lte in-depth (sf)

8/14/2019 LTE In-depth (SF)

http://slidepdf.com/reader/full/lte-in-depth-sf 1/11

LID_SFO_1_120706

Network Architecture

QPSK Quadrature Phase Shift KeyingRRC Radio Resource Control

S1AP S1 Application Protocol

SGW Serving Gateway

SRB Signalling Radio BearerUSIm Universal Subscriber Identity Module

UTRAN Universal Terrestrial Radio Access Netwo

X2AP X2 Application Protocol

ARQ Automatic Repeat Request AS Access Stratum

C-RNTI Cell Radio Network Temporary Identity

DRB Data Radio Bearer

eNB Evolved NodeBEPC Evolved Packet Core

EPS Evolved Packet System

E-RAB E-UTRAN Radio Access Bearer

MME Mobility Management EntityNAS Non Access Stratum

OFDM Orthogonal Frequency Division Multiplexi ng

PCRF Policy and Charging Rules Function

PDCP Packet Data Convergence ProtocolPGW Packet Data Network Gateway

QAM Quadrature Amplitude Modulation

QoS Quality of Service

36.300 23.401

eNB

eNB

PCRF

PGW

HSS

SGW

MME

IMS/Internet/…

• Security: Authentication and key agreement

• Registration: Attach, Tracking Area Update

Provides QoS policiesand charging rules

SGi

S11(GTP)

S1-MME

(S1AP)

S1-U

(GTP)

X2-C(X2AP)

S5

(GTP)

S6a

(Diameter)

Uu

(RRC)

Uu

Subscription profiles

Security parameters

• Bearer mgmt: Default and dedicated bearers

RRC Connection

Signalling RB (SRB)

S1 Connection

NAS Signalling Connection

X2-U(GTP)

+ + = EPS BearerData RB (DRB) S1 Tunnel S5 Tunnel

• Radio Resource Control• Channel aware scheduling

5 UE categories

DL: 10-300 Mb/s

UL: 5-75 Mb/s

GxQoS aware

routingRx

UE identities

USIM id: IMSI

Radio id: C-RNTI

EPC id: GUTI

• Shared data channels

• 1ms Transmission Time Interval• Multi-layer Re-Tx (ARQ and HARQ)• Adaptive modulation (QPSK/xQAM)

• OFDM and MIMO (2 or 4 antennas)

• System Bw: 1.4, ..., 5, …, 20 MHz

LTE Radio Techniques

NAS securit

y

AS security

E-UTRAN + EPC

Control Plane

interface

User Plane

interface

(PDCP)

E-UTRAN RAB (E-RAB)

E-UTRAN Evolved UTRANGTP GPRS Tunnelling Protocol

GUTI Globally Unique Temporary Identity

HARQ Hybrid Automatic Repeat Request

HSS Home Subscriber ServerIMS IP Multimedia Subsystem

LTE Long Term Evolution

MIMO Multiple Input Multiple Output



LID_SFO_2_120706

NAS ProtocolsEMM and ESM

PDN Packet Data Netwo

QoS Quality of Service

SHT Security Header TyTA Tracking Area

TAU Tracking Area Upd

IMEI International Mobile Equipment Id.

MME Mobility Management Entity

NAS Non Access StratumPCRF Policy and Charging Rules Function

PD Protocol Discriminat or

NAS

RRC

PDCP

RLC

MAC

PHY

RRC

PDCP

RLC

MAC

PHY

S1AP

SCTP

IP

L1/L2

S1AP

SCTP

IP

L1/L2

NAS

UE

eNB

MME

Uu S1-MME

Registration in EPS,

IP-addr alloc.

Request IMSI (or IMEI)

Mutual authentication

and key agreement

Activate security context

(ciphering and integrity)

Idle to Conn transition

Request secure NAS conn.

EMM Procedures

UE power off orNW initiated

Registration Proc:

Security Proc:

Attach

Identification

Authentication

Security Mode Ctrl

Tracking Area Update

Service Request

Detach

Connection Mgmt:

MME

Normal (new TA)

or periodic (T3412)

NAS Signalling Conn.

Triggered by:

- UL data/signalling or

- Paging

EMM EPS Mobility Management

eNB Evolved NodeB

EPS Evolved Packet SystemESM EPS Session Management

HSS Home Subscriber Server

Dedicated EPS Bearer CTX Act.

Default EPS Bearer CTX Act.

