lte basic principle introduction v2

8/18/2019 LTE Basic Principle Introduction v2

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S

HUAWEI TECHNOLOGIES CO., LTD.

What’s LTE

LTE Basic Principle Introduction

Name: Paul

Email:[email protected]


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Content

LTE Background

LTE Key Technologies

LTE Network Architecture

LTE Resource Overview

LTE Market Overview


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HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential Page 3

Download speed

150M

LTE

What’s LTE ?

Download

speed

171.2Kbps

2G

Download speed

14.4Mbps

3G

2 day

43 minutes

4 minutes


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LTE Background Introduction

What is LTE？

LTE (Long Term Evolution) is known as the evolution of

radio access technology conducted by 3GPP.

The radio access network will evolve to E-UTRAN (Evolved

UMTS Terrestrial Radio Access Network), and the correlated

core network will evolved to SAE (System Architecture

Evolution).

What can LTE do？

Flexible bandwidth configuration: supporting 1.4MHz, 3MHz,

5MHz, 10Mhz, 15Mhz and 20MHz

Peak date rate (within 20MHz bandwidth): 150Mbps for downlink

and 50Mbps for uplink

Time delay:


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Procedure of LTE Standardization

3GPP started LTE project in December 2004.

The SI (Study Item) was planned to finish in June 2006 but has been delayed until September 2006. Finisresearch and output technical reports.

The WI (Work Item)/standard institution stage was started in September 2006. The first version was plann

September 2007 but has been delayed.

The first GA protocol version was released in the end of 2008. Protocol 36.xxx series are for LTE.

The protocol is still under consummating.


LTE WI stageLTE SI stageDelayed

2006

Mar2006

Jun

2006

Sep

2005

Dec

2006

Dec

2007

Dec

2008

Dec

2007

Jun

2008

Jun

2007

Mar

2007

Sep

2008

Mar

2008

Sep

2009

Mar

LTE eand im

LTE Rel8(Approval)

LTE SI

LTE WI

LTE Rel8(Spec finished)


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SAE Brief Introduction

SAE System Architecture Evolution）considers evolution for the whole system architecture, including：

Flat Functionality. Take out the RNC entity and part of the functions are arranged on e-NodeB in order to redu

enhance the schedule ability, such as interference coordination, internal load balance, etc.

Part of the functions are arranged on core network. To enhance the mobility management, all IP technology is

and control-plane are separated. The compatibility of other RAT is considered.

SGi

S4

S3 S1-MME

PCRF S7

S6a

HSS

O(

S10

UE

GERAN

UTRAN SGSN

“ LTE - Uu ” EUTRAN

MME

S11

S5 ServingSAE

Gateway

PDNSAE

GatewayS1-U



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SON Brief Introduction

SON (Self Organization Network) is the functions of LTE that required by the NGMN (Next Generation M

operators. From the point of view of the operator’s benefit and experiences, the early communication systems had b

compatibility and high cost. New requirements of LTE are brought forward, mainly focus on FCAPSI (Fau

Alarm, Performance, Security, Inventory) management:

Self-planning and Self-configuration, support plug and play

Self-Optimization and Self-healing

Self-Maintenance

Advantages of SON Reduce OPEX. Lower cost for operator in

planning, optimization and maintenance.

Vendor promote the sale of features and tools to

reduce the cost of network optimization after

deployment.


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Content

LTE Background

LTE Key Technologies



LTE Market Overview


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Radio Frame Structures Supported by LTE:

Type 1, applicable to FDD

Type 2, applicable to TDD

FDD Radio Frame Structure:

LTE applies OFDM technology, with subcarrier spacing f=15kHz and 2048-order IFFT.

The time unit in frame structure is Ts=1/(2048* 15000) second

FDD radio frame is 10ms shown as below, divided into 20 slots which are 0.5ms. One

slot consists of 7 consecutive OFDM Symbols under Normal CP configuration

#0 #1 #2 #3 #19#18

One radio frame, T f = 307200T s = 10 ms

One slot, T slot = 15360T s = 0.5 ms

One subframe FDD Radio Frame Structure

Concept of Resource Block:

LTE consists of time domain and frequency domain resources. The minimum unit for schedule is RB

(Resource Block), which compose of RE (Resource Element)

RE has 2-dimension structure: symbol of time domain and subcarrier of frequency domain

One RB consists of 1 slot and 12 consecutive subcarriers under Normal CP configuration

Radio Frame Structure (1)


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TDD Radio Frame Structure:

Applies OFDM, same subcarriers spacing and time unit

with FDD.

