IMP TA1!11!001 Day1 LTE Protocol

UMTS Long TermEvolution (LTE) –protocol aspects

Reiner [email protected]

Training CentreRohde & Schwarz, Germany

Jan 11 | LTE protocols| R.Stuhlfauth, 1MAT 2

3GPP UMTS EvolutionWhat are the major technical „road works“?

As usual: Bandwidth

Reduce Round Trip Time, RTT

All over Packet Switched Connection

-Wider frequency bandwidth-MIMO systems-Additional frequency bands-Higher value modulation schemes

-Node-B upgrade-Fast scheduling methods

-Deployment of IMS (IP Multimedia Subsystem) in core networks-solely Shared Channel setups


Round Trip Time, RTT

ServingRNC

MSC

SGSN

Iub/Iur Iu

•ACK/NACKgeneration in RNC

MME/SAE Gateway

•ACK/NACKgeneration in node B

Node B

eNode B

TTI~10msec

TTI=1msec


IMS: Reference Model (3GPP/3GPP2)

IP MultimediaSubsystem IMS

= All over IP connection


LTE Protocol Architecture


l Reduced number of transport channels

l Shared channels instead of dedicated channels

l Reduction of Medium Access Control (MAC) entities

l Streamlined concepts for broadcast / multicast (MBMS)

l No inter eNodeB soft handover in downlink/uplink

l No compressed mode

l Reduction of RRC states

LTE Protocol ArchitectureReduced complexity


E-UTRA protocol structure

Radio Resource Control (RRC)

Medium Access Control (MAC)

Transport channels

Physical layer

Con

trol/

Mea

sure

men

ts

Layer 3

Logical channelsLayer 2

Layer 1

Radio Link Control, RLC

Déjà vu fromWCDMA?


EUTRAN stack: different channels

PHYSICAL LAYER

Medium Access ControlMAC Transport

channels„How to transmit“

Logical channels„What to betransmitted“

PhysicalchannelsCode, Frequency, etc.

Radio Resource ControlRRC

Con

trol&

Mea

sure

men

ts

Service Access PointSAP

Radio Link ControlRLC


EUTRAN stack: protocol layers overview

PHYSICAL LAYER

Medium Access ControlMAC


Con

trol&

Mea

sure

men

ts

Radio Link ControlRLC

Packet Data ConvergencePDCP

ÉMM ESM User plane


Channel structure: User + Control planeProtocol structure


User plane

PDCP = Packet Data Convergence ProtocolRLC = Radio Link Control

MAC = Medium Access ControlPHY = Physical Layer

SDU = Service Data Unit(H)ARQ = (Hybrid) Automatic Repeat Request

Header compression (ROHC)In-sequence delivery at handover

Duplicate detectionCiphering for user/control plane

Integrity protection for control planeTimer based SDU discard in Uplink…

AM, UM, TMARQ

(Re-)segmentationConcatenation

In-sequence deliveryDuplicate detection

SDU discardReset…

Mapping between logical andtransport channels(De)-Multiplexing

Traffic volume measurementsHARQ

Priority handlingTransport format selection…


Control plane

EPS = Evolved packet systemRRC = Radio Resource Control

NAS = Non Access StratumECM = EPS Connection Management

BroadcastPaging

RRC connection setupRadio Bearer Control

Mobility functionsUE measurement control…

EPS bearer managementAuthentication

ECM_IDLE mobility handlingPaging origination in ECM_IDLE

Security control…


LTE channel mapping


LTE – channels


LTE – channels: control information mapping

PBCHPDCCH PDSCH

DL-SCH BCHDL transport channels

DL physical channels

PCHMCH

PMCH PCFICH PHICH

CFIControl Format Indicator

DCIDownlink Control Information

HIHARQ Indicator

PRACH PUCCH PUSCH

UL-SCHRACHUL transport channels

UL physical channels

UCIUplink Control Information


LTE Identifiers and System Information


Radio Network Transaction Identifiers, RNTI

C-RNTICell RNTI,

identifies a UEhaving a RRC connection

within a cell

TPC-RNTITransmit Power Control

RNTI,For power control, DCI 3,

i.e. multiplexing TPCcommands

P-RNTIPaging-RNTI,

Paging and SystemInformation change info

SI-RNTISystem Information-

RNTI,Broadcast of

System information

RA-RNTIRandom Access-

RNTI,Random Access Response


RNTI - usage

N/AN/APhysical layer Uplink power controlTPC-PUSCH-RNTI

N/AN/APhysical layer Uplink power controlTPC-PUCCH-RNTI

N/AN/ASemi-Persistently scheduled unicasttransmission

(deactivation)

Semi-PersistentScheduling C-

RNTI

DCCH, DTCHDL-SCH, UL-SCHSemi-Persistently scheduled unicasttransmission

(activation, reactivation and retransmission)

Semi-PersistentScheduling C-

RNTI

N/AN/ATriggering of PDCCH ordered random accessC-RNTI

CCCH, DCCH, DTCHDL-SCHDynamically scheduled unicast transmissionC-RNTI

DCCH, DTCHUL-SCHDynamically scheduled unicast transmissionC-RNTI

CCCH, DCCH, DTCHUL-SCHMsg3 transmissionTemporary C-RNTI

CCCHDL-SCHContention Resolution(when no valid C-RNTI is available)

Temporary C-RNTI

N/ADL-SCHRandom Access ResponseRA-RNTI

BCCHDL-SCHBroadcast of System InformationSI-RNTI

PCCHPCHPaging and System Information changenotification

P-RNTI

Logical ChannelTransport ChannelUsageRNTI


Masking of CRC in LTE – general principle

Data or control message Cyclic RedundancyCheck, CRC

Bit - Mask

+

CRC used for error detection

Mask used to send controlInformation. Saves space indata part

LTE is using CRC for 2 reasons: For error detection and to send control information,i.e. killing 2 birds with 1 stone ☺

00110011 1101Data part Original CRC

1101

1111

+

0010

OriginalCRC

Bit Mask

MaskedCRC00110011 0010

Data part Masked CRC

00110011 0010Data part Masked CRC

0010 0010

0000

+ + +

1111 0101

0010 1101 0111

1.step: data + original CRC

2nd step: select maskand XOR with CRC3.step: data + masked CRC

Receiver doesnot know whichMask nor if CRCIs right -> try itOne mask will beSuccesful!

Here: 3 masks

One example:


Uplink allocation using C-RNTI

Downlink Control Information DCIFormat 0

Cyclic RedundancyCheck, CRC

16 bits: bk

Cell-RNTI16 bits: xk

+( ) 2mod, Akrntikk xbc −+=

CRC is scrambled withRNTI to identify the UE

PDCCH

PUSCH

Uplink transport block sent on PUSCH


Downlink transport block sent on PDSCH

Downlink allocation using C-RNTI

Downlink Control Information DCIFormat 1 or 2


16 bits: bk

Cell-RNTI16 bits: xk


CRC is scrambled withRNTI to identify the UE

PDCCH

PDSCH

Downlink transport block sent on PDSCH

DCI Format 2 is usedIn case of MIMO, it canIndicate 1 or 2transport blocks


Downlink allocation using SI-RNTI



16 bits: bk

SI-RNTI16 bits: xk


CRC is scrambled withSystem Information-RNTI

PDCCH

PDSCH

Downlink transport block, containingSystem Information message


Downlink allocation using P-RNTI



16 bits: bk

P-RNTI16 bits: xk


CRC is scrambled withPaging-RNTI

PDCCH

PDSCH

Downlink transport block, containingPaging Information message


Downlink allocation using TPC-RNTI



16 bits: bk

TPC-RNTI16 bits: xk


CRC is scrambled withTransmit Power Control RNTI

PDCCH

PDSCHTPC_cmd1TPC_cmd2

…TPC_cmd N

tpc-Index=1

tpc-Index=2

tpc-Index=N

Multiplexing of power controlCommands in 1 message


E-UTRAN Identities3GPP TS 36.300 subclause 8

l UE identitiesl C-RNTI (Cell Radio Network Temporary Identity)l Random value for contention resolution

l eNodeB identitiesl ECI – E-UTRAN Cell Identifier

– 28 Bit eNB Identifierl ECGI – E-UTRAN Cell Global Identifier

– Composition of MCC (Mobile Country Code), MNC (Mobile Network Code) andECI

l TAI – Tracking Area Identifier– Composition of MCC, MNC and TAC (Tracking Area Code)


System Information Block Typesl Master Information Block (Periodicity of 40 ms)l Essential PHY information to allow receiving further SIBs

l SIB Type 1 (Periodicity of 80 ms)l Cell access information and essential information to allow receiving further SIBs

l SIB Type 2l Common and shared channel information

l SIB Type 3l Serving cell related cell re-selection information

l SIB Type 4l Serving cell information

l SIB Type 5l E-UTRA neighbour cell information

l SIB Type 6l UTRA neighbour cell information

l SIB Type 7l GERAN neighbour cell information

l SIB Type 8l CDMA2000 neighbour cell information

l SIB Type 9l Home eNB identifiers (e.g. femto cell)


LTE Physical LayerDownlink physical control channels


LTE: new physical channels for data and control

Physical Downlink Control Channel PDCCH:Downlink and uplink scheduling decisions

Physical Downlink Shared Channel PDSCH: Downlink data

Physical Control Format Indicator Channel PCFICH:Indicates Format of PDCCH

Physical Hybrid ARQ Indicator Channel PHICH:ACK/NACK for uplink packets

Physical Uplink Control Channel PUCCH:ACK/NACK for downlink packets, scheduling requests, channel quality info

Physical Uplink Shared Channel PUSCH: Uplink data


Physical Downlink SharedChannel (PDSCH)

I would like to receive data onPDSCH but I don‘t know which

resource blocks are allocated for meand how they look like

?

