© 2002

Portable Internet ServicesPortable Internet Services

Chaehag (Steve) YiSOLiD Technologies, INCChaehag (Steve) YiSOLiD Technologies, INC

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Portable Internet - DefinitionPortable Internet - DefinitionIt’s a High-Rate wireless internet access services that can be provided to any user, while moving as well as stationary, with aportable terminal anywhere, anytime.『 Portable Internet 』was named to 『WiBro』. (End of April, 2004)WiBro : Wireless Broadband

Low Cost

High Data Rate

Anytime,Anywhere

Mobility

WiBro

Portable Internet - positioningPortable Internet - positioning

WLLFixed

High Mobility

Nomadic MobilityIMT2000

(3G)

Mobility

2.4GHz Wireless LAN

WiBro

User Data Rate

ADSL/HFC/B-WLL

The next Generation Multimedia Service

Cellular PCS(2G)

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Portable Internet Market ForecastPortable Internet Market ForecastBackground− Demand on (Wire/Wireless) Internet services

in Korea has risen − An efficient frequency band was sought by

Industries; the government reallocated 2.3GHz, once allocated for FWA (WLL), for Portable Internet service (Dec. 2002)

− Why Portable Internet ? => Korean market wants Portable Internet service

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Revenue (10M$ unit)

Subscriber (10K unit)

Portable Internet Market ForecastPortable Internet Market Forecast

Y+5 years from beginning : 8.9M

subscribers, 3 billion dollars revenue

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Standardization by TTAStandardization by TTA

Major System Parameters

Duplexing TDD

Multiple Access OFDMA

10MHzChannel BW

Radio Access Requirement

Frequency ReuseFactor 1

Mobility 60 Km/h

1 KmService Coverage

max. DL / UL = 6 / 2aver. DL / UL = 2 / 1

Frequency Efficiency[bps/Hz/cell(sector)]

Between cells, sectors & Frequency : ≤ 150msHandoff

Throughput(per a User)

max. DL / UL = 3 / 1 [Mbps]min. DL / UL = 512 / 128 [Kbps]

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Network Architecture of Portable InternetNetwork Architecture of Portable Internet

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PSS

HA

RAS

PSS

ACR

AAA

Public IP Network

ACR

PSS

OperatorIP Network

PSS

RASRASRAS

……

ACR : Access Control Router

RAS : Radio Access Station

PSS : Personal Subscriber Station

Schedule for Portable Internet ServiceSchedule for Portable Internet Service

20041st Half

20042nd Half

20051st Half

20052nd Half

2006

TechnologyTechnical

Standard

(June, 2004)

Development of commercial

Service System

Field

Trial Test

Service

Schedule

Selection ofservice carrier

(Dec, 2004)

Pre-commercial

service

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Key component technologiesKey component technologies

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Mobility Support with High Spectral Efficiency − Frequency reuse factor 1 operation

Sub-channel allocation method to minimize RAS interferencesCell edge – Low rate FECSafety Channel

− Fast AMC by CTC with QPSK/16/64 QAM based on channel quality reporting

− Battery life saving by sleep mode

Key component technologiesKey component technologiesGenuine Internet Access − Hybrid ARQ for high quality and low latency

Guarantee enhanced link performance− Various QoS support

Best effort/Real time polling/Non-real time polling− Enhanced handoff

Seamless connection for mobile user

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11

...

DL Preamble

TTG RTG

Downlink Interval Uplink Interval

3

B-2

UL Control Symbol

1

Band 0

2

B-1

BIN

...

...

...

Safety Pattern

5 msec

...

...

...

...

...

...

...

...

...

...

...

...

...

...

Band

Band

Band

Band

Band

BINTile

...

...

...

...SLOT SLOT

...

...

...

