dcit’ 2015 wuhan, hubei, china, 16-18- november...

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LIMOS UMR 6158 CNRS, Clermont-Ferrand, FRANCE

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DCIT’ 2015 Wuhan, Hubei, China, 16-18- November 2015

mailto:[email protected]





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


• 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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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


https://www-304.ibm.com/connections/blogs/aim/resource/IoTcloud.jpg

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


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


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.

8 KM. Hou - DCIT’ 2015 Wuhan, Hubei, China, 16-18- November 2015

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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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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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.


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).


• 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


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


http://stomp.github.com/

http://stomp.github.com/

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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• 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)

• …


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?


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.


« 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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