Physical Downlink ControlChannel (PDCCH)

Check PDCCH for your UE ID. Assoon as you are addressed, you will

find all the information you need there.

LTE downlinkScheduling of downlink data


I would like to read the PDCCH butwhere is it?

?

Physical Control FormatIndicator Channel (PCFICH)

Check PCFICH. It will tell you how manysymbols (1, 2, or 3)in the beginning of the

subframe are allocated for PDCCH.

Physical Control Format Indicator Channel (PCFICH)Indicating PDCCH format

Physical Downlink ControlChannel (PDCCH)


Physical Hybrid ARQ Indicator Channel (PHICH)Acknowledging uplink data packets

Physical Uplink Shared Channel(PUSCH)

I have sent data packets on PUSCHbut I don‘t know whether they have

been received correctly.

?

Physical Hybrid ARQIndicator Channel (PHICH)

Read the PHICH. It carries ACK orNACK for each single packet.


time

frequency

1 resource block =180 kHz = 12 subcarriers

1 slot = 0.5 ms =7 OFDM symbols**

1 subframe =1 ms= 1 TTI*=1 resource block pair

LTE DownlinkOFDMA time-frequency multiplexing

*TTI = transmission time interval

** For normal cyclic prefix duration

Subcarrier spacing = 15 kHz

QPSK, 16QAM or 64QAM modulationQPSK, 16QAM or 64QAM modulation

UE1UE1

UE4UE4

UE3UE3UE2UE2

UE5UE5

UE6UE6


LTE Downlink: FDD channel mapping example

PDSCHPDCCHPCFICH

PBCHS-SCHP-SCH

Frequency

Tim

e

DCI

PDSCH


Demodulation performed by the UE

PDCCH

Channel Bandwidth

1su

bfra

me

= 1m

sec

1101100101 1101100101 1101100101 1101100101

UE checksfor PCFICH

1101100101

UE checks for DCI incommon or dedicated

search space1101100101

0001111010101011110111010

If UE detects RNTI itwill read PDSCH onscheduled resource

UE samples channel bandwidth and 1 subframeAs IQ samples. Demodulation only performed onParticular channels / resources


Downlink: resource element group

R

R

7 OFDM symbol periods

12su

b car

riers

(180

kHz

) REG

1R

EG2

REG

3R

EG4

REG

5R

EG8

REG

7R

EG6

REG

REG

REG

= in some resouce blocks used for PCFICH

= cell specific reference symbol. Precedence over every other resource element content

= optional usage for PDCCH if less than 10 RBs assigned

= optionally used for PHICH

= optionally used for PDCCH, depending on format

= used for PDSCH

R

R

6 OFDM symbol periods

12su

bcar

r iers

(180

kHz

) REG

1R

EG2

REG

3R

EG4

REG

5R

EG8

REG

7R

EG6

REG

REG Variable

mapping schemefor control channels:PDCCH, PCFICHand PHICH


Downlink: resource element group, REG

R

R

REG

1R

EG2

REG

3R

EG4

REG

5R

EG8

REG

7R

EG6

REG

REG

REG

subc

arrie

rs

7 OFDM symbols Resource element group= mapping of control

information to resourceelements

1.Symbol:REG size =6 resourceelements

2. Symbol:REG size = 6 or 4resource elements,depending on # of

antennas

4. Symbol:REG size = 6 or 4 resource

elements, depending onextended or normal cyclic prefix

PDCCH, PCFICH and PHICHuse a certain number of REGs to

send control information



Physical Format Indicator Channel, PCFICH•Indicates how many OFDM symbols are used for PDCCH in that subframe,i.e. the control format indicator, CFI

•Transmitted in every subframe, QPSK modulated

•Coded as 32 bits, transmitted in 4 Resource Element Groups, REG

•Mapping on frequency resource depends on cell identity (see TS36.211 section 6.7.4)

3110 ,...,, bbb2, 3, 41, 2, 3Subframe 0 in FDD mode

21, 2Subframe 1 and 6 in TDDmode

Subframe where PCFICH issent

Number of OFDM symbols for PDCCH when

10DLRB >N 10DL

RB ≤N

Most frequent scenarioC F I

C F I c o d e w o r d< b 0 , b 1 , … , b 3 1 >

1 < 0 ,1 , 1 ,0 ,1 , 1 ,0 , 1 , 1 ,0 , 1 ,1 , 0 ,1 ,1 , 0 ,1 ,1 , 0 ,1 , 1 , 0 ,1 , 1 ,0 , 1 ,1 ,0 , 1 ,1 ,0 ,1 >

2 < 1 ,0 , 1 ,1 ,0 , 1 ,1 , 0 , 1 ,1 , 0 ,1 , 1 ,0 ,1 , 1 ,0 ,1 , 1 ,0 , 1 , 1 ,0 , 1 ,1 , 0 ,1 ,1 , 0 ,1 ,1 ,0 >

3 < 1 ,1 , 0 ,1 ,1 , 0 ,1 , 1 , 0 ,1 , 1 ,0 , 1 ,1 ,0 , 1 ,1 ,0 , 1 ,1 , 0 , 1 ,1 , 0 ,1 , 1 ,0 ,1 , 1 ,0 ,1 ,1 >

4( R e s e r v e d ) < 0 ,0 , 0 ,0 ,0 , 0 ,0 , 0 , 0 ,0 , 0 ,0 , 0 ,0 ,0 , 0 ,0 ,0 , 0 ,0 , 0 , 0 ,0 , 0 ,0 , 0 ,0 ,0 , 0 ,0 ,0 ,0 >


PCFICH mapping on physical resource

R R R RPCFICH PCFICH PCFICH PCFICH

1 2 3 4

First resource block Last resource block

Resource block

f

Channel Bandwidth4

Mapping of PCFICH onto resource elements is based on Physical Layer Cell Identity!

( ) ( )DLRB

cellID

RBsc 2mod2 NNNk ⋅=

223bydrepresentegroupelement-resourcethetomappedis)3(

222bydrepresentegroupelement-resourcethetomappedis)2(

22bydrepresentegroupelement-resourcethetomappedis)1(bydrepresentegroupelement-resourcethetomappedis)0(

RBsc

DLRB

)(

RBsc

DLRB

)(

RBsc

DLRB

)(

)(

NNkkz

NNkkz

NNkkzkkz

p

p

p

p

⋅+=

⋅+=

⋅+==


PCFICH mapping on physical resourceExample: 3 cells with 10 MHz

NCellID =0 NCellID =99

NCellID =231

f0 150 300 450

1 2 3 4

Number of resource element group,i.e. which resource block carries PCFICHValue = first subcarrier of REG

f

2 3 4 1

144 294 444 594

f

2 34 1

36 186 336 486

Channel Bandwidth, here = 50 RB

PCFICH isfrequency interleaved


Physical HARQ Indicator Channel, PHICH•Indicates ACK or NACK of previous uplink data block

•Transmitted in every subframe, BPSK modulated

•Multiple PHICHs on same resource -> separated by orthogonal sequence

•Mapping on frequency resource depends on cell identity (see TS36.211 section 6.7.4)

210 ,, bbb( )seq

PHICHgroupPHICH,nn

RRC layer configures number of groups:PHICH-resource (1/6, ½,1 or 2) multiplied with bandwidth

Orthogonal sequence, Spreading Factor is 2 or 4

PHICH is identified by group and sequence identifiers

( ) ( )

