internet of things: an overview

Internet of ThingsAn overview

Pascal BODIN11-Feb-2017

V20170211

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contents

functional

technical

business

project management

part 0 foreword

part 1 definition?

part 2 functional vs technical

part 3 practicals 1 - consumer

part 4 practicals 2 - business

part 5 architecture

part 6 devices

part 7 positioning

part 8 identification

part 9 communications

part 10 platforms

part 11 central side

part 12 big data

part 13 security

part 14 standardization

part 15 ecosystem

part 16 project perspective

part 17 want to play?

part 18 conclusion

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0. foreword

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who I am

Systev – Independent contractor – connected devices (4 months)

and

Orange Labs – Senior Software Engineer (2 years)

before:

– 11 years as M2M and IoT project manager + software engineer at OrangeLabs

– 4 years as co-founder + system developer + co-manager - home computing

– 14 years as co-founder + system developer + manager - M2M/IoT

– 4 years as team manager at France Telecom R&D

– 10 years as software engineer and/or project leader (McDonnell Douglasthen DEC)

(several periods with 2 simultaneous jobs...)

Master of Science in Engineering from Telecom Bretagne (French GrandeEcole) - 1982

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point of view

integrator's point of view:

– structuring constraints:

– to deliver on committed date and committed budget

– to deliver a working system

– to integrate / rely on legacy subsystems

– to have the broad view

– target is customer satisfaction

– solving technical problems is only a means

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1. definition?

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in the '70s - '80s

[Def01] [Def02]

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in the '70s - '80s

SCADA (Supervisory Control And Data Acquisition)

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in the '90s

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in the '90s

M2M (Machine to Machine)

LBS (Location Based Services)

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in the '00s

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in the '00s

IoT (Internet of Things)

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one definition

Internet of things: the internetworking of physical devices, vehicles (alsoreferred to as "connected devices" and "smart devices"), buildings, andother items—embedded with electronics, software, sensors, actuators,and network connectivity that enable these objects to collect andexchange data.

many, many other ones...

[Def03]

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definitions

many different definitions

related systems have been in use long before IoT acronym was invented

acronyms are successful because they simplify reality

reality:

– on one side: (large diversity of) user needs

– on the other side: (lot of) technologies

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2. functional vs technical

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some use cases – smart cities

Controlling shipping traffic in theNetherlands canals with wireless sensors

Saving water with Smart Irrigation Systemin Barcelona

Traffic and Road Conditions Monitoring inMalaga

[Fct01]

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some use cases – smart agriculture

Precision Farming to control irrigation andimprove fertilization strategies on corncrops

Improving banana crops production andagricultural sustainability in Colombia

Preventing environmental impact inwastewater irrigation area for the largestmeat industry in Australia

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some use cases – smart environment

Rain forest monitoring for climate changecontrol in Peru

Water and Air Quality Monitoring in CivilWorks

Monitoring Bee Health and GlobalPollination

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some use cases – smart home

Smart appliances: remote diagnostics,proactive alerts, etc.

Water treatment: automated consumableordering, etc.

Fire and safety: property monitoring,emergency alert, etc.

[Fct02]

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some use cases – smart xxx

many more use cases!!

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analysis

many different use cases, with many different functions

all markets are affected:

– consumer– business

market push (for consumers?) / market pull (for business?)

provided value?

return on investment?

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supporting technical fields

Question: which technical fields?

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devices

– connected embedded electronic boards– gateways

interface to the physical world– sensors– actuators– I/O, bus

embedded software

secure element

network– wired– wireless– protocols

positioning

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identification

mobile application

server-side application

– container, virtual machine– application server– web server– database management system– data analytics tools– geographical information system– thin client, thick client– graphical user interface

etc.

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summary

many different use cases

many different technologies involved

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3. practicals 1 - consumer market

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home surveillance - specifications

the system must monitor the home

the home occupant informs the system when she leaves the home, andwhen she comes back

if somebody enters the home while the occupant is not supposed to bethere, the system sends an alarm to the occupant's mobile phone. Theoccupant can then watch a video clip of the main room.

Questions:

– do you need more specifications?– which technical components would you use?– what architecture would you design?

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home surveillance – some questions

does the occupant own a smartphone? Android or iOS?

should video clip actually be a live video?

should video clips be archived?

can system devices be AC powered or should they be autonomous?

etc.

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home surveillance – technical components

wireless motionsensor

wireless contactsensor

(wireless) (IP)video camera

(wireless) (IP)video camerawith motiondetection

ADSL gateway /router

cellular gateway /router

server

etc.

cellular videocamera with

motion detection

software

[Pr101] [Pr102][Pr103]

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Internet

cellularnetwork

local wirelessnetwork

home surveillance – one possible architecture

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existing ADSLmodem / router

Internet

cellularnetwork

Wi-Finetwork

home surveillance – another possible architecture

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Internet

cellularnetwork

home surveillance – another possible architecture

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summary

several different technical architectures are often possible

choice depends on various criteria:

– detailed functional requirements– non functional requirements:

– power consumption– ease of installation– cost– evolutivity– etc.

what’s the value for the customer?

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4. practicals 2 - business market

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vehicle convoy surveillance - specifications

a 5 vehicle convoy has to cross Europe

an alarm has to be triggered when:

– distance between two successive vehicles exceeds 100 m– a button is pressed (one button per vehicle)

when an alarm is triggered:– origin of alarm is displayed at control center– real-time tracking of every vehicle

outdoor coverage must be global (Europe) Questions:

– do you need more specifications?– which technical components would you use?– what architecture would you design?

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vehicle convoy surveillance – some questions

how to handle convoy separations due to road rules (traffic lights, etc.)

time period allowed for control center to receive an alarm?

who stops an alarm?

100 m: which precision?

which constraints for antenna installation?

etc.

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vehicule convoy surveillance – technical components

server

etc.

GNSS receiver

short rangetransceiver

cellular module

satellite antennaand modem

microcontrollerboard

alarm button

live trackingcartographic

software

software

[Pr201] [Pr202] [Pr203][Pr204] [Pr205] [Pr206][Pr207]

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in every vehicle

satellitenetwork

cellularnetwork


vehicle convoy surveillance – one possible architecture

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summary

what about an architecture where distances would be computed at controlcenter side?

what’s the value for the customer?

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5. architecture

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architecture?

defines:

– functions– structure– behavior– deployment

different viewpoints:– enterprise viewpoint (business requirements)– information viewpoint (information semantics and processing)– computational viewpoint (functions, interfaces)– engineering viewpoint (distribution of processing)– technology viewpoint (technologies)

[RM-ODP: Reference Model for Open Distributed Processing]

[Arc01]

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computational viewpoint

Central sideRemote side

OS

embedded device

communication services - remote

application software - remote

OS

PC / serverperipherals

communication services - central

software components - central

component

com

po

ne

nt

com

po

ne

nt

software components - remote

com

po

ne

nt

com

po

ne

nt

com

po

ne

nt

application software - central

OS API

communicationservices API

OS API

components APIscomponents APIs

communication protocols

components protocols

application protocols

Customer-dedicatedintegration

Technical components

Communication

Execution platforms

management

secu

rity


my own view - check standardization section for other views

incomplete!

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communication layer:– bidirectional messaging

– file transfer

– voice call

– etc.

technical components layer (almost generic)– alarm with end to end acknowledgement

– mission dispatch handling

– software odometer

– movement detection

– etc.

application layer:– adaptation to end-user needs

this is an ideal view!

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engineering viewpoint

item,“object”

microcontroller board+

communicationmodule

connected device

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question: in home surveillance and vehicle convoy surveillance examples,what were the connected devices?

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gateway central sideconnected device


long distancenetwork

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central sideconnected device


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personal sideconnected device


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many other architectures possible!

