ICTC 2015 Evolution of LTE-Advanced in 3GPP Rel-13/14: a Path to 5G Juho Lee Samsung Electronics
Presentation Outline LTE/LTE-Advanced evolution: an overview LTE-Advanced in Rel-13 Expectation for LTE-Advanced in Rel-14 3GPP plan for 5G 2
LTE/LTE-Advanced Evolution: An Overview 3
3 rd Generation Partnership (3GPP) Project Initiated in December 1998 for development of wireless communication standards backward compatible backward compatible Rel-99 Rel-5 Rel-6 Rel-8/Rel-9 Rel-10/Rel-11 W-CDMA (1999) HSDPA (2002) HSUPA (2005) LTE (2008) LTE-A (2010) Rel-12 Rel-13 B4G (2014) B4G (2016)? DL: 16QAM AMC, HARQ UL: AMC, HARQ DL: OFDMA, MIMO UL: SC-FDMA CoMP, CA, eicic UL MIMO Small cells, TDD-FDD CA FD-MIMO, LAA, emtc, eca 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 4
LTE/LTE-Advanced Roadmap 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 2014 2015 2016 2017 2018 2019 1H 2H 1H 2H 1H 2H 1H 2H 1H 2H 1H 2H 2014.12 2015.3 Rel-12 Stage 3 ASN.1 Start of deployment Rel-13 2015.12 2016.3 Stage 3 ASN.1 Start of deployment Rel-14 Rel-15 2017.3 2017.6 Stage 3 ASN.1 Start of deployment 2018.6 2018.9 Stage 3 ASN.1 5
LTE/LTE-Advanced Evolution: Targets Efficient Frequency Usage Enhancement: Larger bandwidth, more flexibility, new type of frequency resource Effect: Higher peak data rate (300Mbps 4Gbps 25.6Gbps) Higher Spectral Efficiency Enhancement: MIMO, higher order modulation, interference control/suppression Effect: Higher spectral efficiency (2.0bps/Hz 2.5bps/Hz 4 + bps/hz) Support of New Services Enhancements: Broadcast, device-to-device, public safety, new terminal types Effect: Extension of LTE/LTE-A technologies into new applications 6
LTE/LTE-Advanced Evolution: Technologies Efficient Frequency Usage (Rel-10) CA, (Rel-11) Enhanced CA, (Rel-12) TDD-FDD CA, Dual Connectivity (Rel-13) Licensed Assisted Access, Carrier Aggregation Beyond 5 Carriers Higher Spectral Efficiency (Rel-10) DL/UL MIMO Enh, eicic, (Rel-11) CoMP, (Rel-12) Small Cell Enh, NAICS (Rel-13) Full Dimension MIMO Support of New Services (Rel-8/9) embms, (Rel-12) D2D, MTC (Rel-13) Enh MTC, PS-LTE 7
LTE-Advanced Rel-13: Full Dimension MIMO 8
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 Flexible V/H sectorization 3D beamforming Vertical sectors Hotspot 9
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 Legacy system FD-MIMO system Patch antenna Flexible system 8TX (8Hx1V) Feed network Flexible 2D port mapping Passive antennas Baseband+PA CPRIs IP 32TX (8Hx4V) LTE infrastructure FD-MIMO baseband 10
Beamforming with FD-MIMO Example 1: 70/70 degrees without down tilt 2 8 antennas 4 8 antennas 8 8 antennas Example 2: 70/70 degrees with down tilt 2 8 antennas 4 8 antennas 8 8 antennas 11
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 Evaluation scenario Scheduling algorithm Parameter Layout Scenario TX power Carrier frequency Bandwidth Number of UEs HARQ scheme Link adaptation CSI feedback Channel estimation Element configuration UE mobility Value 19 cells with 3 sector 3D UMa (ISD:500m), 3D UMi (ISD:200m) 46dBm(3D UMa), 41dBm (3D UMi) 2GHz 10MHz 10 UEs per cell IR asynchronous retransmission LTE MCS selection with 10% BLER Ideal subband Rel.10 SU-CSI Ideal estimation without error 60º for both vertical and horizontal with 6.5dBi 3Km/h with 3D dropping 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 12
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 throughput Cell vs 5% edge throughput 64 ports 32 ports 1x64 2x32 16 ports 8 ports 4x4 1x32 2x16 4x8 8x4 8x8 4x16 13
LTE-Advanced Rel-13: Licensed Assisted Access 14
Licensed vs Unlicensed Band Licensed band and unlicensed band have different characteristics LAA aims to provide licensed wireless experience in unlicensed band Licensed Band Unlicensed Band License typically requires a fee (a big one) Operator retains exclusive rights for use No license and therefore no fee (free) Anyone can 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) 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) 15