Similar frame structure with FDD. radio frame is 10ms

shown as below, divided into 20 slots which are 0.5ms.

The uplink-downlink configuration of 10ms frame are

shown in the right table.

One slot,

T slot=15360T s

GP UpPTSDwPTS

One radio frame, T f = 307200T s = 10 ms

One half-frame, 153600T s = 5 ms

30720T s

One subframe,

30720T s

GP UpPTSDwPTS

Subframe #2 Subframe #3 Subframe #4Subframe #0 Subframe #5 Subframe #7

Uplink-downlink Configurations

Uplink-downlink

configuration

Downlink-to-Uplink

Switch-point periodicity

0 1 2

0 5 ms D S U

1 5 ms D S U

2 5 ms D S U

3 10 ms D S U

4 10 ms D S U

5 10 ms D S U

6 5 ms D S U

DwPTS

GP: Gu

UpPTS:

TDD Radio Frame Structure

Radio Frame Structure (2)


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LTE Key Technologies- Overview

Sub-frame

Time

System Bandwid

Sub-carriers

Sub-frame

Frequency

Time

Time frequencyresource for User 1



System Bandwidth

MIMO

OFDMA

LTE

SC-FDMA

64QAM


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OFDM & OFDMA

OFDM (Orthogonal Frequency Division Multiplexing) is a

modulation multiplexing technology, divides the system

bandwidth into orthogonal subcarriers. CP is inserted

between the OFDM symbols to avoid the ISI. OFDMA is the multi-access technology related with OFDM, is

used in the LTE downlink. OFDMA is the combination of

TDMA and FDMA essentially.

Advantage: High spectrum utilization efficiency due to

orthogonal subcarriers need no protect bandwidth. Support

frequency link auto adaptation and scheduling. Easy to

combine with MIMO.

Disadvantage: Strict requirement of time-frequency domain

synchronization. High PAPR.

DFT-S-OFDM & SC-FDMA

DFT-S-OFDM (Discrete Fourie

OFDM) is the modulation mult

in the LTE uplink, which is sim

release the UE PA limitation caEach user is assigned part of t

SC-FDMA（Single Carrier Fre

Accessing）is the multi-acces

DFT-S-OFDM.

Advantage: High spectrum util

orthogonal user bandwidth nee

Low PAPR.

The subcarrier assignment sch

mode and Distributed mode.

OFDMA & SC-FDMA

TTI: 1ms

System Band

Sub-band 12Sub-carriers

Time

TTI: 1ms

System Band


Time

Sub-carriers

TTI: 1ms

Frequency

Time

System Bandwidth


User 1

User 2

User 3

Sub-carriers

TTI: 1ms

Frequency

Time

System Bandwidth


User 1

User 2

User 3

User 1

User 2

User 3


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Downlink MIMO

MIMO is supported in LTE downlink to achieve spatial

multiplexing, including single user mode SU-MIMO and multi

user mode MU-MIMO.

In order to improve MIMO performance, pre-coding is used in

both SU-MIMO and MU-MIMO to control/reduce the

interference among spatial multiplexing data flows.

The spatial multiplexing data flows are scheduled to one

single user In SU-MIMO, to enhance the transmission rate

and spectrum efficiency. In MU-MIMO, the data flows are

scheduled to multi users and the resources are shared within

users. Multi user gain can be achieved by user scheduling in

the spatial domain.

Uplink MIMO

Due to UE cost and power consumpti

implement the UL multi transmission

Virtual-MIMO, in which multi single an

to transmit in the MIMO mode. Virtua

Scheduler assigns the same resource

transmits data by single antenna. Sys

the specific MIMO demodulation sche

MIMO gain and power gain (higher Tx

freq resource) can be achieved by Vi

the multi user data can be controlled

also bring multi user gain.

