dcit’ 2015 wuhan, hubei, china, 16-18- november...
TRANSCRIPT
LIMOS UMR 6158 CNRS, Clermont-Ferrand, FRANCE
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DCIT’ 2015 Wuhan, Hubei, China, 16-18- November 2015
Outline • Introduction:
– Panorama of IoT technology
• IoT core technologies:
– IoT node hardware:
• State-of-the-art of IoT Node
• Trend and challenges
- Communication protocol stack:
• State-of-the-art:
– 6LoWPAN and RPL
– Challenges
– Middleware: CoAP, OASIS /MQTT
• State-of-the-art
– CoAP (IETF)
– Trend and challenges
• Conclusion
• Open research issues
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KM. Hou - DCIT’ 2015 Wuhan, Hubei, China, 16-18- November 2015
Introduction
• IoT ‘Internet of Things’ and WoT ‘Web of Things’: Emergent and multidisciplinary science, very active and competitive research area.
• IoT and WoT have unlimited potential applications: air, underground and underwater.
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Source: 6LoWPAN: The Wireless Embedded Internet
Companion Lecture Slides
KM. Hou - DCIT’ 2015 Wuhan, Hubei, China, 16-18- November 2015
• At least 26 billion devices will be connected on the
Internet by 2020 (Gartner),
• IoE ‘Internet of every Things’ creates $19 trillion of
value at stake for companies and industries (Cisco)
• IoT product and service suppliers will generate
incremental revenue exceeding $300 billion in 2020
(Gartner).
• IoT will be the next IT revolution: Industry 4.0, IoE …
• IoT is one of the key issues to support sustainable development (smarter planet ‘smart every where’: smart grid, smart home, smart building, smart care, smart farming …).
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KM. Hou - DCIT’ 2015 Wuhan, Hubei, China, 16-18- November 2015
Panorama of IoT platforms
• Big ICT players: IBM (Bluemix), Microsoft (Azure), SAP (HANA) … provide the IoT cloud-based platforms containing three mains layers:
– Back-end: Integration and Services
– Middleware: connect and collect.
– Front-end: IoT nodes
• The front-end layer is open for diverse players to develop their specific physical devices for specific application (NB-IoT, ISM (IEEE802.15.4, Sigfox, LoRa …)
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Figure 2: IBM Bluemix IoT based platform
KM. Hou - DCIT’ 2015 Wuhan, Hubei, China, 16-18- November 2015
Key components of IoT core technology
WSN Node HW
Operating system
Protocol Stack
Middleware Applications
-100 0 100 200 300 400 500 600 700
0
100
200
300
400
500
X
Y
Radio Radius:100 | Fieldsize X:500 | Fieldsize Y:500 | Node Number:50 | Minimum Intersection Nodes:1 | Optimum Intersection Nodes:2
M1
M2
M3
B4(1 47)
M5N6(10)
M7
N8(3)
M9
M10
B11(14 26)
B12(15 26)
N13(26)
M14
M15
B16(18 41)
B17(1 47)
M18
B19(14 26)
N20(1)
N21(15)
B22(3 9 10)
N23(41)
N24(7)
N25(18)
M26
B27(9 10)
B28(9 15)
B29(2 10)
N30(1)
B31(18 41)
N32(10)
N33(15)
N34(15)
B35(9 15)
N36(41)
N37(41)
N38(5)
B39(14 18)
N40(41)M41
N42(2)
N43(18)
N44(1)
B45(2 5)
N46(14) M47
B48(2 5)
N49(3)
N50(1)
Master: 13(26%)
Lost: 0(0%)
Slave: 37(74%)
Bridge: 15(30%)
Slave without Intersection: 22(44%)
Simulator
=
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IoT Cloud-based platform
KM. Hou - DCIT’ 2015 Wuhan, Hubei, China, 16-18- November 2015
IoT core technology: IoT node - Basic Hardware
• Key features of a IoT Node
Signal conditioner
Wireless
Access medium
Antenna
Power supply
&
Power
management
Unit
Processor
Peripheral
Devices: ADC,
UART, SPI,
I²C, GPIO
Memory: RAM
& ROM
Microcontroller
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Sensor
KM. Hou - DCIT’ 2015 Wuhan, Hubei, China, 16-18- November 2015
IoT Node HW: State-of-the-art and design
trend
• Two main development and design trends:
Commercial Off-The-Shelf ‘COTS’ and System
on Chip ‘SoC’
• COTS: platform for test and validation, real
world experimentation
• SoC: Ultimate goal to achieve the
implementation of long lifetime, low cost and
invisible IoT node integrated and embedded
into environment or object.
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System On Chip: SoC
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IoT node HW: trends and challenges
• Trends and challenges:
– More powerful IoT node: 32-bit core (e.g. WMSN)
– Robust and Energy Efficient Multicore (lifetime):
• Energy efficient IEEE802.15.4: ~45mA
~15mA (2Mbs) (research prototype
<10mA)
• Texas Instruments MSP430 runs at less than
100µA/MHz (FRAM ‘ferroelectric read-only
memory)
• Radio cognitive: IEEE802.15.4, NB-IoT …
• Battery-less IoT node: Energy harvesting.
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KM. Hou - DCIT’ 2015 Wuhan, Hubei, China, 16-18- November 2015
IoT core technology: Operating System
• State-of-the-art:
– Event-driven: TinyOS, Contiki, MUROS
– Multi-thread: RETOS, tKernel, ScmRTOS (RTOS), MANTIS, AmbientRT etc.
