Evolution of 3GPP LTE-Advanced Standard toward 5G

Evolution of 3GPP LTE-Advanced Standard toward 5G KRNet 2013. 6. 24. LG Electronics Byoung-Hoon Kim (bh.kim@lge.com)

Communication Standards Evolution Mobility We are here IMT-Advanced Standard High (~350Km/h) Medium (Vehicular) 1995 2000 2005 2010 1G AMPS 2G CDMA GSM 3G 3G Ev. LTE* Rel 8/9 W-CDMA 802.20 HSDPA/HSUPA CDMA2000/EV-DV/DO? UMB* 802.16m 802.16e LTE-A Rel 10/11 Low (Nomadic) 802.16a/d 802.11n 802.11ac/ad 802.11a/b WLAN 14.4 Kbps 144 Kbps 384 Kbps ~ 50 Mbps ~100 Mbps ~1 Gbps Peak Data Rate 2

3GPP LTE Evolution 2008 2009 2010 2011 2012 2013 2014 3GPP Workshop for LTE-Advanced LTE Rel.8 LTE Rel.9 LTE-A Study LTE-A Rel.10 3GPP Workshop for Rel.12 & Onward (Ljubljana, 6/11-12, 43 company presentations) LTE-A Rel.11 LTE-A Rel.12 D S U U U D S U U U Rel.13 3GPP LTE OFDMA Location Based Service Carrier Aggregation CoMP D S U D D D S U D D eimta Small Cell Amorphous RAN MIMO Dual Layer Beamforming MIMO Enhancements FeICIC M2M Optimization D2D PDCCH epdcch Data MME GW MBMS Relay EPDCCH New Carrier Type 3D MIMO EPC Femto Cell SON OFDMA: Orthogonal Frequency Division Multiple Access, MIMO: Multiple Input Multiple Output, EPC: Enhanced Packet Core, M2M: Machine-to-Machine, D2D: Device-to-Device, SON: Self Organizing Network, FeICIC: Futher Enhanced Inter-Cell Interference Coordination, MDT: Minimization of Driving Test, EPDCCH: Enhanced Physical Downlink Control Channel, CoMP: Coordinated Multi-Point Operation, eimta: Enhanced Interference Mitigation & Traffic Adaptation 3 MDT Mobile Relay Heterogeneous Interworking

UHD Everywhere User Experience Expectation Intelligent Agent Free & Green Peak rate enhancement Balanced QoS Ubiquitous connectivity Ambient sensing/adaptation Throughput enhancement Proximity awareness Cost per bit reduction for end user satisfaction Cooperation Offloading Macro Pico/Femto Mobile device as intelligent agent Application Server WiFi Service brokering UHD video Knowledge building Context reasoning Cloud network Energy saving Transportation Context gathering Traffic More than FHD device Health Lawyer Shopping Restaurant 4

3GPP LTE-Advanced Rel.12 & Onward Requirement Improved Channel Capacity to Cope with Traffic Explosion Improved Data Rates for Enhanced User Experiences Cost Per Bit Reduction UHD 3D Video Source: Cisco Source: Morgan Stanley Improved Backhaul Performance Energy Saving Device & Application Diversification 5

3GPP LTE-Advanced Rel.12 & Onward Core Technology Small Cell / Amorphous RAN eimta 3D MIMO Enhanced Carrier Aggregation D2D LTE/WLAN Radio Interworking High Frequency FDD + TDD + Unlicensed Wi-Fi coordination LTE Enhanced Wireless Backhaul New Carrier Type MTC Enhancement Reference Signal FDD: Frequency Division Duplexing, TDD: Time Division Duplexing, D2D: Device-to-Device, Het-Net: Heterogeneous Network, MTC Machine Type Communication (M2M) 6

Focus Areas in LTE-Advanced Rel.12~ 1. Small Cell Enhancement 2. 3D MIMO 3. Device-to-Device Communication 4. Enhanced Interference Mitigation and Traffic Adaptation 5. New Carrier Type 6. LTE/WLAN Radio Interworking 7. Other Enhancements

SCE: Small Cell Enhancement Enhancement of cellular network for indoor and outdoor scenarios using low power nodes Small Cell Enhancement To cope with mobile traffic explosion With or without macro cell coverage Dense or sparse deployment Different or same frequency for macro and small cell layers 8

Small cells cluster scenarios SCE : Use Cases Common Common design solution for scenarios for scenario #1, #2a,#1, #2b,#2, and #3 Note: Overlapping macro may be present or not F1 Macro cell - Data/control splitting - Data throughput boosting - Offloading - Extended coverage Coordination Small cell F1 or F2 Coordination Cluster Small cell Source: 3GPP TSG R1-130748 9

SCE : Technical Challenges [1] Utilization of Higher frequency bands (3GHz or higher) with wider bandwidth High Frequency Band Relaxation of backhaul requirements Function (C/U) splitting between Macro and small cells Dual Connectivity 10

SCE : Technical Challenges [2] Cooperation of dense network of distributed transmission points UE-centric virtual cells Amorphous Cell Enhanced mobility support (to minimize the handover frequency) Radio Interface based synchronization (network listening, UE assistance) Enhanced inter-cell interference coordination & measurement Interference Management & Discovery Cell on/off, enhanced power control, load balancing Support of small cell discovery Macro UE Pico Discovery signal only f 1 f 2 Improved Spectral Efficiency Higher order modulation (256 QAM for cellular, EVM & Rx impairment issue) Control Signaling Overhead Reduction: Multi-subframe scheduling, cross-subframe scheduling, control-less subframes 11

