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2 Outline Introduction to 3GPP and LTE/LTE-Advanced Features in Release 10/11 LTE-Advanced Technology Trend for Release 12 LTE-Advanced or Beyond Conclusion

3 What is 3GPP? 3GPP (The 3 rd Generation Partnership Project) An organization formed by multiple of standard organizations from different countries It was established in December 1998 Scope: Produce Technical Specification and Technical Reports for a 3G Mobile System based on evolved GSM core networks and the radio access technologies that they support (i.e. UTRA FDD and TDD) Maintain and develop the Global System for Mobile communication (GSM) Technical Specifications and Technical Reports including evolved radio access technologies (e.g. GPRS, EDGE) Organizational Partners: ARIB (Japan) ATIS (USA) CCSA (China) ETSI (Europe) Member fee is paid year by year based on each company s revenue 3~45 units; (x-1) * 3380 Euros TTA (Korea) TTC (Japan) Any company which is member of any standard organization shown above is eligible for member application of 3GPP Market representation partners Source: 3GPP official website

Dual domain (circuit-switch and packet-switch domain) in GSM and UMTS networks Evolve to single domain

4 3GPP Tasks and Achievements Backward compatibility for Releases UTRA: Release 99, 4, 5, 6, 7, 8, 9, 10, 11 E-UTRA (LTE): Release 8, 9, 10, 11 Radio access milestones W-CDMA, TD-SCDMA, HSPA, HSPA+, LTE, LTE-A Core network evolution Dual domain (circuit-switch and packet-switch domain) in GSM and UMTS networks Evolve to single domain (packet-switch domain only) in LTE networks Source: 3GPP official website Source: 3GPP official website Source: 3GPP official website

5 Organization of 3GPP (1/2) Project Coordination Group (PCG) The highest decision making body in 3GPP Meet formally every six months to carry out the final adoption of 3GPP Technical Specification Group (TSG) work items, to ratify election results and the resources committed to 3GPP Technical Specification Group (TSG) Accomplish the technical specification development work within 3GPP There are four TSGs below PCG TSG GERAN, TSG RAN, TSG SA, TSG CT Each TSG has the responsibility to prepare, approve and maintain the specifications within its items of reference TSGs may organize their work in Working Groups (WG) and liaise with other groups as appropriate Each TSG report to the PCG

6 Organization of 3GPP (2/2) Source: 3GPP official website Core Network GSM WCDMA, LTE/LTE-A System Architecture and Requirements

7 3GPP RAN Working Groups RAN Plenary Responsible for the approval of CRs (change request) in existing releases and new features (working item or study item) in new release for access network RAN1 Responsible for the specification of radio layer 1 (physical layer) RAN2 Responsible for the specification of the radio interface architecture and radio layer 2 and 3 protocols (MAC, RLC, PDCP layer), such as radio resource control protocol, radio resource management, etc. RAN3 Responsible for the specification of the overall UTRAN/E-UTRAN architecture and the specification of protocols for the lu, lur, lub, S1 and X2 interfaces RAN4 Responsible for the specification of minimum performance requirements of RF, transmission/receiving, and radio resource management for both UE and BS RAN5 Responsible for the specification of conformance testing based on the requirements defined by other working groups such as RAN4 for radio test cases, RAN2 and CT1 for the signaling and protocol test cases X2 X2 Source: 3GPP TS V Source: 3GPP TS V10.1.0

3GPP Meetings RAN Plenary Four meetings per year in March, June, September, December RAN1/2/3 working groups Six meetings per year 4 regular meetings in February, May, August, November 2 bis meetings

8 3GPP Meetings RAN Plenary Four meetings per year in March, June, September, December RAN1/2/3 working groups Six meetings per year 4 regular meetings in February, May, August, November 2 bis meetings in March, October bis is a prefix or suffix designating the second instance of a thing bis meetings were added since LTE project initiated to speed up the progress to meet the timeline of ITU-Advanced project There were 8 meetings before 2011 in all RAN working groups RAN4 working group Eight meetings per year 4 regular meetings in February, May, August, November 2 bis meetings in March, October 2 ad hoc meetings in January, June No main session in ad hoc meetings RAN5 working group Six meetings per year 4 regular meetings in February, May, August, November 1 bis meetings in September 1 electronic meeting in January Source: 3GPP official website

9 Companies in 3GPP Operators Roles: provide system requirements Companies: Verizon, AT&T, T-Mobile, Vodafone, Deutsche Telekom, Telecom Italia, NTT DCM, CMCC, etc. Network vendors Roles: provide technology suggestions to meet requirements from system views Companies: NSN, Ericsson, Huawei, ZTE, etc. UE vendors Roles: provide technology suggestions from UE complexity views Companies: Qualcomm, Broadcom, Apple, Samsung, htc, RIM, Nokia, etc.

