LTE beyond 3.5G

February 2010Presentation for Departemen Elektro FTUI

Ir. Dwika Sudrajat CTO and Managing Consultant

dwika@m5sinergi.comHP: 08161108571

1

Outline• HSPA+: Next step in 3GPP Migration Path• 3GPP Long Term Evolution (LTE)• LTE Peak User Performance & Mobile WiMAX Rel 1.5• Timeline Comparison• Migration Path Options for Today’s Mobile Operators• Summary and Conclusion

2

“Multi-carrier”: FDM and OFDM

Ch.1

Ch.2 Ch.3 Ch.4 Ch.5 Ch.6 Ch.7 Ch.8 Ch.9 Ch.10

Saving of bandwidth

Ch.3 Ch.5 Ch.7 Ch.9Ch.2 Ch.4 Ch.6 Ch.8 Ch.10

Ch.1

Conventional multicarrier techniques

Orthogonal multicarrier techniques

50% bandwidth saving

frequency

frequency

Key Technology Of LTEOFDM & OFDMA

OFDMA (Orthogonal Frequency Division Multiple Access )

Delivers higher peak data rates and increased system capacity

Services :

Video streaming

High-speed 3D and multiplayer games

Music downloads or high-speed data connectivity.

Smart Antenna

MIMO (multiple input / multiple output )

Increases subscriber data rate

AAS (adaptive antenna system )

Improves cell-edge link budget

LTE OFDM & OFDMA

• OFDM– All carriers are transmitted in parallel

– Only one user is supported at the same time

• OFDMA– Divides the carrier space into many groups

– Many users can be supported at the same time

• TDMA/FDMA operation = OFDMA• Frequency sub-channels are composed of

multiple, non-adjacent carriers

TX#4TX#3

TX#2

TX#6

TX#5

TX#1

Time

Fre

quen

cy b

in

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

0

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Combining TDMA and FDMA

Compatible to channel dynamics in high mobility environment

Demonstrated in HW and Simulations

Demonstrate feasibility of high data rates within a limited spectrum

Optimization of OFDMA, and MIMO-OFDMA modulation schemes: Adaptive bit-loading, inter/intra band coding, utilization of side information

User #1

Total Frequency band

User #69Contention pilots

Guard Band Guard Band

OFDMA for Mobile

Crowded Spectrum: FCC Chart

http://www.ntia.doc.gov/osmhome/allochrt.pdf

Radio/TV/Wireless Allocations: 30 MHz-30 GHz

BTS — Base Transceiver Station

BSC — Base Station Controller

Typical 2G Architecture

MSC — Mobile Switching Center

VLR — Visitor Location Register

HLR — Home Location Register

BTS

BSCMSC/VLR

HLRBSC

GMSC

CO

BSC

BSCMSC/VLR

CO

PSTN

PLMN

CO

Tandem Tandem

SMS-SC

PSDN

PSTN-to-Mobile Call

(STP)

(SCP)

PSTNPLMN

(SSP)(SSP)BSSMS

PLMN(Home)(Visitor)

(STP)

HLR

GMSC

(SSP)

VMSC

VLR

IAM

6

2

Where is the subscriber?

5Routing Info

3Provide Roaming

4

SCP

1

IAM

514 581 ...

ISUP

MAP/ IS41 (over TCAP)

Signalingover SS7

SS7BTS

BSCMSC

VLR

HLRAuC

GMSC

BSS

PSTN

NSS

AE

CD

PSTNAbis

B

H

MS

BSS — Base Station System

BTS — Base Transceiver Station

BSC — Base Station Controller

NSS — Network Sub-System

MSC — Mobile-service Switching Controller

VLR — Visitor Location Register

HLR — Home Location Register

AuC — Authentication Server

GMSC — Gateway MSC

2.5G Architectural Detail

SGSN — Serving GPRS Support Node

GGSN — Gateway GPRS Support Node

GPRS — General Packet Radio Service

IP

2G+ MS (voice & data)

PSDNGi

SGSN

Gr

Gb

Gs

GGSN

Gc

Gn

2G MS (voice only)