Bearer Resource Allocation Req

PDN Connectivity Req

ESM Procedures

MMENAS Signalling Conn.

Default EPS bearer:- Static QoS (from HSS)

- One per PDN Connection

Dedicated EPS bearer:

- Dynamic QoS (from PCRF)

- One or more /PDN Connection

Sec. Header Type

EPS Bearer ID

Protocol

Discriminator

Procedure Transaction ID

Message Type

Other Infirmation Elements

(mand/opt/cond)

Only for

ESM messages

5678 1234

EMM or ESM

Links Request with Response

Protected

or not

Plain NAS Message

SHT PD=EMM

Message

Authentication

Code (4 oct)

Sequence Number

Plain NASMessage

Protected Message



LID_SFO_3_120706

MME

PDNSGW

PGW

SGSN

HSS

May be optimised by:

• UE & location-specific TA lists

• Alignment of TAs and RAs

• Idle Mode Signalling Reduction (ISR

• UE-specific list

• based on mobility history

• refreshed each TAU

1TIN = GUTI

Initial Attach

Old GUTI

1 Bearer/session

CreationTA 2

2 TA change

no TAU needed

TIN = GUTI

TA 1

3 RAT Change

• RAU is needed

• PTMSI & RAI derived

from GUTI

”old” PTMSI, RAI

1

old PTMSI & RAI

ISR = activated

3

UE Context

Retrieval

UE MM and PDN

Contexts

HSS maintains

double registration

K ASME CK, IK

PDN CTX

PDP CTX

3

Bearer modification

possible QoS change

SGSN address,

ISR = activated

3

new PTMSI, RAI

ISR = activatedRA 1RA 2

While ISR Active4

• UE can move between

RA1/TA1/TA2 with no update

• Independent periodic TA/RA timers

• UE stores PTMSI/RAI and GUTI

TIN = RAT-related TMSI

23.401, 24.3015 RAU ISR Deactivation

Signalled to UE in RAU Accept

TIN = PTMSI

No LTE Coverage

ISR meaningless

ISR Deactivation Triggers

• No LTE coverage

• RAU to pre-R8 SGSN

• Failed periodic registration

• Bearer act/mod after ISR act.

Idle Mode Mobility

RAT Radio Access TechnologyRAU Routing Area Update

SGW Serving Gateway

TA Tracking AreaTAU Tracking Area Update

TIN Temporary Id used in Next Update

TMSI Temporary Mobile Subscriber Ident

ASME Access Security Management EntityCK Ciphering Key

GUTI Globally Unique Temporary Id.

HSS Home Subscriber ServerIK Integrity Key

ISR Idle Mode Signalling Reduction

MM Mobility Management

MME Mobility Management EntityPDP Packet Data Protocol

PDN Packet Data Network

PGW Packet Data Network GatewayPTMSI Packet TMSI

RA Routing Area

RAI Routing Area Identity



LID_SFO_4_120706

SGSN

E-UTRAN PDN

MME

ePDG/

AAA

eNB

GERAN

UTRAN

Non-3GPP

IP-access

BSC/

RNC

SGW

PGW

e.g. WLAN, WiMAX

Fixed access etc

• Access authentication

• QoS authorization

• Generates charging data

S2a/S2b (PMIP)

If Gn-SGSN:

PGW assumes

GGSN roleIf Gn-SGSN:

EPS QoS mapped to

UMTS QoS profile

If Gn-SGSN:

MME assumes

SGSN role

Always:

Convert K ASME

CK, IK

Non-optimised Mobility

IETF mobility solutions used:

- MIPv4 or DSMIPv6

- MIP tunnel UE PGW/ePDG

Handover/Cell Change• Standard 3GPP signalling

• EPS adapts to target system

(Security, QoS, containers)

UE Mobility Capability

R8 Feature Group Indicators:

• PS HO to UTRAN/GERAN?

• Meas event B1 and/or B2?

RAN Features:

• PS HO support?

• DTM support?

• QoS support?