10 Standard Team in MediaTek Established in July 2007, currently belonged to CTO/ACT Main tasks: Technology research for advanced wireless mobile communication systems Technical recommendation and support for product teams First project is IEEE P802.16m ~ Attend IEEE TGm meetings Second project is WiMAX Release ~ Attend WiMAX Forum TWG Third project is 3GPP LTE/LTE-A ~ present Attend 3GPP RAN Plenary, RAN1, RAN2, RAN4, RAN5, CT1

11 What is 1G/2G/3G/4G? Mobile communication technologies are often divided into generations First generation of mobile radio systems launched commercially in 1980s Analog system, mainly for voice service Nordic Mobile Telephone (NMT), Advanced Mobile Phone System (AMPS), Total Access Communication System (TACS) etc. Second generation of mobile radio systems launched commercially in 1991 First digital system, mainly for voice service and partially for data service GSM, which is a TDMA-based system developed by ESTI GPRS (2.5G), EDGE (2.75G) Continue working till now Third generation of mobile radio systems launched commercially in 2001 Digital system, for both voice and data services but more focus on voice service UMTS using WCDMA developed by 3GPP, CDMA 2000 developed by 3GPP2 Mobile radio systems fulfilling the requirements of IMT-2000 are also called 3G such as TD-SCDMA, WiMAX 1.0 (3.5G) Start to prevail after Apple iphone 3G released in July 2008 Fourth generation of mobile radio systems ready for launching in 2010 Digital system, mainly for data service LTE-Advanced developed by 3GPP and WirelessMAN-Advanced developed by IEEE, which are OFDM-based systems Mobile radio systems fulfilling the requirements of IMT-Advanced are also called 3G However, for advertising, T-Mobile started to call HSPA+ as 4G as well

12 IMT-2000 and IMT-Advanced Projects ITU-R Working Party 5D (WP5D) is responsible for IMT systems 3G (IMT-2000) 4G (IMT-Advanced), completed by 2011 Source: 4G: LTE/LTE-Advanced for Mobile Broadband by Erik Dahlman

13 What is LTE/LTE-Advanced? (1/2) LTE is the abbreviation of Long Term Evolution It means a system as the long-term evolution of UMTS from 3G to 4G LTE project is initiated in 2004, focusing on enhancing Universal Terrestrial Radio Access (UTRA) and optimizing 3GPP s radio access architecture Targets were to have average user throughput of 3~4 times the Release 6 HSPA in downlink (100 Mbps) and 2~3 times in uplink (50 Mbps) Downlink technology: OFDMA Uplink technology: SC-FDMA First release is Rel-8 frozen in Dec. 2008; second release is Rel-9 frozen in Dec LTE is usually viewed as 3.9G because it does not meet the requirements of IMT- Advanced Project LTE-Advanced In order to meet the requirements of IMT-Advanced Project, LTE system is further enhanced First release is Rel-10 frozen in March 2011 LTE-Advanced is included in ITU-R recommendations for IMT-Advanced Project in Oct LTE-Advanced is usually viewed as TRUE 4G Continue to evolve with new releases Rel-11 LTE-A was initiated in March 2011 and is expected to be frozen in December 2012 Rel-12 LTE-A was initiated in September 2012 and planed to be frozen in June 2014

14 What is LTE/LTE-Advanced? (2/2) Source: 4G: LTE/LTE-Advanced for Mobile Broadband by Erik Dahlman etc. LTE-Advanced LTE

15 Outline Introduction to 3GPP and LTE/LTE-Advanced Features in Release 10/11 LTE-Advanced Technology Trend for Release 12 LTE-Advanced or Beyond Conclusion

