Juho Lee

Samsung Electronics

ICTC 2015

Evolution of LTE-Advanced in

3GPP Rel-13/14: a Path to 5G

2

Presentation Outline

• LTE/LTE-Advanced evolution: an overview

• LTE-Advanced in Rel-13

• Expectation for LTE-Advanced in Rel-14

• 3GPP plan for 5G

3

LTE/LTE-Advanced Evolution: An Overview

4

3rd Generation Partnership (3GPP) Project

• Initiated in December 1998 for development of wireless communication standards

• Collaboration between groups of telecommunications associations

– China: CCSA (China Communications Standards Association)

– Europe: ETSI (European Telecommunications Standards Institute)

– Japan: ARIB (Association of Radio Industries and Businesses), TTC (Telecommunication Technology Committee)

– Korea: TTA (Telecommunications Technology Association)

– USA: ATIS (Alliance for Telecommunications Industry Solutions)

– India: TSDSI (Telecommunications Standards Development Society of India)

• Specification work done in Technical Specification Groups

– GERAN (GSM/EDGE Radio Access Network): GERAN specifies GSM radio technology, including GPRS and EDGE

– RAN (Radio Access Network): RAN specifies UTRAN and E-UTRAN

– SA (Service and System Aspects): SA specifies service requirements and overall architecture of 3GPP system

– CT (Core Network and Terminals): CT specifies the core network and terminal parts of 3GPP

W-CDMA (1999)

HSDPA (2002)

HSUPA (2005)

LTE (2008) LTE-A (2010)

B4G (2014) B4G (2016)

DL: 16QAM

AMC, HARQ

UL: AMC, HARQ DL: OFDMA, MIMO

UL: SC-FDMA

CoMP, CA, eICIC

UL MIMO

backward compatible backward compatible

Rel-99 Rel-5 Rel-6 Rel-8/Rel-9 Rel-10/Rel-11

Small cells,

TDD-FDD

CA

Rel-12

FD-MIMO,

LAA, eMTC,

eCA

Rel-13

?

5

LTE/LTE-Advanced Roadmap

2014 2015 2016 2017 2018 2019

1H 2H 1H 2H 1H 2H 1H 2H 1H 2H 1H 2H

Rel-12

Rel-13

Rel-14

Rel-15

2014.12 2015.3

Stage 3 ASN.1 Start of deployment

Stage 3

2015.12

Start of deployment

Stage 3

2017.3

Start of deployment

Stage 3

2018.6

LTE Rel-8: First release of LTE specification (developed in 2008)

LTE-A Rel-10/Rel-11: LTE with 4G capabilities (developed in 2010/2012)

LTE-A Rel-12/Rel-13: LTE with Beyond 4G capabilities

2016.3

ASN.1

2017.6

ASN.1

2018.9

ASN.1

6

LTE/LTE-Advanced Evolution: Targets

• Enhancement: Larger bandwidth, more flexibility, new type of frequency resource

• Effect: Higher peak data rate (300Mbps 4Gbps 25.6Gbps)

Efficient Frequency Usage

• Enhancement: MIMO, higher order modulation, interference control/suppression

• Effect: Higher spectral efficiency (2.0bps/Hz 2.5bps/Hz 4+bps/Hz)

Higher Spectral Efficiency

• Enhancements: Broadcast, device-to-device, public safety, new terminal types

• Effect: Extension of LTE/LTE-A technologies into new applications

Support of New Services

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LTE/LTE-Advanced Evolution: Technologies

• (Rel-10) CA, (Rel-11) Enhanced CA, (Rel-12) TDD-FDD CA, Dual Connectivity

• (Rel-13) Licensed Assisted Access, Carrier Aggregation Beyond 5 Carriers

Efficient Frequency Usage

• (Rel-10) DL/UL MIMO Enh, eICIC, (Rel-11) CoMP, (Rel-12) Small Cell Enh, NAICS

• (Rel-13) Full Dimension MIMO

Higher Spectral Efficiency

• (Rel-8/9) eMBMS, (Rel-12) D2D, MTC

• (Rel-13) Enh MTC, PS-LTE

Support of New Services

8

LTE-Advanced Rel-13:

Full Dimension MIMO

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Concept of Full Dimension MIMO (1/2)

3 dimensional beamforming operation with 2D antenna array

Dynamic and flexible vertical or horizontal or 3D sectorization

3D UE-specific beamforming with high-order multiuser MIMO

Vertical sectors

Hotspot

Flexible V/H sectorization 3D beamforming

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Concept of Full Dimension MIMO (2/2)