RAN Container:

UE RAC and

RB description

RAN Container:

Radio interface

HO Command msg

Optimised Mobility

Tunneling of non-3GPP msgs

- UE pre-registration- Handover execution

CDMA2000

HRPD S101 (GTPv2)

Trusted

Connected Mode Mobility


PMIP Proxy Mobile IPRAC Radio Access Capability

RAN Radio Access Network

RB Radio Bearer

RNC Radio Network ControllerSGSN Serving GPRS Support No

GGSN Gateway GPRS Support Node

GTP GPRS Tunnelling ProtocolHRPD High Rate Packet Data

IETF Internet Engineering Task Force

IK Integrity Key

K ASME ASME KeyMIPv4 Mobile IPv4

AAA Authentication, Authorization, Accounting

ASME Access Security Management EntityBSC Base Station Controller

CK Ciphering Key

DSMIPv6 Dual Stack Mobile IPv6

DTM Dual Transfer ModeePDG Evolved Packet Data Gateway

If S4-SGSN:

EPS QoS mapped to

UMTS QoS profile


http://slidepdf.com/reader/full/lte-in-depth-sf 5/11LID_SFO_5_120706

CS Fallback

GERAN/

UTRANMSC/

VLR

BSC/

RNCPSTN/ISDN

SGsAP

SCTP/IP

L1/L2

E-UTRANPDN

(IMS)SGW

MME

PGW

GMSC

Voice Domain Selection (UE):

- Terminal capabilities

- User preference/setting

- Network policy/indication

- Registration status (IMS/CS)

- Ongoing call/session

• Registration (Attach & LAU)

• Paging and Service Request

• SM transfer (no fallback)

SGs

23.272, 29.118

Simultaneous PS Session:

- Handed over and continued

- Suspended during CS call

- Disconnected (GBR service)

SGSN

HSS

CS or IMS

call?CS call7

SM-SC

SM

4

PS Handover

involving SGSN

and SGW

3Paging with

CN domain = CS

Paging

(if ISR active)3

1Combined Attach or

TA/LA Update

CS Call setup6

5 Paging Respose MT call: MSISDN2( IMSI LAI MME)

Mapping from TA

to (default) LA

CS Fallback

• No IMS voice support in UE/NW

(or CS voice preferred in UE)

• Requires TA, LA alignment

• Combined registration needed

(PS session)


SCTP Stream Control Transmission PrSGsAP SGs Application Protocol

SM Short Message

SM-SC Short Message Service CenterTA Tracking Area

CSFB Circuit Switched Fallback

DTM Dual Transfer ModeGBR Guaranteed Bit Rate

HO Handover

IMS IP Multimedia SubsystemISR Idle Mode Signalling Reduction

LA Location Area

LAI Location Area IdentityLAU Location Area Update

MGCF Media Gateway Control Function

MSISDN Mobile Station ISDN NumberMT Mobile Terminating

SMS over

SGs or IP?



NAS

RRC

PDCP

RLC

MAC

PHY

RRC

PDCP

RLC

MAC

PHY

S1AP

SCTP

IP

L1/L2

S1AP

SCTP

IP

L1/L2

NAS

UE

eNB

MME

Uu S1-MME

36.321

A/N ACK/NACK

BSR Buffer Status Report

CQI Channel Quality IndicatorC-RNTI Cell RNTI

DL-SCH Downlink Shared Channel

HARQ Hybrid Automatic Repeat RequestLogCH Logical Channel

MCS Modulation and Coding Scheme

PDCCH Physical Downlink Control ChannelPDU Protocol Data Unit

PHICH Physical HARQ Indicator Channel

PHR Power Headroom Report

• Channel and QoS aware • Dynamic scheduling:

UE monitors PDCCH each TTI

• Semi - Persistent scheduling:

Preconfigured periodic resource

• Random access: Initial access,

HO access, TA update (UE init)

• Addressing: x-RNTI

• TA Update: eNB init when needed,

UE init when TA timer expires

• Buffer Status Reporting (BSR) Periodic, new higher prio data,

# padding bits > BSR size

• Power Headroom Reporting (PHR)

Periodic, when pathloss change > X

MAC Control Procedures

RA-PREAMBLE

PDCCH: RA-RNTI

RA-RESPONSE:

UL grant, TA, C-RNTI

C-RNTI/ P-RNTI/ SI-RNTI

DATA/ PAGING/ SYS INFO

DATA [ TA UPDATE ]

DATA [ BSR/PHR ]

Scheduling

PDCCH: MCS & PRBs

DL-SCH

PUCCH/PUSCH: A/N

UL-SCH

PHICH: A/N

HARQ Operation

• 8-process Stop-and-Wait HARQ

• DL: Asynchronous, Adaptive

• UL: Synchronous, eNB controlled

MAC Architecture (eNB)

LogCHs

De-multiplexing LogCH

Multiplexing

DL assign.