3G rel99 Architecture (UMTS) — 3G Radios

SS7

IP

BTS

BSCMSC

VLR

HLRAuC

GMSC

BSS

SGSN GGSN

PSTN

PSDN

CN

CD

GcGr

Gn Gi

Abis

Gs

B

H

BSS — Base Station System

BTS — Base Transceiver Station

BSC — Base Station Controller

RNS — Radio Network System

RNC — Radio Network Controller

CN — Core Network

MSC — Mobile-service Switching Controller

VLR — Visitor Location Register

HLR — Home Location Register

AuC — Authentication Server

GMSC — Gateway MSC

SGSN — Serving GPRS Support Node

GGSN — Gateway GPRS Support Node

AE PSTN

2G MS (voice only)

2G+ MS (voice & data)

UMTS — Universal Mobile Telecommunication System

Gb

3G UE (voice & data)

Node B

RNC

RNS

Iub

IuCS

ATM

IuPS

3G rel4 Architecture (UMTS) — Soft Switching

SS7

IP/ATM

BTS

BSCMSC Server

VLR

HLRAuC

GMSC server

BSS

SGSN GGSN

PSTN

PSDN

CN

CD

GcGr

Gn Gi

Gb

Abis

Gs

B

H

BSS — Base Station System

BTS — Base Transceiver Station

BSC — Base Station Controller

RNS — Radio Network System

RNC — Radio Network Controller

CN — Core Network

MSC — Mobile-service Switching Controller

VLR — Visitor Location Register

HLR — Home Location Register

AuC — Authentication Server

GMSC — Gateway MSC

SGSN — Serving GPRS Support Node

GGSN — Gateway GPRS Support Node

ANc

2G MS (voice only)

2G+ MS (voice & data)

Node B

RNC

RNS

Iub

IuCS

IuPS

3G UE (voice & data)

Mc

CS-MGW

CS-MGWNb

PSTNMc

ATM

3G rel5 Architecture (UMTS) — IP Multimedia

Gb/IuPS

A/IuCS

SS7

IP/ATM

BTS

BSCMSC Server

VLR

HSSAuC

GMSC server

BSS

SGSN GGSN

PSTN

CN

CD

GcGr

Gn Gi

Abis

Gs

B

H

IM — IP Multimedia sub-system

MRF — Media Resource Function

CSCF — Call State Control Function

MGCF — Media Gateway Control Function (Mc=H248,Mg=SIP)

IM-MGW — IP Multimedia-MGW

Nc

2G MS (voice only)

2G+ MS (voice & data)

Node B

RNC

RNS

Iub

3G UE (voice & data)

Mc

CS-MGW

CS-MGWNb

PSTNMc

IuCS

IuPS

ATM

IM

IPPSTN

Mc

MGCF

IM-MGW

MRF

CSCF

Mg

Gs

IP Network

3GPP LTE and SAE• SAE architecture

MME – Mobility Management Entity UPE – User Plane EntityAS – Access SystemRed indicates new functional element / interface

3GPP LTE and SAE

• Status of the work for LTE–Downlink Parameter for OFDM

Transmission BW1.25 MHz 2.5 MHz 5 MHz 10 MHz 15 MHz 20 MHz

Sub-frame duration 0.5 ms

Sub-carrier spacing 15 kHz

Sampling frequency 1.92 MHz(1/2 3.84 MHz)

3.84 MHz 7.68 MHz(2 3.84 MHz)

15.36 MHz(4 3.84 MHz)

23.04 MHz(6 3.84 MHz)

30.72 MHz(8 3.84 MHz)

FFT size 128 256 512 1024 1536 2048

Number of occupied

sub-carriers†, ††

76 151 301 601 901 1201

Number of OFDM symbols per sub frame

(Short/Long CP)

7/6

CP length

(μs/samples)

Short (4.69/9) 6,(5.21/10) 1*

(4.69/18) 6,(5.21/20) 1

(4.69/36) 6,(5.21/40) 1

(4.69/72) 6,(5.21/80) 1

(4.69/108) 6,

(5.21/120) 1

(4.69/144) 6,(5.21/160) 1

Long (16.67/32) (16.67/64) (16.67/128) (16.67/256) (16.67/384) (16.67/512)