⋅=

prefixcyclicextendedfor82

prefixcyclicnormalfor8DLRBg

DLRBggroup

PHICHNN

NNN

Sequence index Orthogonal sequenceseqPHICHn Normal cyclic prefix

4PHICHSF =N

Extended cyclic prefix2PHICH

SF =N0 [ ]1111 ++++ [ ]11 ++

1 [ ]1111 −+−+ [ ]11 −+

2 [ ]1111 −−++ [ ]jj ++

3 [ ]1111 +−−+ [ ]jj −+

4 [ ]jjjj ++++ -

5 [ ]jjjj −+−+ -

6 [ ]jjjj −−++ -

7 [ ]jjjj +−−+ -

Given by MIB


PHICH principle

t=0 t=1 t=2 t=3 t=4 t=5 t=6 t=7 t=8 t=9 t=0 t=1 t=2 t=3 t=4 t=5

PD

CC

H

PUSC

HD

ata

PHIC

HA

CK

/NA

CK

PUSC

HD

ata

Downlink

Uplink

n+4 n+4 n+4

1 frame = 10 subframes

8 HARQ processesRTT = 8 msec


PHICH physical resource mapping

t=0 t=1 t=2 t=3 t=4 t=5 t=6 t=7 t=8 t=9 t=0 t=1 t=2 t=3 t=4 t=5

DC

I0

PUSC

HD

ata

PHIC

HA

CK

/NA

CK

PUSC

HD

ata

Downlink

Uplink

n+4 n+4 n+4

•UL Frequencydomain: Lowestindex resourceblock•Demodulationreferencesymbol, DMRS,3bit

PUSCH datasent on

Uplink resourcestarting at:

•Mapped onfrequencyresourcestarting at•PHICH groupcalculatedbased on

Sysinfo:Number of

PHICHgroups

PHICHSFDMRS

groupPHICH

indexlowestRAPRB

seqPHICH

groupPHICHPHICH

groupPHICHDMRS

indexlowestRAPRB

groupPHICH

NnNIn

NINnIn

2mod)/(

mod)(_

_

__

+=

++=


PHICH mapping on physical resource

R R R RPHICH PHICH

PHICH Group1

REG 1


Resource block

f

Mapping of PHICH onto resource elements is based on Physical Layer Cell Identity!

RRC valuePHICH-duration: normal (= 1

OFDM symbol) or extended (=3OFDM symbols)

Optional used for PHICH

PHICH group resource = 3 Resource Element Groups

PHICH Group1

REG 2

PHICH Group1

REG 3


PHICH mapping on physical resourceExample: 3 cells with 10 MHz, each cell has 2 PHICH groups configured

NCellID =0 NCellID =99

NCellID =231

f96 306 504

3 1 2

Number of resource element group,i.e. which resource block carries PHICHValue = first subcarrier of REG

PHICH isfrequency interleaved

PHICH group1102 312 510 PHICH group2

f114 318 516

3


1 2

f138 348 546

2


3 1

PHICH area


Physical Downlik Control Channel PDCCH

f

NCCE =f(Bandwidth,#OFDM symbolsand PHICHConfiguration)

#OFDM symbols

DCIDCI DCIDCI DCIDCI DCIDCI DCIDCI

•PDCCH transmits a list of control messages•Control message is called Downlink Control information DCI•Number of DCIs is variable

1 DCI is of length1, 2, 4 or 8 CCE

Number of Control Channel Elements, i.e.the resource available for DCI transmission


PDCCH resourcesR R R RREG REG REG REG

1 Control Channel Element, CCE = 9 REGs = 72 bits

Resource block

R R R RREG REG REG REG RREG

CCE

CCE

CCE

CCE

CCE CCE CCE

CCE CCE CCE CCE CCE CCE CCE CCE

PDCCH can be sizeof either 1, 2, 4 or 8 CCEs

= aggregation level


Downlink Control Channel (PDCCH)� PDCCH carries L1 and L2 control information� It is QPSK modulated� Each PDCCH is transmitted via one or several consecutive Control

Channel Elements (CCEs). Content of these CCEsis the Downlink Control Information (DCI).

� DCI contains DL or UL scheduling, or UL power control� CRC is scrambled with UE-specific identity� UE monitors a set of PDCCH candidates for assigned DCIs in

every non-DRX subframe (Each possible DCI format is checked.)

5767283

2883642

1441821

72910

Number ofPDCCH

bits

Number ofResource-

Element Groups

Numberof CCEs

PDCCHformat

1 PDCCH � 1,2,4 or 8 CCEs

1 CCE � 9 Resource Element Groups REG

1 REG � 6 Resource Elements RE in 1st symbol4 RE in 2nd and 3rd symbol


PDCCH search space


f

Resources used for PCFICH

Resources used for PHICH

DCIs DCIs DCIsDCIs

Common search space Dedicated search spaces

PDSCH with:System information

PagingCCCH

…

PDSCH with:Dedicated

data

PUSCHResourcesTo send

Dedicated data

or

e.g. UEs in idle mode tomonitor system information+ paging

e.g. UEs in connected mode tomonitor resource allocation.

Note: search spaces may overlap

NCCE =f(Bandwidth,#OFDM symbolsand PHICHConfiguration)

#OFDM symbols


PDCCH search space: # of REG per RB

R

R

REG

1R

EG2

REG

3R

EG4

REG

5R

EG8

REG

7R

EG6

REG

REG

REG

subc

arrie

rs

7 OFDM symbols


2. Symbol:REG size = 4

(assume 1 or 2antennas)


PCFICH indication: PDCCH size1 OFDM symbol => 1 Ressource Block = 2 REGs2 OFDM symbols => 1 Ressource Block = 5 REGs3 OFDM symbols => 1 Ressource Block = 8 REGs

Capacity of PDCCH depends on•configuration of PHICH,•Channel bandwidth and

•number of OFDM symbolsused for PDCCHtime

frequ

ency


PDCCH search space: CCE number

Capacity of PDCCH depends on•configuration of PHICH,•Channel bandwidth and

•number of OFDM symbols

Num PHICH Groups 1System Bandwidth Num Rb 1 2 3 4

1.4 MHz 6 N/A 2 4 63 MHz 15 2 7 12 N/A5 MHz 25 4 13 21 N/A

10 MHz 50 10 27 43 N/A15 MHz 75 15 40 65 N/A20 MHz 100 21 54 88 N/A

Number of Available CCEs 1 & 2 AntennasNum Symbols PDCCH

Example: this table gives the available numberof control channel elements, CCE(remember 1CCE = 9 REGs)used to carry PDCCH information

Number of CCE used for PDCCH transmission


PDCCH search space calculation

2168

4164Common

2168

284

6122

661

UE-specific

Size [in CCEs]Type

)(LkS

)(LM

Search space Number of PDCCHcandidates

Aggregation level L

UE has to monitor PDCCH for various sizes, e.g. aggregation levels separately

UE common: PDCCH candidatesizes are 4 or 8 CCE

UE specific: PDCCH candidatesizes are 1, 2, 4 or 8 CCE

CCE CCE CCE CCE CCE CCE CCE CCE CCE CCE CCE CCE CCE CCE CCE CCE

1 PDCCH candidate


PDCCH search space calculation

2168

4164Common

2168

284

6122

661

UE-specific

Size [in CCEs]Type

)(LkS

)(LM

Search space Number of PDCCHcandidates

Aggregation level L

UE has to monitor PDCCH for various sizes, e.g. aggregation levels separately


1 PDCCH candidate


1 PDCCH candidate

UE has to blind detect whichAggregation level is used,e.g. here the UE will decode bothsearch space format possibilitiesand tries to detect a proper result,based on CRC checksum!