Pre-coding vectors

User k data

User 2 data

User 1 data

Channel Information

User1

User2

User k

Scheduler Pre-coder

S1

S2

Pre-coding vectors

User k data

User 2 data

User 1 data

Channel Information

User1

User2

User k

Scheduler Pre-coder

S1

S2

User 1 data

Channel

Scheduler

MIMO

Decoder User k data

User 1 data

User 1 data

Channel

Scheduler

MIMO

Decoder User k data

User 1 data

DL-MIMO Virtual-MI

MIMO


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LTE 4Rx：Coverage Gain 3dB Capacity Gain 6

2Rx

4Rx

UL 4Rx helps UL coverage by 60%50~100%

2Rx

4Rx

2Rx4Rx

Cell edge use

UL cell level t

UL user perfo

edge > cell m

No increase C

Stable KPIs

Gain

UL User

Tput

Field

Higher diversity andarray gains =>

maximize SINR

3dB

UL Cell Edge User Tput UL Cell Level Tput

LTE 4T DL C ll Ed U T t G i 36%


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LTE 4Tx：DL Cell Edge User Tput Gain 36%Cell Capacity Gain 20%!

~36% ～20%

2Tx2Tx

4Tx4Tx

DL MAC

Throughput

(Mbps)

RSRP=-119dBm

RSRP=-92dBm

Ave DL user T

4x2

4Tx

Array and diversity gains by using 4

antennas to transit 2 data streams

improvement36%

20%

Field Res

DL Cell Edge User Tput DL Cell Level Tput


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Description• Two component carriers (CC) can be aggr

wider transmission bandwidth for downlink,or non-contiguous .

CA Overview

Benefits•Improved throughput

•Improved spectrum flexibility: CA with carri

frequency bands

Dependency• 2 RRU to support inter-band CA

• Terminal support to get aggregated bandw


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CA : Testing Result for O Operator

0

500

Non-CA(BW 20M) CA(BW: 20M+20M)

U

e

T

M

b

BW:10M+20M. 2*2 MIMO

Lab Peak Rate Test

BW：20M＋20M100

Field Peak Rate Test: 290([email protected][email protected]

Avg THP=290M

Avg PCC=146Mbps

Avg SCC=144Mbps

Chipset Vendor QCT Intel Hisilicon

DL CA（10M+10M）

2013Q2 2013Q4 2013Q3

DL CA（20M+20M）

2014Q2 2013Q4 2013Q3

Field Load Test: 290M([email protected]+20M@1.

0

500

Non-CA(BW 10M) CA(BW: 10M+20M)

U

e

T

M

b

BW:10M+20M. 2*2 MIMO

BW：10M＋20M200

18 |


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Resource Grid in Time Frequency Domai

One downlink slot, Tslot

Resource element

OFDM symbolsDLsymb N OFDM symbolsDLsymb N

N s c

s u b c a r r i e r s

R B

Resource block

RBsc

DLsymb N N resource elements

N R B

D L


N s c R

B

One uplink slot, Tslot

0l Nl

N R B

U L

N R B

U L


N

s c R

B

SC-FDMA symbolsULsymb N


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Scalable Bandwidth Supported

Transmission

Bandwidth [RB]

Transmission Bandwidth Configuration [RB]

Channel Bandwidth [MHz]

Resourceblock

Channeledge

Channeledge

DC carrier (downlink only)Active Resource Blocks

Channel bandwidthBW

Channel [MHz]

1.4 3 5 10 15 20

Transmission bandwidthconfiguration N RB

6 15 25 50 75 100

Transmission bandwidth configuration NRB in E-UTRA channel bandw

Figure shows the relation between the Channel bandwidth (BWChannel)

Transmission bandwidth configuration (NRB).


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Achievable & Supported Peak Data Rates

Achievable LTE Peak Data RatesAccounts for overhead at different bandwidths& antenna configurations

DL UL

Bandwidth 2x2 4x4 1x2

5MHz 37Mbps 72Mbps 18Mbps



UE Cat. 1 2 3 4

DL 10 50 100 150

UL 5 25 50 50

UE Supported Peak Data RBased on FDD UE category in 3GPP s

Peak data rates scale with the bandwidth

2x2 MIMO supported for initial LTE deployments

Similar peak data rates defin


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LTE Downlink Speed Calculate,20MHz,2x2 MIMO