3GPP LTE and SAE

–Uplink Parameters (Variant including TD SCDMA framing also

supported) Transmission BW 1.25 MHz

2.5 MHz 5 MHz 10 MHz 15 MHz 20 MHz

Timeslot duration 0.675 ms

Sub-carrier spacing 15 kHz

Sampling frequency 1.92 MHz

(1/2 3.84 MHz)

3.84 MHz 7.68 MHz(2 3.84 MHz)

15.36 MHz

(4 3.84 MHz)

23.04 MHz

(6 3.84 MHz)

30.72 MHz

(8 3.84 MHz)

FFT size 128 256 512 1024 1536 2048

Number of occupied sub-carriers†, ††

76 151 301 601 901 1201

Number of OFDM symbols

per Timeslot(Short/Long CP)

9/8

CP length (μs/samples) Short 7.29/14 7.29/28 7.29/56 7.29/112 7.29/168 7.29/224

Long 16.67/32 16.67/64 16.67/128 16.67/256

16.67/384

16.67/512

Timeslot Interval (samples) Short 18 36 72 144 216 288

Long 16 32 64 128 192 256

SC-FDMA (1)

• Low PAPR

• Cyclic prefix guard interval: enable cost-effective frequency domain block processing at receiver side

• Two types of SC transmission– Localized transmission: multi-

user scheduling gain in frequency domain

– Distributed transmission: robust transmission for control channels and high mobility UE

ConstellationMapping

M-pointDFT

Spreading

Add Cyclic Prefix

InputBit Stream Serial to

Parallel

Symbol to subcarrier mapping

N-pointIFFT

Parallel to serial

0S1S

1MS

0s1s

1Ms

0x1x

1Nx

0X1X

1NX

M-pointDFT

Spreading

Symbol to subcarrier mapping

N-pointIFFT

0

0

0

M-pointDFT

Spreading

Symbol to subcarrier mapping

N-pointIFFT

0

0

0

0

Localized: contiguous subcarriers

Distributed: evenly spaced subcarriers

SC-FDMA (2)

• Localized transmission– Need to feedback channel state information

– Mainly for low-to-medium mobility users

• Distributed transmission– Mainly for high mobility users

• Orthogonal resource subspace division– Transmission bandwidth is divided into localized band and distributed band

– Each band is further divided into several subbands for inter-cell interference avoidance/concentration

– A subband out of each band in a cell is operated in whispering mode; UEs using a channel belonging to the same subband in neighboring cells can be operated in speaking mode

L-subband 3L-subband 3 L-subband 3

frequency

* Different colors denote different UEs’ channel D-subband 1 D-subband 3

D-subband 2

Localized band Distributed band

SC-FDMA Parameters

Transmission BW 5 MHz 10 MHz 15 MHZ 20 MHz

Subframe duration 0.5 ms

Subcarrier spacing 15 kHz

Sampling frequency 7.68 MHz 15.36 MHz 23.04 MHz 30.72 MHz

FFT size 512 1024 1536 2048

Number of occupied subcarriers

301 601 901 1201

Number of blocks of symbols per subframe

6 Long blocks + 2 Short blocks

CP length (us/samples)(4.04/31) 7,(5.08/39) 1

(4.1/63) 7,(4.62/71) 1

(4.12/95) 7,(4.47/103) 1

(4.13/127) 7,(4.39/135) 1

OFDM: Parallel Tx on Narrow Bands

Channel impulse response

1 Channel (serial)

Channeltransfer function(Freq selective fading)

Channels are “narrowband”(flat fading, ↓ ISI)

2 ChannelsFrequency

Frequency

8 ChannelsFrequency

FrequencyTime

Signal is “broadband”

MIMO: Spatial Diversity, Spatial Multiplexing w/ Multiple Antennas

Example: Simple Selection Diversity (Rx only), Diversity Gains..