PDCCH aggregation of control channel elements

CC

EC

CE

CC

EC

CE

CCE

Bad RF conditions:eNodeB selects aggregation level = 4

Good RF conditions:eNodeB selects aggregation level = 1

The aggregation level of CCE is selected by the eNodeB according to the RF conditions

DCI

Here: DCI isscrambled and spreadover 4 CCEs

DCI


PDCCH common search space calculation

( ){ }CCE,mod /k kL Y m N L i ⋅ + +

Search space position is given as:

Where Yk = 0, for common search space

Aggregation Level L TTI Yk 0 1 2 34 0 0 0 4 8 12

1 0 0 4 8 122 0 0 4 8 123 0 0 4 8 124 0 0 4 8 125 0 0 4 8 126 0 0 4 8 127 0 0 4 8 128 0 0 4 8 129 0 0 4 8 12

8 0 0 0 81 0 0 82 0 0 83 0 0 84 0 0 85 0 0 86 0 0 87 0 0 88 0 0 89 0 0 8

PDCCH Candidate

Com

mon

Sea

rch

Spac

e

This example gives the PDCCH channelnumbers, i.e. start CCE for the commonsearch space.Here NCCE = 26 and #PHICH groups = 2

See before: depends on bandwidth and PHICH configuration


Aggregation Level L TTI Yk 0 1 2 3 4 51 0 5048 4 5 6 7 8 9

1 44717 23 24 25 0 1 22 41521 25 0 1 2 3 43 27283 9 10 11 12 13 144 62118 4 5 6 7 8 95 17373 5 6 7 8 9 106 40362 10 11 12 13 14 157 5838 14 15 16 17 18 198 50287 3 4 5 6 7 89 35166 14 15 16 17 18 19

2 0 5048 8 10 12 14 16 181 44717 20 22 24 0 2 42 41521 24 0 2 4 6 83 27283 18 20 22 24 0 24 62118 8 10 12 14 16 185 17373 10 12 14 16 18 206 40362 20 22 24 0 2 47 5838 2 4 6 8 10 128 50287 6 8 10 12 14 169 35166 2 4 6 8 10 12

PDCCH Candidate

PDCCH dedicated search space calculation

( ){ }CCE,mod /k kL Y m N L i ⋅ + +

Search space position is given as:

( )1 modk kY A Y D−= ⋅

This example gives the PDCCH channel numbers, i.e. start CCE for the dedicated searchspace extracted. Here NCCE = 26 and #PHICH groups = 2 and UEs RNTI = 10.E.g. UE expects PDCCH candidate 0 to start at CCE = 4 in subframe = 0

See before: depends on bandwidth and PHICH configuration

Where Y-1 = RNTI, A = 39827 and D = 65537

UE specificHopping toavoid blockingor PDCCHcongestion


Downlink Control Information DCI formats

Reporting about precoding matrix,only in closed loop spatialmultiplexing

2nd transport block only activewhen in MIMO mode spatialmultiplexing

f

Frequency allocation could bedistributed or contiguous

DCI format willIndicate whichTransmission modeIs applied

PDCCH PDSCH


DCI formats

l DCI format 0 is used for the scheduling of PUSCH.l DCI format 1 is used for the scheduling of one PDSCH codeword.l DCI format 1A is used for the compact scheduling of one PDSCH codeword and random

access procedure initiated by a PDCCH order.l DCI format 1B is used for the compact scheduling of one PDSCH codeword with

precoding information.l DCI format 1C is used for very compact scheduling of one PDSCH codeword.l DCI format 1D is used for the compact scheduling of one PDSCH codeword with

precoding and power offset information.l DCI format 2 is used for scheduling PDSCH to UEs configured in closed-loop spatial

multiplexing mode.l DCI format 2A is used for scheduling PDSCH to UEs configured in open-loop spatial

multiplexing mode.l DCI format 3 is used for the transmission of TPC commands for PUCCH and PUSCH

with 2-bit power adjustments.l DCI format 3A is used for the transmission of TPC commands for PUCCH and PUSCH

with single bit power adjustments.


Downlink Control Information DCI content

� Flag for format0/format1A differentiation 1 bit� Hopping flag 1 bit� Resource block assignment max 13bits� Modulation and coding scheme and redundancy version 5bits� New data indicator 1 bit� TPC command for scheduled PUSCH 2 bits� Cyclic shift for demodulation reference signals 3 bits� UL index (only for TDD) 2 bits� Downlink Assignment Index (DAI) (only for TDD) 2 bits� CQI request 1 bit

DCI format 0 is used for the scheduling of PUSCH.



� Resource allocation header (allocation type 0 or 1) 1 bit� Resource block assignment max 25 bits� Modulation and coding scheme 5 bits� HARQ process number 3/4 bits(FDD/TDD)� New data indicator 1 bit� Redundancy version 2 bits� TPC command for scheduled PUSCH 2 bits� Downlink Assignment Index (DAI) (only for TDD) 2 bits

DCI format 1 is used for the scheduling ofone PDSCH codeword



� Flag for format0/format1A differentiation� Resource block assignment� Modulation and coding scheme� HARQ process� New data indicator� Redundancy version� TPC command for scheduled PUSCH� Downlink Assignment Index (DAI) (only for TDD)

DCI format 1A is used for the compact scheduling ofone PDSCH codeword (allocation type 2) andrandom access procedure initiated by a PDCCH order



� Localized/Distributed VRB assignment flag� Resource block assignment� Modulation and coding scheme� HARQ process number� New data indicator� Redundancy version� TPC command for scheduled PUSCH� Downlink Assignment Index (DAI) (only for TDD)� TPMI information for precoding – number� PMI confirmation for precoding

DCI format 1B is used for the compact scheduling ofone PDSCH codeword with precoding information



� 1 bit indicates the gap value� Hopping flag� Resource block assignment� Transport block size index

DCI format 1C is used for very compact scheduling ofone PDSCH codeword (allocation type2)

CRC scrambled with P-,RA-, or SI-RNTI (system

info RNTI) and usedmodulation scheme is

always QPSK



� Localized/Distributed VRB assignment flag� Resource block assignment� Modulation and coding scheme� HARQ process number� New data indicator� Redundancy version� TPC command for PUCCH� Downlink Assignment Index (for TDD only)� TPMI information for precoding� Downlink power offset

DCI format 1D is used for the compact scheduling ofone PDSCH codeword with precodingand power offset information



� Resource allocation header (allocation type0/1) 1 bit� Resource block assignment max 25bits� TPC command for PUCCH 2 bits� Downlink Assignment Index (for TDD only) 2 bits� HARQ process number 3 / 4 bits (FDD/TDD)� Transport block to codeword swap flag 1 bit� Precoding information 3 or 6 bits (2 or 4 antennas)

DCI format 2 is used for 2 Transport Blocks

Modulation and coding scheme 5 bitsNew data indicator 1 bitRedundancy version 2 bit

Modulation and coding schemeNew data indicatorRedundancy version

Transport block 1 Transport block 2


DCI – transport block to codeword mapping

transport block 1transport block 21

transport block 2transport block 10

codeword 1(enabled)

codeword 0(enabled)

transport blockto codeword

swap flag value

-transport block 2enableddisabled

-transport block 1disabledenabled

codeword 1(disabled)

codeword 0(enabled)transport block 2transport block 1

Transport block to codeword swap flag

2 transportblocks enabled

1 transportblocks enabled



� Resource allocation header� Resource block assignment� TPC command for PUCCH� Downlink Assignment Index (for TDD only)� HARQ process number� Transport block to codeword swap flag� Precoding information

DCI format 2A is used for 2 Transport Blocks



Transport block 1 Transport block 2



� TPC command number 1� TPC command number 2� ,…,� TPC command number N

DCI format 3 is used for the transmission ofTPC commands for PUCCH and PUSCHwith 2-bit power adjustments

Idea to send several TPC commandsto different UEs in parallel



� TPC command number 1� TPC command number 2� ,…,� TPC command number M

DCI format 3A is used for the transmission ofTPC commands for PUCCH and PUSCHwith single bit power adjustments

Idea to send several TPC commandsto different UEs in parallel


PDCCH layer 1/2 control channel contentsTransmission modes

l For DCI formats 1A and 1C, UE may be addressed via S-RNTI or P-RNTI orRA-RNTI (all common search space)

l UE-specific search space for the following transmission modes:1. Single-antenna port; port 02. Transmit diversity3. Open-loop spatial multiplexing4. Closed-loop spatial multiplexing5. Multi-user MIMO6. Closed-loop Rank=1 precoding7. Single-antenna port; port 5


Association of DCI formats to transmission modes

l Single-antenna port; port 0l Transmit diversityl Open-loop spatial multiplexingl Closed-loop spatial multiplexingl Multi-user MIMOl Closed-loop Rank=1 precodingl Single-antenna port; port 5


PDCCH layer 1/2 control channel contentsTransmission modes for C-RNTI usage


PDCCH layer 1/2 control channel contentsTransmission modes for SPS C-RNTI usage


PDCCH layer 1/2 control channel contentsTransmission modes for Temp. C-RNTI usage


DCI format – blind detection

Aggregation Level TTI Yk 0 1 2 3 4 51 12620 20 21 22 23 24 252 12620 40 42 44 46 48 504 12620 80 08 12620 0 8

PDCCH Candidate

•Based on L3 signaling, the UE knows which transmission mode•The size of the DCI message is known by the UE•The UE calculates the dedicated search space•Blind detection based on DCI format and aggregation level

Here 4aggregationlevels arepossible

For aggregation level 1 and 2there are 6 candidates,

For aggregation level 4 and 8are 2 candidates

-> UE blind detects 6+6+2+2= 16 possible DCIs

Example: UE is in transmission mode 3:DCI format 1A and 2A are possible.