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summary (and some observations)

many different architectures

electronics + communication + software => complexity

processing is distributed over various components => complexity

wireless network => possible loss of connectivity

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6. devices

6.1. device architecture6.2. important microcontroller characteristics6.3. interfacing with peripherals6.4. storage6.5. software development6.6. summary

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communicationmodule

microcontroller+ memoryinterfaces

locationmodule

userinterface

communicationnetwork

data storage

device architecture

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device architecture

[Dev01] [Dev02][Dev03] [Dev04]

microcontr. board: $12.50GSM/GPS module: $49.95GSM antenna: $2.95GPS antenna: $3.95

analoginputs

digital I/O

microcontroller+ memory

location+ communication

module

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6. devices


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communicationmodule


locationmodule

userinterface


data storage

device architecture

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important microcontroller characteristics

what is a microcontroller?

– on same chip: CPU + (some) memory + clock generator + peripherals

architecture:

– von Neumann, Harvard, modified Harvard

– one core or multicore

memory types and sizes:

– read-only memory (program): ROM/PROM/EPROM/EEPROM/Flash...

– read/write memory (data): RAM/SRAM/DRAM/MRAM/FRAM...

– data memory and program memory can be separated

memory width:

– 4-bit, 8-bit, 16-bit, 32-bit

– data memory width may be different from program memory width

– etc.

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important microcontroller characteristics

processing power

– depends on clock speed and architecture

– options: floating point operations, digital signal processing, etc.

power consumption– various low-power modes

cost

supporting hardware tools– development board

– programmer / debugger

– open source schematic

supporting software tools– integrated development environment

– open source code

support

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legacy microcontroller - example

Freescale 68HC11E1

– 8 bits

– 3 MHz

– RAM: 512 bytes - EEPROM: 512 bytes

– 38 General Purpose I/O (GPIO)

– 1 x Asynchronous Serial Communications Interface (SCI)

– 1 x Synchronous Serial Peripheral Interface (SPI)

– 8 x 8-Bit Analog-to-Digital Converter (ADC)

– 16-bit Timer System

– address / data bus for external memory

– bootstrap mode

– price: ⋍ US$7 (10 000)

[Mic01]

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recent microcontroller - example 1

Microchip PIC16F1705

– 8-bit data memory, 14-bit program memory

– 32 MHz

– RAM: 1 KB - Flash: 14 KB

– 2 x Capture / Compare / Pulse Width Modulation

– 1 x Universal Asynchronous Receiver Transmitter (UART)

– 1 x SCI - 1 x Inter Integrated Circuit (I2C)

– 8 x 10-bit ADC

– timers: 4 x 8-bit, 1 x 16-bit

– price: ⋍ US$0.88 (10 000)

[Mic02]

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recent microcontroller - example 2

NXP LPC1837JET256– 32 bits - ARM Cortex-M3 core

– 3-stage pipeline, modified Harvard architecture

– 180 MHz

– RAM: 136 KB - Flash: 1024 KB

– 6 x PWM

– 4 x UART - 2 x I2C - 2 x SPI

– 2 x CAN - 2 x USB - 1 x Ethernet

– 8 x 10-bit ADC

– 4 x 32-bit timers

– price: ⋍ US$8 (10 000)

[Mic03]

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6. devices


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communicationmodule


locationmodule

userinterface


data storage

device architecture

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interfacing with peripherals

sensors: pressure, temperature, light level, heat, magnetic field, airflow,tilt, acceleration, switch, push button, etc.

actuators: relay, motor, stepper motor, servomotor, etc.

other devices: printer, display, On-Board Diagnostics connector, RFId tagreader, etc.

interface can be wired or wireless.

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interfacing with peripherals - GPIO

general purpose digital input/output (GPIO):

– read or set a voltage (high / low)

[Per01]

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interfacing with peripherals - GPIO

an optocoupler may be required

software debounce may be required (a hardware debouncer is sometimesprovided by the microcontroller)

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interfacing with peripherals - ADC / DAC

important parameters: resolution and sampling rate

analog to digital converter (ADC):

– converts an analog voltage to a digital value

– signal conditioning may be required

– some microcontrollers provide integrated Op Amp (e.g. PIC16F527)

digital to analog converter (DAC):– converts a digital value to an analog voltage

[Per02]

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interfacing with peripherals - serial interface

V.24 / RS-232

– minimum 3 wires: transmitted data, received data, signal ground

– asynchronous communication (start bit, stop bit)

– additional wires for control signals (request to send, ready for sending, dataset ready, calling indicator, etc.)

– voltage level:

– V.28:

– bit to 1: -15 V < voltage < -3 V

– bit to 0: +3 V > voltage > +15 V

– distance: < 15 m

– connectors: DB-25, DB-9

– USA: RS-232 (TIA-232)

[Per03]

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bytes are serialized using an UART (Universal Asynchronous Receiver Transmitter)

voltage levels are shifted from board voltage to V.28

UART

Address bus

Control bus

RX TTL

TX TTL

GND

level shifter

TX V.24

RX V.24

GND

CPU

microcontroller

for short distances, levelshifting may be omitted

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interface characteristics:

– asynchronous => a byte starts with a start bit and ends with stop bit(s)

– speed (b/s)

– byte format (number of data bits, parity, number of stop bits)

a byte is framed. Similar to message framing described incommunications section.

mark or previous stop bit

start bit

data bits (5 to 8) +parity (E, O, M, S, N)

stop bit(s)

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interfacing with peripherals - SPI

Serial Peripheral Interface– defined by Motorola (then Freescale, then NXP Semiconductors, now

Qualcomm) (1985?)

MOSI: Master Output, Slave Input SCLK: Serial ClockMISO: Master Input, Slave Output SS: Slave Select

[Per04] [Per05]

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interfacing with peripherals - SPI

synchronous communication

full duplex, clock up to a few MHz

one master, one chip select per slave

4 wires

Applications:– short distance communication (in main board vicinity)

– exemples:

– sensors (temperature, pressure, etc.)

– memory (EEPROM, etc.)

– LCD

– etc.

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interfacing with peripherals - I2C

Inter-Integrated Circuit

– defined by Philips (the NXP Semincoductors now Qualcomm) (1980's)

[Per06] [Per07]

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interfacing with peripherals - I2C

multi-master

clock up to a few MHz

2 wires

applications:

– same than SPI

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interfacing with peripherals - CAN

Controller Area Network

– defined by Bosch (1986)

[Per08]

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interfacing with peripherals - CAN

mainly for vehicles

2-wire bus

multi-master, message broadcast system with asynchronouscommunication

bus access: CSMA/CD+AMP (Carrier Sense Multiple Access / Collision Detectionwith Arbitration on Message Priority)

maximum speed: 1 Mb/s

distance: up to several hundreds of meters (with “low” bit rate)

[Ser03]

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interfacing with peripherals - Bluetooth

Bluetooth:

– designed in 1994 by Ericsson

– originally: to replace RS-232 cables

– range: less than 100 m

– Serial Port Profile (SPP). Many other profiles (audio, file, telephony, etc.)

[Blu01]

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at a software point of view

writing low-level code to handle interfaces:

– serial interface: not too complex

– SPI, I2C: not too complex either

– CAN, Bluetooth: use existing drivers!

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6. devices


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communicationmodule


locationmodule

userinterface


data storage

device architecture

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storage

when on-chip memory is not enough

additional memory:

– important parameters:

– bus type (serial, parallel)

– max number of program / erase cycles (e.g. 3 000, 100 000)

– write time (e.g. page erase - word / page write)

– soldered IC:

– EEPROM 512 Kb (<=> 64 KB) - 8 pins - SPI - ⋍ US$1.3

– 8 Gb (<=> 1 GB) - 48 pins - multiplexed A/D buses - ⋍ US$8.0

– memory card:

– MMC, SD, miniSD, microSD, etc.

– ex.: microSD 1 GB ⋍ US$27

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6. devices


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development environment

● source code edition● compilation / link● simulation● debugging

● load / run● emulation● debugging

LPCXpresso

VxWorks GNU toolchainTASKING ...

PC running Linux,OSX, Windows

microcontroller board

Atmel Studio

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execution environment

Morpheus3

VxWorks

RTX

OS

RTOS

specific runtime

interrupt handlers+ background task

...