UL grants

Schedulers

DL & UL

CQI, SR

HARQ

(8 proc)

UL-SCH

HARQ A/NHARQ A/N

LogCHs QoS parameters

UE capabilities

DL-SCH

1 Transport Block (= MAC PDU)

per TTI to PHY

HARQ

(8 processes)

PUCCH?

Use Grant!

RESP?

GRANT?

Send SR!

Initiate RA!N

YY

N

Y

N

Scheduling Request Sequence(UL Grant needed)

SR is repeated until an

UL Grant is received PRB Physical Resource Block

P-RNTI Paging RNTI

PUCCH Physical Uplink Control ChannePUSCH Physical Uplink Shared Channe

RA Random Access

RA-RNTI Random Access RNTIRNTI Radio Network Temporary Ident

SI-RNTI System Information RNTI

SR Scheduling RequestTA Timing Advance

TTI Transmission Time Interval

UL-SCH Uplink Shared Channel

BSR

PHR

Medium Access Control Protocol



Layer 1 Information Processing - Part 1

P2 Parity 2 bits

PhyCH Physical Channel

RV Redundancy VersionS Systematic bits

TB Transport Block

TTI Transmission Time Interv

CONV Convolutional Coder

CRC Cyclic Redundancy Check

DL-SCH Downlink Shared ChannelFDD Frequency Division Duplex

MIMO Multiple Input Multiple Output

P1 Parity 1 bits

DL-SCH Channel Coding

CRC 24(bit error

detection)

Code Block

Segmentation

Turbo CodingR=1/3

(bit error

correction)

Sub-block

Interleaving

ScramblingModulation

Antenna &

resource mapping

Code Block

Concatenation

Rate matching

(circular buffer)

Example:

Fixed Reference Channel

R.11 FDD

If input > 6144 bits

CRC24 added per block

Parity bits are

interlaced

MIMO:

1 or 2

TB/TTI

Depends on:

- Wanted code rate

- Available PhyCH bits

- Redundancy version

12960 bits 12984

4352 /block

(3 blocks) 13068/ block

Includes 12

termination bits

Described in 36.2

3 blocks: 26400 bits

= 1 Code Word

8800 /block

1 TB

S

P1

P2

Circular Buffer Rate Matching

S S

P1

.

.

.

P2P1

P2

.

.

.

Redundancy version 0 (RV0)

always contains ALL

systematic bits

RV1

Convolutional

coder 1

CONV

coder 2

Inter

leaver

Turbo Coder

1 code block

(4352 bits)

Systematic bits (S) + 3 bits

Parity 1 bits (P1) + 3

Parity 2 bits (P2) + 3

3Termination bits

RV2

36.212



Layer 1 Information Processing - Part 2DL-SCH Scrambling and Modulation

RE Resource Element

RNTI Radio Network TemporaTB Transport Block

Tx Transmission/Transmit

XOR Exclusive-Or

DL-SCH Downlink Shared Channel

IFFT Inverse Fast Fourier TransformOFDM Orthogonal Frequency Division Multiplex ing

QAM Quadrature Amplitude Modulation

QPSK Quadrature Phase Shift Keying

36.211

Cell-specific

Scrambling

Modulation

(QPSK/xQAM)

LayerMapping

(symbols

1-4 layers)

Precoding(mapping to

1,2 or 4

antennas)

RE Mapping

.

.

.

.

.

.

RE Mapping

OFDM (IFFT)

OFDM (IFFT)

.

.

.

.

.

.

Code Word q1

(if MIMO)

Code Word

q0

Depends on Tx mode:

- Single antenna tx

- Tx diversity

- Spatial multiplexing

- Beamforming

Pseudo-random

bit sequence

’Mixing’ data,

control channels

and reference

signals

Not standardised

6600 16QAM

symbols

2 layers26400 bits

(3 code blocks)2 antenna

ports

6600 REs needed

(8400 available/port)

Mod. symbol RE

Xi Yi

Extend to

desired

length

Initiate

sequence

Cinit Cn

Cinit = (RNTI × 214 ) + (q × 213 ) + ns/ 2 × 29 + PhyCell-ID

Purpose

dependent

Fixed rules

in specs

Code Word

number

Slot

number

Code

Word

Scrambling Sequence

Randomizes inter-cell interference

Phy Cell IDPhy Cell ID

RNTI

UE ’de-masks’ all DL signals

with cell-specific scrambling seq.