Each DCI format has 16 possiblePositions in the dedicated search space

+ aggregation level.-> so the UE will do 16 (DCI 1A) +16 (DCI2A) = 32 blind detections


LTE Physical LayerUplink physical channels


LTE Uplink: channel mapping example

frequency

time

Allocated bandwidth

Total available bandwidth

Unscheduled Resource Blocks Scheduled PUCCH

Demodulation Reference Signal PUSCH

Sounding Reference Signal

Scheduled Resource Blocks Demodulation Reference Signal PUCCH

1su

bfra

me


Uplink channel coding + mapping

CCCH DCCH DTCHLogicalChannels

(MAC SDUs)

TransportChannels

(MAC PDUs)

PhysicalChannels

(signal)

RACH UL-SCH

PUSCHPRACHPUCCH

MAC Multiplexing

PHY Encoding, Modulation, MappingLayer 1 + 2Control

Either or


Uplink Control Information, UCI

PDSCH UCI on PUSCH or PUCCH:

•CQI, Channel Quality Indication

•Precoding Matrix Information, PMI

•Rank Indicator, RI

•ACK/NACK

•Scheduling requests

[W(i)] PMI= Whichprecoding matrixshall be used?

RI= number ofuseful transmission

layers, i.e.Min{NRX,NTX}

CQI= Transportformat andmodulationscheme?

New data orRetransmit?

ACK/NACK


PUCCH scheduling request, SR

SchedulingRequestConfig ::=CHOICE {release NULL,setup SEQUENCE {

sr-PUCCH-ResourceIndex INTEGER (0..2047),

sr-ConfigIndex INTEGER (0..155),

dsr-TransMax ENUMERATED {n4, n8, n16, n32, n64, spare3, spare2, spare1}}

}

SchedulingRequest

opportunity

Periodicity given in number of subframes by sr-ConfigIndex

SchedulingRequest

opportunity

SchedulingRequest

opportunity

0=m

0=m1=m

1=m2=m

2=m3=m

3=m

One subframe

0PRB =n

1ULRBPRB −= Nn

)1(SRIPUCCH,

)1(PUCCH nn =

UE specific indexpoint to position ofPUCCH

Maximum transmission of SRs

MAC-PDU

PUSCH

MAC layer has data to send, but no PUSCH available=> UE is allowed to send scheduling request


Uplink Control Channel (PUCCH)

QPSK+BPSK

QPSK+BPSK

QPSK

QPSK

BPSK

N/A

Modulation

22

21

20

2

1

On/Off

Bits persubframe

(CQI/PMI or RI)+ACK/NACK (normal CP only)

(CQI/PMI or RI)+ACK/NACK (normal CP only)

CQI/PMI or RI (any CP),(CQI/PMI or RI)+ACK/NACK (long CP only)

ACK/NACK, ACK/NACK+SR

ACK/NACK, ACK/NACK+SR

Scheduling Request (SR)

Contents

2b

2a

2

1b

1a

1

PUCCHformat

� Carries Uplink Control Information (UCI) when no PDSCH is transmitted� TDD: PUCCH is not transmitted in subframes containing the UpPTS field

� Channel quality reporting comprises Channel Quality Indicator (CQI),Precoding Matrix Indicator (PMI) and Rank Indicator (RI)

� CQI/PMI/RI are only signaled via PUCCH when periodic reporting isrequested. Scheduled/aperiodic reporting is only done via PUSCH


LTE Uplink:PUCCH: physical uplink control channel

freq

uenc

y

1 ms subframe

resource i

resource i

resource j

resource j

A control channel resource is defined by a code and two resource blocks,consecutive in time, with hopping at the slot boundary .

PUCCH region

Frequency diversity benefit given by this design

( )

( )

=+

−−

=+

=

12mod2modif2

1

02mod2modif2

sULRB

s

PRB

nmmN

nmm

n


PUCCH resource allocation

Format 2, 2a, 2b (m=0) Format 2, 2a, 2b (m=1)

Format 2, 2a, 2b (m=0)Format 2, 2a, 2b (m=1)

Format 1, 1a, 1b +2, 2a, 2b (m=…)

Format 1, 1a, 1b +2, 2a, 2b (m=…)

Format 1, 1a, 1b (m=…)

Format 1, 1a, 1b (m=…)Format 1, 1a, 1b (m=…)



Format 1, 1a, 1b (m=…)Format 1, 1a, 1b (m=NHORB)

Format 1, 1a, 1b (m=NHORB)Format 1, 1a, 1b (m=…)

Format 2, 2a, 2b (m=…) Format 2, 2a, 2b (m=N(2)RB)

Format 2, 2a, 2b (m=…)Format 2, 2a, 2b (m=N(2)RB)


Channel bandwidth

Resource blocksreserved for format2, 2a and 2b = N(2)

RBoptional

Resource blocksreserved forPUCCH = NHO

RB

Resource reserved for PUSCH

Edge of channelbandwidth

Only 1 RBfor mixed format

PUCCH RB index


PUCCH reference symbols position

N/A22a, 2b

122

231, 1a, 1b

Extended cyclicprefix

Normal cyclicprefix

PUCCHformat

Number of reference symbols per slot

N/A1, 52a, 2b

31, 52

2, 32, 3, 41, 1a, 1b

Extendedcyclic prefix

Normal cyclicprefix

Set of valuesPUCCHformat

Reference symbol location

0 1 2 3 4 5 6 0 1 2 3 4 5 6 0 1 2 3 4 5 6 0 1 2 3 4 5 6 time

Example: normal CPPUCCH format 1a

0 1 2 3 4 5 6 0 1 2 3 4 5 6 0 1 2 3 4 5 6 0 1 2 3 4 5 6 time

Example: normal CPPUCCH format 2a

PUCCHallocation

frequency

frequency


PUCCH formats 1, 1a & 1b: coding chain

ACK/NACKand/or

ACK/NACK + SR)()(

, nr vuα + *

PUCCHSequence z(n)

Cyclicallyshifted CAZAC

sequence12 possiblecyclic shifts

=

=otherwise

02mod)('if1)( 2πj

Ss e

nnnS

Scrambling with PUCCH indexspecific scramblingCode.

Sequence index )( soc nn Orthogonal sequences [ ])1()0( PUCCHSF −Nww L

0 [ ]1111 ++++

1 [ ]1111 −+−+

2 [ ]1111 +−−+

Spreadingwith orthogonal

cover code.3 possiblesequences

1 or 2 bits

Based on higher layer parameters PUCCH index and delta_shift

Depends on cellidentity + SC-FDMA symbol

numer andtimeslot


PUCCH formats 1, 1a & 1b: Multiplexing

ACK/NACKor

ACK/NACK + SR)()(

, nr vuα + *

PUCCHSequence z(n)



Spreadingwith orthogonal

cover code.3 possiblesequences

12 cyclic shift sequences and3 orthogonal sequences =>

Up to 36 UEs can sharemultiplexed PUCCH

resources But…Interference dueto multipath is

likely …

Scrambling with PUCCH indexspecific scramblingCode.

PUCCH resource format 1 = #Ref. Symbols * 12PUCCHshift∆


PUCCH formats 1, 1a & 1b: Multiplexing

111101751011

1091016489

97815367

85614245

73413123

61212k=0CSindex=0CSindex=1

OCindex=2OCindex=1OCindex=0

deltaoffset=0deltaoffset=1

PUCCH orthogonal cover OCCell specificcyclic shift offset

Example:Normal Cyclic prefixDelta_shift = 2

UE withIndex 14 usesOC with index = 2And cyclic shiftWith index = 4

PUCCHshift∆

= inter-cellInterferenceReduction by cellSpecific offset

=cyclic shiftdifference foradjacent ACKResources,HereΔ=2

To reduce interference,not all combinationsare allowed, hereDelta_shift = 2,reduces multiplexingto 18 PUCCH

PUCCHshift∆


PUCCH format 1, 1a & 1b: timing + allocation

t=0 t=1 t=2 t=3 t=4 t=5 t=6 t=7 t=8 t=9 t=0

AC

K/

NA

CK

PDSC

H

k+4

1 frame = 10 subframes

PDC

CH

0=m

0=m1=m

1=m2=m

2=m3=m

3=m

One subframe

0PRB =n

1ULRBPRB −= Nn

PUCCH resource is k+4 subframeslater than PDSCH

Position of PDCCHcontaining DCIdefines the PUCCHlocation.

