft combining of original and Re-transmissions to enhance efficiency. This provides fast & efficient error correction.spectrum efficiency significant.


Physical Layer in Interaction with MAC-e

HSUPA Peak Bit Rates

Coding rate 1code x SF4 2codes x SF4 2codes x SF22codes x SF2

+ 2 d SF4

1/4

2codes x SF4

480 kbps 960 kbps 1.92 Mbps 2.88 Mbps

3/4 720 kbps 1.46 Mbps 2.88 Mbps 4.32 Mbps

4/4 960 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)

Physical Channels for One HSUPA UE

BTS

DL CHANNELSE-AGCH: E-DCH Absolute Grant

ChannelBTS

CH

CHH

E-RGCH: E-DCH Relative Grant Channel

E-HICH: E-DCH Hybrid ARQ Indicator Rel99

ciat

ed D

PC

ciat

ed D

PC

x E

-DP

DC

-DP

CC

H

-RG

CH

ChannelAssociated DPCH, Dedicated Physical

Channel.

DCHE

-HIC

H

-AG

CH

Ass

oc

Ass

oc

1-4

x E- E UL CHANNELS

E-DPDCH: Enhanced Dedicated Physical Data Channel

EE

UEE-DPCCH: Enhanced Dedicated

Physical Control ChannelAssociated DPCH, Dedicated Physical

Ch l


Channel

HSUPA UL physical channelsE DPDCH: Enhanced Dedicated Physical Data ChannelE-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• 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.


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

cd,1 d

DPDCH1

cd 3 d

Rel. `99 New in Rel. 6 for HSUPA:E-DPDCH & E-DPCCH

I d,3 d

DPDCH3

cd,5 d

DPDCH5

E-DPDCH:used to carry the E-DCH transport channel.There may be 0, 1, 2 or 4 E-DPDCH on each radio link

I+jQ

cd,2 d

DPDCH

Sdpch

radio link.

E-DPCCH:used to transmit control information associated with the E-DCH.

DPDCH2

cd,4 d

DPDCH4 Configurati

on #DPDCH HS-

DPCCHE-

DPDCHE-

DPCCH

Maximum number of simultaneous UL DCHs

j

Q

cc c

DPCCH

cd,6 d

DPDCH6

1 6 1 - -

2 1 1 2 1

3 1 4 1


DPCCH 3 - 1 4 1

E-DPDCH : SF-Variation & Multi-Code OperationSF 1 SF 4 SF 64SF 8

CC4,0 = (1,1,1,1)

CC64,0

CC64,1

CC64,2

SF = 1 SF = 2 SF = 4 SF = 64SF = 8

CC1,0 = (1)

CC2,0 = (1,1)

CC4,1 = (1,1,-1,-1) ••• • • N E-

CC2 1 = (1,-1)

CC4,2 = (1,-1,1,-1)• •

• • • NDPDCH

EDPDCHk

CCSF,k

E DPDCHCCSF,SF/4 if SF

4CC2,1 (1, 1)

CC4,3 = (1,-1,-1,1) CC64,63

CC64,62

0

E-DPDCH1 4CC2,1 if SF = 2

E-DPDCH2CC4,1 if SF = 4CC if SF 2E-DPDCH: SF = 256 - 2 2 CC2,1 if SF = 2

E-DPDCH3

E-DPDCH4CC4,1

E-DPDCH: SF = 256 - 2SF = 2 1920 kbit/s

Multi-Code operation:up to 2 x SF2 + 2 x SF4


1E-DPDCH1 CCSF,SF/2

E-DPDCH2CC4,2 if SF = 4CC2,1 if SF = 2

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

1 subframe = 2 ms

1 radio frame, Tframe = 10 ms

k SFChannel Bit Rate[kbps]

Bit/ Fram

e

Bit/ Subfram

e

Bit/Slot

Ndata

E-DPCCH content:• E-TFCI information (7 bit)

i di t E DCH T t Bl k Si i t i TTI 0 64 60 600 120 401 32 120 1200 240 802 16 240 2400 480 1603 8 480 4800 960 320