SISO, MISO, SIMO, MIMO, SDMA…

SISO– Single Input, Single Output

MISO

– Multiple Input, Single Output

SIMO

– Single Input, Multiple Output

MIMO

– Multiple Input, Multiple Output

SDMA

Adaptive Antenna Gains (Tx or Rx)Diversity

• differently fading paths• fading margin reduction• no gain when noise-limited

Coherent Gain• energy focusing• improved link budget• reduced radiation

Interference Mitigation• energy reduction• enhanced capacity• improved link budget

Enhanced Rate/Throughput• co-channel streams• increased capacity• increased data rate

TDMA Overview

C B A C B A C B A C B A

C

A

B

Time

f0

Freq

uenc

y

Channel PartitioningMAC protocols. Issues

TDMA: time division multiple access • Access to channel in "rounds"

• Each station gets fixed length slot (length = pkt trans time) in each round

• Unused slots go idle

• Example: 6-station LAN, 1,3,4 have pkt, slots 2,5,6 idle

• Does not leverage statistical multiplexing gains here

A A

B B

C C

Freq

uenc

y

Time

f2

f1

f0

FDMA Overview

Need substantial guard bands: inefficient

CDMA

Sender Receiver

Code A

A

Code B

B

AB

AB

CBC

A

Code A

AB

C

Time

Freq

uenc

y

BC

B

A

Base-band Spectrum Radio Spectrum

spread spectrum

Summary of Multiple Access

FDMA

TDMA

CDMA

time

time

time

pow

er

pow

er

pow

er

frequency

frequency

frequency

OFDMA: a mix of FDMA/TDMA: (OFDM modulation) Sub Channels are allocated in the Frequency Domain, OFDM Symbols allocated in the Time Domain. Dynamic scheduling leverages statistical multiplexing gains, and allows adaptive

modulation/coding/power control, user diversity

TDMA

TDMA\OFDMA

t

N

m

OFDMA

3GPP Long Term Evolution (LTE)

• 3GPP (LTE) is Adopting: – OFDMA in DL with 64QAM– All IP e2e Network– Channel BWs up to 20 MHz– Both TDD and FDD profiles– Flexible Access Network– Advanced Antenna Technologies– UL: Single-Carrier FDMA (SC-FDMA), (64QAM optional)

• LTE is adopting technology & features already available with Mobile WiMAX– Can expect similar long-term performance benefits and

trade-offs

33

LTE: Not a Simple 3G Upgrade

• LTE Represents a Major Upgrade from CDMA-Based HSPA (or EV-DO)–No longer a “simple” SW upgrade:

• CDMA to OFDMA, represent different technologies

• Circuit switched to IP e2e network

–Also requires new spectrum to take full advantage of wider channel BWs and …

–Requires dual-mode user devices for seamless internetwork connectivity

34

LTE Projections & Mobile WiMAXFDD 2 x 20 MHz Channel BW

Parameter

Reported LTE Results

WiMAX Rel 1.5Motorola1 T-Mobile2 Qual-

comm3

BS Antenna 2x2 4x4 2x4 4x2 2x2 4x4

Channel BW 2 x 20 MHz 2 x 20 MHz

Mod-Code Rate 64QAM-5/6 64QAM-5/6

64QAM-? 64QAM-5/6

DL Peak User Rate

117 Mbps

226 Mbps

144 Mbps

277 Mbps

144.6 Mbps

289 Mbps

MS Antenna 1x2 1x2 1x2

Mod-Code Rate 64QAM4-? 16QAM4-? 64QAM-5/6

UL Peak User Rate

? ? 50.4Mbps

75 Mbps

69.1 Mbps

35

1. Motorola website, “LTE In Depth” , Reference does not show UL peak rate projections2. “Trials–Ensuring Success for Innovation”, Joachim Horn, T-Mobile, NGMN Conference presentation, June 25-27,20083. “3GPP Long-Term Evolution (LTE)”, Qualcomm, January 20084. 64QAM is optional for UL in LTE specification, 16QAM is mandatory

1. Motorola website, “LTE In Depth” , Reference does not show UL peak rate projections2. “Trials–Ensuring Success for Innovation”, Joachim Horn, T-Mobile, NGMN Conference presentation, June 25-27,20083. “3GPP Long-Term Evolution (LTE)”, Qualcomm, January 20084. 64QAM is optional for UL in LTE specification, 16QAM is mandatory