...

...

Esterel

Lustre

bare metal

Ada

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bare metal

let's look more closely at a microcontroller architecture

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bare metal

some events generated by peripherals

input level changed

character sentcharacter received

counter limit reached

end of conversion

bit receivedframe receivedframe sent

watchdog timeout

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bare metal

an event generates an interrupt

attach an interrupt handler to the interrupt you want to handle

example: analog to digital conversion

time

background task

end ofconversion

interrupt handler

background task

interruption

savecontext

restorecontext

startconversion

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bare metal

usual OS services not available:

– process

– thread

– synchronized access to shared resources (memory, peripherals)

– inter-thread communication

– device drivers

– file system

– etc.

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bare metal

it's less complex than it appears for small applications

very useful for some classes of requirements:

– (very) small memory footprint

– low power consumption

– low cost

available tools:– some commercial or open source code is available (flash file system,

TCP/IP stack, etc.)

– macro definitions preventing use of assembly language

– hardware debugger with trace capture

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bare metal

available tools (cont'd):

– well known design patterns:

– ring buffer

– finite state machine (FSM)

– etc.

Note: ring buffer and FSM can be used in OS context

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outPtr inPtr

data

bare metal

ring buffer (or circular buffer):

– fixed-size memory array, used as an interface between a producer and aconsumer

– pointer outPtr points to first non empty element

– pointer inPtr points to first empty element

– to get next element: read outPtr, read data, increment outPtr

– to put a new element: read inPtr, write data, increment inPtr

– when at the end of the array, pointer is reset to start of array

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bare metal

ring buffer (cont'd):

– a ring buffer is a FIFO (First In, First Out)

– when put rate is greater than get rate, buffer gets full:

– new data overwrites oldest one, or

– put is not performed

– beware: put and get operations must be atomic

examples of use:– receive buffer for a serial interface

– message queue for communication between two different pieces ofcode

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state S1

state S2

event E1 (+ condition C1)

actions A to perform

bare metal

finite state machine:

– an abstract machine that can be in one of a finite number of states

– the machine is in only one state at a time (current state)

– transition from one state to another one is triggered by an event(possibly guarded by a condition)

– one possible way to graphically depict an FSM:

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RTOS

an RTOS (or an OS) provides many services:

– tasks

– task notifications

– queues

– semaphores

– mutexes

– timers

– memory protection

– etc.

easier to write feature-rich applications but:– experience is still required

– debugging can be more complex (but easier as well!)

– an RTOS must be configured for the hardware platform

– larger footprint

– etc.

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6. devices


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summary

complex technical subset of IoT:

– analog electronics

– digital electronics

– bus

– software

device software ≠ web server software!!!!

if you can reuse an existing design, do it!

more and more open source designs are available

location, communication: see next sections

communicationmodule


locationmodule

userinterface


data storage

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7. positioning

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positioning - GNSS

GNSS: Global Navigation Satellite System

mostly for outdoor use

working principles:

– constellation of satellites

– every satellite sends messages: satellite position, message time

– satellite time is very accurate (atomic clock)

– listening to 3 satellites, the GNSS receiver estimates its location on earth(distance = difference of time x speed of light)

– that's only an estimate (the receiver does not have an atomic clock)

– using a 4th satellite, the receiver synchronizes its clock

– => real location can be computed

satellite orbits: MEO (20 000 km), GEO (36 000 km)

speed of light (approx.): 3 x 108 m/s: 10 m <=> 33 ns

fix: position

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positioning - GPS

GPS: US system

– 31 operational satellites

– MEO orbit: 20 200 km

– accuracy:

– depends on receiver quality, on satellites being used, etc.

– documented as better than 8 m with 95% confidence level

– usual accuracy: 20 m

– Dilution of Precision (DOP – PDOP/HDOP/VDOP):

– how error in measures impact error in computed location

– good when < 6

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positioning - other GNSS

GLONASS: Russia (formerly USSR) system

– 24 operational satellites

– MEO: 19 100 km

Galileo: Europe

– target: 24 satellites + 6 spares

– MEO: 23 200 km

– accuracy: 8 m horiz. 9 m vert. 95% of time

– 12 operational satellites, 4 testing, 2 not fully available

– operational (15-Dec-2016)

BeiDou (北斗 ): China

– target: 5 GEO satellites + 30 MEO satellites

– currently: 17 satellites – operational over China

Japan (QZSS), India (NAVIC)

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positioning - GNSS accuracy

example of accuracy:

– GPS receiver indoor, not far from a window => lower reception quality

– one location every 2 s, for 15 minutes

– several locations are more than 60 m far from the real location

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positioning - GNSS augmentation systems

To increase accuracy (and integrity):

– differential GPS

– a GPS receiver placed at a location known with very good accuracy isused to generate corrections send to other GPS receivers

– another receiver is required

– => ⋍ 3 – 5 m accuracy

– SBAS (Satellite-Based Augmentation Systems)

– additional satellites broadcast corrections

– no other receiver required

– => ⋍ 1 – 3 m accuracy

– USA: WAAS (Wide Area Augmentation System)

– Europe: EGNOS (European Geostationary Navigation Overlay Service)

– India: GAGAN (GPS Aided Geo Augmented Navigation

– Japan: MSAS (Multi-functional Satellite Augmentation System)

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positioning - GNSS augmentation systems

A-GPS (Assisted GPS)

– mainly for PLMN terminals (your mobile phone...)

– almanac (coarse orbit and status information for all satellites) and ephemeris(precise orbit for one satellite) data are sent to the GPS receiver using themobile network

– this reduces TTFF (Time To First Fix)

– data generated by mobile operators, or by OTT players (Google, etc.)

RTK (Real-Time Kinematic)

– signal phase is used, to get an accuracy up to a few centimeters

– fix computation can be quite long

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positioning - interface

command + datainterface

communicationmodule


locationmodule

userinterface


data storage

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interface:

– usually: serial (V.28 or board voltage)

– usually: implements subset of NMEA 0183 standard

– most manufacturers provide their own protocol:– SiRF (then CSR, now Samsung) – u-blox - SkyTraq – ST – Broadcom – etc.

$GPGGA,123519,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47

Where: GGA Global Positioning System Fix Data 123519 Fix taken at 12:35:19 UTC 4807.038,N Latitude 48 deg 07.038' N 01131.000,E Longitude 11 deg 31.000' E 1 Fix quality: 0 = invalid 1 = GPS fix (SPS) 2 = DGPS fix 3 = PPS fix 4 = Real Time Kinematic 5 = Float RTK 6 = estimated (dead reckoning) (2.3 feature) 7 = Manual input mode 8 = Simulation mode 08 Number of satellites being tracked 0.9 Horizontal dilution of position 545.4,M Altitude, Meters, above mean sea level 46.9,M Height of geoid (mean sea level) above WGS84 ellipsoid (empty field) time in seconds since last DGPS update

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most receivers are multi-constellations (GPS, GLONASS, Galileo,BeiDou)

important: antenna placement

may be important: tamper protection

– antenna cable short circuit and antenna removal events

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positioning - network - misc.

network positioning:

– trilateration (several time measures)– triangulation (several angle measures)– cell identification– “fingerprinting”– beacons

dead reckoning: first known position then inertial sensor fusion(accelerometer + magnetometer and filtering)

position may be available at– device side– network side

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positioning - indoor

all previous technologies may be used for indoor positioning, dependingon constraints

but no easy-to-integrate, generic system exists today

domain still open to more innovation

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summary

GPS is not the only GNSS!

accuracy increases

time to first fix decreases

other systems: keep an eye on

how to communicate with a GNSS receiver: check communications section

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8. identification

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identification

some systems have to identify / authenticate external objects:

– truck trailers

– shipping containers

– bottles of perfumes

– bottles of wine

– etc.