(1)PUCCHCCE

)1(PUCCH Nnn +=

Location of PUCCH format 1,1a or 1B is given as:

Given by SIB 2

Position of CCE usedto send DCI on PDCCH

Resource optionallyreserved forPUCCH format2, 2a or 2b


PUCCH formats 2, 2a & 2b: coding chain

ACK/NACKand/or

CQI/PMI or RI

)()(, nr vuα

+PUCCH

Sequence z(n)



Scrambling with C-RNTIspecific scramblingCode.

20 bits

Depends onPUCCH index +

SC-FDMAsymbol numerand timeslot

( ) ( ) RNTI16cell

IDsinit 21212 nNnc +⋅+⋅+= 0 1 2 3 4 5 6

Z(n) is mappedOn data part ofPUCCH resource block

Format 2 = 20 bits

Format 2a = 21 bits

Format 2b = 22 bits

1

2

CAZACSequence as

Referencesymbol

Format 2a and 2b „steals“ the additional 1 or 2 bits tosubstitutes the reference symbol


PUCCH format 2, 2a & 2b: timing + allocationPUCCH resource follows rulesOf CQI and RI reporting

RankIndicator Wide

bandCQI

PMIRank

IndicatorWidebandCQI

PMI

WidebandCQI

PMI

Periodicity given in number of subframes by various RRC parameters

RBsc

(2)PUCCH Nnm =

UE specific RRC parameter:cqi-ReportConfig

UE specificPUCCH indexIdentifies position of PUCCH


MACMedium Access Control


MAC structure – UE side

RandomAccess Control

PCCH BCCH CCCH DCCH DTCH MAC-controlLogical Channels

PCH BCH DL-SCH UL-SCH RACHTransport channels

(De-) Multiplexing

Logical Channel Prioritization(UL only)

HARQ

Control

Data transferRadio resource allocation

Data transfer, CQI feedback,scheduling request + HARQ feedback


Layer 2 Structure for DownlinkMultiple applications


Layer 2 Structure for Uplink

Multiplexing

...

HARQ

Scheduling / Priority Handling

Transport Channels

MAC

RLC

PDCP

Segm.ARQ

Segm.ARQ

Logical Channels

ROHC ROHC

Radio Bearers

Security Security


MAC PDU structure

e.g. buffer status reports, C-RNTI,DRX commands,Timing advance,

power headroom,…

MAC Controlelement 1

...

R/R/E/LCIDsub-header

MAC header

MAC payload

R/R/E/LCID[/F/L]sub-header

R/R/E/LCID/F/Lsub-header

R/R/E/LCID/F/Lsub-header

... R/R/E/LCID/F/Lsub-header

R/R/E/LCID paddingsub -header

MAC Controlelement 2 MAC SDU MAC SDU Padding

(opt)

Fix sizeVariable size


MAC – prioritized bit rate PBRLogicalchannel

A

Logicalchannel

B

Logicalchannel

C

Total MAC-PDU size

PBR forLogicalchannelA

PBR forLogicalchannelB

PBR forLogicalchannelC

RRC configures eachLogical channel with aPrioritized bit rate PBR.MAC-PDU will be servedIn decreasing order ofPriority.

MAC-PDU is larger,So highest priority channel

Can send more data


RLC structure


Radio Link Control Protocol, RLC

Medium Access ControlMAC


Control &

MeasurementsRadio Link Control

RLC

User Plane

RLC SDU

RLC PDU

RLC SDUheader

Variable size possible

Lower layer notifiesTransmission opportunity

Logical channel


EUTRAN stack: RLC architecture

Transmittingtransparent

entity

Receivingtransparent

entity

Acknowledgedmodeentity

Transmittingunacknowledged

entity

Receivingunacknowledged

entity

BCCH/PCCHCCCH DTCHDCCH/

DTCH

TM-SAP AM-SAP UM-SAPC

ontro

l

Transparentmode

Acknowledgedmode

Unacknowledgedmode

SAP = Service Access Points


RLC PDU structure

SDU = Service Data UnitPDU = Packet Data Unit

Segmentation and concatenation of SDUs is possible (except TM mode)

Total size indicated by lower layer


PDCP structurePacket Data Convergence Protocol


PDCP structure viewRadio Bearers, RB

UE/E-UTRAN

PDCPsublayer

...

RLCsublayer

PDCP - PDU

RLC - SDU

C-SAP

PDCP-SAP PDCP-SAP

RLC UM-SAP RLC AM-SAP

...

PDCP entity PDCP entity

RRC control

Each PDCP entity carries data from 1 Radio Bearer

RB can be signaling radio bearer SRBorData radio bearer, DRB


PDCP functional overview

Radio Interface (Uu)

UE/E-UTRAN E-UTRAN/UETransmittingPDCP entity

Ciphering

Header Compression (u-planeonly)

ReceivingPDCP entity

Sequence numbering

Integrity Protection(c-plane only)

Add PDCP header

Header Decompression (u-plane only)

Deciphering

Remove PDCP Header

In order delivery and duplicatedetection (u-plane only)

Integrity Verification(c-plane only)

Packets associatedto a PDCP SDU

Packets associatedto a PDCP SDU

Packetsnot

assoc iat edto

aP

DC

PS

DU

Pa cket sn ot

assoc ia tedto

aP

DC

PS

DU

Max SDU size= 8188 octets

No compressionof data so far, onlyheader

Based on hyper frameand sequence number= COUNT

Timer baseddiscard function


PDCP re-establishment

Handover, withstatusReportRequired

Status reportAcknoledging PDUs

PDCP re-establishmentincluding retransmissions

Re-establishment resetsciphering and integrity protection


PDCP lossless handover in uplink

1 2 3 4 5 6

1

2

3

4

5

1

2

UE sends PDCP sequence number

PDCP PDUNr. 3 and 5are lost PDCP PDU

Nr. 1 and 2are ACK

S-GW12

4

Handover

3 4 5 6

After Handover: UE sends PDCP sequence number …

3

4

5

6

SourceeNB

TargeteNB

34

56


PDCP lossless handover in downlink

1 2 4

4

3

2

1

1

2

UE receives PDCP Nr. 1, 2 and 4

PD

CP

PD

UN

r. 3

islo

st

PDCP PDUNr. 1 and 2are ACK

S-GW1 2

4

Handover

3 4 5 6

6

5

4

3

SourceeNB

TargeteNB

98

76

3 4 5 LP

35LP

eNB retransmits packetsNr. 3 and 4, even if 4Is already received.

LP = Last Packet


RRC procedures


EstablishRRCConnection

ReleaseRRCConnection

UTRARRCConnectedModeUTRA:Inter-RATHandover

GSM:Handover

EstablishRRCConnection

ReleaseRRCConnection

URA_PCH CELL_PCH GSMConnected

Mode

EstablishRRConnection

ReleaseRRConnection

IdleMode

CampingonaUTRANcell1 CampingonaGSM/GPRScell1

GPRSPacketIdleMode1

GPRSPacket

TransferMode

Initiationoftemporaryblockflow

Releaseoftemporaryblockflow

Cell reselection

CELL_DCHoutofservice

inservice

CELL_FACH

outofservice

inservice

outofservice

inservice

RRC Protocol states WCDMA <-> LTE

RRC Idle state

RRC connectedstate

WCDMA protocol statesLTE protocol states


LTE Interworking with 2G/3GTwo RRC states: CONNECTED & IDLE

Handover

CELL_PCHURA_PCH

CELL_DCH

UTRA_Idle

E-UTRARRC CONNECTED

E-UTRARRC IDLE

GSM_Idle/GPRSPacket_Idle

GPRS Packettransfer mode

GSM_ConnectedHandover

Reselection Reselection

Reselection

Connectionestablishment/release



CCO,Reselection

CCO withNACC

CELL_FACH

CCO, Reselection


LTE Interworking with CDMA2000 1xRTT andHRPD (High Rate Packet Data)

Handover1xRTT CS Active

1xRTT Dormant

E-UTRARRC CONNECTED

E-UTRARRC IDLE

HRPD Idle

Handover

Reselection Reselection


HRPD DormantHRPD Active


System information broadcast

Master Information Block (on BCH),periodicity 40 ms:

System bandwidth, number oftransmit antennas, PHICH

configuration, SFN

System Information Block Type 1(on DL-SCH), periodicity 80 ms:PLMN IDs, Tracking Area Code,Cell identity, Access restrictions,

scheduling information,…

System information blocks withsame scheduling requirements

can be mapped to same SImessage (DL-SCH)

