Software Defined Modems for “The Internet of Things”€¦ · Software Defined Modems for “The...
Transcript of Software Defined Modems for “The Internet of Things”€¦ · Software Defined Modems for “The...
Software Defined Modems for “The Internet of
Things”
Dr. John Haine, IP Operations Manager
www.cognovo.comwww.cognovo.com
What things?
� “20 billion connected devices”
� Manufactured for global markets
� Low cost
� Lifetimes from months to decades
� Different...
Networks
Frequencies
Protocols
� Evolving networks & spectrum allocations
� Versatility & programmability required
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Multiple systems and bands
� Cellular
� GSM, HSPA, LTE(A),
EVDO, WiMax,...
� Short range
� WiFi, Zigbee, UWB,
� Conventional cellular
bands, 400 – 2600 MHz
� License-exempt – 2400 &
5800 MHz
� “Digital Dividend” � WiFi, Zigbee, UWB,
Bluetooth,...
� Emerging techniques
� “WhiteSpace”
� Other systems
� Tetra & derivatives
� “Digital Dividend”
spectrum
� “Shared” bands
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Focus on the radio modem
“Apps”IP packets
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Modem – HSPA, LTE etc
OS – Android etc.
“Photons”Radio
Digital
processing
I/Q stream
Relative computational load for LTE Video
decoder:
~500 MO/s
DSP
arithmetic:
~50 GO/s
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LTE Modem
Baseband Complexity
200
250
300
350
400
450
500
Bitr
ate,
Mbp
s
LTE 50GOp/s
LTE-A 1Gbps 300GOp/s
60
...Arithmetic
6
0
50
100
150
1990 1995 2000 2005 2010 2015
GSM
GPRS 200MOp/s
HSPA 5GOp/s
HSPA+ 20GOp/s
0
10
20
30
40
50
60
1990 1995 2000 2005 2010 2015
Cum
ulat
ive,
Mod
ulat
ion
& C
odin
g S
chem
es
GSMGPRS
HSPA
HSPA+
LTE
LTE-A
WCDMA
Bit shuffling...
Conventional Modem Architecture
Applications
Protocol
Stack
Layer 1
7
Software
HardwareProtocol
Processor
System
RF
H/w Drivers
DSP
Dedicated
arithmetic
hardware
Conventional Modem Architecture
� Hardware is inflexible
� Different / upgraded / new protocols
� Multi-mode needs separate hardware engines – increases chip
area & cost
� Distributed memory less efficient, increases area / cost
� Difficult development process� Difficult development process
� FPGA prototyping cannot fully model final device
� Software development depends on chip availability
� Hardware bugs need software work-arounds which may not
be ideal
� Cost of large chip developments rising exponentially
� Need to amortise over maximum number of applications
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Processor SystemApplication software
Product development – the software paradigm
My PC is a...
� Typewriter
� Calculator
� Phone
� TV receiver
� Music player
...often simultaneously!
Software development...
� Is well understood
� Allows continuous improvement
� “Infinite flexibility”
� A platform for unpredictable
products
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Drivers
“Real-world” interfaces
Example - universal radio/TV receiver for the PC
http://www.crestatech.com/products/ctc200.html
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http://www.crestatech.com/products/ctc200.html
http://www.mirics.com/
Software Defined Modem (a/k/a SDR)
Processor SystemApplication software
� Hardware architecture becomes standards – independent
� Simplify production logistics – single hardware platform for
multiple standards & standards combinations – the “world
modem”
� Update firmware in the field to fix problems and/or change air
interface
� Extend product lifetime11
Drivers
Multi-band radio module
Barriers to SDM
Computation load – Moore’s Law is not enough!
� As geometry gets smaller, voltage gets lower, clock speeds
static or decreasing
� Overall single processor Mips/MHz/mW stops improving
� Large processor systems have to become multi-core
Standards complexityStandards complexity
� Ever more complex modulation & coding schemes
� Wider RF bandwidth
� Need for legacy support
� Management of task scheduling within and amongst protocols
RF technology
� Wideband operation, multiple frequencies
� Time and frequency duplex modes
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Lifting the barriers
Vectorisation
� Operate on large blocks of samples (vectors) (e.g. FFT)
� SIMD computing architectures apply same operation on multiple
data values in the same processor cycle - vector arithmetic
Multi-processing
� VLIW computing architectures allow multiple operations on � VLIW computing architectures allow multiple operations on
independent data in the same processor cycle
� Multiple processors on same die to increase MiPs/MHz/mW
� Novel hardware architectures to enable deterministic
performance
Programming
� Automatic compilers to support multiprocessing
� SDM OS to support task scheduling across multiple cores
� System tools for multiprocessing design, development and debug
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Lifting the barriers
Integrated RF technologies
� New methods such as MEMs for RF switching
� Monolithic filtering technologies such as FBARs
� DPD / ET for efficient wideband power amplifiers
� Multi-mode & multi-band integrated radios
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Software Defined Modem (SDM)
Design
Environment
Applications
System
SDK
System
integration &
Modem specific
operation
Protocol Plane Control Plane
Layers 2, 3, 4
Protocol
Stack
Layer 1
Data Plane
Physical
Layer
PHY Kernel PHY Kernel
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PHY coding &
optimisation
SDK
Kernel
SDK
Software
Hardware
integration &
modelling
Generic s/w
execution
environment
Modem Compute Engine
Stack
SDM-OSPHY Kernel
Library
Layer 1
Processor
PHY
Processor
Protocol
Processor
System
RADIO
DigRF
Ideal M2M module architecture
� Flexible broadband RF
� Software defined modem
� All signal processing in programmable
processor
� Air interface defined by software
download, at any stage in product life-
cycle
Modem
Microcontroller
system
Interfaces
cycle
yields...
� One hardware platform for all standards
� Upgrade / change air interface during
end-product manufacture or after sale
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RF transceiver
DSP
Standardisation & regulatory barriers to SDM
� Mode incompatibility
� Device may need to be multiple-network aware
� Protocols need to permit “listening” for “foreign” air-
interfaces – difficult for “legacy” modes
� Approvals
� Approvals given for defined hardware platform and software � Approvals given for defined hardware platform and software
version – SW version may change frequently as bugfixes &
improvements are made
� Tests may need to recognise operation in “foreign” modes
� Separate approval regimes may apply to modes in the same
device
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SDM as an enabler for the “Internet of Things”
� Advances in silicon integration & computer
architectures now allow advanced radio modems to be
implemented in software (the “software defined
radio”)
� RF technology allows multi-band / multimode
operationoperation
� Future products will be able to have a single radio
platform to provide radio connectivity across many
diverse networks and bands - massive scale economies
can result
� Standards and approvals regimes need to adapt to the
new possibilities that SDM creates
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