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identification

RFID (Radio Frequency Identification):

– tag / label with (almost) unique identity

– passive (no battery) or active (battery)

– read-only or read/write

– reader: transmits

– a passive tag uses incoming energy to transmit back its data

– as usual, distance depends on power, antenna and frequency

– from a few tens of centimeters up to a few meters (more is possible)

NFC (Near-Field Communication):

– purposely short distances only (a few centimeters)

– for secure applications (e.g., contactless payment)

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identification

questions: how to identify objects on a global basis, and let everyorganization exchange object data?

part of the answer: GS1– international not-for-profit organization

– delivers standards, services and solutions

– standards:

– barcodes

– EPCglobal: tag data, tag protocols, reader protocols, ONS (ObjectName Service), discovery services, etc.

– etc.

a world in itself...

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9. communications

9.1. overview9.2. framing9.3. wireless networks9.4. wired networks9.5. messaging protocols

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communications - overview

central part of IoT systems

wireless or wired

a given system can use several network technologies

– to increase connectivity reliability

– to increase connectivity coverage

– to provide specific properties (low power, QoS, etc.)

– to support legacy equipments

– to lower operating costs / capital costs

– etc.

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communications - important characteristics

shared or not

geographic coverage + possibility to adapt it

latency

connectivity setup time

addressability

required power for transmission

terminal cost

communication cost

ease of integration

throughput

confidentiality

reliability

availability

etc.

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9. communications


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framing

before going farther, let’s look at how to transmit messages over a seriallink, for instance to

– use a location module

– use a communication module

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framing

communicationmodule


locationmodule

userinterface


data storage

command + datainterfaces

command + datainterfaces

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framing

control bytes:

– to configure the module (link speed, power mode, etc.)

– to signal specific events

data bytes:– for a GNSS receiver: location, satellite information, etc.

– for a communication module: data to be sent to / received from remote side

multiplex control bytes and data bytes

error control

sequence control

flow control

time-out control

transparency

=> framing + acknowledgement + possible repetition

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framing

header payloadcheck

sequence

detailed frame structure depends on protocol

header may contain:

– packet numbering

– number of last good packet received

– frame class

– etc.

check sequence:– result of a mathematical operation performed on payload bytes

– receiver performs the same operation and compares result

Questions: – how to know when a frame starts and when it stops?

– how to ensure transparency for payload?

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framing - delimitation

several solutions for delimitation:

– byte count

– flag bytes

– etc.

byte count:

flag bytes:

header payloadcheck

sequence

payloadsize

header payloadcheck

sequence

B E

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framing - delimitation

byte count: in case of error in the middle of a frame or in the count itself,how to re-synchronize?

flag byte: how to allow E byte to be present in payload?

=> transparency

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framing - transparency

use a predefined escape byte, ESC for instance

on transmission side:

– when E is in payload, insert an ESC before it

– when ESC is in payload, insert another ESC before it

on reception side:– when ESC is received, delete it and keep following byte

another solution: reduce payload allowed byte set!

etc.

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framing - always required?

framing is always required

but error processing may be ignored in some environments (typically onshort links in non-noisy environments)

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framing - NMEA 0183 example

$GPGGA,123519,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47

flag byte

only readableASCII characters

(no CR)flag byte: CR

checksequence

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9. communications


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wireless - PMR

Professional Mobile Radio

– not accessible to consumer

– frequency + associated bandwidth allocated to a user for a given period

– user: private or public organization (company, city, association, etc.)

– cost: annual fee (“license fee”) per terminal. In France:

– fee = I x bf x c x k4 + n x G

– I: bandwidth, in MHz

– bf: depends on frequency

– c: depends on coverage

– k4: constant

– n: number of mobile users

– G: constant

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wireless - PMR

Frequency (bands):

– 40 MHz, 80 MHz, 150 MHz, 400 MHz, etc.

Technology:

– analog – voice + data (modem) – 6,25 or 12,5 kHz channels – 1200 b/s

– digital:

– DMR (Digital Mobile Radio) – 2 slot TDMA over 12,5 kHz channels –9000 kb/s for 2 slots

– dPMR – FDMA over 6,25 kHz channels – 4800 b/s

– TETRA (TErrestrial Trunk RAdio) – 4 slot TDMA over 25 kHz channels –7200 b/s per slot – for shared networks

– TETRAPOL – FDMA – for shared networks

– TEDS, GSM-R

Coverage:

– from ⋍ 30 km (mono-site) up to wide area coverage (multi-sites / trunk)

TDMA: Time Division Multiple AccessFDMA: Frequency Division Multiple Access

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wireless - PMR - data

data communication:

– usually, using a dedicated connector on transceiver

– analog:

– let's forget about it...

– digital:

– DMR: status messages (≤ 128 bytes) - short messages (≤ 36 bytes) –packet data

– dPMR: short messages (≤ 100 bytes) - packet data

– TETRA: short messages (≤140 bytes) - packet data

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wireless - PMR

in 2012:

– around 26.000 PMR networks in France

users:

– taxis, public transports, ambulances, airports, highways, security, industry,constructions, etc.

– public organizations: cities, hospitals, etc.

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wireless - unlicensed

France regulation:

– AFP = Appareils de Faible Puissance et de Faible Portée

– freely accessible

– 6.8 MHz, 13.6 MHz, 27.0 MHz, 40.7 MHz, 433.0 MHz, 434.0 MHz, 863-868... MHz, 2.4 GHz, 5.7-5.9 GHz, 24... GHz, 61 GHz, 122-123 GHz, 244-246 GHz

– ERP: depends on frequency - from 1 mW to 500 mW

– some restrictions on duty cycle, on channel spacing, etc.

– some other frequencies, for specific equipments

– usual range: up to a few kilometers, unobstructed LoS

– throughput: from several 100s of b/s to several 1000s of b/s

ERP: Effective Radiated PowerLoS: Line of Sight

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wireless - unlicensed long range

for a given radiated power and a given bit error rate, range can beincreased either by:

– using lower bit rate with traditional modulation technologies. But this narrowsspectrum => precise frequency reference is required to decode receivedmodulation.

or by– using spread spectrum modulation. But processing is complex.

Examples:

– SIGFOX (choice 1) - technology + network operator

– range: documented as up to 40 km LoS

– LoRa (Semtech) (choice 2) - technology (chipsets)

– range: documented as up to 15 km LoS

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interfacing with comm. module

example: Microchip LoRaWAN RN2483

serial link: 57600 b/s, 8 bits, no parity

frame:

– ASCII, terminated by CR LF

– three command types: sys mac radio– examples:

– sys sleep 100– sys set nvm 300 AA– mac reset 868– radio set mod lora

[Com01]

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wireless - PLMN

Public Land Mobile Network

two main families of standards / technologies:

– 3GPP: 3rd Generation Partnership Project

– GSM, GPRS, EDGE, HSDPA, HSUPA, MBMS, LTE, LTE Advanced...

– 3GPP2: 3rd Generation Partnership Project 2

– CDMA2000, UMB, LTE...

shared between anybody who subscribes

broad coverage, but target is population, not territory

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wireless - 3GPP

data services:

– CSD (Circuit Switched Data): obsolete

– SMS (Short Message Service)

– 140 to 160 characters / bytes

– USSD (Unstructured Supplementary Service Data)

– specific services

– packet data - IP compatible

– throughputs (beware: uplink ≪ downlink):

– 2.5G: 8 to 40 kb/s (GPRS) – EDGE = GPRS x 3

– 3G: 2 Mb/s non-moving, 384 kb/s moving

– 3.5G: 14.4 Mb/s (HSDPA)

– 4G: 100 Mb/s and more (LTE)...

GPRS: General Packet Radio ServiceEDGE: Enhanced Data rates for GSM EvolutionHSDPA: High-Speed Downlink Packet AccessLTE: Long Term Evolution

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wireless - 3GPP IoT-oriented

three LPWA technologies in Release 13:

– NB-IoT (Narrow-Band IoT)

– EC-GSM-IoT (Extended Coverage GSM for the IoT)

– LTE-M (LTE for Machines)

LPWA : Low Power Wide Area

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wireless - NB-IoT

power consumption decreased => battery life > 10 years (!)

spectrum efficiency improved

extended coverage (rural and deep indoors)

low device complexity => low cost

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wireless - EC-GSM-IoT

based on eGPRS (EDGE for GPRS)

software upgrade of existing GSM networks

battery life > 10 years (!)

