Development of LTE Femtocell September 2 nd 2009

Development of LTE Femtocell September 2 nd, 2009 Jinri Huang SK Telecom /26

Contents 1. Story of SK Telecom 2. Femtocell background 3. SKT’s Wi. Bro Femtocell 4. SKT’s perspectives on LTE Femtocell 5. Conclusions 1 /26

Story of SK Telecom u 25 -Year Mobile Experience u Several world-first… World First Satellite DMB Service S-DMB World 1 st EV-DO World 1 st CDMA Commercial IS-95 A/B AMPS 1996 C 2 K 1 X 2000 WCDMA 2003 2005 World First Wi. MAX HSUPA 2007 2006 HSDPA World First MNO Service in Vietnam (S Telecom) 1984 1 G 2 G 3 G 2 /26

Business Innovation u Leading Korea’s mobile market with new technologies & innovative services. − Mobile Phone Service − Wireless Internet Service − Ubiquitous & Convergence Service − Video Telephony Service − Others. u More than 50% market share in Korea Music Download Mobile Money Satellite Digital Mobile Broadcasting UCC Service u No. 1 in major 3 Customer Networking Satisfaction Indices for 11 years Social. Service Pazama Widgets Mobile Banking Total Mobile Brand 3 G Multimedia Portal GPS Navigation Video Phone MAP Navigation Fixed/Mobile Portal Segmentation for young customers Ringback Tone CDMA 1 x. EV-DO 2000 1 x ‘ 99 3 D Game Portal ’ 00 ’ 01 ’ 02 WCDMA ’ 03 Wi. Bro ’ 04 ’ 05 HSDPA ’ 06 HSUPA ’ 07 ’ 08~ 3 /26

Network coverage IS-95 A/B CDMA 1 X/EVDO WCDMA (HSPA) Wi. Bro (m-Wi. Max) ‘ 06 ‘ 07~’ 08 IS-95 A/B 1 X/DO ‘ 09 Seoul JEJU IS-95 A/B: Nationwide 1 X/DO: Cover 92% Population Nationwide Coverage Metropolitan Area (Seoul) & Hot Zones in other Major Cities 800 MHz (BW 25 MHz) 2. 1 GHz (BW 20 MHz) 2. 3 GHz (BW 27 MHz) 53% of total subscribers 47% of total subscribers Data by Aug. 2009 4 /26

Contents 1. Story of SK Telecom 2. üFemtocell background 3. SKT’s Wi. Bro Femtocell 4. SKT’s perspectives on LTE Femtocell 5. Conclusions 5 /26

Femtocell at a glance 2006 Concept proposed 2007 Femto Forum established 2008 Femtocell test 2009 World first Femtocell standardization Today Commercially launched Femtocell services − Sprint, Verizon, SOFTBANK, NTT Do. Co. Mo, Chunghwa Telecom, Star. Hub Many other operators waiting in the wings, including SKT 6 /26

Why Femtocell? Cooper’s law: The number of conversations including both data and voice has doubled every 2. 5 years Technological contributions u Wider spectrum (25×) u Frequency division (5×) u Modulation and coding (5×) u Topology / smaller cells (1600×) 1 Trillion 10 Billion 100 Million 100 1 1900 1950 2000 From 1954 to 1999, 106 times capacity increase: Smaller and smaller cells is the key factor further improvement of future network capacity 1, 000 = 25 × 5 × 1600 7 /26

Why Femtocell? High penetration loss due to high frequency Low data rate due to sharing with other UEs Poor indoor coverage & Poor indoor capacity Too expensive for traditional DAS solution u Traditional macro solution is not so satisfactory for UMTS syst -ems for indoor coverage 8 /26

What can Femtocell bring? Short-term: coverage & capacity is the king For users ü Improved coverage, quality and data rate ü Potential services ü Lower price Benefits Long-term: development of new business/services For operators ü Decreased management work ü Decreased transmission cost ü Decreased churn rate ü No need to rent sites ü Increased ARPU 9 /26

Contents 1. Story of SK Telecom 2. Femtocell background 3. üSKT’s Wi. Bro Femtocell 4. SKT’s perspectives on LTE Femtocell 5. Conclusions 10 /26

Conventional in-building systems u Macro BS with RF Extensions – High Cap. Ex & Low Capacity • High price : Macro BS [In-building Configuration] • High construction cost : installing RF cables • Limited capacity : Limited to one BS capacity [Core Network Office] [Base station Office] RF cable -MIMO Path 1 Wi. MAX BS (2 2 MIMO) Wi. MAX ASN-GW u High Core N/W Combiner Used by the other System Wi. MAX RU Donor RF cable -MIMO Path 2 Optic Wi. MAX MRDU To support MIMO, an additional RF Cable req. [Config. in a floor] Cap. Ex is critical obstacle for successful business. – Internal survey shows that the major portion of BWA demands happen inbuilding. 11 /26

