3g & 4g the story from start
TRANSCRIPT
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The Evolution of TDMA
to 3G & 4G WirelessSystems
Manasvi Mehta
BCA 16UPTEC Allahabad
+917275142550
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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
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Cellular Telephony
Handsets
Nokia5160
EricssonPD 328
MotorolaStarTAC®ST7790 Phone
Nokia8860
Various TDMA phones available today
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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
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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
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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
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Wireless Data Terminals
Nokia 9110
3COMPalm VII
Nokia3G visionSierra PCMCIACDPD Modem
The newEricssonR380 phone,whichfeatureswireless datafunctions
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WIRELESS COMPUTING
WIRELESS
GROWTH
INTERNET
GROWTH
RF & DIGITAL
TECHNOLOGY
MOBILE
SOFTWARE
- web access- e-mail- file transfer- location services- streaming audio
& video
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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
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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
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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
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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
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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
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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
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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
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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
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EDGE Link Throughput
9
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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)
% %
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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
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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