16 Main Enhancements in Release 10/11 LTE-Advanced Carrier aggregation Goal: Expand system bandwidth Aggregate several component carriers in different frequency locations as one big trunk to improve spectrum utilization and obtain trunking gain at the same time HetNet enhancements BW ( 1 overhead) N cells log2(1 + SINR i ) NMU N SU streams Goal: Increase frequency reuse and reduce interference level Extend picocell coverage with large handover bias for better picocell utilization and improved system throughput Enhance inter-cell interference coordination mechanism when picocell coverage is extended MIMO enhancements Goal: Increase spectrum efficiency Enhance DL-MIMO from upto 4 layers to upto 8 layers Introduce UL-MIMO Introduce multi-bs MIMO/CoMP (coordinated multi-point) operation

17 Carrier Aggregation (CA): Deployment Scenarios Source: 3GPP TS

18 Carrier Aggregation (CA): Feature comparison of Release 10 and 11 Release 10 carrier aggregation At most 2 component carriers can be aggregated for both DL and UL Signals over all component carriers are from/to the same site Single uplink timing advance at UE side For TDD, UL/DL ratios of all component carriers should be the same Intra-band carrier aggregation is supported in band 1 and 40 Inter-band carrier aggregation is supported for band 1 plus ban 5 Release 11 carrier aggregation (newly added features) Signals over all component carriers can be from/to different sites Multiple uplink timing advance at UE side For TDD, UL/DL ratios of component carriers in different frequency bands can be different Enhancements on UL control channel for efficient feedbacks More band combinations are supported Source: 4G: LTE/LTE-Advanced for Mobile Broadband by Erik Dahlman etc.

19 HetNet Enhancements: Techniques in Rel-8/9/10/11 for ICIC Techniques in Rel-8/9/10 FDM ICIC in Rel-8/9 FDM-based ICIC mechanism mainly for data channels (PDSCH and PUSCH) Non-CA-based eicic in Rel-10 TDM-based ICIC mechanism mainly for control channels (PDCCH) CA-based ICIC in Rel-10 CC-based ICIC mechanism mainly for broadcasting and control channels (PSS/SSS, PBCH, SIB1/paging in PDSCH, PDCCH) Cross-carrier scheduling is needed New techniques in Rel-11 Non-CA-based feicic Handover bias (at most 9 db) for cell range expansion (CRE) Tx side enhancements on CRS (RE muting) Rx side enhancements on broadcasting channels (PSS/SSS, PBCH) and CRS for control and data channels (PDCCH, PDSCH) CA-based ICIC in Rel-11 CC-based ICIC mechanism mainly for broadcasting and control channels (PSS/SSS, PBCH, SIB1/paging in PDSCH, PDCCH) FDM-based control channel is needed (epdcch) 19

20 HetNet Enhancements: Non-CA-based eicic in Release 10/11 PDCCH is wideband physical signals and FDM ICIC is not enough if large-handover-bias (at most 9 db) cell range extension is applied Time domain non-ca-based eicic focuses on the solution for inter-cell interference coordination for control channels (PCFICH/PHICH/PDCCH) Subframe-based interference coordination Downlink eicic over X2 interface Non-zero-power almost blank subframe (ABS) Both Tx and Rx solutions are adopted PDCCH 20

21 HetNet Enhancements: CA-based ICIC in Release 10 If CA is enabled, CA-based ICIC can be applied Macrocell: Pcell is on CC#0; Scell is on CC#1 Small cells (Picocell/hotspot): Pcell is on CC#1; Scell is on CC#0 Cross-carrier scheduling needs to be enabled for PDCCH interference avoidance PDCCH in Pcell schedules data transmission in both Pcell and Scell Subframe shifting can be applied for PSS/SSS, PBCH interference avoidance Release 8/9 FDM ICIC can be applied for SIB1/paging in PDSCH interference avoidance PDCCH PDCCH 21

22 MIMO Enhancements: DL-MIMO and UL-MIMO in Release 10 MIMO technologies supported in downlink for LTE/LTE-A Transmit diversity Codebook based precoding Non-codebook based precoding Multi-user MIMO In Rel-10 LTE-A system, up to 8-layer MIMO is supported in downlink There are nine transmission modes to support different MIMO technologies TM9 is newly added in Release 10 to support up to 8-layer DL MIMO MIMO technologies supported in uplink for LTE/LTE-A Transmit diversity Codebook based precoding Multi-user MIMO In Rel-10 LTE-A system, up to 4-layer MIMO is supported in uplink There are two transmission modes to support different MIMO technologies Transmission mode 1: support single antenna transmission over contiguous resource allocation Transmission mode 2: support multiple antenna transmission over either contiguous or non-contiguous resource allocation (newly added in Release 10) Only transmit diversity is supported in uplink control channel (PUCCH) Spatial Orthogonal-Resource Transmit Diversity (SORTD) is used for format 1/1a/1b, 2/2a/2b, 3 Non-codebook based precoding is not supported in uplink