E-UTRAN

MasterInformationBlock

UE

SystemInformationBlockType1

SystemInformation

SI-RNTI is used on PDCCH toaddress System Information

Block Type 1 and SI messages


System information

l ETWS = Earthquake and Tsunami Warning System

MIB:Physical layer info

SIB Type 1:Access restrictions,SIB scheduling info

SIB Type 2:Common and

shared channel info

SIB Type 3:Cell reselection info

SIB Type 4:Cell reselection info,

intra-fr. neighbour info

SIB Type 5:Cell reselection info,

inter-fr. neighbour info


for UTRA


for GERAN


for CDMA2000

SIB Type 9:Home eNB identifier

(HNBID)

SIB Type 10:ETWS primary

notification

SIB Type 11:ETWS secondary

notification


Initial access procedure

UE eNB

Random Access Preamble1

Random Access Response 2

Scheduled Transmission3

Contention Resolution 4

Sent on PRACHresources associated with

RA-RNTI

Generated by MAC sent on DL-SCH with RA-RNTI; assignment

of Temporary C-RNTI, timingadvance, initial uplink grant

Sent on UL-SCH; includesNAS UE identifier and RRCCONNECTION REQUEST

Early contention resolution(mirroring of uplink message)generated by MAC sent on

DL-SCH


Initial access procedure

UE eNB

Random Access Preamble1

Random Access Response 2

Scheduled Transmission3

Contention Resolution 4

Sent on PRACHresources associated with

RA-RNTI

Generated by MAC sent on DL-SCH with RA-RNTI; assignment

of Temporary C-RNTI, timingadvance, initial uplink grant

Sent on UL-SCH; includesNAS UE identifier and RRCCONNECTION REQUEST

Early contention resolution(mirroring of uplink message)generated by MAC sent on

DL-SCH

Hopping flagFixed size resource block assignmentTruncated modulation and coding schemeTPC command for scheduled PUSCHUL delayCQI request


Paging

Paging

UE EUTRAN

Paging procedure is used to:

•Transmit paging information to a UE

•Inform about System Information Change

•Send Earthquake and Tsunami Warning


RRC Connection Establishment

RRCConnectionSetup

RRCConnectionRequest

UE EUTRAN

RRCConnectionSetupComplete


RRC Connection Reconfiguration

RRCConnectionReconfigurationComplete

RRCConnectionReconfiguration

UE EUTRAN

RRCConnectionReconfigurationFailure

RRCConnectionReconfiguration

UE EUTRAN

Also used forhandover


Signaling Radio Bearer, SRBSRBs are radio bearers for RRC and NAS control message transmission

SRB 0 for RRC messages using CCCH

SRB 1 for RRC messages (optional piggybacked NAS)using DCCH and beforeestablishment of SRB2

SRB 2 for NAS messages using DCCH.Lower priority than SRB1

Configured after security activation


EPS Bearer Service Architecture

P-GWS-GW PeerEntity

UE eNB

EPS Bearer

Radio Bearer S1 Bearer

End-to-end Service

External Bearer

Radio S5/S8

Internet

S1

E-UTRAN EPC

Gi

S5/S8 Bearer


Default EPS bearer setupUE EUTRAN

Initial access and RRC connection establishmentattach request and PDN connectivity request

Authentication

NAS security

UE capability procedure

AS security

RRC connection reconfigurationAttach accept and default EPS bearer context request

Default EPS bearer context accept


LTE Registrationincl. security activation

UE SS

RRC ConnectionnSetup

RRC ConnectionSetupComplete

NAS ATTACH REQUEST

NAS : AUTHENTICATION REQUESTNAS : AUTHENTICATION RESPONSE

NAS : SECURITY MODE COMMAND

NAS : SECURITY MODE COMMAND COMPLETE

RRC : SECURITY MODE COMMAND

RRC : SECURITY MODE COMMAND COMPLETE

RRC ConnectionReconfiguration

NAS ATTACH ACCEPT

NAS : ACTIVATE DEFAULT EPS BEARER CONTEXT REQ

RRC ConnectionReconfigurationComplete

NAS : ATTACH COMPLETE

NAS : ACTIVATE DEFAULT EPS BEARER CONTEXTACCEPT

contains

contains

RRC ConnectionnRequest

PDN CONNECTIVITY REQUEST


Defau

lt EPS

bear

er se

tup

RRC Connection ReleaseRRC←16

UL Information TransferAttach CompleteActivate Default EPS Bearer Context Accept

RRCNASNAS

→15RRC Connection Reconfiguration CompleteRRC→14

RRC Connection ReconfigurationAttach AcceptActivate Default EPS Bearer Context Request

RRCNASNAS

←13Security Mode Command CompleteRRC→12Security Mode CommandRRC←11

UL Information TransferSecurity Mode Command Complete

RRCNAS

→10

DL Information TransferSecurity Mode Command

RRCNAS

←9UE Capability InformationRRC→8UE Capability InquiryRRC←7

UL Information TransferAuthentication Response

RRCNAS

→6

DL Information TransferAuthentication Request

RRCNAS

←5

RRC Connection Setup CompleteAttach RequestPDN Connectivity Request

RRCNASNAS

→4RRC Connection SetupRRC←3RRC Connection RequestRRC→2SYSTEM INFORMATION (BCCH)RRC←1MessageLayer

Message SequenceUE eNBNo.


RRC measurement reportingl Measurement objects defines on what the UE has to

measure, e.g. frequency carrierl Reporting configuration periodic or event-triggered criteria

which cause to send measurement report + information of what toreport

l Measurement identities: A list of measurement identities whereeach measurement identity links one measurement object withone reporting configuration.

l Quantity configurations: The quantity configuration defines themeasurement quantities and associated filtering used for all eventevaluation and related reporting of that measurement type.

l Measurement gaps: Periods that the UE may use to performmeasurements, i.e. no (UL, DL) transmissions are scheduled.


RRC measurement reporting

l Event A1 (Serving becomes better than threshold)l Event A2 (Serving becomes worse than threshold)l Event A3 (Neighbour becomes offset better than serving)l Event A4 (Neighbour becomes better than threshold)l Event A5 (Serving becomes worse than threshold1 and neighbour

becomes better than threshold2)

l Event B1 (Inter RAT neighbour becomes better than threshold)l Event B2 (Serving becomes worse than threshold1 and inter RAT

neighbour becomes better than threshold2)


Non Access Stratummessages, procedures

& architecture


Protocol States (NAS and AS)

� EMM states:

� EMM-DEREGISTERED(UE location not known)

� EMM-REGISTERED(entered by Attach or Tracking Area Update procedure)

� RRC states:

� RRC_IDLE (no RRC context stored in eNodeB)

� RRC_CONNECTED (UE has E_UTRAN RRC connection and context)

EMM=EPS Mobility Management

ECM = EPS Connection Management

� ECM states:

� ECM-IDLE(no NAS signalling connection, UE performs cell(re)selection and PLMN selection)

� ECM-CONNECTED(UE location/cell ID known in MME, UE performshandover)


LTE NAS architecture, MS side

EMM SM- SAP

CM

RRCPDCP-EUTRAN Access Stratum sublayer

EMMASSAP

RB1 Bearer

ControlRB2

RB n

PDCPSAP

EMM

ESM

EMMREG- SAP

ESMREG-SAP

PDMM Sublayer

EBI

Radio Bearer from User plane


GUTI: Globally Unique Temporary Identifier

octet 13M-TMSI (continued)



octet 10M-TMSI

octet 9MME Code

octet 8MME Group ID (continued)

octet 7MME Group ID

octet 6MNC digit 1MNC digit 2

octet 5MCC digit 3MNC digit 3

octet 4MCC digit 1MCC digit 2

octet 3Type of identityodd/evenindic

1111

octet 2Length of EPS mobile identity contents

octet 1EPS mobile identity IEI

12345678


EMM states

EMM-DEREGISTERED EMM-REGISTERED

Attach accept

Detach,Attach Reject,TAU reject,E-UTRAN interface switched off due to Non-3GPP handover,All bearers deactivated

UEs location not known


EMM functions

l NAS signalling;l NAS signalling security;l Inter CN node signalling for mobility between 3GPP access networks

(terminating S3);l UE Reachability in ECM-IDLE state (including control and execution of paging

retransmission);l Tracking Area list management;l PDN GW and Serving GW selection;l MME selection for handovers with MME change;l SGSN selection for handovers to 2G or 3G 3GPP access networks;l Roaming (S6a towards home HSS);l Authentication;l Authorization;l Bearer management functions including dedicated bearer establishment;l Lawful Interception of signalling traffic;l Warning message transfer function (including selection of appropriate eNB);l UE Reachability procedures.