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)


4 4 960 9600 1920 640

5 2 1920 19200 3840 1280

• „Happy" bit (1 bit)indicating if UE could use more resources or notHappy 1Not happy 0

E-DPDCH & E-DPCCH frame structure and contentThe 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.Th E DPCCH S di F i fi d 256 O b f i 10 i f i biThe 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-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 / f th R t i i/ further RetransmissionHappy 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 channelsE AGCHE-AGCHE-DCH Absolute Grant Channel

carries DL absolute grants for UL E-DCHcontains: UE-Identity (E-RNTI) & max. UE power ratioy ( ) pE-DCH absolute grant transmitted over 1 TTI (2/10 ms)SF = 256 (30 kbps; 20 bit/Slot)

NodeB

E-RGCHE-DCH Relative Grant Channel

carries DL relative grants for UL E-DCH;

UEcarries DL relative grants for UL E DCH;complementary to E-AGCHcontains: relative Grants („UP“, „HOLD“, „DOWN“) & UE-IdentityE-DCH relative grant transmitted 1 TTI (2/10 ms)

E-DCH transmission:after E-AGCHafter E-RGCHNon-scheduled transmission


E DCH relative grant transmitted 1 TTI (2/10 ms)SF = 128 (60 kbps; 40 bit/Slot)

E-DCH Radio Network Temporary Identifier:allocated by S-RNC for E-DCH user per Cell

HSUPA DL physical channels

UENodeB

E-HICHE-HICHE-DCH Hybrid ARQ Indicator Channel

carries H-ARQ acknowledgement indicator for UL E-DCHcontains ACK/NACK (+1; -1) & UE-IdentityE DCH l i i d 1 TTI (2/10 )


E-DCH relative grant transmitted 1 TTI (2/10 ms)SF = 128 (60 kbps; 40 bit/Slot)

HSUPA DL physical channelsE-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)

E HICH E DCH H b id ARQ I di t Ch lE-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)• 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


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 well3/4. 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-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:• 1code x SF41code x SF4• 2codes x SF4• 2codes x SF2 (max imum supported in NSN RU 10)• 2codes x SF2 + 2codes x SF4Link adaptation ensures the highest possible data rate is achieved both for users with good signal quality (higher coding rate), typically close to the


g g q y ( g g ), yp ybase 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)• HSUPA varies the effective Coding between 1/4 – 1(4/4)

NodeB

UE

2/43/44/4 UE1/42/43/44/4 UE


Note that support for 4/4 coding is optionally given by UE and not supported in NSN RU 10!

Modulation in HSUPA

• 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)

“Dual-Branch BPSK

• (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

1-Bit Keying(Q)

IQPSK:

2-Bit Keying16 QAM-1 1 16 QAM64QAM


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 (3GPPThey 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).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- DCHCategory

max. E-DCHCodes

min. SF

2 & 10 msTTI E-DCH

support

max. #. of E-DCH Bits* / 10 ms TTI

max. # of E-DCH Bits*

/ 2 ms TTI

Referencecombination

ClassCodes support / 10 ms TTI / 2 ms TTI Class

1 1 4 10 ms only 7110 - 0.73 Mbps

2 2 4 10 & 2 ms 14484 2798 1 46 Mbps2 2 4 10 & 2 ms 14484 2798 1.46 Mbps3 2 4 10 ms only 14484 - 1.46 Mbps

4 2 2 10 & 2 ms 20000 5772 2.92 Mbps5 2 2 10 ms only 20000 - 2.0 Mbps

6 4 2 10 & 2 ms 20000 11484 5.76 Mbps7* 4 2 10 & 2 ms 20000 22996 11.52 Mbps& p

Extracted from TS 25.306: UE Radio Access Capabilities7* 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 ArchitectureUE: MAC / MAC h dli E DCH ifi f ti lit b t MAC & MAC i th UE i t d t il dUE: 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 PDUMAC e PDU• E-TFC selection: Enhanced Transport Format Combination selection according to scheduling information (Relative &

