3G & 4G the Story From Start

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The Evolution of TDMA

to 3G & 4G WirelessSystems

Manasvi Mehta

BCA 16UPTEC Allahabad

+917275142550



AT&T Wireless Services

• TDMA

– European GSM over 250 million

– North American TDMA ~ 50 million

– Japanese PDC ~ 50 million

• CDMA

– North American CDMA ~ 60 million (including S. Korea)

AT&T serves over 14 million subscribers with digital TDMA technology and some remaining analog technoloand provides packet data service with CDPD technolog

Other TDMA operators- Rogers AT&T- Cingular (SBC & BellSouth)- throughout Mexico, Central & South America



Cellular Telephony

Handsets

Nokia5160

EricssonPD 328

MotorolaStarTAC®ST7790 Phone

Nokia8860

Various TDMA phones available today



TDMA parameters

• 30 KHz channels (like analog &CDPD)

• 20 m/sec speech frames

• 24.3 k/baud symbol rate

• 3 time-slots/users

• 7.4 kbps ACELP speech coding

• Differential pi/4-QPSK modulation



TDMA Capacity Roadmap

Reuse N = 7 N = 5 N = 4

xDual band base •Operation at 800 or 1900 MHz Calls

can be set up on either frequencyband and handed between them tomanage traffic

•Additional spectrum at 1900 MHzadds directly to capacity of cell

xSmart Antennas •Base station antennas systems that use

digital signal processing to cancelinterference

2000 2001 2002

xBase Station Power Control •Base stations only transmit power required to reachmobile with adequate signal quality resulting in lowerinterference

xDynamic Channel Assignment •Network automatically assigns radio frequencies to cell

sites for more efficient utilization of frequencies

xDiscontinuous Transmission•Mobiles transmit only during when user is speaking.

Lowers interference in the system and increases talk time



IS-136 Smart Antenna Test Bed

•Reuse of 3/9 to 4/12, instead of 7/21, approximately 2x capacity

• Two dual polarization uplink antennas, downlink multibeam antenna with 4 -30° beams

•Shared linear power amplifier unit with Butler matrices

•Real-time downlink power control with beam tracking



Wireless Data Terminals

Nokia 9110

3COMPalm VII

Nokia3G visionSierra PCMCIACDPD Modem

The newEricssonR380 phone,whichfeatureswireless datafunctions



WIRELESS COMPUTING

WIRELESS

GROWTH

INTERNET

GROWTH

RF & DIGITAL

TECHNOLOGY

MOBILE

SOFTWARE

- web access- e-mail- file transfer- location services- streaming audio

& video



datarate

1 M

384 k

64 k

9.6 k IS-136

IS-136+

EDGE

WidebandOFDM

Macrocellular Wireless Data Evolutio& AT&T’s Roadmap

CDPDGSM

IS-95

GPRS

IS-95+

WCDMA

1995 2000 2005

PDC

5 M

HDR



EDGE TechnologyEnhanced Data-rates for Global

Evolution• Evolutionary path to 3G services for GSM

and TDMA operators

• Builds on General Packet Radio Service

(GPRS) air interface and networks• Phase 1 (Release’99 & 2002 deployment)

supports best effort packet data atspeeds up to about 384 kbps

• Phase 2 (Release’2000 & 2003deployment) will add Voice over IPcapability



GPRS Airlink

• General Packet Radio Service (GPRS)

• Same GMSK modulation as GSM

• 4 channel coding modes

• Packet-mode supporting up to about 144 kbps• Flexible time slot allocation (1-8)

• Radio resources shared dynamically betweenspeech and data services

• Independent uplink and downlink resourceallocation



EDGE Airlink• Extends GPRS packet data with adaptive modulation/coding

• 2x spectral efficiency of GPRS for best effort data

• 8-PSK/GMSK at 271 ksps in 200 KHz RF channels supports8.8 to 59.2 kbps per time slot

• Supports peak rates over 384 kbps• Requires linear amplifiers with < 3 dB peak to average

power ratio using linearized GMSK pulses

• Initial deployment with less than 2x 1 MHz using 1/3 reusewith EDGE Compact as a complementary data service



GPRS Networks• consists of packet wireless access network and

IP-based backbone

• will support GPRS, EDGE & WCDMA airlinks

• provides an access to packet data networks

– Internet

– X.25

• provides services to different mobile classesranging from 1-slot to 8-slot capable

• radio resources shared dynamically betweenspeech and data services



Compact vs Classic• Classic

– 4/12 reuse

– continuous downlinks on first 12 carriers

– 2.4 MHz x2 minimum spectrum• Compact

– 1/3 reuse in space

– frame synchronized base stations

– reuse of 4 in time for control channels– partial loading for traffic channels

– discontinuous downlinks

– 600 KHz x2 minimum spectrum



EDGE Channel Coding and FrameStructure

464 bits

1 data block

Convolutional CodingRate = 1/3

Length = 7

Puncture Interleav

e

Burst N

Burst N+1

Burst N+2

Burst N+3BurstFormat

8PSK Modulate

1392 bits 1392 bits

348 bits/

burst

348 bits468.75 bits

156.25symbols/slot

0 1 2 3 4 5 6 7

8 Time Slots

1 Time Slot = 576.92 µs

Tailsymbols

3

Datasymbols

58

Tailsymbols

3

Datasymbols

58

Trainingsymbols

26

Guardsymbols

8.25

Modulation: 8PSK, 3 bits/symbolSymbol rate: 270.833 kspsPayload/burst: 348 bitsGross bit rate/time slot: 69.6 kbps - overhead = 59.2 kbps user data

20 msec frame with 4 time-slots for each of 8 bearers



EDGE Modulation, Channel Coding & Bit Rates

Scheme Modulation Maximum

rate [kb/s]

Code Rate Family

MCS-9 59.2 1.0 A

MCS-8 54.4 0.92 A

MCS-7 44.8 0.76 B

MCS-6 29.6 0.49 A

MCS-5

8PSK

22.4 0.37 B

MCS-4 17.6 1.0 C

MCS-3 14.8 0.80 A

MCS-2 11.2 0.66 B

MCS-1

GMSK

8.8 0.53 C



EDGE Link Throughput

9



EDGE Compact System Performance

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70

Probability throughput < = X per timeslot

X (kb/s)

26 users/sector at 3.5 kbps average load per user

0

10

20

30

40

50

60

70

80

90

100

0 1000 2000 3000 4000 5000

Probability packet delay < = X

X (msec)

% %



0

50

100

150

200

250

300

9 18 27 36 45

single-slot

Multi-slot

Average User Throughput (kb/s)

EDGE Classic Multi-slot Gain

Ave. # of users per sector



EDGE Evolution

• Best effort IP packet data on EDGE

• Voice over IP on EDGE circuit bearers

• Network based intelligent resource assignment• Smart antennas & adaptive antennas

• Downlink speeds at several Mbps based on wideband

OFDM and/or multiple virtual channels

3G & 4G the Story From Start

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