Full Dimension MIMO system: 2D array structure with AAS (Active antenna system)

2D patch antenna array with PA integration

Flexible port to antenna array mapping (UE specific and/or cell-specific)

Enable 3D (vertical and horizontal) beamforming

Patch antenna

Feed network

8TX

(8Hx1V)

32TX

(8Hx4V)

FD-MIMO baseband

CPRIs

IP

LTE

infrastructure

FD-MIMO system

Baseband+PA

Passive antennas

Legacy system Flexible system

Flexible 2D port

mapping

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Beamforming with FD-MIMO

• Example 1: 70/70 degrees without down tilt

2×8 antennas 4×8 antennas 8×8 antennas

2×8 antennas 4×8 antennas 8×8 antennas

• Example 2: 70/70 degrees with down tilt

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Preliminary Performance Evaluation (1/2)

Evaluation of FD-MIMO with system level simulation

Based on new channel model: 3D UMa, 3D UMi

Number of antenna ports: 8, 16, 32, 64 ports

Overhead assumption: no overhead

Scheduling algorithm Evaluation scenario

Simple PF scheduling is applied

• Step1: Select best UE with SU-CSI

• Step2: Add UE if sum of PF metric is increased

with considering MU interference

• Step3: Recalculate CQI for MU scheduling

Parameter Value

Layout 19 cells with 3 sector

Scenario 3D UMa (ISD:500m), 3D UMi (ISD:200m)

TX power 46dBm(3D UMa), 41dBm (3D UMi)

Carrier frequency 2GHz

Bandwidth 10MHz

Number of UEs 10 UEs per cell

HARQ scheme IR asynchronous retransmission

Link adaptation LTE MCS selection with 10% BLER

CSI feedback Ideal subband Rel.10 SU-CSI

Channel estimation Ideal estimation without error

Element configuration 60º for both vertical and horizontal with

6.5dBi

UE mobility 3Km/h with 3D dropping

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Preliminary Performance Evaluation (2/2)

System performance of MU-MIMO

By increasing number of antennas in V or H domain:

Narrower beam provides significant MU gain (1x8)(1x64): x2.2 in avg, x4 in edge

With 2D array structure:

Can achieve significant gain with 3D beamforming (1x8)(8x8): x1.76 in avg, x3.3 in edge

Cell vs 5% edge throughput Cell throughput

64 ports

32 ports

16 ports

8 ports

1x64

2x32

4x16

8x8

1x32 2x16

4x8 8x4

4x4

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LTE-Advanced Rel-13:

Licensed Assisted Access

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Licensed vs Unlicensed Band

Licensed Band

Unlicensed Band

• License typically requires a fee (a big one)

Operator retains exclusive rights for use

• High transmission power (ex. 46dBm)

Suitable for providing large coverage

• Communication based on resource

allocation, link adaptation, HARQ

QoS can be guaranteed

• A frequency resource is used by single

radio access technology (ex. LTE, WCDMA)

• No license and therefore no fee (free)

Anyone can use

• Low transmission power (ex. 23dBm)

Coverage is limited

• Communication based on collision

avoidance

QoS cannot be guaranteed

• A frequency resource is used by multiple

radio access technologies (ex. Bluetooth, WiFi)

Licensed band and unlicensed band have different characteristics

LAA aims to provide licensed wireless experience in unlicensed band

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• Conventional LTE/LTE-A: Data and control signaling on licensed carrier

• WiFi: Data and control signaling on unlicensed carrier

• LAA: Data on licensed and unlicensed carrier but control on licensed carrier only

Licensed Assisted Access (LAA) Concept

Licensed f

Licensed f

Unlicensed f

Unlicensed f

UnLicensed f

Licensed f

Licensed Assisted

Mobility support, reliable data/control pipe

Data fat pipe

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Benefits of LAA

Enhanced User Experience Unified LTE Network

Cellular mechanism over unlicensed band

(coverage, mobility, QoS control) Same core elements

Improved spectral efficiency vs WiFi

(link adaptation, HARQ, interference management) Same mobility and security framework

Source: Huawei

18

LAA Deployment Scenarios

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LAA Performance (Indoor)

• System level evaluation for 3 setups

– WiFi performance in an area with two WiFi operators

– WiFi performance in an area with one WiFi operator and one LAA operator

– LAA performance in an area with one WiFi operator and one LAA operator

• Observations

– A: WiFi performance has improved LAA is a better neighbor to WiFi

– B: LAA performance is higher than WiFi LAA is more efficient than WiFi

Average User Perceived Throughput 5% Cell Edge UE Throughput

0

20

40

60

80

100

120

WiFi in WiFi only WiFi in WiFi+LAA LAA in WiFi+LAA

Mbps

Low load

Medium load

High load

A

B

0

10

20

30

40

50

60

70

80

WiFi in WiFi only WiFi in WiFi+LAA LAA in WiFi+LAA

Mbps

Low load

Medium load

High load

A

B

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LTE-Advanced Rel-13:

Carrier Aggregation Beyond 5 Carriers

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CA Beyond 5 Carriers

• Carrier aggregation history

– Rel-10: Introduction of CA (up to 5 carriers, 100MHz)

– Rel-11: TDD CA enhancement (flexible UL/DL ratios)

– Rel-12: TDD-FDD CA, dual connectivity (inter-eNB CA)

– Rel-13: CA with 32 CCs

• Carrier aggregation (CA) is the most successful LTE-A feature

– Every year, CA capability in terminals are enhanced 4CC CA coming soon

• In order to fully utilize unlicensed band, next generation CA is necessary

– Up to 32 component carriers: up to 640MHz and 25.6Gbps

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Key Specification Support

Carrier Aggregation of up to 32 CCs

• With the availability of unlicensed spectrum on 5.8GHz, significantly larger spectrum can be used for carrier aggregation

- Current CA specification supports up to 5 CCs and 100MHz

Category 8, 4Gbps

- Next generation CA specification will support up to 32 CCs

Combined bandwidth of up to 640MHz

At least on paper, data rate of 25.6Gbps

• Like all CA enhancements so far, collocated (or with ideal backhaul) scenario is assumed

• Key area of specification support is to enhance how uplink and downlink control information is conveyed

PUCCH on SCell

• Rel-12: PUCCH on SCell was introduced to support dual connectivity eNBs with non-ideal backhaul

- Due to non-ideal backhaul, L1 signaling cannot be

exchanged in real time

• Rel-13: PUCCH on SCell will be introduced to support inter-site eNB CA more efficiently

- Offloading of uplink L1 signalling

PUCCH PUCCH

PCell

SCell Ideal backhaul

Licensed band Unlicensed band

…1 2 3 4 5 6 32

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LTE-Advanced Rel-13:

Enhanced Machine Type Communications Narrow Band Internet of Things (NB-IoT)

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Further LTE PHY Layer Enhancements for MTC

• Key objectives

– UE Cost reduction (e.g. 1.4MHz narrowband operation)

– Coverage enhancement (15 dB improvement)

– UE Power Consumption reduction

• Expected benefits

– New revenue generation for operators by means of boosting coverage of LTE based MTC UE

– Enable new cellular IoT device targeted services

System bandwidth

MTC UE bandwidth (1.4MHz)

Coverage improvement (+15dB)

Reduced MTC UE power consumption

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Rel-13 Enhanced MTC vs Rel-12 MTC

• Feature comparison

Feature Cat-4 Cat-1 Rel-12 MTC Rel-13 eMTC

UE RF Bandwidth 20 MHz 20 MHz 20 MHz 1.4 MHz

DL Peak Rate 150 Mbps 10 Mbps 1 Mbps ~200 kbps

Max No of DL Layers 2 1 1 1

UL Peak Rate 50 Mbps 5 Mbps 1 Mbps ~200 kbps

No of RF Rx chains 2 2 1 1

Max UE Tx power 23 dBm 23 dBm 23 dBm ~20 dBm

Duplex Mode Full Full Half (optional) Half (optional)

Relative BOM Cost 125% 100% 50% 20-25%

Rel-12 MTC Rel-13 MTC Description

RF bandwidth 20 MHz 1.4 MHz Impact on control channels(PHICH, PCFICH, (E)PDCCH) and data channel scheduling

Reduced BW operation

Control: System BW Data: Reduced BW

Control : Reduced BW Data : Reduced RB

EPDCCH or new channel format for control channels

Coverage enhancement

No Yes Physical channel repetition, etc. required

Max. Tx Power 23 dBm ~20 dBm

Max. TBS size 1000 bits(unicast) 2216 bits(broadcast)

1000 bits (unicast and broadcast)

• Cost comparison (RP-141180)

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Narrow Band Internet of Things (NB-IoT)

• Need for efficient support of low throughput (up to ~40 kbps) and low complexity Machine Type

Communications with a very narrow bandwidth

– E.g., should be possible to reuse a GSM carrier(s) of 200kHz

• Targets

– Improved indoor coverage: 20 dB extension compared to legacy GPRS, i.e., target MCL = 164 dB

– Support for massive number of low throughput devices: ~ 50,000 devices / macro cell site