Peak Rate=[100*12*14*(1-9.5%-0.2%-12%-0.17%-0.2%-1.375

=154.33Mbps100: 100RB,20MHz

12:12 Subcarriers, One RB has 12 Subcarriers

14:14 OFDM Symbols, One Subframe has 14OFDM symbols

9.5%:RS Overload

0.2%:P-SCH,S-SCH Overload

12%:PDCCH Overload0.17%:PCFICH and PHICH Overload

0.2%:PBCH and PDSCH Overload

1.375%:PDSCH Overload

6: 64QAM, RE has 6 bits

2:2x2MIMO


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LTE Uplink Speed Calculate,20MHz

Peak Rate=[96*12*2*7(1-1/7-1/14)*4]/1ms

=50.69Mbps96: 96RB,20MHz,PUSCH available 96RB,

12:12 Subcarriers, One RB has 12 Subcarriers

2 and 7:2 slot, one slot has 7 symbols(Normal CP)

1/7:RS Overload expense

1/14:SRS Overload expense

4: 16QAM, RE has 4 bits

T i i B d idth C l l ti


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Transmission Bandwidth Calculation

Scenarios Dens Urban Urban Suburban Rural

Trans. Bandwidth(20MHz, S111) 170Mbps 145Mbps 102Mbps 93Mbps

Results:

Bandwidth= (S1 User Plane Data Flow+S1 Control Plane+X2 Data Flow)*Scenario Burst Coefficie

=(S1 User Plane Data Flow+S1 User Plane Data*2%+S1 User Plane Data*3%)*Scenario

=S1 User Plane Data Flow*(1+5%)*Scenario Burst Coefficient/89.5%

Calculation Functions:

Bandwidth Scenarios DL Mbps) UL Mbps)

2T2R(20MHz) Dense Urban, Urban 34.3 19.8

2T2R(20MHz) Suburban, Rural 26.3 14.0

Cell Average Throughput:

Scenario Dense

Urban

Ur

coefficient 1.4 1.

Scenario Burst Coeffi


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Content

LTE Background LTE Key Technologies



LTE Market Overview


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Main Network Element of LTE

The E-UTRAN consists of e-NodeBs, providing the user

plane and control plane.

The EPC consists of MME, S-GW and P-GW.

eNB

MME / S-GW MME / S-GW

eNB

eNB

S 1

S 1

S 1

S 1

X2

X 2X 2

E-UTRAN

internet

eNB

RB Control

Connection Mobility Cont.

eNB Measurement

Configuration & Provision

Dynamic Resource

Allocation (Scheduler)

PDCP

PHY

MME

S-GW

S1

MAC

Inter Cell RRM

Radio Admission Control

RLC

E-UTRAN EPC

RRC

Mobility

Anchoring

EPS Bearer Control

Idle State Mobility

Handling

NAS Security

P-GW

UE IP address

allocation

Packet Filtering

RRC: Radi

PDCP: Pack

RLC: Rad

MAC: Med

PHY: Phy

EPC: Evo

MME: Mob

S-GW: Serv

P-GW: PDN

Compare with traditional 3G network, LT

becomes much more simple and flat, wh

lower networking cost, higher networkin

shorter time delay of user data and contr

Network Interface of LTE

The e-NodeBs are interconnected with each other by means of the X2 interface, which enabling direct tra

data and signaling.

S1 is the interface between e-NodeBs and the EPC, more specifically to the MME via the S1-MME and t

the S1-U

LTE N k El F i


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eNB

RB Control

Connection Mobility Cont.

eNB Measurement

Configuration & Provision

Dynamic Resource

Allocation (Scheduler)

PDCP

PHY

MME

S-GW

S1

MAC

Inter Cell RRM

Radio Admission Control

RLC

E-UTRAN

RRC

Mobility

Anchoring

EPS Bearer Co

Idle State MobHandling

NAS Securi

e-Node functionalities:

RRM: RB control, admission control, connection mobility

control, scheduling; IP header compression and encryption of user data

stream; Selection of an MME at UE attachment;

Routing of User Plane data towards Serving Gateway;

Schedule the paging and broadcast messages from

MME;

Measurement and measurement reporting configuration

for mobility and scheduling;

MME functionalities:

NAS signaling and security;

AS Security control;

Idle state mobility handling; EPS (Evolved Packet System) bearer control;

Support paging, handover, roaming and authentication. S-GW functionalities:

Packet routing and forwarding; Lo

point for handover; Lawful intercep

charging per UE, PDN, and QCI; A

and QCI granularity for inter-opera

P-GW functionalities:

Per-user based packet filtering; UE IP address allocation;

UL and DL service level charging, gating and rate enforcement;

LTE Network Element Function


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Introduction of LTE Radio Protocol Stack

Two Planes in LTE Radio Protocol:

User-plane: For user data transfer

Control-plane: For system signaling transfer

Main Functions of User-plane:

Header Compression

Ciphering

Scheduling

ARQ/HARQ

eNB

PHY

UE

PHY

MAC

RLC

MAC

PDCPPDCP

RLC

eNB

PHY

UE

PHY

MAC

RLC

MAC

RLC

NAS

RRC RRC

PDCP PDCP

Main Functions of Control-plane:

RLC and MAC layers perform the sa

user plane

PDCP layer performs ciphering and

RRC layer performs broadcast, pagi

management, RB control, mobility fu

reporting and control

NAS layer performs EPS bearer man

security control

User-plane protocol stack

Control-plane protocol stack

Comparison of UTRAN & E UTRAN Network Archite


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Comparison of UTRAN & E-UTRAN Network Archite

eNB

MME / S-GW MME

eNB

S 1

S 1

S 1

X2

X 2X 2

The main difference between UMTS and LTE: the removing of RNC network element a

introduction of X2 interface, which make the network more simple and flat, leading lowe

cost, higher networking flexibility and low latency

UTRAN

LTE Interworking With 2G/3G Networks


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LTE Interworking With 2G/3G Networks

LTE-UE

Evolved UTRAN (E-UTRAN)

Evolved P

MME

S6a

Serving

Gateway

S1-U

S11

S1-MME

PDN

Gateway

PCRF

S7

SGiS5/S8

HSS

SGSN

S3UTRAN

Iu-PS

S4

Evolved

Node B

(eNB)

cell

LTE-Uu

GERANGb

Gr

GGSNGn Gi


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Content



LTE Resource Overview LTE Market Overview

LTE Resource Capacity Assessment System


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eNodeB

eNodeB

LTE Resource Capacity Assessment SystemCAir InterfaceTerminal

Ethernet

MPT CPU

Utility

BBP CPU

Utility

Ethernet

Utility

RRC

Connected Usr

PRB Utility

Spectrum

Efficiency

Flow License

Utility

Sub. License

Utility

User Plane

PRACH Utility

PDCCH Utility

PUCCH Utility

SRS Utility

Paging Utility

Control Plane

eNodeB Transmission

Equipment Transmission

Avg. Sub. DL

Throughput

Avg. DL

Throughput

License

LTE Resource Capacity Assessment


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LTE Resource Capacity Assessment

Item Description Scenario nalysis

RRC License

Utility

RRC License Utility

If network User grow very fast, cell reach th

of initial RRC license, suggest expansion ne

connected user license.

PRB Utility PRB Utility RatioIf the cell with high PRB Utility Ratio, sugges

parameters related or adding new site.

ThroughputCell traffic mean

throughput

If network throughput grow very fast, reac

limitation of initial throughput license, sugg

expansion network throughput license.

PDCCH UtilityPDCCH Utility

Ratio

If cell with high PDCCH utility ratio, due to

high traffic load, suggest improving co

adding new site.


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Content



LTE Resource Overview LTE Market Overview


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• GSA: 360 commercial LTE networks launched in 124 countries

• Huawei acquired 320+ LTE Contracts with 154 Commercial Launched Networks by S

• Huawei won 140+ LTE contracts in capital cities.

• Huawei deployed LTE in 9 of 10 Global Financial Central Cities

360 LTE networks are commerciallylaunched in 124 countries (up to Jan. 2015)

GSA: 360 commercial LTE network launched by Jan 20


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450

265

146

46

16

2

300

2015

(forecast )

20132012201120102009 2014H1

GSA forecasts 450 commercial

LTE networks by end 2015

GSA: 360 commercial LTE network launched by Jan. 20

Source: GSA Evolution to LT

360

2014Q4

312FDD Only

87% launched FDD m

8% launched TDD mo

5% launched FDD &T

360 total launched

# of Global LTE Commercial Networks in Bands


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# of Global LTE Commercial Networks in Bands

360 LTE Commercial Networks Launched on All Spectrum

Source: GSA Evolution to LTE report and Huawe

Different bands m ay ap

Each network may have several spectrums, t

7

850MHz

8

APT 700MHz

10

2.1GHz

1.9GHz

12

AWS

36

US.