– Hybrid: Contiki (not native), HEROS (native).
• Event-driven is not adapted to:
– Complex hard real-time application
– Distributed Component Based Model implementation (collaborative processing …)
– Multi-connection server (CoAP: delay)
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KM. Hou - DCIT’ 2015 Wuhan, Hubei, China, 16-18- November 2015
IoT core technology - Operating System:
Challenges
• Challenges:
– Energy Efficient (resource-aware:
multicore and robustness), real-time
collaborative processing and small
memory footprint.
• Operating system is the key
technology to implement time
redundancy fault tolerant IoT node.
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IoT core technology: communication protocol
stack
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Many dedicated routing protocols were developed:
Robustness, scalability and interoperability are still an
open question.
IPv6 for IoT: 6LoWPAN&RPL (IETF)
Name OS platform Standard
version
Note
ContikiRPL Contiki RFC6550 Support officially TelosB
platform
OpenWSN OpenWSN RFC6550
TinyRPL TinyOS Draft-ietf-roll-
rpl-17
Support TelosB and
Epic platforms
(only storing mode and
single DODAG)
NanoQplus NanoQplus Draft-ietf-roll-
rpl-13
RPL implementations for real-world devices [Chen Yibo, PhD thesis]
Resume 6LoWPAN
• Two main implementations:
– ContikiRPL ‘SICS: Swedish Institute of
Computer Science’
– TinyRPL ‘UC Berkey’
• Simulator: Cooja (SICS)
• Small resource: Low power CPU and memory
(<30KB of memory)
• Challenges: – Large scale network still needs to be tested and evaluated (i.e.
DIO overhead)
– Edge router or LBR ‘LLN Border Router’ may solve this
problem (RPL).
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• State-of-the-art of Tiny Server (IETF):
– TinyCoAP, CoapBlip, CoAP for
Contiki, libcoap, CoAPy, jCoAP,
Californium …
– Memory footprint of CoAP for Contiki:
• 8.5KB of ROM
• 1.5KB of SRAM
15 KM. Hou - DCIT’ 2015 Wuhan, Hubei, China, 16-18- November 2015
WoT protocol standard?
Other protocols:
- MQTT (IBM), AMQP (NASA, Google),
STOMP, RabbitMQ …
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Item OASIS/MQTT CoAP
Traffic flow P2PP, P2P, MP2MP P2P
Communication
protocol
TCP UDP
Computing model Client/Server Server
License OPEN OPEN
KM. Hou - DCIT’ 2015 Wuhan, Hubei, China, 16-18- November 2015
WoT: trend and challenges
• Both OASIS/MQTT and CoAP will
be the standard?
• Challenge: How to implement
energy efficient mashups?
–Relevant data (uncertainty
data),
–Volatile and persistent data
(Big data)
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KM. Hou - DCIT’ 2015 Wuhan, Hubei, China, 16-18- November 2015
• Intermittent data loss (Lossy link,
sleep&wakeup mode)
• Network dysfunction due to environment
change.
• Nodes are always sleep: Network
disconnected for unknown reason
• Nodes are always wakeup: Battery
exhausted prematurely (try continuously to
send message)
• Unknown reasons …
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Why IoT node fails?
• Inconsistent specification
• Software errors
Message synchronization
Logical (Operation) error
Data consistency
• Hardware errors
Transient faults
Permanent faults
• Lack of resource (e.g. stack overflow)
• …
19 KM. Hou - DCIT’ 2015 Wuhan, Hubei, China, 16-18- November 2015
Dependable IoT node
• Classical techniques:
– Primary backup, DMR and TMR enable to
implement fault tolerant system (space and
time redundancy).
– Formal languages
• How to implement low cost, fault tolerant and
energy constraint IoT node?
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Hardware failures
• High speed low power CMOS technology
Hardware main sources of failure:
– More sensitive to external disturbances,
such as radiation effects electromagnetic
influence, parameter fluctuations, and high
temperatures, aging, application
dependent, latch-up etc. (Mixed-Signal IP
and SoC Design )
• Taking into account the current status of ultra low
power CMOS and mixed signal technology, how to
implement a low cost and robust energy efficient IoT
node? 21
Dependable IoT node: Open research issues
• Open research issues: auto fail detection and
auto configuration
– Formal Software and auto-check
– Time redundancy: auto fail detection and
auto configuration (combine software and
ultra low energy hardware fail detector,
multicore architecture)
• Soft errors recovery: restart, execute the
substitute task …
• Permanent errors: restart with new
hardware configuration (multicore
architecture)
– http://edss.isima.fr/sites/smir
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Conclusion
• The weak point of IoT large scale deployment concerns
its robustness at front-end level.
• How to design a low cost, fault tolerant and energy
efficient IoT is an open research issue.
• The IoT will drive new research fields and uncountable
applications.
• The IoT will revolutionize (big bang) the ICT and
continue to push ahead the current trend: super data
centers and smart tiny data centers (trillion?) in order to
meet the requirements divers applications.
• The economic and social impact of IoT is an open
question, but one thing is sure IoT will change the way
of our every day living.
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« This work was founded by the French National
Research Agency, the European Commission (Feder
funds) and the Région Auvergne in the Framework
of the LabEx IMobS3 »
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KM. Hou - DCIT’ 2015 Wuhan, Hubei, China, 16-18- November 2015