23 MIMO Enhancements: CoMP Operation in Release 11 (1/2) Scenario 1 Scenario 2 enb Coordination area High Tx power RRH Optical fiber Scenario 3 & 4 Source: 3GPP R enb Low Tx power RRH (Omni-antenna) Optical fiber 23 Scenario 3: Different cell IDs for enb and each RRH Scenario 4: Same cell ID for both enb and RRHs Supported CoMP operation schemes: Dynamic point selection Coordinated scheduling/beamforming

24 Outline Introduction to 3GPP and LTE/LTE-Advanced Features in Release 10/11 LTE-Advanced Technology Trend for Release 12 LTE-Advanced or beyond Conclusion

New spectrum acquisition/re-farming Enhancement of Spectrum efficiency Cell splitting/densification Small cell level An example path to 10-fold 2x spectrum 2~3x spectrum efficiency

25 Data Explosion in Next Five Years Anticipating 12-18x traffic growth from 2011 to 2015 Global average. Vary across regions and operators! CISCO: 10x (2015 versus 2011) UMTS Forum: 12x (2015 versus 2010) Likely > 2x every year in the first years How to deal with the capacity growth? New spectrum acquisition/re-farming Enhancement of Spectrum efficiency Cell splitting/densification Small cell level An example path to 10-fold 2x spectrum 2~3x spectrum efficiency Feasible with much improved SINRs in small-cell deployment LTE Rel-8 can achieve 4bps (InH) compared to 1.45bps (UMa) (TR36.814, uncorrelated antennas) Overhead reduction 3~4x from cell splitting ( Small-cell ) Similar gain observed already with HetNet (1 macro + 4 picos) 25

26 Technology Trend in Release 12 LTE-A or Beyond Small cells Goal: Increase frequency reuse One macrocell on mobility layer (Ex: 2 GHz) for mobility management A lot of small cells on capacity layer (Ex: 3.5 GHz) for capacity boosting New carrier type Goal: Reduce overhead and inter-cell interference level Reduced reference signals (no data; no reference signals) Finer control channel granularity (FDM-based control channel design) Carrier-based migration BW ( 1 overhead) N cells log2(1 + SINR i ) NMU N SU streams Enhanced distributed data application (edda) Goal: Reduce control signaling overhead in protocol layers Improve both control signaling and power efficiency for smart phones based on the traffic pattern Low cost from network or core network point of view Low cost is typically the target for Machine-type communication traffic Uplink reporting, small packet, infrequent, delay tolerant, etc Background traffic Always-on, keep-alive, delay tolerant, OS, LCS, APP, etc. Offline traffic of interactive application Non-interactive state, interactive messaging (IM) application, interactive APP, etc.

essential to support the needed capacity along with offload of traffic to existing licensed/ unlicensed band access

27 What are Small Cells? Small cells include microcell, picocell, femtocell, relay, low-txpower RRHs, WiFi APs A large deployment of small cells is essential to support the needed capacity along with offload of traffic to existing licensed/ unlicensed band access technologies Heterogeneous Networks (HetNet) Macrocells + small cells + WiFi access points Small cells (low power nodes) Picocell, femtocell, relay Specification of different elements in HetNet Operators status: In planning dbm Small Cells 27

28 Small Cells: Network Architecture (1/2) Local access LPN: For capacity boosting only via separate frequency, but under macro coverage (DCM, Huawei, Ericsson, etc.) Source: 3GPP RAN Tdocs NSN Ericsson Huawei Panasonic 28 DoCoMo

? Ericsson: inter-site CA: MAC only Inter-eNB multiflow: RLC or PDCP Small cell RB

29 Small Cells: Network Architecture (2/2) To what layer does the multi-point nature of transmission and reception expose to?? Ericsson: inter-site CA: MAC only Inter-eNB multiflow: RLC or PDCP Small cell RB based? Packet based? Full RRC function (CP+UP) from macro, and partial RRC (UP) from small cell? Source: 3GPP RAN Tdocs Huawei 29

