1. lte uu interface protocol stack

7/25/2019 1. LTE Uu Interface Protocol Stack

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www.huawei.com

Copyright 2015 Huawei Technologies Co., Ltd. All rights reserved.

LTE Air Interface &Signaling A-Z

Workshop

Prepared by: Ramy KhalilNA NPS Department


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Contents

1- LTE Uu interface protocol Stack

2- LTE Physical layer Basic concepts and processing procedures

3- LTE Signaling procedures and UE initialization flow

4- LTE Typical signaling procedures

Page1


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Contents


LTE Protocol stack Introduction

NAS, RRC, PDCP, RLC & MAC Functions

Signal processing in PHY layer

OFDM & SC-FDMA overview

MIMO Introduction.

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Introduction

eNB

UE

E-UTRA

1.4MHz, 3MHz,5MHz, 10MHz,15MHz, 20MHz

Uu

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Copyright 2015 Huawei Technologies Co., Ltd. All rights reserved. Page4

Introduction


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UE

PDN-GW

E-UTRAN EPC

MME

S-GW

eNB

S1-MME

S1-U

S5/S8

S11

LTE Control Plane and User Plane

NAS ControlPlane

RRCControlPlane

User

Plane

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User plan Protocol stack

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DL & UL Data processing of User Plan

Page8


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DL & UL Signaling processing ofControl Plan

Page9


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Contents



NAS, RRC, PDCP, RLC MAC Functions



MIMO Introduction.

Page10


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NAS Signaling

UE eNB

MME

EMM (EPS MobilityManagement)

ESM (EPS SessionManagement)

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NAS EMM and ESM ProceduresEMM Procedures ESM Procedures

Attach Default EPS Bearer Context Activation

Detach Dedicated EPS Bearer Context Activation

Tracking Area Update EPS Bearer Context Modification

Service Request EPS Bearer Context Deactivation

Extended Service Request UE Requested PDN Connectivity

GUTI Reallocation UE Requested PDN Disconnect

Authentication UE Requested Bearer Resource Allocation

Identification UE Requested Bearer Resource Modification

Security Mode Control ESM Information Request

EMM Status ESM Status

EMM Information

NAS Transport

Paging

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Radio Resource Control

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RRC States

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RRC Signaling Radio Bearer

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eNB

RLC

MAC

PHY

PDCP

RRC

NAS Signaling

Control Plane

EncryptionIntegrity Checking

User PlaneIP Header CompressionEncryption

Sequencing and Duplicate Detection

Packet Data Convergence Protocol

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IP Header Compression

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Radio Link Control

eNB

RLC

MAC

PHY

PDCP

RRC

NAS Signaling

TM (Transparent Mode)

UM (Unacknowledged Mode)

AM (Acknowledged Mode)Segmentation and Re-assembly

Concatenation

Error Correction

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Transmission Modes

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AM Use ARQ

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Concatenation & Segmentation

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Medium Access Control

eNB

RLC

MAC

PHY

PDCP

RRC

NAS Signaling

Channel Mapping and Multiplexing

Error Correction - HARQ

QoS Based Scheduling

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Scheduling

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Scheduling strategies

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TB, TTI & Transmission Format

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HARQ

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If receiver demodulate Receiver will combine

The data in error, it will retransmitted data

Save the data and and initial data. If

Feedback NACK correct, receiver would

feedback ACK.


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ARQ vs. HARQ

ARQ

Implemented at RLC LayerSlow Retransmission

Not optimized for Radio Interference

HARQ

Not New used in HSPA and HSPA+Implemented at MAC and PHY Layers

Fast RetransmissionOptimized for Radio Interference

Improved system efficiency

eNBUE

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LTE Channels

RLC

MAC

PHY

LogicalChannels

Transport

Channels

Physical

Channels Radio

Channel

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LTE Release 8 Transport Channels

BCH

eNBUE

PCH

DL-SCH

RACH

UL-SCH

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Physical Layer

eNB

RLC

MAC

PHY

PDCP

RRC

NAS Signaling

Error Detection

FEC Encoding/Decoding

Rate Matching

Mapping of Physical Channels

Power WeightingModulation and Demodulation

Frequency and Time Synchronization

Radio Measurements

MIMO Processing

Transmit DiversityBeamforming

RF Processing

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Contents






MIMO Introduction.