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wireless - LTE-M

simplified term for LTE-MTC CatM1

lower device complexity - cost reduced to 25% of current eGPRSmodules

extended coverage

battery life > 10 years (!)

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wireless - LPWA comparison

10 year life impossible if received signal too low

data rate can be decreased => longer TX => lower battery life

[Com04]

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interfacing with 3GPP module

AT commands, defined in 3GPP TS 27.007 (and TS 07.07)

commands:

[Com02]

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interfacing with 3GPP module

responses:

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wireless - 3GPP - IP connectivity

APN (Access Point Name):

– name of gateway between 3GPP network and the Internet - real name:GGSN

– defined by the operator

– defines following gateway characteristics:

– static or dynamic IP address

– public or private IP address

– allowed protocols (TCP, UDP, etc.)

– allowed ports

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wireless - 3GPP - IP connectivity with IP stack in µc board

mobile network the Internet

GGSN (APN)

1 - attach

2 – define and activate context + start comm.

=> comm. module knownto network

=> IP address assigned tocomm. module

3 – start a PPP session

=> IP address assigned toremote device

communicationmodule


AT commands

GGSN: GPRS Gateway Support Node[Com03][Com04]

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wireless - 3GPP - IP connectivity

1/ attach:

AT+CGATT=1

OK

2/ define PDP context 3:

AT+CGDCONT=3,"IP","orange.m2m.spec"

OK

activate PDP context 3:

AT+CGACT=1,3

OK

establish communication using PDP context 3:

ATD*99***3#

CONNECT

3/ start a PPP session

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wireless - 3GPP - IP connectivity with IP stack in µc board -router


GGSN

1 - register




AT commands

3 – define NAT / PAT rule

=> comm. moduleperforms NAT / PAT

communicationmodule


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wireless - 3GPP - IP connectivity without IP stack in µc board


GGSN (APN)

1 - attach




3 – send / receive data

communicationmodule


AT commands

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wireless - 3GPP - programmable comm. module


GGSN (APN)

1 - attach




3 – send / receive data

communicationmodule +

application

API

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wireless - satellites

geostationary orbits

– characteristics:

– 36.000 km above the Earth

– satellite seen from Earth as stationary

– coverage restricted to desired zone

– minimum end-to-end latency: 2 x 36.000 km / 300.000 km/s => 240 ms

– Inmarsat:

– BGAN M2M: IP at up to 448 kb/s – latency from 800 ms – globalcoverage except polar regions

– IsatM2M: messages of 25 (up) / 100 (down) bytes – latency 30 to 60 s –global coverage except polar regions

– IsatData Pro: messages of 6.4 (up) / 10 (down) kB – latency 15 to 60 s –global coverage except polar regions

– Thuraya

BGAN: Broadband Global Area Network

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wireless - satellites

low earth orbit (LEO)

– characteristics:

– satellites constantly in motion around the Earth

– altitude: 170 – 2000 km => period: 90 – 130 min.

– low power

– higher latency !

– Orbcomm:

– messages of 6 to 30 bytes

– average latency: 6 min.

– global coverage

– Globalstar

– Iridium

– Argos

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wireless - short distance

Wi-Fi

– wireless local area network (WLAN) technology based on IEEE802.11standards

– Wi-Fi Alliance owns the brand (not an abbreviation...)

– range: usually up to 100 m outdoors

Bluetooth

– originally designed to replace serial cables – personal area network (PAN)

– managed by the Bluetooth Special Interest Group

– range: less than 100 m

– many profiles

– Bluetooth Low Energy (part of V4.0)

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wireless - short distance

ZigBee

– managed by ZigBee Alliance

– low-power

– range: up to 100 m

– mesh network => long distance by retransmitting data

Z-Wave

– managed by Z-Wave Alliance - for home automation

– low-power

– range: around 30 m

– mesh network

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wireless - comparison

Techno Shared Range Latency Setup time

PMR no from 30 km up to widearea

depends on architecture 0

unlicensed yes up to 10 (40) km depends on architecture 0

2.5G/3G yes wide area from 100 ms up to 1 s from 2 s to 5 s

4G yes wide area 50 ms 1 s

satellitesgeo

yes global 800 ms to 60 s depends

satellitesLEO

yes global min depends

Wi-Fi yes local ms s

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wireless - comparison - 2/2

Techno Addressability TX power Equipment cost Comm.cost

PMR full W 100s € 0 €

unlicensed full mW 10s € 0 €

2.5G/3G restricted W 100s € flat rate

4G restricted W 100s € --> 10s € flat rate

satellitesgeo

restriced W 1000s € high

satellitesLEO

restricted W 100s € high

Wi-Fi full mW 10s € 0 €

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wireless - 3 dimensions

3 dimensions, for wireless networks:– technology

– regulations

– operator

example 1:– 4G is a technology mainly used for public cellular networks

– operators (Orange, Verizon, etc.) have to buy licenses

– 4G can be used on private networks as well

example 2:– Sigfox is an operator using its proprietary technology on license-free bands

– the technology could be used on licensed bands as well

example 3:– LoRa is a technology used on license-free bands

– there are several operators (Orange, Bouygues Telecom, etc.)

– the technology can be used by consumers as well

– the technology can be used on licensed bands as well

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9. communications


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wired

leased lines

– permanent connection between two locations

– analog or digital – symmetric throughput (unlike ADSL)

– example for France:

– Orange Transfix: up to 2048 Kb/s

– for IoT / M2M: more or less obsolete

Public Switched Telephone Network (PSTN)

– requires a modem (modulator – demodulator)

– up to 56 Kb/s

– cost proportional to duration (depends on package)

– long setup time (up to 20 or 30 s)

– for IoT / M2M: not so used

Asymmetric Digital Subscriber Line (ADSL)– pseudo permanent connection

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wired

Local Area Network (LAN)

– Ethernet

field buses:– PROFIBUS

– DeviceNet

– INTERBUS

– FOUNDATION

– Modbus

– Sercos

– PROFINET

– Powerlink

– EtherCAT

– etc.

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9. communications


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messaging protocols

just a few words about TCP:

– TCP is a stream-oriented protocol:

– “Hello world” can be received as “Hell” and then “o world”

– “Hello” and then “ world” can be received as “Hello world”

– => framing is required

– see communications / framing section. Simpler, for TCP, thanks to TCPcharacteristics:

– ordered data transfer

– error-free data transfer

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messaging protocols

message framing:

– ASN.1: defined 30 years ago by CCITT (now ITU-T) – not so used inM2M/IoT...

– Google re-invented a solution in 2008: Protocol Buffers – not so used eitherin M2M/IoT... (but framing not provided...)

– CBOR (Concise Binary Object Representation): IETF - 2013

– advantages:

– reliable solutions

– data endianness independency

– transparent serialization/deserialization

– forward compatibility

– drawbacks:

– some complexity

– Protocol Buffers needs framing

– libraries in various languages to encode / decode frames

– not so difficult to define your own mechanism

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messaging protocols

applying web technologies to IoT / M2M communications is often not theright choice:

– HTTP: request / response (=> polling), ASCII, complex parsing

– XML: verbose

– JSON: still too verbose

one benefit:– go through firewalls and proxies

but should IoT / M2M communications be transported along with webcommunications?