Other Key Parameter ComparisonsParameter LTE Mobile WiMAX Rel 1.5

Duplex FDD and TDD FDD and TDD

Frequency Band for Performance Analysis

2000 MHz 2500 MHz

Channel BW Up to 20 MHz Up to 20 MHz

Downlink OFDMA OFDMA

Uplink SC-FDMA OFDMA

DL Spectral Efficiency1 1.57 bps/Hz/Sector (2x2) MIMO2

1.59 bps/Hz/Sector (2x2) MIMO

UL Spectral Efficiency1 0.64 bps/Hz/Sector (1x2) SIMO2

0.99 bps/Hz/Sector (1x2) SIMO

Mobility Support Target: Up to 350 km/hr Up to 120 km/hr

Frame Size 1 millisec 5 millisec

HARQ Incremental Redundancy Chase Combining

Link Budget Typically limited by Mobile Device Typically limited by Mobile Device

Advanced Antenna Support

DL: 2x2, 2x4, 4x2, 4x4UL: 1x2, 1x4, 2x2, 2x4

DL: 2x2, 2x4, 4x2, 4x4UL: 1x2, 1x4, 2x2, 2x4

36

1. Spectral efficiency is based on NGMN Alliance recommended evaluation methodology

2. Reference for LTE Spectral Efficiency: Motorola website, “LTE in Depth”. 1. Spectral efficiency is based on NGMN Alliance recommended evaluation methodology

2. Reference for LTE Spectral Efficiency: Motorola website, “LTE in Depth”.

What is MIMO? Multiple Input Multiple Output

4x1 STTDCode Rate = 1

4x2 STTDCode Rate = 2

4x4 Spatial MultiplexingCode Rate = 4

UL virtual MIMO

UL Adaptive MIMO

Down link

Up link

MIMO Increases throughput

MIMO Channels

(Rich-Scattering Channels)

3GPP Timeline

39

Mobile WiMAX time to market

advantage

IMT-Advanced

2008 2009 2010 2011 2012

CDMA-Based OFDMA-Based

LTE & LTE Advanced

IP e2e Network

3GPP

HSPA+Rel-7 & Rel-8

Ckt Switched Network

HSPARel-6

Upgrade Path for Existing Operators

40

Radio Access Network Core Network

2G, 3G, GSM, EVDO, HSPA

Backhaul Network

2G, 3G, Core Network

All-IP Core Network

Next Generation Access Network

Data Overlay or Replacement

LTE

Comparable CAPEX

LTE in 2+ years.Both require new spectrum

Conversion to all-IP core & increased backhaul capacity required in either case

Increased BH Capacity

T1,E1s

Support for Legacy RAN

Comparing the End-to-End Network

41

Source: LTE/SAE: 3GPP, Mobile WiMAX: WiMAX Forum Network Specification Release 1.0

LTE/SAE User Plane & Data FlowLTE/SAE User Plane & Data Flow

L1

L1

L1

-

L2

Relay

L1

-

Serving GWE-UTRAN

UE/MS LTE-Uu

PDN GW

L1

-

L2

L1

-

L2

Relay

S1-U S5 SGi

UDP/IP UDP/IP

PDCP GTP U

UDP/IP

GTP UGTP U GTP U

RLC RLC UDP/IP

e.g. IP,PPP

e.g. IP,PPP

L2

Application

PDCP

MAC MAC

Multiple layers, Many nodes and proprietary protocols

42

Thank You for Your Attention

Appendix

43

WLAN (802.11n/이후 ) WiBro I/II 3G LTE 4G

(new capabilities)

Spectrum

5~6GHz ( 및 2.4~2.5GHz)

Unlicensed band

2.3~2.4GHz,

?