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LTE Transport Channel Processing


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Transport Block CRC

CRC

CalculateCRC

Transport Block

Transport Block

Transmitter

Possible radiointerface errors

CRCTransport Block

CalculateCRC

CRC

Compare

Receiver


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Code Block CRC Attachment andSegmentation

CRCTransport Block

Transport Block CRC

CRC

Code Block #1 Code Block #2 Code Block #3

Code Block CRCFiller Bits


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Channel CodingTransport Channel Coding Options

Transport Channel Coding Method Rate

DL-SCH

Turbo Coding 1/3UL-SCH

PCH

MCH

BCH Tail Biting Convolutional Coding 1/3


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Rate Matching

dk(1)

dk(0)

dk(2)

Sub-block

Interleaver

Sub-block

Interleaver

Sub-block

Interleaver

vk(1)

vk(0)

vk(2)

Bit

Collection

wk

Virtual

Circular

Buffer

Bit Selection

and Pruning

ek


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AntennaPorts

OFDM Signal Generation

Codewords

Scrambling

Scrambling

ModulationMapper

Modulation

MapperLayer

Mapper Precoding

Layers

Resource

ElementMapper

Resource

ElementMapper

OFDMSignal

Generation

OFDMSignal

Generation

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Scrambling

eNB eNB

PRB PRB

F1 F1

Interference

NoScrambling

PRB PRB

LessInterference

Cell RNTI

specificscrambling

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The scrambling feature statistically improves the interference by scrambling the

information with a scrambling code based on the physical cell ID and RNTI.


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Modulation Mapper

I

Q

1-1

1

-1

0

1

I

Q

1-1

1

-1

00

01

10

11

I

Q

1 3-1-3

1

3

-1

-3

0000 0010

0001 0011

0100 0110

0101 0111

1000

1001

1100

1101

1010

1011

1110

1111

BPSK QPSK 16QAM

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64 QAM Modulation Mapper

I

Q

1 3 5 7-1-3-5-7

1

3

5

7

-1

-3

-5

-7

000011 000001 001001 001011

000010 000000 001000 001010

000110 000100 001100 001110

000111 000101 001101 001111

010011 010001 011001 011011

010010 010000 011000 011010

010110 010100 011100 011110

010111 010101 011101 011111

100011

100010

100110

100111

110011

110010

110110

110111

100001

100000

100100

100101

110001

110000

110100

110101

101001

101000

101100

101101

111001

111000

111100

111101

101011

101010

101110

101111

111011

111010

111110

111111

64QAM

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Codeword, Layer and Antenna PortMapping

1 Layer 2 Layers 3 Layers 4 Layers

1 1 2 1

Rank 1 Rank 2 Rank 3 Rank 4

2 2 2 21 1

Codeword

1, 2 or 4

AntennaPorts

2 or 4

AntennaPorts

4 Antenna

Ports

4 AntennaPorts

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Contents





OFDM SC-FDMA Overview

MIMO Introduction.

Page47

O (O h leneral Revision


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OFDM(Orthogonal Frequency

Division Multiple Access)

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eneral Revision

OFDM is a type of Multi-Carrier Transmission.

OFDM is a special case of FDM Technology.

It is a way of FDM but with the condition of orthogonality

OFDM is the DL Accessing Technique for LTE.

Think About the benefi ts?


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Frequency Division Multiplexing

Frequency

Guard Band

Channel

Bandwidth

Subcarrier

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OFDM Subcarriers

Frequency

Channel

Bandwidth

OrthogonalSubcarriers

Centre SubcarrierNot Orthogonal

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Inverse Fast Fourier Transform

Coded

Bits

Serial

to

Parallel

Subcarrier

Modulation

IFFT

Inverse FastFourier

Transform

RF

Complex

Waveform

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FFT

Fast Fourier

Transform

Fast Fourier Transform

Receiver

Subcarrier

Demodulation

CodedBits

Parallelto

Serial

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OFDM Symbol Mapping

Time

Frequency

Amplitude

OFDM

Symbol

Cyclic

Prefix

Modulated

OFDM

Symbol

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Inter Symbol Interference

1stReceivedSignal Delayed

Signal

Interference

Caused

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OFDM & SC-FDMA

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OFDM


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OFDMPeak to Average Power Ratio

Amplitude

Time

OFDM

Symbol

PAPR (Peak to AveragePower Ratio) Issue

Peak

Average

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Contents



RRC, PDCP, RLC & MAC Functions



MIMO Introduction

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MIMO Historical Overview


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Overview

Multi antenna systems is the use of multiple receive and/or transmit antennas

If one transmitting and many receiving, is called SIMO(single input multi output)

If many transmitting and one receiving, is called MISO(multi input single output)

If many transmitting and many receiving, is called MIMO(multi input multi output)

Multi antenna techniques are used to increase system performance including

capacity, coverage, QoS.


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Benefit of MIMO


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MIMO Channel Model


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MIMO Modes

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UL MIMO Technology

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i


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Beam Forming

The idea of beam forming is to direct the antenna

radiation pattern towards a certain group of users in a

certain place

This is done by multiplying by a certain pre-codingMatrix calculated from user feedback about the channel

spatial characteristics

Beam Forming increases the SINR and decreases theinterference

It is not used till now in any operator


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MIMO Transmission modes

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Adaptive MIMO scheme

CQI, RI & PMI

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1. lte uu interface protocol stack

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