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messaging protocols - MQTT

MQTT acronym comes from Message Queue (not present in MQTT!) andTelemetry Transport (but MQTT is not restricted to telemetry)

maintained by OASIS Consortium (Organization for the Advancement of Structured InformationStandards)

mixes messaging with publish / subscribe (one to many - applicationdecoupling)

based on TCP/IP (MQTT-SN for non TCP/IP networks)

small transport overhead

abnormal disconnection notification

free open source implementations:– Eclipse Mosquitto (server)

– Eclipse Paho (clients in various languages)

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messaging protocols - CoAP

Constrained Application Protocol

maintained by the IETF (Internet Engineering Task Force) - RFC7252

request / response – designed to easily interface with HTTP

based on UDP or equivalent

low transport overhead

low parsing complexity

resource discovery (a client queries a server)

several free open source implementations of CoAP (client, server)

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messaging protocols - other

many other protocols:

– Open Wireless Telematics Protocol (designed by Mobile Devices)

– Cloud Connector (designed by Digi)

– etc.

not so difficult (for really experienced developer) to define one's ownprotocol

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device management protocols

OMA DM: specified by Open Mobile Alliance (OMA)

OMA DM supports:

– device provisioning (device initialization and configuration)

– software updates (application and system software)

– fault management (reporting faults, querying status)

for M2M: OMA Lightweight M2M (LWM2M)

– based on CoAP

– open source implementation: Eclipse Wakaama project

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summary

many different technologies

understanding real user needs is important, to choose right networktechnology/technologies

perhaps the most important part of a system, as it transfers data from onside to the other one

perhaps the most difficult part of a system, at a technical point of view

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10. platforms

10.1. architecture and services10.2. RESTful API

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platforms

beware: the word « platform » may have different meanings

– software development framework

– software application providing communication (and possibly managementand storage) services

– a hosted application providing above services

– hardware system

– hardware system and associated software stack

– etc.

in what follows: hosted application, that makes easier to integratedevices into applications

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platforms

central sideconnected device


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platforms


OS

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OS




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Communication

Execution platforms

management

secu

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platforms

functions usually provided by a platform (as seen by a user):

– device provisioning

– device management

– device authentication

– support of some communication protocols

– user authentication

– data persistence (raw data or decoded data?)

– device groups

– user groups

– easy way to add new communication protocols

– etc.

two logical interfaces: one for devices, one for applications

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platforms

connected device central side

platformplatform

code solvingcustomer problem

code solvingcustomer problem

customerpays for this,

not for theplatform

relative sizes of softwarecode,

for a complex system

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platforms

perceived value is often not in the platform

a platform may prevent from using some devices (which do not implementa supported protocol)

a platform usually creates a protocol break

when updating the platform, ALL users are impacted

developing a communication layer + minimum device management is notcomplex for an experienced team

=> think twice before deciding on using a platform

anyway, using a platform may be very nice, for some (simple)applications, to demonstrate a new service, or for very large sets ofdevices

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many platforms ?

Afero deviceWISE Microtronics end-to-end platform Sine-Wave AggreGate dweet.io Mobius SIMPro AirVantage Electric Imp MODE SmartThings Ark Enterprise2Cloud mozaiq Solair ARTIK Cloud EVRYTHNG Murano TempoIQ AT&T's M2X Exosite myDevices The ThingBox AWS IoT FlowCloud Nabto thethings.iO Axeda IoT Platform Gaonic Neo ThingFabric AXON GoFactory Net4Things ThingPlug Ayla IoT Cloud Fabric Golgi Netatmo Connect ThingSpeak Beebotte IFTTT netObjex Thingsquare Berg iMotion NetPro ThingWorx Blynk Impact n.io UnificationEngine Bosch IoT Suite Initial State Octoblu Verizon's M2M platform Busit IoT Acceleration Platform OpenMTC Vortex Canopy Itron OpenSensorCloud Waygum Carriots Hologram Cellular Platform OpenSensors waylay CloudConnect Home2Cloud Open.Sen.se WyzBee Combicloud IBM IoT Cloud Parse Xively Concirrus IoTfy People Power - now FabrUX Yaler Connext DDS IoT lab Plat-One Zatar Coversant IoT Cloud IoT-X PubNub Dashboard of Things iQmenic REDtone IOT Canopy dataplicity Kii resin.io DeviceHive Datavenue Lelylan restack FI-WARE Deutsche Telekom's M2M Device Cloud Loop RuBAN Home*Star / IOTDB Device Connection Platform Lumata Samsung SAMIIO IoTivity DeviceCloud M2M Intelligence SAP HANA Kaa DeviceHub MachineShop SensorLogic macchina.io DevicePilot mbed Device Server SkyNet Nimbits

Node-RED OpenIoT OpenRemotecheck http://www.monblocnotes.com/node/1979

open source

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platforms - example - Sierra Wireless

connectivity management

– SIM inventory

– usage tracking

– etc.

application enablement– RESTful API

– data storage

– rules engine

– device protocol support

– etc.

device management– device monitoring

– command transmission

– OTA firmware update

– configuration deployment

– etc.

[Pla02]

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platforms - how to use one

usual steps, to use a platform for a new development:

– register

– check list of supported devices, and select one, possibly a simulatedone

– download client source code or library

– build an « Hello World » client (send/receive data)

– test it

– check send/receive data using available web application

– download central application source code or library

– build an « Hello World » application (send/receive data)

– test it

– test the whole system

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10. platforms

10.1. architecture and services10.2. RESTful API

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overview

REST: representational state transfer

invented in 2000 - an architecture, not a protocol

– client-server

– stateless

– cacheable

– layered system

– uniform interface

– [code on demand]

for web services: RESTful APIs

– base URL

– HTTP method (GET, HEAD, PUT, POST, DELETE, TRACE, CONNECT)

– data elements - JSON

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example - when you visit google.com from France

client server

GET / HTTP/1.1User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0) Gecko/20100101 Firefox/10.0Host: google.comAccept: */*

open TCP socket with address google.com

HTTP/1.1 302 FoundCache-Control: privateContent-Type: text/html; charset=UTF-8Location: https://www.google.fr/?gfe_rd=cr&ei=J8-MWPedMPL-8AePwISQDAContent-Length: 259Date: Sat, 28 Jan 2017 17:04:39 GMTAlt-Svc: quic=":443"; ma=2592000; v="35,34"

<HTML><HEAD><meta http-equiv="content-type" content="text/html;charset=utf-8"><TITLE>302 Moved</TITLE></HEAD><BODY><H1>302 Moved</H1>The document has moved<A HREF="https://www.google.fr/?gfe_rd=cr&ei=J8-MWPedMPL-8AePwISQDA">here</A>.</BODY></HTML>

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example - AirVantage API

client server

GET /api/v1/users/current?access_token={token} HTTP/1.1

....

{ uid: "81210eca05484d34a29bc6c34dc31bf7", email: "[email protected]", name: "David Sciamma", company: { uid: "97ba9e22078548a2847912a87152e3f4", name: "Sierra Wireless" }, profile: { uid: "df1c0f7d5f8c4db2b45978f98e1093ad", name: "Manager" }}

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example - AirVantage API

after authentication:

– get received data

– send command to a device

– get monitoring data

– etc.

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11. central side

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OS

embedded device



OS




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communication server

database

geographic information system (GIS) functions

data filtering and processing

user interface(s)

etc.

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communication server:

– provides an interface to communicate with devices

– may handle several different network technologies

– switching to another network technology or supporting a new one should beeasy and rapid

– other usual requirements:

– security concerns: authentication, integrity, privacy, (non-repudiation)

– reliability

– scalability

– etc.

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example:

– for PMR or unlicensed radio

antennastransceivers+ modems

communicationserver

[Cen01]

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example:

– for 3GPP

communicationserver

Internet

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3GPP example (cont'd):

– uplink (from devices to server):

– server IP address must be reachable => public or VPN

– downlink:

– device IP address characteristics depend on APN

– static or dynamic?

– public or private?

– several solutions depending on user need and required genericity:

– device initiates and maintains a TCP session

– server sends an SMS to device, requesting its connection

– devices connects periodically

– private APN => VPN

– etc.

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databases

3 main technologies:

– relational database

– object database

– NoSQL database

another dimension to be considered sometimes:– spatial database (but GIS function can be provided as a service)

a question may arise:– do application data have to be separated from “technical” data?

– there is no one right answer

another question:– should all device generated data be mirrored in the central database?

