4g standard participation and technology evolution...

4G Participation and Technology Evolution4G Participation and Technology Evolution

Copyright © MediaTek Inc. All rights reserved.

Pei-Kai Liao

MediaTek Inc.

OutlineOutline

▪ Introduction to 3GPP and LTE/LTE-Advanced

▪ Features in Release 10/11 LTE-Advanced

▪ Technology Trend for Release 12 LTE-Advanced or Beyond

▪ Conclusion

What is 3GPP?What is 3GPP?

▪ 3GPP (The 3rd 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)

Source: “3GPP official website”• ATIS (USA)• CCSA (China)• ETSI (Europe)

– Member fee is paid year by year based on each company’s revenue

– 3~45 units; 6000 + (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”

3GPP Tasks and Achievements3GPP 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




Organization of 3GPP (1/2)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 – 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

Organization of 3GPP (2/2)Organization of 3GPP (2/2)Core Network


GSM

WCDMA, LTE/LTE-A System Architecture and Requirements

3GPP RAN Working Groups3GPP 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.

X2

X2

Source: “3GPP TS 36.300 V10.1.0”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

Source: “3GPP TS 36.300 V10.1.0”

Source: “3GPP TS 36.300 V10.1.0”

3GPP Meetings3GPP 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• 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


Companies in 3GPPCompanies 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 viewsto meet requirements from system views– Companies: NSN, Ericsson, Huawei,

ZTE, etc.

▪ UE vendors– Roles: provide technology

suggestions from UE complexityviews

– Companies: Qualcomm, Broadcom, Apple, Samsung, hTC, RIM, Nokia, etc.

StandardStandard TeamTeam inin MediaTekMediaTek

▪ 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– 2007.07 ~ 2011.01– 2007.07 ~ 2011.01– Attend IEEE 802.16 TGm meetings

▪ Second project is WiMAX Release 2.0– 2009.10 ~ 2011.06– Attend WiMAX Forum TWG

▪ Third project is 3GPP LTE/LTE-A– 2009.08 ~ present– Attend 3GPP RAN Plenary, RAN1, RAN2, RAN4, RAN5, CT1

WhatWhat isis 1G/2G/3G/4G?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

IMTIMT--2000 and IMT2000 and IMT--Advanced ProjectsAdvanced 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

What is LTE/LTEWhat is LTE/LTE--Advanced? (1/2)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. 2009– LTE is usually viewed as 3.9G because it does not meet the requirements of IMT-– 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.

2010– 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

What is LTE/LTEWhat is LTE/LTE--Advanced? (2/2)Advanced? (2/2)

Source: “4G: LTE/LTE-Advanced for

Mobile Broadband “ by Erik Dahlman etc.

LTE

LTE-Advanced

LTE

OutlineOutline



▪ Technology Trend for Release 12 LTE-Advanced or Beyond

▪ Conclusion

Main Enhancements in Release 10/11 Main Enhancements in Release 10/11 LTELTE--AdvancedAdvanced

▪ 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– Goal: Increase frequency reuse and reduce interference level– Extend picocell coverage with large handover bias for better picocell

∑ ∑−

+⋅⋅−⋅

MU streamsSUN N

icellsSINRNoverheadBW )1(log)1( 2

– Extend picocell coverage with large handover bias for better picocellutilization and improved system throughput

– Enhance inter-cell interference coordination mechanism when picocellcoverage 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

Carrier Aggregation (CA):Carrier Aggregation (CA):Deployment ScenariosDeployment Scenarios Source: 3GPP TS 36.300

Carrier Aggregation (CA):Carrier Aggregation (CA):Feature comparison of Release 10 and 11Feature 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 supportedSource: “4G: LTE/LTE-Advanced for

Mobile Broadband “ by Erik Dahlman etc.

HetNetHetNet Enhancements: Enhancements: Techniques in RelTechniques in Rel--8/9/10/11 for ICIC8/9/10/11 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)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

HetNetHetNet Enhancements:Enhancements:NonNon--CACA--based based eICICeICIC in Release 10/11in 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

HetNetHetNet Enhancements: Enhancements: CACA--based ICIC in Release 10based 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

MIMO Enhancements:MIMO Enhancements:DLDL--MIMO and ULMIMO and UL--MIMO in Release 10MIMO 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▪ 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

MIMO Enhancements: MIMO Enhancements: CoMPCoMP Operation in Release 11 (1/2)Operation in Release 11 (1/2)

▪ Scenario 1

eNB

Coordination area

High Txpower RRH

Optical fiber

▪ Scenario 2

Low Tx power RRH(Omni-antenna)

eNB

Optical fiber

▪ Scenario 3 & 4 Scenario 3: Different cell IDs for eNB

and each RRH

Scenario 4: Same cell ID for both eNB and RRHs

23

Supported CoMP operation schemes:

• Dynamic point selection• Coordinated scheduling/beamforming

Source: 3GPP R1-110564

OutlineOutline



▪ Technology Trend for Release 12 LTE-Advanced or beyond

▪ Conclusion

Data Explosion in Next Five YearsData 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

25

– 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)

Technology Trend in Release 12 LTETechnology Trend in Release 12 LTE--A A or Beyondor 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

∑ ∑−

+⋅⋅−⋅

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icellsSINRNoverheadBW )1(log)1( 2

– Carrier-based migration

▪ 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.

What are Small Cells?What are Small Cells?

▪ Small cells include microcell, picocell, femtocell, relay, low-Tx-power 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 technologiesband access technologies

▪ Heterogeneous Networks (HetNet)

– Macrocells + small cells + WiFiaccess points

– Small cells (low power nodes)

• Picocell, femtocell, relay

– Specification of different elements in HetNet

▪ Operators status: In planning

27

Small Cells

23-46 dBm

Small Cells:Small Cells:Network Architecture (1/2)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

28

Panasonic

NSN

Ericsson

DoCoMo

Huawei

Small Cells:Small Cells:Network Architecture (2/2)Network Architecture (2/2)

▪ To what layer does the multi-point nature of transmission and reception

expose to?? – 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?

Ericsson:

29

Huawei

Source: 3GPP RAN Tdocs

New Carrier TypeNew Carrier Type

▪ 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)

PDCCH

PDCCH

PDCCH

PDCCH

PDCCH

• 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

eDDAeDDA::Why we need Why we need eDDAeDDA??

▪ 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 forsophisticated 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

eDDAeDDA::Example of different Example of different ttraffic patternsraffic patterns

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Good understanding of the traffic is needed to: - Evaluate significance of problems- Evaluate efficiency of solutions

Example Traces from 3GPP study on DDA

2012/10/12Copyright © MediaTek Inc. All rights reserved. 32

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eDDAeDDA: : Problematic trendsProblematic 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

2012/10/12Copyright © MediaTek Inc. All rights reserved. 33

OutlineOutline



▪ Technology Trend for Release 12 LTE-Advanced or beyond

▪ Conclusion

ConclusionConclusion

▪ 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

4g standard participation and technology evolution...

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