Frame StructureFrame Structure

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Parameter Value

System Bandwidth 10 MHz

Sampling Frequency (Fs) 10 MHz

Sampling Interval (1/Fs) 100 nsec

FFT Size (NFFT) 1024

# of used sub-carriers 864

# of data sub-carriers 768

# of pilot sub-carriers 96

Sub-carrier spacing 9.765625KHz

Effective symbol duration (Tb=1/Δf) 102.4 μs

CP period (Tg= Tb/8) 12.8 μs

OFDMA symbol period (Ts= Tb+Tg) 115.2 μs

TDD frame length 5 ms

Parameters for OFDMA SignalParameters for OFDMA Signal

Technical Issues in Portable InternetTechnical Issues in Portable Internet

RAS vs. RepeaterTerminal TypeModem Implementation

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RAS vs. Repeater

Capacity or Coverage

TDD Repeater Feasibility

RAS Architectures

Normal RAS + Pico RAS

Normal RAS + Repeater

Centralized RAS digital part with multiple RF parts

RAS vs. RepeaterRAS vs. Repeater

Centralized RAS ArchitectureCentralized RAS Architecture

Donor

optic

optic

optic

Remoteβ

Remoteα

Remoteα

Remoteβ

Remoteβ

Remoteβ

RemoteβRemote

α

Remoteγ

Remoteγ

Remoteα

Remoteα Remote

γ

optic

optic

optic

optic

optic

Remoteα

optic

optic

optic

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Legacy Data Terminals

Terminal – RequirementsTerminal – Requirements

Pros Cons

Note PC Abundant softwareGood multimedia environment

Difficult to use for mobile userLong time for ON/OFF

PDA-like PortabilityCheap price

Poor multimedia environmentNo Killer application

Mobile Phone Portability and Mobility Expensive Solution

Portable Internet Terminal

Portability and Mobility (like Mobile Phone)

Good Multimedia Environment (like Note PC)

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Terminal – Component DevicesTerminal – Component Devices

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Application Processor− Various Multimedia Codec,− 2D/3D Graphic Engine− Low Power Consumption

Communication Module− Multi-mode: Bluetooth, WLAN, Cellular

Display: High Resolution, Low Power ConsumptionStorageKeyboard

Terminal Modem Block Diagram - TxTerminal Modem Block Diagram - Tx

S /P &M a p p in g

C o m p a c t_ U L _ M A PM e s s a g e (N E P , N S C H )

IF F T

A d d C P&

P /S

In te rp o la tio nD A CR FP A

H -A R QA C K /N A C K

S o u rc e C T CE n c o d e r

H -A R QE n c o d e r

M o d u la tio n(Q P S K , 1 6 Q A M )

C T CB u ffe r

T im e /F re q .S y n c

L .OC lo c k

F ro m M S S R xC o m p a c t U L M A P P e r B it

P e r S y m b o l

P e r O F D M S y m b o l

C o n tro l S ig n a l

C Q I E n c o d in g

A C K /N A C KE n c o d in g

R a n g in g E n c o d in g

F ro m M S S R xID c e ll, s

F ro m M S S R x , C IN R

F ro m M S S R x , A C K /N A C K s

T o B S R x , R a n g in g

- F ro m M S S R x T im e a n d F re q u e n c y S y n c In fo rm a tio n- F ro m B S T x , R a n g in g [R N G _ R S P ]

F ro m M S S R xH -A R Q A C K /N A C K

B IT M A P

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Terminal Modem Block Diagram - RxTerminal Modem Block Diagram - RxP e r B itP e r S y m b o l

P e r O F D M S y m b o l

C o n tro l S ig n a l

L N A R F A D C M ix e r D e c im a t io nR x

B u ffe r

P r e a m b leD e te c t

C o a r s eF r e q /T im e

S y n c .

T im eS y n c

F r e q .S y n c

S /P&

R e m o v eC P

IF F T

D E M U X

F .B u f fe rC IN R M e a s u r eC e l l S e a r c h in g

K n o w n P r e a m b leP a t te r n

P r e a m b lea n d P ilo t

E x tr a c t&

C h a n n e lE s t im a t io n

E q u a liz e rC o m p a c t_ D L /U L _ M A PM e s s a g e D e c o d in g

D e m o d u la t io n(Q P S K , 1 6 Q A M ,

6 4 Q A M )S IN K

C T CD e c o d e r

H -A R QD e c o d e r

A C K /N A C K

C o m p a c t_ D L _ M A PM e s s a g e (N E P , N S C H )

T im eS y n c .

F r e q .S y n c .

L .O

C lo c k

T o M S S T x C IN R M e a s u r e

T o M S S T x ID c e ll , s S e a r c h in g

T o M S S T x C o m p a c t_ U L _ M A P

T o M S S T x R N G _ R S P

T o M S S T x A C K /N A C K M e s s a g e

D e m a p p in g&

P /S

T h e F ir s t 2 O F D MS y m b o l p e r F r a m e

M A P M e s s a g eO F D M S y m b o l

A l l F r a m e

D E M U X

T o M S S T x H -A R Q A C K /N A C K B IT M A P

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How FPGA can helpHow FPGA can helpImplementation Issues

DSP vs. LogicTime to market

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