– again: there is no one right answer

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Geographic Information Systems

some applications need

– to perform spatial operations and / or

– to display spatial information

at a technical point of view, two different elements:– functions:

– spatial queries against spatial database

– spatial libraries

– data:

– digital maps

– georeferenced data

at an architectural point of view:– web GIS

– rich client

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all-in-one (functions + data) web GIS:

– Google Maps JavaScript API

– Bing Maps APIs

– etc.

functions only web GIS:– MapServer (Open Source)

– GeoServer (Open Source)

– etc.

functions only rich client GIS:– GRASS GIS (Open Source)

– QGIS (Open Source)

– uDig (Open Source)

– etc.

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data:

– OpenStreetMap (Open Source)

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many providers of commercial products:

– rich client / desktop GIS

– web GIS

– data (vector, bitmap, additional layers)

GIS is a complex matter:– do not try to reinvent the wheel

– take some time to get some experience

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User Interface

as for GIS: web or rich client

web:

– ⊕ good for large number of distributed users

– ⊕ can be good for supporting multi-device / multi-OS

– ⊕ good for software updates

– ⊖ usually bad for user-perceived response time

– ⊖ usually bad for « real-time » or complex user interfaces

– ⊖ usually bad for license cost

– etc.

rich client:– almost the other way round...

mixing the two of them can be a good solution

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12. big data

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big data

data sets too large / too complex to be processed with traditional tools

we are not talking about Terabyte (1012 bytes)

we are talking about Petabyte (1015 bytes), Exabyte (1018 bytes), etc.

Volume, Velocity, Variety

some tools:

– Hadoop (distributed processing - MapReduce, YARN, HDFS)

– Spark (analytics over Hadoop file system)

– Cassandra (distributed NoSQL)

– ElasticSearch (analytics)

– many, many, many more tools

– check http://bigdata.andreamostosi.name/

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where is big data?

Q: why big data is not addressed in the central side section?

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where is big data?

A:

– currently, big data technologies are used at central side

– remember: an IoT system is a whole

– more power processing available on the edge and in devices

– => big data processing could be distributed over devices soon

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an example

cellularnetwork

400 MB / vehicle / month

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an example

for electric vehicle prototypes: data about battery, electric engine,location, speed, etc.

for 100 vehicles during one year:

– 400 MB x 100 x 12 = 480 GB - this is not big data!

for 1 million vehicles during one year:– 400 MB x 1 000 000 x 12 = 4.8 x 1015 B (4.8 Petabytes) - this is big data

but...

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an example

but

– current mobile data plans are currently too expansive for such volumes

– mobile network coverage is currently not full => buffering is required =>memory cost

– there is enough processing power AND energy in a vehicle => processingcan be performed on the fly, so that only main results are sent to the centralside

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more generally

there is no one fits all architecture

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13. security

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information security

we talk about information security only

three objectives, according to the CIA triad:

– confidentiality

– integrity

– availability

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checklist

business processes:

– who is in charge?

– how to address security?

device hardware and physical security:

– secure boot process

– no active debug interface

– physical protection against tampering

– etc.

device application:

– signed software

– signed remote software updates

– unused ports are disabled

– good practice coding standard

– well define source code management

– safe failures

– etc.

[Sec01]

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checklist

device operating system:

– most current patches

– plan for remote update

– non-essential services are remoed

– etc.

device wired and wireless interfaces:

– unauthorized connections are prevented

– IP packets forwarding between interfaces is disabled

– unused ports are closed

– if existing, default connection password is unique to each device

– connections are secured (TLS...)

– etc.

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checklist

authentication and authorization:

– code and data are binded to a specific devie hardware

– a password can’t be null or blank

– protection against repeated login attempts

– stored passwords are encrypted

– etc.

encryption and key management for hardware:

– true random number generator

– tamper proof location for sensitive data

– etc.

web user interface:

– strong user authentication

– automatic session timeout

– input validation

– etc.

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checklist

mobile application:

– minimum required amount of personal information is stored

– personal user data is encrypted

– stored passwords are encrypted

– etc.

privacy:

– only authorised personnel have access to personal data of users

– personal data is anonymized

– data retention policy

– product owner is informed about data collection

– etc.

cloud and network elements:

– latest security patches

– webserver identification switched off

– etc.

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checklist

secure supply chain and production:

– test and calibration software erased before dispatch

– duplicate serial numbers are detected

– securely controlled area may be required

– etc.

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summary

security is a world by itself

it applies to all subcomponents

a broad view is required

rely on real experience

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14. standardization

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standardization

some “old” standards:

– V.24, V.28, etc.– MODBUS, Fieldbus, etc.– SPI, I2C, etc.

but that's really far from being enough

let's dream:

– any remote side should be able to communicate with any centralside

– any central side should be able to communicate with any centralside

– any side receiving a new type of data should be able to knowwhether it has to process this data, and/or what it means(semantics, ontology)

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standardization

in Europe: ETSI (European Telecommunications Standards Institute)

most of ETSI M2M standardization work has been transferred tooneM2M in 2012

oneM2M is a global partnership project (China, Japan, Europe, NorthAmerica, etc.)

OMA (Open Mobile Alliance) is member of oneM2M

goal:

develop technical specifications which address theneed for a common M2M Service Layer that can bereadily embedded within various hardware and software

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standardization

AE: Application Entity - CSE: Common Services Entity - NSE: Network Services Entity

[Sta01]]

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ITU-T - technical overview

[Sta02]

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ITU-T - types of devices and relationship with physical things

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standardization

many other standardization organizations:

– Open Connectivity Foundation– Thread Group– Hypercat Consortium– Industrial Internet Consortium (IIC)– Global Standards Initiative on Internet of Things (IoT-GSI)– ITU Joint Coordination Activity on IoT (JCA-IoT)– TIA TR-50– Open Mobile Alliance (OMA)– OMG Data-Distribution Service for Real-Time Systems (DDS)– IEEE IoT Architecture Working Group

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standardization

many other standardization organizations (cont'd):

– Internet Engineering Task Force (IETF)– IPSO Alliance– W3C Web of Things Community Group– W3C Semantic Sensor Network Incubator Group– ZigBee Alliance– ULE Alliance– Z-Wave Alliance– etc. (see http://www.monblocnotes.com/node/2034)

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standardization

Q: so many standards... What to do with them?

A: what you want

more seriously:

– for an integrator:– try to use standardized interfaces and products– stay informed

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15. ecosystem

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ecosystem

what we saw:

– many different use cases

– several different technologies

=> ecosystem and value chain are complex

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ecosystem

usually, value chain is depicted like this:

Devices Connectivity Integration Applications Customers

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ecosystem

more realistic view:

Softwaredeveloper

Middlewaredeveloper

Softwarecomponentdeveloper

Devicemanufacturer

Locationtechnology

provider

Wirelessmodule

manufacturer

Networkoperator

Integrator Installer

Geocoded dataprovider

CustomerServiceprovider

Embedded OSdeveloper

User

Sensor /actuator

manufacturer

Embeddedsoftware

developer

Electronicboard

manufacturer

Hosting

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ecosystem

many different type of activities

– it's quite common that one company runs several activities important activity: integration

– the integrator tries to get a working system! another important activity, often forgotten about:

– installation (at home, in a vehicle, in a factory...)– bad installation => lot of glitches, very difficult to diagnose

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16. project perspective

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usual difficulties

a project must deliver a technical solution that matches user needs

difficulties:

– complex ecosystem– user needs not defined correctly– too many standards / lack of standards– unreliable communication network– system distributed over several physical components– electronics and software do not obey same life cycles– some specific software expertise required– high reliability sometimes required– etc.

following examples: how some difficulties were handled (or not)

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example - user needs - 1/4 A

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example - user needs - 1/4 B

project: RFP for a waste collection management system

time spent talking with the customer led project team to understand thatthere was no need for real-time data transmission

proposal: truck data downloaded by wire at the end of the day

– => lower operating cost than competitors' proposals– contract signed, while the provider had no experience about waste

collection management system

understand customer needs better than himself

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project: RFP for a taxi dispatch system

taxi drivers had no experience of a dispatch system

neither the provider

agreement about « agility »:

– minimum viable product delivered as soon as possible– feedback from drivers and dispatch people

– => modification of some delivered functions– => decision about new ones to be added– => new version

– several successive versions

be agile

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project: RFP for a bus schedule checking system

« big brother » feeling: bus drivers could decide to go on strike

– => first delivered functions were providing immediate value to busdrivers (free voice calls, attack alarm)

– => no more problem with trade unions

rapidly deliver value to the users

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project: for a customer, develop a system allowing to check innerworkings of several car prototypes

provider's Business Unit asked their R&D to develop the system. Theydecided on a monthly 40 MB data package (usual data packages: 10MB).