30 New Carrier Type PDCCH PDCCH PDCCH PDCCH PDCCH Problems in legacy carrier There is always reference signal transmitted even when there is no data transmission Introduce inter-cell interference even when there is no data transmission Base station power wasting TDM-based control region doesn t provide efficient mechanism for control overhead adjustment and intercell interference coordination Large granularity for control region size adaptation (OFDM symbol based) Limitation of control capacity (maximal 3/4 OFDM symbols) Require subframe muting for intercell interference coordination (ICIC) Improvements with new carrier type (NCT) Reduced reference signal overhead DMRS (dedicated pilots) + CSI-RS (CSI pilots) + reduced CRS (common pilots) Almost no reference signal transmission when no data transmission FDM-based control region Small granularity for control region size adaptation (PRB based) No limitation of control capacity (adjustable between control and data) Only PRB-pair muting or low-power transmission is needed for ICIC New carrier type supports both non-stand-alone and stand-alone use cases Carrier-based migration is possible Carrier aggregation with legacy carrier + non-stand-alone NCT Carrier aggregation with stand-alone NCT + non-stand-alone NCT

31 edda: Why we need edda? New wireless data network, e.g. 3G or LTE, was designed and implemented to support large amounts of data traffic, focusing on bandwidth and throughput Long, uninterrupted data sessions (video conferencing, FTP, etc.) Periodic packets (voice call) Nowadays, popular applications on smart phone have much more sophisticated traffic pattern than what the architect originally designed for Chattiness of applications, i.e. traffic is based on user interaction, QoS requirement is not a constant Keep alive messages or background traffic of application or OS Short, infrequent data sessions Although the overall importance may be diminishing, voice is still the most important application for a mobile network and requires serious efforts to guarantee performance VoLTE which requires IMS is a major change to replace the legacy CS voice service

32 edda: Example of different traffic patterns IM: DL Inter-Arrival Distribution Heavier Background: DL Inter-Arrival Distribution 1 1 Example Traces from 3GPP study on DDA Good understanding of the traffic is needed to: - Evaluate significance of problems - Evaluate efficiency of solutions CDF Packet Inter-Arrival Time (seconds) CDF Packet Inter-Arrival Time (seconds) CDF Gaming: DL Inter-Arrival Distribution CDF Interactive Content Pull: DL Inter-Arrival Distribution CDF Light Background: DL Inter-Arrival Distribution Packet Inter-Arrival Time (seconds) Packet Inter-Arrival Time (seconds) Packet Inter-Arrival Time (seconds) Copyright MediaTek Inc. All rights reserved. 2012/10/12 32

33 edda: Problematic trends A lot of traffic need to be supported in CHEAP ways CHEAP = low overhead, e.g. low signaling overhead, all the time CHEAP = efficient data transmission Objectives Low signaling overhead for signaling for Uu L1/L2/L3, NAS, Core Network High Uu transmission efficiency Good and controlled QoS Good UE battery performance Copyright MediaTek Inc. All rights reserved. 2012/10/12 33

34 Outline Introduction to 3GPP and LTE/LTE-Advanced Features in Release 10/11 LTE-Advanced Technology Trend for Release 12 LTE-Advanced or beyond Conclusion

35 Conclusion 3GPP participation 3GPP is a huge standard organization and not very friendly for middle or small size companies to participate Due to high technology reputation barrier, it s not easy to have significant impact on specification technology direction in 3GPP if the research team size is not above a certain level Experienced delegates and research engineers are very important Future technology trend in R12 LTE-Advanced or beyond Future technology trend in R12 LTE-Advanced or beyond The prevail of smart phones boost the amount of traffic High-density small cell deployment HetNet will be next main technology focus in LTE Signaling overhead optimized for different types of traffic pattern is also one of the focuses Machine type communication and Device-to-device are another two important technologies to be included in LTE LTE system is expanding its application scenarios, such as indoor hotspot, home wireless etc. It is expected that LTE system will continue to evolve and play an important role for mobile wireless communications in next decade

Original Circular Letter

LTE-Advanced Original Circular Letter LTE-Advanced will be an evolution of LTE. Therefore LTE- Advanced must be backward compatible with LTE Release 8. LTE-Advanced requirements will meet or even exceed