Licensed Assisted Access (LAA) Concept Conventional LTE/LTE-A: Data and control signaling on licensed carrier Licensed f Licensed f WiFi: Data and control signaling on unlicensed carrier Unlicensed f Unlicensed f LAA: Data on licensed and unlicensed carrier but control on licensed carrier only Data fat pipe UnLicensed f Licensed Mobility support, reliable data/control pipe f Licensed Assisted 16
Benefits of LAA Source: Huawei Enhanced User Experience Cellular mechanism over unlicensed band (coverage, mobility, QoS control) Improved spectral efficiency vs WiFi (link adaptation, HARQ, interference management) Unified LTE Network Same core elements Same mobility and security framework 17
LAA Deployment Scenarios 18
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 Mbps Average User Perceived Throughput Mbps 5% Cell Edge UE Throughput 120 100 Low load Medium load 80 70 Low load Medium load 80 60 High load A B 60 50 40 High load B 40 30 20 20 10 A 0 WiFi in WiFi only WiFi in WiFi+LAA LAA in WiFi+LAA 0 WiFi in WiFi only WiFi in WiFi+LAA LAA in WiFi+LAA 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 19
LTE-Advanced Rel-13: Carrier Aggregation Beyond 5 Carriers 20
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 21
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 Licensed band Unlicensed band 1 2 3 4 5 6 32 PCell Ideal backhaul SCell PUCCH PUCCH 22
LTE-Advanced Rel-13: Enhanced Machine Type Communications Narrow Band Internet of Things (NB-IoT) 23
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 System bandwidth Coverage improvement (+15dB) MTC UE bandwidth (1.4MHz) Reduced MTC UE power consumption Expected benefits New revenue generation for operators by means of boosting coverage of LTE based MTC UE Enable new cellular IoT device targeted services 24
Rel-13 Enhanced MTC vs Rel-12 MTC Feature comparison RF bandwidth 20 MHz 1.4 MHz Reduced BW operation Coverage enhancement Rel-12 MTC Rel-13 MTC Description Control: System BW Data: Reduced BW Control : Reduced BW Data : Reduced RB Impact on control channels(phich, PCFICH, (E)PDCCH) and data channel scheduling EPDCCH or new channel format for control channels No Yes Physical channel repetition, etc. required Max. Tx Power 23 dbm ~20 dbm Max. TBS size 1000 bits(unicast) 2216 bits(broadcast) Cost comparison (RP-141180) 1000 bits (unicast and broadcast) 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% 25
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 26
Expectation for LTE-Advanced in Rel-14 27
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) 28
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 29
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 30
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) 31
3GPP Plan for 5G 32
5G timeline in 3GPP (SP-150149) RAN#69 Sep 15 RAN#70 Dec 15 5D#23 Feb 16 RAN#72 Jun 16 5D#26 Feb 17 5D#27 Jun 17 5D#28 Oct 17 5D#31 Oct 18 5D#32 Jun 19 RAN#86 Jun 20 5D#34 Feb 20 5D#36 Oct 20 IMT 2020 Evaluation criteria Requirements Initial submissions of proposals Evaluation IMT-2020 specifications IMT 2020 requirements 3GPP requirements Initial 3GPP submission Final 3GPP submission RAN Workshop RAN SI: scope & requirements channel modeling RAN WG SI: evaluation of solutions RAN WG WI: specification of solutions RAN-SA Workshop SA system work SA1 SMARTER SI SA1 SMARTER WI HSPA/LTE evolution RAN#71 Mar 16 Rel-13 freeze 33
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 Massive Machine-type Comm. Ultra Reliability / Low Latency Mobile Cloud Computing UHD Streaming Smart Home/ Smart City U-Health/Wearables Smart Vehicle Industrial Automation 34
5G Requirement (to be developed from Dec 2015) Example requirement set 35
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 36
Thank you 37