EMM: EPS Mobility ManagementEMM-NULL

EMM-TRACKING-AREA-UPDATING-

INITIATED

EMM-DEREGISTERED

- DETACH requested(not power off)

EMM-REGISTERED

Any state

EMM-DEREGISTERED-

INITIATED

- ATTACHrequested

DETACH requested(power off)

- DETACH accepted- Lower layer failure

- TAUrequested

- TAU accepted- TAU failed

EMM-REGISTERED-

INITIATED

EMM-SERVICE-REQUEST-INITIATED

- SR accepted- SR failed

- SR initiated

-

TAU rejected(#13, #15, #25)

-

- ATTACH rejected- Network init. DETACH requested- Lower layer failure

- enableS1 mode

- disable S1 andS101 mode

TAU rejected(other causes)

-

ATTACHaccepted anddefault EPS bearercontext activated

-

- enable S1 andS101 mode

- disableS1 mode

- Network init. DETACH requested- local DETACH- intersystem change to cdma2000®

HRPD completed

- SR rejected(#13, #15, #18,#25, #39)


Idle mode signaling reduction ISR

P-TMSIRAT-related TMSI

P-TMSIGUTI or RAT-related TMSI

RAU Acceptindicating "ISR Activated"

P-TMSIAny valueRAU Acceptnot indicating "ISR Activated"

GUTIRAT-related TMSI

GUTIP-TMSI or RAT-related TMSI

TAU Acceptindicating "ISR Activated"

GUTIAny valueTAU Acceptnot indicating "ISR Activated"

P-TMSIAny valueAttach Accept via GERAN/UTRAN(never indicates "ISR activated")

GUTIAny valueAttach Accept via E-UTRAN(never indicates "ISR activated")

TIN value to be set by the UE when receivingmessage

Current TIN value stored by UEMessage received by UE

•ISR is signalled explicitly by core network, i.e. TAU message

•Reduces signaling when inter-RAT cell reselection

•Sets TIN, Temporary Identity used in Next update


MME proceduresAuthentication

procedure

Authentication +Identity request

procedure


MME: Attach procedure


Initial attach procedure – complete view3. Identification Request

1. Attach Request

new MME OldMME/SGSN

Serving GW PCRF HSS

3. Identification Response

PDN GW

2. AttachRequest

eNodeBUE

4. Identity Request

4. Identity Response5a. Authentication / Security

17. Initial Context Setup Request / Attach Accept

First Uplink Data

19. RRC Connection Reconfiguration Complete18. RRC Connection Reconfiguration

20. Initial Context Setup Response

24. Modify Bearer Response

23. Modify Bearer Request

First Downlink Data

25. Notify Request

26. Notify Response

(B)

(A)

16. Create Session Response

12. Create Session Request

8. Update Location Request

9. Cancel Location

11. Update Location Ack

9. Cancel Location Ack

10. Delete Session Request

10. Delete Session Response

13. Create Session Request

15. Create Session Response

7. Delete Session Response

7. Delete Sesion Request

First Downlink Data (if not handover)

(C)

EIR

5b. ME Identity Check5b. Identity Request/Response

10. PCEF Initiated IP-CANSession Termination

7. PCEF Initiated IP-CANSession Termination

14. PCEF Initiated IP-CAN SessionEstablishment/Modification

6. Ciphered Options Request

6. Ciphered Options Response

23a. Modify Bearer Request

23b. Modify Bearer Response

(D)

21. Direct Transfer22. Attach Complete

(E)

(F)


Tracking Area Updatel Periodic Tracking Area Updates in idle mode keep the network

informed about whether a UE is in EUTRAN coverage or not. Asimilar mechanism is required at AS level so that the networkcan be kept informed that UE is in coverage while in ‘long lived’connected mode DRX.

l Indicate that in Connected Mode, network needs to be kept informedabout whether UE is in EUTRAN coverage by periodic updates atAS level


MME: Tracking Area Update


ECM, EPS connection management

ECM-IDLE ECM-CONNECTED

RRC connectionestablished

RRC connectionreleased

•No signaling connection between UE and network•UE monitors paging•UE performs tracking area update•Location of UE known based on TAI (if EMM registered)

•signaling connection between UE and MME•UE has RRC signaling radio bearer established•Mobility is handover procedure•Location of UE known based on cell ID


ESM: EPS session management


EMM connection management


Service Request procedureMME Serving GW PDN GW

2. NAS: Service Request

1. NAS: Service Request

7. S1-AP: Initial Context Setup Complete

3. Authentication/Security

HSS

4. S1-AP: Initial Context Setup Request

5. Radio Bearer Establishment

6. Uplink Data



UE eNodeB


PCRF

(A)10. PCEF Initiated IP-CANSession Modification


Go from EMM_IDLE toEMM_CONNECTED

When UL data is to be sentOr for MT/MO CS procedures


l PDN Connectivityl Allows UE to request connectivity to IPv4, IPv6 or IPv4v6 networkl Coupled to Establishment of a Default EPS Bearer

l Default EPS Bearerl Owns IP Address(es) for IPv4, IPv6 or IPv4v6 Connectionl Typically low QoSl Intended for „plumbing“ services (e.g. DNS, ICMP, ...)

l Dedicated EPS Bearerl Always linked to a Default EPS Bearerl Shares IP Address(es) with linked Default EPS Bearerl Requires Traffic Flow Template (TFT) to select Packetsl QoS depends on Application

LTE IP Connectivity


ESM: Default EPS Bearer

Default bearer = established with every new connection to PDN.Established over lifetime of PDN connection

No guaranteed bit rateIdentifies traffic flows that receive common QoS treatment

Initiated by network


ESM: Dedicated EPS bearer

Dedicated bearer = Traffic Flow Template TFT and QoS specific.(e.g. IP address, Port number, protocol information)

Quality of Service negociated between UE and network

Initiated by network,can be requested by UE


l TFT Operationsl Create new TFTl Add packet filters to existing TFTl Replace packet filters in existing TFTl Delete packet filters from existing TFTl Delete existing TFT

l Directionl ULl DLl Bi-directional

l Filter Typesl IPv4 remote addressl IPv6 remote addressl Protocol/NextHeaderl Local Portl Local Port Rangel Remote Portl Remote Port Rangel Security Param Indexl Type of Service/Traffic Classl IPv6 Flow Label

Traffic Flow Template (TFT) = IP Filtering


EPS Bearer – example with 2 unicast EPS bearer

Application / Service Layer

Radio Bearer S1 Bearer S5/S8 Bearer

UL Traffic Flow TemplatesDL Traffic Flow Templates

UL TFT -> RB IDUL TFT -> RB ID

DL TFTDL TFT

UE eNBServingGW

PDNGW


IP address allocation in LTE

l Home network allocates IP address (static or dynamic)l Visited network allocates IP address (static or dynamic)l External allocation, IP address is allocated by external PDN

l PDN types IPv4, IPv6 and IPv4v6 are supported

l A UE which is IPv6 and IPv4 capable shall request for PDN type IPv4v6.l A UE which is only IPv4 capable shall request for PDN type IPv4.l A UE which is only IPv6 capable shall request for PDN type IPv6.

l UE indicates to the network if it would like to receive the IPv4 addressduring default EPS beares setup or via DHCP after the default bearersetup procedure


IPv6 address allocation

PDN-GW

Default Bearer Establishment

Router solicitation message

Router advertising message

ExternalPDN

Ipv6 prefix(if externalAllocation)

•Contains IPv6 prefix as in default bearer•Link local identifier to generate IPv6 address

UE generates IPv6 address

UE IPv6 address is globallyUnique ->

IPv6 prefix is linked to IMSI


CSFB – Circuit Switched FallbackUE/MS MMEBSS/RNS MSCeNodeB SGSN Serving

GW

2. Optional Measurement Report Solicitation

4. A/Iu-cs message (with CM Service Request)4. CM Service Request

Location Area Update or Combined RA/LA Update

5. CM Service Reject 5. CM Service RejectIf the MSCis changed

3. PS HO as specified in 23.401 [2] (preparation phase and start of execution phase)

6. CS call establishment procedure

1a. Extended Service Request

1b. S1-AP Message with CS Fallback indicator

7. PS HO as specified in 23.401 [2] (continuation of execution phase)


There will be enough topicsfor future trainings ☺

Thank you for your attention!

Comments and questionswelcome!

Documents

IMP TA1!11!001 Day1 LTE Protocol