SKT’s Wi. MAX business Femtocell (Wi. Bro) GPS IBcell. EMS Ethernet (UTP or Optic Fiber) Switch UTP Cable IBcell-AP (Omni ant. ) IBcell-AP (Patch ant. ) IBcell-ACR IBcell : The name of SK Telecom’s Wi. Bro business Femtocell UTP Cable IBcell. Digital IBcell-RRH IBcell Digital + RRH type BS Digital part : IBcell-Digital BS RF part : IBcell-RRH 12 /26

Installation example u Big Enterprise Case –In-building IBcell-ACR u SME Case –IBcell-ACR supports multiple buildings IBcell-ACR 13 /26

Advantages of IBcell solution u High Performance –Over 20 Mbps/7 Mbps DL/UL throughput is provided by each IBcell-AP u High Flexibility –Tiny-sized IBcell-AP, easy installation, UTP cable based N/W construction –Power over Ethernet (Po. E) u Low Cap. Ex –Comparing to the conventional solution, less than 50% of Cap. Ex needed. • E. g. : 20 -story building, 1 IBcell-ACR included. Much higher business opportunity than the conventional! 14 /26

Contents 1. Story of SK Telecom 2. Femtocell background 3. SKT’s Wi. Bro Femtocell 4. üSKT’s perspectives on LTE Femtocell 5. Conclusions 15 /26

Why LTE Femtocell? Is it ready? u 3 GPP recommended femtocell architecture Iu_CS UE Uu HNB Iuh GW MSC Iu_PS UE Uu He. NB HNB S 1 GW MME S 1_U SGW SGSN Femtocell architecture in R 8 S 1_M ME Femtocell architecture in R 9 u Vendors made out LTE Femtocell plan u Chip vendors planned to develop LTE femtocell chips u Operators sensed the possible application of LTE femtocell −Leverage nationwide WCDMA/HSPA networks −Utilize high data rate for home, offices, hotspots, etc. 16 /26

Difference of LTE Femtocell from WCDMA Femtocell u Backhaul of higher requirement u Voice/SMS support u TDD or FDD? u Multimode LTE femtocell AP WCDMA CN HNB GW UE Dual-mode W/L Femto AP LTE CN He. NB GW −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 17 /26

SKT’s perspectives on LTE Femtocell 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 • 10 MHz or 20 MHz bandwidth I/F • Ethernet Connectivity (Gigabit Ethernet) H/O • Full mobility supported. RF Extension • Distributed Antenna System SON (Self-organizing Networks) • Synchronization • Auto-configuration (Automatic Neighbour cell setting) - Autooptimization. • Autonomous network element managed by FMS/XMS. NTP or IEEE 1588 for cost effective solution. 18 /26

A deployment example • Star Configuration UTP Ethernet Network UTP • Chain Configuration Wifi Conf. 19 /26

Mobility support • Cell 1 • Cell 2 • Macro Cell 1 • Macro Cell 2 Full Mobility Support • Indoor Cell Femto §Femto to Femto Mobility §Femto to Macro Mobility §Macro to Femto Mobility §Inter-RAT Mobility (to 3 G network CDMA and W-CDMA). • Local MME 1 • Local MME 2 • Femto Pool • MME Macro • Macro Pool u MME/SGW Pooling: reduce and minimize the MME relocation u Local MME: manage femtocell inside the building and interact with Macro MME to absorb signalling traffic 20 /26

SON challenges: interaction b/w He. NB and e. NB u interference mitigation Challenges!! CSG He. NB Macro LTE Femto UE u u Macro LTE Femto UE UE Reduce the interference to improve the capacity No X 2 interface in femtocell 21 /26

SON challenges: load balancing Challenges!! Load balancing Macro LTE Femto UE 3 UE 1 u u UE 2 Absorb the traffic for macro cell, reducing the burden of macro e. NB Basic idea and essence −Cell reselection/handover 22 /26

SON challenges: handover optimization Macro LTE UE Challenges!! Movement Too many possible serving cells u Interaction, i. e. , information exchange is essential to improve HO efficiency u 23 /26

Contents 1. Story of SK Telecom 2. Femtocell background 3. SKT’s Wi. Bro Femtocell 4. SKT’s perspectives on LTE Femtocell 5. üConclusions 24 /26

Conclusions u LTE Femtocell is important for future network improvement u It is time for the ecosystem to begin developing LTE Femtocell u SKT has experience on developing Wi. Bro business Femtocell u SKT has interest in LTE Femtocell Technical issues, e. g. , SON challenges are essential for LTE network optimization u 25 /26

Thank You! 26 /26