Development of LTE Femtocell

September 2nd, 2009

Jinri Huang

SK Telecom

2 /26

Contents

Story of SK Telecom1.

Femtocell background2.

SKT’s WiBro Femtocell3.

SKT’s perspectives on LTE Femtocell

4.

Conclusions5.

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1984

1996

2000

2003

2005World 1st CDMA World 1st CDMA CommercialCommercial C2K 1X

AMPS

IS-95A/B

WCDMA

WiMAX

EV-DO

HSDPA

S-DMB

2G 3G

World First World First Satellite Satellite

DMB DMB ServiceService 2007

2006

HSUPA

1G

World 1stWorld 1st

25-Year Mobile Experience

MNO Service MNO Service in Vietnamin Vietnam

(S Telecom) (S Telecom)

World FirstWorld First

Story of SK Telecom

Several world-first…

World FirstWorld First

4 /26

Business Innovation Leading Korea’s mobile market with new technologies & innovative services.

More than 50% market share in Korea

No. 1 in major 3 Customer Satisfaction Indices for 11 years

− Mobile Phone Service− Wireless Internet Service− Ubiquitous & Convergence Service− Video Telephony Service− Others.

‘99

CDMACDMA2000 1x2000 1x HSDPAHSDPA1xEV-DO1xEV-DO WCDMAWCDMA WiBroWiBro

’00 ’01 ’03 ’05’02 ’04 ’07’06

HSUPAHSUPA

’08~

Music Download

3D Game Portal

Satellite Digital Mobile

Broadcasting

Social Networking Service

UCC Service

GPS Navigation

Mobile Banking

3G Multimedia Portal

Ringback Tone

Fixed/Mobile Portal

MAP Navigation

Video Phone

Total Mobile Brand

Mobile Money

Widgets

Segmentation for young customers

Pazama

5 /26

IS-95A/B: Nationwide 1X/DO: Cover 92% Population Nationwide Coverage

Metropolitan Area (Seoul) &Hot Zones in other Major Cities

SeoulSeoulSeoulSeoul

JEJUJEJUJEJUJEJU

‘‘0606‘‘0606‘‘07~’0807~’08‘‘07~’0807~’08

‘‘0909‘‘0909

WiBro (m-WiMax)IS-95A/B

CDMA 1X/EVDO

1X/DO1X/DO1X/DO1X/DO

IS-95A/BIS-95A/BIS-95A/BIS-95A/B

SeoulSeoulSeoulSeoul SeoulSeoulSeoulSeoul

JEJUJEJUJEJUJEJUJEJUJEJUJEJUJEJU

WCDMA(HSPA)

800MHz (BW 25MHz) 2.1GHz (BW 20MHz) 2.3GHz (BW 27MHz)

53% of total subscribers 47% of total subscribers -

Network coverage

Data by Aug. 2009

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Contents

Story of SK Telecom1.

Femtocell background2.

SKT’s WiBro Femtocell3.

SKT’s perspectives on LTE Femtocell

4.

Conclusions5.

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Concept proposed2006

Femto Forum established2007

Femtocell test2008

World first Femtocell standardization2009

Commercially launched Femtocell servicesToday

Many other operators waiting in the wings, including SKT

− Sprint, Verizon, SOFTBANK, NTT DoCoMo, Chunghwa Telecom, StarHub

Femtocell at a glance

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1,000,000 = 25 × 5 × 5 × 1600

Technological contributions

Wider spectrum (25×)

Frequency division (5×)

Modulation and coding (5×)

Topology / smaller cells (1600×)

Why Femtocell?

From 1954 to 1999, 106 times capacity increase:

1

100

1 Million

100 Million

10 Billion

1 Trillion

1900 1950 2000

Cooper’s law: The number of conversations including both data and voice has doubled every 2.5 years

Smaller and smaller cells is the key f-actor for further improvement of future network capacity

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High penetration loss due to high frequency

Low data rate due to sharing with other UEs

Too expensive for traditional DAS solution

Poor indoor Poor indoor coverage & Poor coverage & Poor indoor capacityindoor capacity

Traditional macro solution is not so satisfactory for UMTS syst-ems for indoor coverage

Why Femtocell?

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For users

Benefits

For operators

Improved coverage, quality and data rate

Potential services

Lower price

Decreased management work

Decreased transmission cost

Decreased churn rate

No need to rent sites

Increased ARPU

Short-term: coverage & capacity is the king

Long-term: development of new business/services

What can Femtocell bring?

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Contents

Story of SK Telecom1.

Femtocell background2.

SKT’s WiBro Femtocell3.

SKT’s perspectives on LTE Femtocell

4.

Conclusions5.

12 /26

Macro BS with RF Extensions– High CapEx & Low Capacity

• High price : Macro BS

• High construction cost : installing RF cables

• Limited capacity : Limited to one BS capacity

High CapEx is critical obstacle for successful business.– Internal survey shows that the major portion of BWA demands happen in-b

uilding.

Donor Optic

Combiner

[Config. in a floor]

[Base station Office]

[In-building Configuration]

WiMAXASN-GW

[Core Network Office]

WiMAX BS (22 MIMO)

Core N/W

Used by the other System

To support MIMO, an

additional RF Cable req.