– Ultra low cost

– Improved power efficiency: up to 10-year battery life of 5Wh (e.g., AA battery)

– Relaxed delay sensitivity: 10 seconds for uplink event-triggered reporting

• Current status and standardization plan for inclusion in Rel-13 – GERAN conducted a feasibility study on CIoT from May 2014 to August 2015 (TR 45.820)

– RAN started a work item NB-IoT in Sep 2015 with targeting completion in March 2016

• 180 kHz UE RF bandwidth for both downlink and uplink

• Supported scenarios: stand-alone, LTE in-band, LTE guard band

• Strive for a single solution among proposed technologies

– Downlink: OFDMA w/ 15 kHz subcarrier spacing vs 3.75 kHz subcarrier spacing

– Uplink: SC-FDMA w/ 2.5 kHz subcarrier spacing vs

GMSK FDMA w/ 5 kHz subcarrier spacing (3.75k symbols/s) and channel bonding

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Expectation for LTE-Advanced in Rel-14

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FD-MIMO Enhancement

• Completion of Rel-13 FD-MIMO work item will enable specification support for

– Non-precoded CSI-RS for 16 ports that is mapped to TXRUs in 2D (ex: 4 x 4, 2 x 8, 8 x 2)

– Beamformed CSI-RS

– CSI taking into account the 2D array structure (codebook, periodic/aperiodic reports)

– Enhanced SRS and DMRS

• Rel-14 eFD-MIMO will build upon the above features to provide

– Support for 32 antenna ports and more with (potentially) more flexible antenna array configuration

– Improved performance, extended applicability (use cases)

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LAA Enhancement

• Potential areas of enhancement include LAA UL support (if precluded from Rel-13) and other

left-over items from Rel-13

– Framework for uplink LBT to be defined in Rel-13

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Latency Reduction

• Latency reduction is always important to maximize user experience

• A study item has already started aiming to provide specification support in Rel-14

• Important to keep backward compatibility to support Rel-14 as well as legacy UEs

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V2X

• Motivation

– V2X services require low latency and high reliability

– Market opportunity for enhanced D2D to be used for V2V applications

• Aspects for consideration

– Communications: massive-scale resource allocation with low overhead

– Network: real-time data collection, computing and routing

– Sensing: enhanced positioning accuracy

– Inter-PLMN support, spectrum for V2V (dedicated spectrum or shared spectrum)

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3GPP Plan for 5G

33

5G timeline in 3GPP (SP-150149)

IMT-2020 specifications

Evaluation

5D#23Feb 16

5D#26Feb 17

5D#27Jun 17

Requirements

Evaluation criteria

Initial submissions of proposals

5D#28Oct 17

5D#32Jun 19

5D#31Oct 18

5D#34Feb 20

5D#36Oct 20

RAN#70Dec 15

channel modeling

RAN#69Sep 15

RAN#72Jun 16

RAN#86Jun 20

RAN SI: scope & requirements

HSPA/LTE evolution

IMT

20

20

RAN WG SI: evaluation of solutions RAN WG WI: specification of solutions

Fina

l 3G

PP

subm

issi

on

Init

ial 3

GPP

su

bmis

sion

IMT 2020

requirements

RAN#71 Mar 16

Rel-13 freeze

RAN Workshop

3G

PP

requ

irem

ents

SA system work

RAN-SA Workshop

SA1 SMARTER SI SA1 SMARTER WI

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5G Usage Scenario

• Support for various usage scenarios such as eMBB, mMTC, and UR/LL

• New RAT(s) to utilize various spectrum bands up to 100 GHz

Enhanced Mobile Broadband

Mobile Cloud Computing

UHD Streaming

Ultra Reliability / Low Latency

Smart Vehicle Industrial Automation

Massive Machine-type Comm.

Smart Home/ Smart City

U-Health/Wearables

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5G Requirement (to be developed from Dec 2015)

• Example requirement set

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Details of 3GPP plan for 5G standards

• There will be a new, non-backward compatible, radio for 5G

– LTE evolution will continue in parallel

• Phasing approach

– Phase 1 (Rel-15) to be completed around Sep 2018 to address a more urgent subset of the commercial needs

– Phase 2 (Rel-16) to be completed by Dec 2019 for the IMT2020 submission and to address all identified use cases and requirements

• Detailed work plan in 3GPP RAN

– Study item on channel model for high frequency bands above 6 GHz started in September 2015

– RAN to approve in December 2015 a study item to develop scenarios and requirements for 5G radio technology

– RAN to approve in March 2016 a study item for RAN WGs to evaluate technology solutions for 5G radio technology

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Thank you