Wilamowski B.M., Irwin J.D. The Industrial Electronics Handbook. Second Edition: Industrial Communication Systems

Подождите немного. Документ загружается.

12-1

12.1 Introduction

Sensors.are.used.in.industrial.plants.and.facilities.to.monitor.the.performance.and.the.operational.

envi

ronment

.in.orde

.to.prov

ide

.bett

.insi

ght

.into.oper

ational

.requ

irements

.and.pote

ntial

.safe

prob

lems.

. e.moni

tored

.para

meters

.can.be.temp

erature,

.vibr

ation,

.pres

sure,

.ow,.humi

dity,

.valv

posit

ions,

.gas.leak

.re.outb

reaks,

.equi

pment

.cond

ition,

.and.othe

rs.

. e.data.coll

ected

.by.the.sens

ors

are.used.to.make.info

rmed,

.just

-in-time

.decis

ions

.on.plan

.oper

ational

.perf

ormance

.and.cond

itions.

.In.

addi

tion,

.by.using.inte

lligent

.tech

niques

.to.anal

yze

.histo

rical

.sens

.data.in.conj

unction

.with.histo

rical

oper

ational

.perf

ormance,

.cert

ain

.char

acteristics

.and.patt

erns

.in.typi

cal

.oper

ational

.cond

itions

.can.be.

iden

tied,

.prov

iding

.the.poss

ibility

.to.opti

mize

.plan

.safe

ty,

.prod

uction,

.turn

arounds

.and.shut

downs,

main

tenance

.ope

rations,

.and.err

.and.fau

.tole

rance.

Recent

.adva

nces

.and.stan

dardization

.work.with

.the.eld.of.wire

less

.tech

nology

.have.enab

led

the.deve

lopment

.of.low-p

ower

.and.low-c

ost

.solu

tions

.capa

ble

.of.robu

.and.reli

able

.wire

less

.com-

unication

. [ASS

02].

. e. IEEE. Std. 802.

15.4

. [802

.15.4]

. den

. the. phys

ical

. laye

. (PHY

)

. and. the.

medi

.acce

.contr

.(MAC).subl

ayer

.for.low-r

ate

.wire

less

.pers

onal

.area.netw

orks.

.Feat

ures

.such.

as.low.comp

lexity,

.cost

.and.power

.make.it.a.suit

able

.cand

idate

.for.wire

less

.sens

.netw

orks

.(WSN

[YXZ

06].

.With.a.growi

.numb

.of.solu

tions

.base

.on.the.IEEE.Std.802.

15.4

.PHY.and.MAC,.it.

has.beco

.the.de.fact

.stan

dard

.for.many.WSN.solu

tions,

.both.stan

dardized

.and.prop

rietary.

. e.

mult

i-hop

. mesh. netw

ork

. topo

logies

. and. self

-conguring

. and. self

-healing

. capa

bilities

. oer

. by.

A Survey of Wireless

Sensor Networks for

Industrial Applications

12.1. Introduction.....................................................................................12-1

12.2

. Wirel

ess

.Sen

sor

.Net

work

.Basi

cs....................................................12-2

Wireless.Sensor.Node. •. Wireless.Sensor.Network.Stack

12.3. Motivation.and.Drivers.for.Wireless.Instrumentation.............12-3

12.4

. Indu

strial

.App

lications

.and.Req

uirements.................................12-4

Standardized.Solutions. •. Reliable.Network.Performance. •. Battery.

Lifetime. •. Friendly.Coexistence.with.Wireless.Local.Area.

Networks. •. Security. •. Operation.in.Harsh.and.Hazardous.

Environments

12.5. Technology.Survey.and.Evaluation..............................................12-6

IEEE.Std.802.15.4. •. ZigBee. •. WirelessHART. •. ISA-100. •. .

Coexistence.in.the.2.4.GHz.Band

12.6. Conclusion........................................................................................12-9

Abbreviations...............................................................................................12-9

References.....................................................................................................12-9

Stig Petersen

SINTEF Information and

Comm

unication

Tec

hnology

Simon Carlsen

Statoil ASA

12-2 Industrial Communication Systems

these.technologies.have.made.them.a.viable.addition.to,.or.replacement.of,.traditional.wired.instru-

ment

.networks.for.factory.automation.and.communication.