3D MIMO: 3 Dimensional Beamforming Advent of Active Antenna System (AAS) Each antenna element combined with active transceiver (including PA) 3D MIMO Massive MIMO antenna elements 3D beamforming and single/multi-user MIMO based on 2D AAS One sub-array Coverage for higher vertical angle Whole antenna Antenna gain Antenna attenuation Higher signal level in sub-array Lower signal level in sub-array Coverage for lower vertical angle Coverage for ground level 12

3D MIMO: Use Case UE specific vertical/horizontal beamforming Dynamic TX/RX beamforming Carrier/RAT specific tilting Vertical/horizontal sectorization Source: www.nokiasiemensnetworks.com 13

3D MIMO: Technical Challenges Modeling a 2D array structure at enb 3D Channel Model 3D channel modeling including multipath fading in azimuth and elevation Elevation angular spread of departure & arrival (ESD, ESA) Mean elevation angle of departure & arrival (MED, MEA) Location of UEs in horizontal and vertical domains Mobility of UEs in horizontal and vertical domains. enb & UE Design Decision on the number of antenna units to be supported Issues to be considered Means to ensure the coverage of common control channels RRM measurements and procedures with large number of antenna ports Cell edge improvement and interference reduction Overheads for reference signals and feedback UE complexity (especially for UE-side massive MIMO antennas) Impact on legacy UEs 14

D2D: Device-to-Device Communication UE directly discovers and communicates with peer UE over-the-air D2D Energy-efficient discovery of peer UEs Spatial reuse of time/frequency resources Latency reduction Proximity-based services UE1 UE2 UE1 UE2 enb enb enb enb SGW/PGW SGW/PGW Data path of the evolved packet service (in 3GPP) 15

D2D: Use Cases [1] Public Safety Public safety message delivery by UE relaying and information flooding Out of network coverage Emergency when network is destroyed (destroyed) Commercial Network Enhancement Social network Discover friends in the vicinity Find people with common interest Mobile advertisement Neighborhood stores Individual offer Source: Qualcomm 16

D2D: Use Cases [2] D2D scenarios: In network coverage 3GPP D2D Initial Focus Within network coverage Outside network coverage Out of network coverage Partial network coverage D2D communication type: Unicast Discovery Direct Communication Non public safety & public safety requirements At least public safety requirements Public safety only Public safety only Groupcast Broadcast UE relay 17

D2D: Technical Challenges UE Discovery of UEs Identification of a certain UE in its proximity in a battery efficient way Synchronization and measurement of channels from UEs Receive over UL resource (or transmit over DL resource) D2D Tx timing relative to UL/DL cellular channel Tx/Rx timing Maintenance of dual connectivity One link with enb, the other with UE(s) Mitigation of in-band emission Group communication, relaying, security, privacy, etc. enb Control of D2D links Scheduling of individual D2D transmission and high-level control Coordination of interference Maximization of spatial reuse without causing serious interference Single or multiple-operator scenarios Charging, accounting, security, privacy, etc. WLAN incorporation 18

eimta: Enhanced Interference Mitigation & Traffic Adaptation eimta Dynamic and flexible resource configuration for TDD in consideration of traffic load enb transmits DL data in UL resource when DL traffic is heavy. Fixed subframe type vs. flexible subframe type Symmetric Traffic Situation Heavy DL Traffic Situation Buffer Status (Time 1) DL buffer UL buffer UL traffic DL buffer UL buffer UL traffic Buffer Status (Time 2) Time 1 Time 2 Resource used for DL/UL 19

eimta: Technical Challenges Subframe-type dependent UL power control and DL measurement Separate UL power control parameters for each type of subframes Separate DL channel measurement/report each type of subframes D S U U U D S U U U Power Control & Coordinated Scheduling D S U D D D S U D D enb-to-enb interference enb transmission in UL resource A cell operating enb-to-ue transmission UE-to-UE interference UE transmission in UL resource A cell operating UE-to-eNB transmission Signaling enb-to-enb backhaul signaling enb-to-enb interference power level UL/DL traffic condition in each cell enb-to-ue signaling of reconfiguration of DL/UL subframes Explicit Layer-1 signaling by a UE group-common control channel 20

NCT: New Carrier Type Reference signal and control overhead reduction relative to LTE legacy carrier LTE/WLAN Radio Interworking Reduced Common Reference Signal (Tracking RS) for Improved enb energy saving, spectral efficiency, interference coordination, embms services, etc. Challenges in RRM measurement and mobility support Standalone NCT vs. non-standalone NCT (aggregated to legacy carrier) Reference Signal 21

LTE/WLAN Radio Interworking RAN-level interworking of LTE & WLAN in addition to core network based interworking mechanisms LTE/WLAN Radio Interworking Collocated or non-collocated enb (LTE) / AP (WLAN): APs controlled by cellular operators WLAN included in operator s cellular RRM Enhancement of access network mobility and selection - Radio link quality, backhaul quality, load, etc. Power efficient WLAN scanning WLAN coordination LTE/WLAN LTE 22

Other Technologies for Rel. 12 & Onward [1] Evolution from previous release/study Low cost MTC Cost reduction & coverage enhancement for MTC devices Low cost MTC devices Relay Node (Concentrator) Smart monitoring Smart Home D2D Group Scheduling DL 4 Tx MIMO enhancements Feedback enhancement Codebook enhancement for 4Tx MIMO MTC server Normal UE Backhaul Multi-cell MIMO user : Single-cell MIMO user : CoMP Enhancements Non-ideal backhaul, RRM, SRS enhancement enba DL UE Data CSI X2 interface enbb UE Network assisted advanced receiver Receiver performance enhancement through cooperation between transmitter and receiver Mitigate interferences caused by data/control channel enbc 23

Other Technologies for Rel. 12 & Onward [2] Enhanced MDT (Minimization of Driving Test) Smart logging and reporting SON enhancements Inter-RAT mobility load balancing Mobile Relay Group mobility support by mobile relay 24