Transcript Document

Presented at the First Workshop on Computer Architecture Evaluation Using Commercial Workloads
(held with HPCA-4, Las Vegas, February 1, 1998)
3G :The Next Generation
Sridhar
Rajagopal
Contributions from: Edouard Bugnion, Jack Lo, and Parthas Ranganathan
Outline
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3G Wireless
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The World of Mobile Multimedia
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Introduction - 3G Standards
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Implementation Issues
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My idea of the future
3G Wireless
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1G
– Analog voice communications (AMPS)
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2G
– Digital voice
– Data Services
Low to Medium rate (9.6 kbps)
– DAMPS, GSM, IS-95
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3G
–
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Integrate Multimedia Services
High Data Rates
Adaptability of mobile device to the environment.
Unite different communication platforms
Different standards
Different means of communication
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Mobile Multimedia Services
Mobile Multimedia Services
The World of Mobile Multimedia
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Take Part in a Video Conference from a Remote
Location
Share Information to Feel Closer
Get What You Want When You Want It!
Explore your Intellectual Curiosity in a Mobile
Environment
Various Security Functions
Electronic Account Settlement in a Mobile Environment
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http://www.nttdocomo.com/….
Modes Of Operation
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Packet Data Services
Real Time Services
Mixed Services
– Supports variable rates of transmission
– Different QoS requirements
– Different rates for different environments
2 Mbps : Indoor
384 kbps : Pedestrian
144 kbps : Vehicular
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Adaptability of the Mobile
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Communication : Anytime, Anywhere……..
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A ‘Single Appliance’ that can work at
– Indoor : Wireless /(Wired Ethernet)
– Outdoor : Wireless
– Home : Cable Modem / DSL / Wireless
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REASON for Adaptability : driven by COST
– Wires are here to stay!
United we Stand
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Different 2G standards
– GSM, IS-95.
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Work in the African Jungles, the Sahara Desert, Antartica?
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Harmonization :
– UMTS/IMT-2000 : ETSI,ARIB,3GPP,ANSI,ITU
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Goal :
–Global Communication
3G Layer Structure
Packet Data
Application
OSI
Layers
3-7
Signaling
Services
TCP
Voice
Services
UDP
High Speed
Circuit Network
Layer Services
IP
PPP
Link Access
Control (LAC)
OSI
Layer
2
Medium
Access
Control
(MAC)
LAC Protocol
MAC
Control
States
Multiplexing
OSI
Layer
1
Circuit Data
Application
Null LAC
Best Effort Delivery
(RLP)
QoS Control
Physical Layer
http://www.itu.int/imt/2-radio-dev/index.html
Wireless Network Configuration
http://www1a.mesh.ne.jp/...
Mobile Communication Network
3G Standards - Radio Access Network
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Improved Capacity (3 dB)
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Coverage & Link Budget Improvements
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Power, the Common Resource
– Adjust Power to limit interference & get QoS.
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Multiple Parallel Services on a single connection
– OVSF
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Link Improvements
– Multiuser Detection, Transmit Diversity, Adaptive Antennas….
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Asynchronous Base Station operation
3G Standards - Radio Access Network
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Interfrequency Handover
– Hierarchical Cell Structure (HCS) [ Macro & Micro Overlap]
– ‘Hot Spots’
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SCR’s
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Support for Adaptive Antenna Arrays
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TDD Mode
The Air Interface
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5 MHz Bandwidth
– Resolve more multipaths, capacity
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Basic Chip Rate
– 4.096 Mcps
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Basic Frame Length
– 10ms
Transport Channels
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Unidirectional
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Dedicated / Common
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Broadcast Control (DL)
Forward Access (DL)
Paging (DL)
Random Access (UL)
Dedicated (UL/DL)
Channel Structure
DPCCH
DPDCH
DPCCH
DPDCH
DPCCH
TFCI
Data1
TPC
Data2
Pilot
N
bits
TFCI
N
bits
data1
N bits
TPC
N
bits
data2
FDD
N bits DOWNLINK
pilot
T = 2560 chips, 10*2k bits (k=0..7)
slot
1 Frame = 16 slots
Data
DPDCH
DPCCH
N bits
data
FDD
Pilot
TFCI
FBI
TPC
N bits
pilot
N bits
TFCI
N bits
FBI
N bits
TPC
T = 2560 chips, 10*2 k bits (k= .0. 6)
slot
UPLINK
Spreading and Modulation
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QPSK Modulated
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Scrambling Code Length = 1 Frame (40960 chips)
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Truncated Complex Gold Code (218 -1 ) for Scrambling
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Uplink
– Users distinguished by Scrambling Codes
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Downlink
– Users distinguished by their Walsh codes
– Scrambling code to distinguish cells.
Channel Coding
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Rate 1/3 Convolutional Code
– Low Delay , Moderate Error (10-3)
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Concatenated Rate 1/3 + Outer RS + Interleaving
– High Quality (10-6 BER)
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Turbo Codes
– High Rate, High Quality
Random Access Channel
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For Acquisition of a Dedicated Channel
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MS selects spreading codes for preamble/message
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MS selects spreading factor for message
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Randomly selects signature & access slot for burst
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MS - Closed Loop Power Control
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Transmits
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If no ACK, repeat!
Implementation Issues
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‘Single Appliance’
How should the hardware look?
Current Application
– Nokia 9110 Communicator
Embedded AMD 486 processor
2 Mb user data
8 Mb memory
GEOS Operating System (ver 3.0)
Dimensions: 158 x 56 x 27 mm
Weight: 253 g
Data speed :14,400 bps
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Implementation Issues
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Various applications have different needs
– Desired Bandwidth
– Error Rate
– Security
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All applications can use the same memory.
Make it Software- reconfigurable.
MIT Oxygen Project :
– Microchip wiring that can be automatically reprogrammed for different
tasks.
– Software controlled Logic Operations
– Software controlled wire routing.
Implementation Issues
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Adaptation to different environments
– Seamless handover
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Reconfigurability issues
WAP (Wireless Application Protocol) Support
– Internet services on Mobile appliances.
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Directions :
– Dynamically Reconfigurable FPGA’s
– mNIC
My Idea of the Wireless Future
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A laptop 5 times lighter
Have a mobile phone attached
Ear plug for hands-free talking
Size adjustable
Low Power
Can be attached in front of you
Wireless access, anytime, anywhere
Can be folded & kept in your pocket!
Low COST!
Reusable Paper Printer at the Bottom
The Past ……….
The Future is here …….