Absolute Grants) received from UTRAN via L1

UTRAN sideNode B: 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 resources between UEs; implementation proprietary • E DCH Control: receives scheduling requests & transmits scheduling assignments• 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


g• Disassembly: Remove MAC-es header,extract MAC-d PDU’s & deliver to MAC-d

MAC Architecture: UE SideMAC-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

MAC-d

MAC es/ MAC-c/shMAC-hsMAC-es/MAC-e


FACH RACH DSCH DCH DCHCPCH PCH FACH DSCHHS-DSCH

associatedDL Signalling

E-DCHassociated

UL Signallingassociated

DL Signallingassociated

UL Signalling

MAC Architecture: UTRAN side1 MAC e entity in Node B for each UE & 1 MAC es tit f h UE i S RNC RNC1 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 &Node

• 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).

RNC

• E-DCH Control: receives scheduling requests &transmits scheduling assignments.

• De-multiplexing: de-multiplexing MAC-e PDUs • H-ARQ: generating ACKs/NACKs

MAC ControlMAC C t lMAC ControlMAC Control

MAC Control

NodeB

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

DCCH DTCHDTCHMAC ControlCCCH CTCHBCCHPCCHMAC ControlMAC Control

MAC-es

Configurationwith MAC-c/sh

MAC-dConfigurationwithout MAC-c/sh

Configuration

Iur or

MAC-e MAC-hs MAC-c/sh

HS-

Configurationwith MAC-c/sh


FACH RACH DSCHIur orlocal DCH DCH

CPCHPCH

associatedDL Signalling

associatedUL Signalling

E-DCH associatedDL Signalling

associatedUL Signalling

DSCH Iub

HSUPA Fast Packet Scheduling

HSUPA (Rel. 6) Fast Packet Scheduling: • Node B controlled• resources allocated on Scheduling Request• short TTI = 2 / 10 ms

HSUPA (Rel. 6) Fast Packet Scheduling: • Node B controlled• resources allocated on Scheduling Request• short TTI = 2 / 10 msshort 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

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 g g ( ) p

high UL resource efficiency L1 signalling overhead

g g ( ) phigh UL resource efficiency

L1 signalling overhead

Scheduling Request(buffer occupation,...)

UEScheduling Grants

( t fS-RNC

IubNode

B

(max. amount ofUL resources to be used)

E-DCHdata transmission

E-DCHdata transmission


HSUPA Link Adaptation

MAC-e (UE) decides E-DCH Link Adaptation (TFC; effective Coding)on basis of:• Channel quality estimates (CPICH Ec/Io)

SchedulingRequest

SchedulingGrants

• Channel quality estimates (CPICH Ec/Io)• Every TTI (2/10 ms)

UENode

B

Grants

UE

Rel. 6 HSUPA:dynamic Link Adaptation

Rel. 6 HSUPA:dynamic Link Adaptation

Rel. 99:Fixed

Turbo Coding 1/3

Rel. 99:Fixed

Turbo Coding 1/3

dynamic Link Adaptation effective Coding 1/4 - 4/4

higher UL data rates

higher resource efficiency

dynamic Link Adaptation effective Coding 1/4 - 4/4

higher UL data rates

higher resource efficiency


higher resource efficiency higher resource efficiency

HSUPA Fast H-ARQS Q CS Q CHSUPA: Fast H-ARQ with UL E-DCH

• Node B (MAC-e) controlled• SAW* H-ARQ protocol • based on synchronous DL (L1) ACK/NACK

HSUPA: Fast H-ARQ with UL E-DCH• Node B (MAC-e) controlled• SAW* H-ARQ protocol • based on synchronous DL (L1) ACK/NACK

Short delay times(support of QoS services)

Short delay times(support of QoS services)