Licensed band

2.5~2.6GHz,

2G/3G 대역Licensed band

3.4GHz ~ 6GHz

Licensed & Unlicensed band

Bandwidth

(MHz)

20, 40/

20, 40, 80, (100)

I : 10

II : 10, 20, 401.25, 2.5, 5, 10, 15,

205, 10, 20, 40, 80, (100)

Duplexing TDD TDD FDD & TDD FDD & TDD, Hybrid

Modulation & Multiple

Access

OFDM/TDMA

(CSMA/CA 기반 )

OFDMA

DL: OFDMA,

OFDM-CDMA

UL: SC-FDMA, OFDMA

DL: OFDMA, MC-CDMA, …

UL: SC-FDMA, OFDMA,

GMC-FDMA, …

Peak Data Rate

216Mbps/

1Gbps

I : ~ 50Mbps

II : ~ 210Mbps

DL: 100Mbps/20MHz

UL: 50Mbps/20MHz100Mbps ~ 1Gbps

Mobility Nomadic I : 60km/h

II : ?350km/h > 350km/h

Cell coverage

Pico, hot spot Micro/pico Macro/microMacro/micro/pico/hot

spot/relay link

( 다중 동작 모드 )

Comparison of WLNA, WiBro, 3G LTE, and 4G

MSC

HLR

SMS-SC

A Ref (A1, A2, A5)

STM over T1/T3

A Ref (A1, A2, A5)

STM over T1/T3

PSTNSTM over T1/T3 or

AAL1 over SONET

BSC

BSC

Proprietary Interface

BTS

BTS

Proprietary Interface

BTS

IS-95

MS

IS-95

MS

BTS — Base Transceiver StationBSC — Base Station ControllerMS — Mobile StationMSC — Mobile Switching CenterHLR — Home Location RegistrySMS-SC — Short MessageService — Serving Center

STM — Synchronous Transfer Mode

Ater Ref (A3, A7)

A1 — Signaling interface for call control and mobility

Management between MSC and BSC

A2 — 64 kbps bearer interface for PCM voice

A5 — Full duplex bearer interface byte stream (SMS ?)

A3 — Signaling interface for inter-BSC mobile handoff

A7 — Bearer interface for inter-BSC mobile handoff

2G cdmaOne (IS-95 + IS-41)

CDMA2000 1x Network

BTS — Base Transceiver StationBSC — Base Station ControllerMS — Mobile StationMSC — Mobile Switching CenterHLR — Home Location RegistrySMS-SC — Short MessageService — Serving Center

STM — Synchronous Transfer ModePDSN — Packet Data Serving Node

AAA — Authentication, Authorization, and AccountingHome Agent — Mobile IP Home Agent

A10 — Bearer interface between BSC (PCF) and PDSN for packet dataA11 — Signaling interface between BSC (PCF) and PDSN for packet data

MSC

PSTN

A Ref (A1, A2, A5) STM over T1/T3

STM over T1/T3 or

AAL1 over SONET

HLR

SMS-SC

BSCProprietary Interface

BTS

BTS

IS-2000

MS

PDSN

HomeAgent

IPFirewall

IPRouter

Internet

PrivataData

Network

IPRouter

AQuarter Ref (A10, A11)

IP over Ethernet/AAL5

AAA

RADIUS over UDP/IP

1xEVDO — IP Data Only

IS-2000

IPBTS

IS-2000

IPBTS

IP BSC IPRouter

PDSN HomeAgent

IPFirewall

IPRouter

Internet

PrivataData

Network

IP BTS - IP Base Transceiver StationIP BSC - IP Base Station ControllerAAA - Authentication, Authorization, and AccountingPDSN - Packet Data Serving NodeHome Agent - Mobile IP Home Agent

AAA

RADIUS over UDP/IP

Nextgen MSC ?

1XEVDV — IP Data and Voice

Packet switched voice

P ST N

SIPProxy

SIP

SIP

SGW

SS7

MGCF(Softswitch)

SCTP/IP

H.248 (Maybe MGCP)

MGW

Circuit switched voice

PDSN +Router

AAA HomeAgent

Internet

IPFirewall

IPRouter

PrivataData

Network

IS-2000

IPBTS

SIP Proxy — Session Initiation Protocol Proxy Server

MGCF — Media Gateway Control Function

SGW — Signaling Gateway (SS7)

MGW — Media Gateway (Voice)

IS-2000

IPBTS

IP BSC