R&D work was done by beginners in the domain. They implemented athin client architecture, and were very proud of it (M2M 2.0!) But monthlydata volume was more than 400 MB! And data was lost for every lengthyloss of connectivity.

keep broad view in mind

don't think you are clever than other people when you enter a newdomain

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example - technology - 1/4 A

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example - technology - 1/4 B

GPRS was documented as THE solution for packet data over GSMnetworks

one undocumented trap:

– connectivity reset by the operator on a periodic basis

not a big deal for developers used to wireless technology

but a problem for many developers used to LAN

never assume things work as documented

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for a taxi dispatch system:

– the provider ordered an onboard device from a very well knowncompany (new product)

– two design flaws appeared after first tests (HW + SW)

no time for correction: a software workaround had to be implemented

never assume things work as documented (bis)

plan for contingencies

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for corrected version of previous device, manufacturer introduced newfunctions required by other customers

– => design too complex– => cost too high

it was decided to perform design in-house.

costly effort:

– => skills ramp-up– => development of an SDK + testing tools

but return on investment:

– control over roadmap– cost reduction by using device for all projects (some components

not assembled, depending on project)– etc.

control core technology

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request to an electronic design company: design a low powerconsumption device, sending some sensor data to a central application,on a periodic basis.

they designed a board with:

– a low power microcontroller– a low power communication module

but, to upload the few KB of data on a periodic basis, they used FTP(instead of byte streaming over TCP for instance)

– => longer connections– => data overhead– => more power used!

keep the broad view in mind

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example - legal aspects - A

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example - legal aspects - B

project: first french « Pay As You Drive » service, for a car insurancecompany

the system was designed and developed

then, authorization was requested from CNIL (French Personal DataProtection Agency)

– answer was: « no »

system had to be re-designed

think about legal aspects before it's too late

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17. want to play?

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hardware for devices

many, many, many open source and/or free (or low cost) materials

microcontroller boards:

– BeagleBone Black Wireless (Wi-Fi BT) 69 €

– ESP-WROVER-KIT (Wi-Fi, camera interface) 44 €

– CHIP Pro (Wi-Fi BT - open source) US$ 16

– Arduino

check http://systev.com/iot-device-dev-kits/ electronics:

– https://www.adafruit.com/

– http://www.cooking-hacks.com/

– http://www.seeedstudio.com/

– https://www.tindie.com/

– Farnell, Mouser, RS

check http://www.monblocnotes.com/node/2114

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software for devices

software development tools for devices:

– BeagleBone Black Wireless: Linux

– ESP-WROVER-KIT: dedicated RTOS SDK

– CHIP Pro: Linux

– Arduino: Arduino IDE

various software stacks:– protocols (refer to previous slides)

– etc.

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software for central side and communications

open source platforms

– DeviceHive

– FI-WARE

– Home*Star

– IoTivity

– Kaa

– Nimbits

– Node-RED

– OpenIoT

– OpenRemote

– SiteWhere

– thinger.io

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18. conclusion

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conclusion

developing IoT systems can be challenging because:

– large diversity of user needs– sometimes difficult to get real user needs– different software development paradigms– integration of technologies from different fields

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conclusion

perhaps more than in other domains:

– spend time with users– get (really) experienced with involved technologies– get the overall view– be agile– design/use hardware that allows for agility (easy (remote) update)

but, in any case, if you choose this domain, you'll have fun!

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thanks!

systev.com

@PascalBod06

fr.linkedin.com/in/pascalbodin/

[email protected]

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credits and references[Def01] https://material.io/icons/[Def02] https://openclipart.org/detail/237859/factory[Def03] https://en.wikipedia.org/wiki/Internet_of_things

[Fct01] http://www.libelium.com/resources/top_50_iot_sensor_applications_ranking/[Fct02] https://www.aylanetworks.com/iot-use-cases/connected-home

[Pr101] http://homelive.orange.fr/accueil/[Pr102] http://www.samsung.com/fr/consumer/mobile-devices/smartphones[Pr103] https://openclipart.org/detail/155101/server

[Pr201] https://www.u-blox.com/en/product/neo-m8-series[Pr202] http://www.ti.com/product/CC3200MOD/description[Pr203] https://www.sierrawireless.com/products-and-solutions/embedded-solutions/automotive-modules/[Pr204] https://developer.mbed.org/platforms/FRDM-K64F/[Pr205] https://openclipart.org/detail/210237/misc-depression-button[Pr206] https://www.u-blox.com/en/product/c027[Pr207] https://www.iridium.com/products/details/iridiumedge

[Arc01] http://www.rm-odp.net/[Arc01] https://openclipart.org/detail/232991/sedan[Arc02] https://openclipart.org/detail/177832/radiator[Arc03] https://openclipart.org/detail/24535/street-lamp[Arc04] https://openclipart.org/detail/202078/printer-inkjet

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credits and references[Dev01] https://www.adafruit.com/products/2590[Dev02] https://www.adafruit.com/products/2542[Dev03] https://www.adafruit.com/products/2461[Dev04] https://www.adafruit.com/products/1991

[Per01] https://wiki.openwrt.org/doc/hardware/port.gpio[Per02] http://maxembedded.com/2011/06/the-adc-of-the-avr/

[Per03][Per04] https://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus[Per05] https://learn.sparkfun.com/tutorials/serial-peripheral-interface-spi[Per06] http://www.engineersgarage.com/contribution/i2cinter-integrated-circuittwitwo-wire-interface[Per07] http://maxembedded.com/2014/02/inter-integrated-circuits-i2c-basics/

[Per08] https://autoelectricalsystems.wordpress.com/2015/11/10/basics-of-controller-area-network-can-bus-part-1/

[Com01] http://www.microchip.com/wwwproducts/en/RN2483[Com02] https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1515[Com03] http://www.wikiwand.com/it/Gateway_GPRS_Support_Node[Com04] http://www.robotshop.com/eu/fr/plateforme-developpement-beaglebone-black-beagleboard.html

[Com05]

[Pla01] http://www.aeris.com/technology/aercloud/

[Pla02]

http://eu.mouser.com/Connectors/D-Sub-Connectors/D-Sub-Standard-Connectors/_/N-9gybx?No=50&P=1ytmhdqZ1yzv7x2Z1z0z812

https://www.sierrawireless.com/iot-blog/iot-blog/2016/08/lpwa_for_the_iot_part_2_standard_vs_proprietary_technologies/

https://www.sierrawireless.com/products-and-solutions/sims-connectivity-and-cloud-services/iot-cloud-platform/

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credits and references[Cen01] https://openclipart.org/detail/17312/antenna-square

[Sec01] https://iotsecurityfoundation.org/

[Sta01] http://onem2m.org/images/files/deliverables/Release2/TS-0001-%20Functional_Architecture-V2_10_0.pdf[Sta02] http://www.itu.int/rec/T-REC-Y.2060-201206-I

[Pro01] https://openclipart.org/detail/259142/garbage-truck[Pro02] https://openclipart.org/detail/204589/old-british-taxi[Pro03] https://openclipart.org/detail/144367/chiva[Pro04] https://openclipart.org/detail/139267/eco-car[Pro05] https://dir.indiamart.com/impcat/gprs-modem.html[Pro06] https://openclipart.org/detail/116599/solar-panel[Pro07] https://openclipart.org/detail/181618/crashed-car