12.2 Wireless Sensor Network Basics

In.a.WSN,.a.wireless sensor node.is.an.individual.device.in.the.network.which.measures.a.physical.

phenomenon.and.transmits.the.sensor.reading.to.the.network.manager.. e.data.transmission.used.

by.the.wireless.sensor.nodes.in.a.WSN.is.specied.by.a.network.protocol..A.WSN stack.is.traditionally.

used.as.a.layered.and.abstract.description.of.the.network.protocol.design.

12.2.1 Wireless Sensor Node

A.typical.wireless.sensor.node.consists.of.several.elements.as.shown.in.Figure.12.1.. e.sensing.unit.is.

a.sensor.element.which.measures.a.physical.phenomenon.(e.g.,.temperature,.pressure,.or.vibration)..

An.analog-to-digital.converter.quanties.and.converts.the.sensor.data.to.the.digital.representation.

needed.for.further.processing.and.communication.. e.processing.unit.analyses.and.processes.the.digi-

tal

.representation.of.the.sensor.data.and.is.also.responsible.for.handling.the.local.radio-frequency.(RF).

transceiver.. e.digital.sensor.data.are.encapsulated.in.data.packets.according.to.the.communication.

protocol,.before.being.transmitted.to.their.destination.. e.communication.unit.provides.the.wireless.

interface.which.handles.transmission.and.reception.of.data.packets..It.consists.of.an.antenna.and.an.RF.

transceiver.. e.memory.and.storage.are.support.units.for.the.processing.unit,.used.for.both.temporary.

and.permanent.storage.of.rmware,.conguration.parameters,.and.sensor.data.. e.power.unit,.which.

normally.consists.of.a.battery.and.some.control.circuitry,.provides.power.to.all.the.components.of.the.

sensor.node..For.some.applications,.a.sensor.node.might.also.be.equipped.with.a.location engine,.which.

estimates.the.spatial.location.of.a.sensor.node.based.on.received.signal.strengths.from.neighboring.

sensor.nodes.. e.location.engine.could.either.be.a.separate.microprocessor.or.implemented.as.an.

algorithm.on.the.main.processing.unit.

One

.of.the.main.challenges.for.many.WSN.applications.is.the.desire.to.have.a.long.battery.lifetime..

Low.power.consumption.is.therefore.a.key.parameter.for.a.wireless.sensor.node..As.a.result,.the.avail-

able

.hardware.resources.on.a.sensor.node.are.limited.. e.processing.unit.is.typically.a.low-power.

microprocessor.capable.of.entering.a.deep-sleep.mode.with.very.low.power.consumption.when.there.is.

no.scheduled.activity.

12.2.2 Wireless Sensor Network Stack

For.communication.protocols.and.standards,.stacks.are.used.as.a.layered.and.abstract.description.of.the.

network.protocol.design..A.stack.consists.of.several.layers.where.each.layer.is.a.collection.of.functions.

related.to.the.specic.task.of.the.layer..A.layer.is.responsible.for.providing.information.and.services.to.

Sensing Processing Co m m u n i c a t i o n

Memory/

storage

Power

FIGURE 12.1 Wireless.sensor.node.

A Survey of Wireless Sensor Networks for Industrial Applications 12-3

the.layer.above.it,.and.it.receives.information.and.services.from.the.layer.below.it.. is.information.and.

service.exchange.is.performed.in.a.well-dened.and.standardized.message-exchange.format.

.most. commonly. used.WSN.stack. is.a.simplied.version. of. the. seven-layered.Open.Systems.

Interconnection.(OSI).Basic.Reference.Model.[X.200].. e.WSN.stack.consists.of.four.layers;.the.PHY.

layer,.the.MAC.layer,.the.network.layer,.and.the.application.layer.. e.structure.of.the.WSN.stack.is.

visualized.in.Figure.12.2.

.PHY layer.handles.functionality.related.to.the.RF.transceiver,.and.it.is.the.interface.to.the.physi-

cal

.medium.where.the.communication.occurs..It.handles.the.transmission.and.reception.of.data.packets.

and.provides.control.mechanisms.for.selecting.operating.channels,.performing.clear.channel.assess-

ment,

.and.RF.energy.detection.

.MAC layer.provides.access.to.the.radio.channel.and.is.responsible.for.radio.synchronization..It.

also.handles.acknowledgment.frames,.association/disassociation.with.other.radio.devices,.and.security.

control..Its.main.task.is.to.provide.a.reliable.link.between.two.peer.MAC.entities.