700MHz

55

DD800

68

2.6GHz

FDD91

1.8GHz158

3.5 GHz(B4

9

2.3GHz

21

1

450 MHz

10

900MHz

GSA Status o f LTE Ecosystem Camera, 2Femtocell,

133Mobile

20

USB Modem


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0

100

200

300

400

500

600

700

800

900

1000

1800b3

1900b2

1900b25

2100b1

2600b7

700b12

700b13

700b14

700b17

700b28

800b20

850b5

900b8

AWSb4

TDD1900b39

TDD2300b40

TDD2600b38

T2b

Source: GSA Status of the LTE Ecosystem report

(up to 10.2014)

GSA

Status o f LTE Ecosystem

LTE user device: 2218 (including 1045 Smartphone)

133 20

Phone,

1045

Router,559

USB Modem,191

Current status o f LTE netwo rks (over 1 Mil l ion subs cribers)


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58.8[09-2014] 9.9

16.6[09-2014]

5.8[09-2014]

8.1

9[09-2014]

1[09

~75% coverage

(Q3-2012)

38.

5[09-2014]

[09-2014]

8.9[09-2014]

1.4[09-2014]

LTE Total: 280+ Million

Rogers

5.2

9[09-2014]

DTT-Moblie US

2.5[09-2014]

Source: GSA Evolution to LTE re

31.6[09-2014]

2.3[09-2014]

Vodafone

Germany

5.6[09-2014]

EE

http://www.telecomskorea.com/wp-content/uploads/2010/05/lgt_uplus.jpg


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174

153

82

41

28

10

HW Ericsson NSN ALU ZTE SS

Huawei Leading Global LTE Markets

1063

SS ALU

8

LTE Commercial

Networks

LTE TDD Commercia

Networks

EricssZTE

Source: GSA Evolution to LTE report and Huawei Wireless M

Huawei LTE in Six Continents


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Huawei LTE in Six Continents

32

Con

17Com

Netw

14LTE

CapUK

Singapore

Sweden

Korea

PhilippinesNorway

Germany

Brazil Austria

Saudi Arabia

Kuwait

Canada

New Zealand

Bahrain

India

Colombia

Russia

FinlandCzech

Republic Denmark Hong Kong

South Africa UAE

Japan MexicoMalaysia

Australia

ThailandSpain

Netherlands

Huawei dominates global FDD2600 and 1800 netw

http://www.google.com.hk/url?sa=i&rct=j&q=%E4%BF%84%E7%BD%97%E6%96%AF&source=images&cd=&cad=rja&docid=pK9jsB91bIe17M&tbnid=lnXqT77Huc56MM:&ved=0CAUQjRw&url=http://www.novasgroup.com.cn/country.aspx?countryId=6&ei=KNBWUaqUC8eckQXK64DACQ&psig=AFQjCNG2XaQX3cIXU9B-YVmcMOsk_9lXUA&ust=1364730275775633http://www.google.com.hk/url?sa=i&rct=j&q=%E4%BF%84%E7%BD%97%E6%96%AF&source=images&cd=&cad=rja&docid=pK9jsB91bIe17M&tbnid=lnXqT77Huc56MM:&ved=0CAUQjRw&url=http://www.novasgroup.com.cn/country.aspx?countryId=6&ei=KNBWUaqUC8eckQXK64DACQ&psig=AFQjCNG2XaQX3cIXU9B-YVmcMOsk_9lXUA&ust=1364730275775633


42/43


4 7 1027

2514

4563

88

158 LTE 1800 commercial networks launched 91 LTE 2600 FDD commercial

(Jan. 2015)

EricsNSN

ZTE

HuaweiEricsson

NSNZTE SS ALU

ALU SS

893 LTE 2600 FDD device944 LTE 1800 devices were announced

Source: GSA Evolution to LTE report and Huawei Wireless MI

(up to Jan. 2015)

Source: GSA S


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Thank you

lte basic principle introduction v2

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