• Retransmission strategies:Incremental Redundancy & Chase Combining

• 1st Retransmission 40 / 16 ms (TTI = 10 / 2 ms)• limited number of Retransmissions*• lower probability for RLC Retransmission

• Retransmission strategies:Incremental Redundancy & Chase Combining

• 1st Retransmission 40 / 16 ms (TTI = 10 / 2 ms)• limited number of Retransmissions*• lower probability for RLC Retransmission

less Iub/Iur traffic less Iub/Iur traffic

• lower probability for RLC Retransmission• Support of Soft & Softer Handover• lower probability for RLC Retransmission• Support of Soft & Softer Handover

UEE-DCH PacketsE-DCH Packets

UE

NodeB

L1 ACK/NACKL1 ACK/NACK

RetransmissionRetransmissioncorrectly received

packetscorrectly received

packets

RNC

Iub

B

MAC-e controls L1 H-ARQ:MAC-e controls L1 H-ARQ:

IR: Incremental RedundancyCC: Chase CombiningHARQ: Hybrid Automatic Repeat RequestSAW: Stop and Wait


• storing & retransmitting payload• packet combining (IR & CC)• storing & retransmitting payload• packet combining (IR & CC)

SAW: Stop-and-Wait* HARQ profile - max. number of

transmissions attribute

HSUPA Fast HARQHARQ protocol characteristicsp• Stop- & wait-HARQ is used (SAW);• HARQ based on synchronous DL ACK/NACKs• HARQ based on synchr. UL retransmissions:Q y• 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-

d b hi h i i d f i l )empted by higher priority data for a particular process);• 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• 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:• 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 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 HandoverSHO Gains:

Softer Handover: • UE connected to cells of same

Node B (same MAC-e entity)

Softer Handover: • UE connected to cells of same

Node B (same MAC-e entity)

Soft Handover:UE connected to UTRAN

via different Node Bs

Soft Handover:UE connected to UTRAN

via different Node Bs

SHO Gains:full Coveragefor HSUPA

( y)• combining Node B internal• no extra Iub capacity needed

( y)• combining Node B internal• no extra Iub capacity needed

Node B

UE SectorcellsIub

N d B

Node BUE

S-RNC:S-RNC:

IubIub

Node B

RN

Node B

E-DCHS 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.b id ti l /

E-DCH Active Set:• set of cells carrying the

E-DCH for 1 UE.b id ti l /

Iu

C Iub

RNC

E-DCHAS

AS


CN • can be identical / a subset of DCH AS

• is decided by the S-RNC

• can be identical / a subset of DCH AS

• is decided by the S-RNC

C 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• 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..Intra Node B macro-diversity (Softer Handover) and Inter Node B macro-diversity (SHO) should be supported for the E-DCH with HARQ(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 ythe S-RNC


HSUPA Power ControlTS 25 14TS 25.14;

5.1.2DPCCH• Always transmitted• Inner-Loop Power Control!• Inner-Loop Power Control!• Setting of E-DPCCH & E-DPDCHpower relative to DPCCH power• PtxUE < min [Ptx,maxUE; max

NodeB

UE

Ptx,cell*]

Configuration DPDC HS- E-DPDCH E-DPCCHUL DCH max configurations for Rel 99, HSDPA & HSUPAConfiguration

#iDPDC

HHS-

DPCCHE-DPDCH E-DPCCH

1 6 1 - -2 1 1 2 1


3 - 1 4 1Taken from specification TS 25.213;4.2.1

• Power Management/Control for E DCH

Power Control• Power Management/Control for E-DCH

No special power management/control mechanism is needed for E-DCH.

• Power Control: DPDCH & DPCCH• 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 signallingand 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. ...

• 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 aDuring 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 co rse mod le follo ing 3GPP specifications ere sed

ReferencesFor 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) p g g ( )• 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 25.301 V6, Radio interface protocol architecture • TS 25.302 V6, Services provided by the physical layer• TS 25.306 V5 – V8: UE Radio Access capabilities• 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 2TS 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