Sequence Generation

(PDSCH example)

D li k T i i P d



NACK P1

Minimum HARQ RTT = 8 subframes

need 8 Processes

DL

UL

1 subframe

DL Retransmissions:

Always scheduled

(may be adaptive)

PDCCH: DL Assignment

• UE-ID: RNTI

• PRBs: bitmap/RIV

• MCS (TB size implicit)

• HARQ info: RV, NDI

• HARQ Process Id

• PUCCH TPC

PUCCH

DATA

P1

Re-Tx

P1

DATA

P5

PDSCH

• On PUCCH: Periodic (2-128ms)

• PUSCH: Aperiodic (on eNB request)

• Both: Wideband or subband

PCFICH

CQI: downlink channel quality

PMI: preferred precoding

RI: preferred # layers

PMI Precoding Matrix IndicationPRB Physical Resource Block

PUCCH Physical Uplink Control CH

PUSCH Physical Uplink Shared CH

RI Rank IndicatonRIV Resource Indication Value

MIMO Multiple Input Multiple OutputNDI New Data Indicator

P (HARQ) Process

PCFICH Physical Control Format Indicator CH

PDCCH Physical Downlink Control CHPDSCH Physical Downlink Shared CH

RNTI Radio Network Temporary Id.RTT Round-Trip Time

RV Redundancy Version

SPS-RNTI Semi Persistent Scheduling RN

TB Transport BlockTPC Transmit Power Command

CQI Channel Quality IndicatonC-RNTI Cell RNTI

CSR Channel Status Reporting

DCI Downlink Control Informat ion

HARQ Hybrid Automatic Repeat RequestMCS Modulation & Coding Scheme

DL/UL Scheduling

Dynamic (C-RNTI):

- PDCCH read each TTISemi-persistent (SPS-RNTI):

- Preconfigured resource

- ’PDCCH-less’

Bitmap allowsDistributed

PRB allocation

CSR

(A/N)

PUSCH

ACK P5DATA P7

CSR

PUCCH PUCCH

Physical

Resource Blockpair

Downlink Transmission ProceduresScheduling and HARQ

U li k T i i P d



Scheduling Request

• TA valid: SR on PUCCH

• TA invalid: SR on PRACH

• TA timer: 500-10240 ms

UL Retransmissions

PHICH: non-adaptiv

With PDCCH: adaptiv

DCI Format 0

• UE-ID: RNTI

• PRBs: RIV

• MCS, RV, NDI

• PUSCH TPC

• CQI request ind.

PUSCH withUL control info

PHICH

NACK for P1

(acts as

implicit grant)

DL

UL

1 subframe

PUSCH

Scheduling

Request

DATA

P7

DATA P1Re-Tx P1

A/N (CSR)

PUSCH

DATA P5

PHICH

A/N for P5

DCI 0 & DCI 1/2

UL grant &

DL assignm.

DCI 3

Transmit Power

Commands to

multiple UEs

UCI Formats:

1: Scheduling Request

1a: ACK/NACK, 1 TB

1b: ACK/NACK, 2 TB

2: CQI/PMI/RI2a: CQI..., 1 A/N

2b: CQI..., 2 A/N

PUCCH

region

PUSCH

for all

UEs

PUCCH

Sounding RS (SRS)

• Periodic SRS (2-160ms) used for:

- UL CH quality estimation

- input for TA regulation

- input for power control

• Wideband or hopping narrowband

PUSCH transmission

forbidden in all

SRS symbols

PUCCH Physical Uplink Control CHPUSCH Physical Uplink Shared CH

RI Rank Indicaton

RIV Resource Indication Value

RNTI Radio Network Temporary Id.RV Redundancy Version

NDI New Data IndicatorPDCCH Physical Downlink Control CH

PHICH Physical HARQ Indication CH

PMI Precoding Matrix Indication

PRACH Physical Random Access CHPRB Physical Resource Block

SR Scheduling RequestSRS Sounding Reference Sig

TA Timing Advance

TB Transport Block

TPC Transmit Power CommanUCI Uplink Control Informat io

CQI Channel Quality IndicatonCSR Channel Status Reporting

DCI Downlink Control Informat ion

HARQ Hybrid Automatic Repeat Request

MAC Medium Access ControlMCS Modulation & Coding Scheme

Uplink Transmission ProceduresScheduling and HARQ

lte in-depth (sf)

Documents