RF cable-MIMO Path 2

RF cable-MIMO Path 1

WiMAX

MRDU

WiMAXRU

Conventional in-building systems

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Ethernet(UTP or Optic Fiber)

IBcell-ACR

UTP Cable

IBcell-AP (Omni ant.)

SwitchGPS

IBcell-EMS

IBcell-RRH

UTPCable

IBcell-AP (Patch ant.)

IBcell-Digital

BS Digital part : IBcell-Digital BS RF part : IBcell-RRH

IBcell Digital + RRH type

IBcell : The name of SK Telecom’s WiBro business Femtocell

SKT’s WiMAX business Femtocell (WiBro)

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Big Enterprise Case–In-building IBcell-ACR

SME Case–IBcell-ACR supportsmultiple buildings

SME Case–IBcell-ACR supportsmultiple buildings

Installation example

IBcell-ACR

IBcell-ACR

IBcell-ACR

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High Performance–Over 20Mbps/7Mbps DL/UL throughput is provided by each IBcell-AP

High Flexibility–Tiny-sized IBcell-AP, easy installation, UTP cable based N/W construction

–Power over Ethernet (PoE)

Low CapEx–Comparing to the conventional solution, less than 50% of CapEx needed.

•E.g.: 20-story building, 1 IBcell-ACR included.

Much higher business opportunity than the conventional!

Advantages of IBcell solution

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Contents

Story of SK Telecom1.

Femtocell background2.

SKT’s WiBro Femtocell3.

SKT’s perspectives on LTE Femtocell

4.

Conclusions5.

17 /26

3GPP recommended femtocell architecture

Vendors made out LTE Femtocell plan

Chip vendors planned to develop LTE femtocell chips

Operators sensed the possible application of LTE femtocell

−Leverage nationwide WCDMA/HSPA networks−Utilize high data rate for home, offices, hotspots, etc.

Why LTE Femtocell? Is it ready?

UE HNBHNB

GWSGSN

MSC

Uu Iuh

Iu_CS

Iu_PS

Femtocell architecture in R8

UE HeNBHNB

GWSGW

MME

Uu S1

S1_MME

S1_U

Femtocell architecture in R9

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Backhaul of higher requirement

Voice/SMS support

TDD or FDD?

Multimode LTE femtocell AP

−It is not likely to have only one type of UE

−It is not likely to buy multiple different types of femto AP

−It can save cost for operators

Difference of LTE Femtocell from WCDMA Femtocell

UE

Dual-mode W/L Femto AP

WCDMA CN

LTE CN

HNB GW

HeNB GW

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Category LTE Business Femto

Service Area • In-Building, could also be considered for Hot Spot coverage.

Target Service • PS (Fixed and Pedestrian): Data.

Topology/Configuration • Star and Daisy Chain configurations • Point to Point Wifi connection also considered.

Capacity & Performance • MIMO needed• 10MHz or 20MHz bandwidth

I/F • Ethernet Connectivity (Gigabit Ethernet)

H/O • Full mobility supported.

RF Extension • Distributed Antenna System

SON (Self-organizing Networks) • Auto-configuration (Automatic Neighbour cell setting) - Auto-optimization.

• Autonomous network element managed by FMS/XMS.

Synchronization • NTP or IEEE1588 for cost effective solution.

SKT’s perspectives on LTE Femtocell

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A deployment example

Ethernet Network

•Chain Configuration

•Star Configuration

Wifi Conf.

UTP

UTPUTP

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Mobility support

•Macro Cell 1•Cell 1 •Cell 2

•Indoor Cell Femto

•Macro Cell 2

•Local MME 2 •MME Macro

•Femto Pool •Macro Pool

MME/SGW Pooling: reduce and minimize the MME relocation

Local MME: manage femtocell inside the building and interact with Macro MME to absorb signalling traffic

Femto to Femto Mobility

Femto to Macro Mobility

Macro to Femto Mobility

Inter-RAT Mobility (to 3G network CDMA and W-CDMA).

Full Mobility Support

•Local MME 1

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interference mitigation

Reduce the interference to improve the capacity No X2 interface in femtocell

SON challenges: interaction b/w HeNB and eNB

Macro LTE Femt

o

UE

Macro LTE

Femto

UE UE

CSG HeNB

Challenges!!

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Absorb the traffic for macro cell, reducing the burden of macro eNB

Basic idea and essence−Cell reselection/handover

SON challenges: load balancing

Macro LTE

Femto

UE3

UE2UE1

Load balancing

Challenges!!

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Too many possible serving cells Interaction, i.e., information exchange is essential to improve HO

efficiency

SON challenges: handover optimization

Macro LTE

UE Movement

Challenges!!

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Contents

Story of SK Telecom1.

Femtocell background2.

SKT’s WiBro Femtocell3.

SKT’s perspectives on LTE Femtocell

4.

Conclusions5.

26 /26

LTE Femtocell is important for future network improvement

It is time for the ecosystem to begin developing LTE Femtocell

SKT has experience on developing WiBro business Femtocell

SKT has interest in LTE Femtocell

Technical issues, e.g., SON challenges are essential for LTE network optimization

Conclusions

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Thank You!