.network layer.handles.functions.for.how.to.join.and.leave.a.network..It.provides.mechanisms.for.

end-to-end.(source.to.destination).packet.delivery,.which.for.mesh.network.topologies.might.involve.

multiple.hops..To.achieve.multi-hop.routing,.it.is.necessary.to.have.updated.routing.tables.. e.discov-

ery

.and.maintenance.of.routing.tables.is.also.the.task.of.the.network.layer.

.application layer.provides.services.to.user-dened.application.processes..It.handles.fragmenta-

tion

.and.reassembly.of.data.packets,.and.it.is.responsible.for.dening.the.network.role.(end-device,.

router.node,.or.network.coordinator).of.the.device.. e.application.layer.is.oen.referred.to.as.the.appli-

cation

.programmers.interface.(API).

12.3 Motivation and Drivers for Wireless Instrumentation

To.enable.the.introduction.of.any.new.technology.in.the.industry,.a.major.driver.and.motivational.factor.

is.the.potential.nancial.gains,.i.e.,.reduced.costs.and/or.increased.revenue..Secondly,.if.new.technology.

has.the.potential.to.benet.other.important.aspects.such.as.health,.safety,.and.the.environment.(HSE),.

they.would.also.be.considered.interesting.

Wireless

. sensors/transmitters. have. many. benets. over. their. traditional. wired. counterparts..

Eliminating.the.need.for.cables,.combined.with.the.self-conguring.capabilities.of.WSNs,.reduces.the.

installation.cost.compared.to.wired.transmitters,.both.when.it.comes.to.the.construction.of.new.plants.

and.facilities.and.to.modication.projects.on.existing.facilities..In.addition,.wireless.transmitters.allow.

Application layer

Network layer

MAC layer

Physical layer

Physical medium

FIGURE 12.2 Wireless.sensor.network.stack.

12-4 Industrial Communication Systems

for.the.extension.of.data.collection.into.areas.either.too.remote.or.too.hostile.to.be.viable.for.wired.

inst

rumentation.

.One.of.the.main.moti

vational

.facto

.for.goin

.wire

less

.is.ther

efore

.to.prov

ide

.a.cost

ecient

.way.of.impr

oving

.prod

uction

.optim

ization

.by.addi

.addi

tional

.meas

urement

.poin

.to.a.pro-

uction

.site.. e.new.meas

urement

.poin

.can.eith

.be.perm

anent

.or.of.a.temp

orary

.natu

re,

.due.to.the.

low.ins

tallation

.cos

.and.the.add

.ex

ibility

.and.sca

lability

.of.the.WSN

Another

.bene

t

.of.wire

less

.tran

smitters

.comp

ared

.to.wire

.ones.is.that.cabl

.can.be.cut.or.dam-

ged

.by.movi

.mach

ines

.and.vehi

cles,

.by.huma

.oper

ators,

.or.by.the.envi

ronment

.itse

.in.the.shap

of.extr

eme

.weat

her

.cond

itions,

.vibr

ations

.and.stra

in,

.junc

tion

.corr

osion,

.and.expo

sure

.to.chem

icals

.or.

othe

.ui

ds.

12.4 Industrial applications and requirements

WSNs. are. currently. considered. primarily. for. noncritical. monitoring. and. control. applications..

The.WSN.tech

nology

.is.stil

.not.matu

.enou

.to.be.a.viab

.cand

idate

.for.crit

ical

.moni

toring

appl

ications

. or. clos

ed-loop

. cont

rol

. [SMC

N06].

. Howe

ver,

. even. for. nonc

ritical

. moni

toring

. and.

cont

rol-related

.usag

.ther

.is.a.mult

itude

.of.appl

ications,

.incl

uding

.cond

ition

.and.perf

ormance

moni

toring,

.surv

eillance

.and.moni

toring,

.envi

ronmental

.moni

toring,

.proc

ess

.cont

rol,

.emer

gency

mana

gement,

.and.asse

.and.pers

onnel

.trac

king

.and.moni

toring.

.For.some.of.thes

.appl

ications,

the.wire

less

.tran

smitter

.will.func

tion

.eith

.as.a.repl

acement

.or.exte

nsion

.of.the.trad

itional

.wire

fiel

dbus-based

. (i.e

. FOUN

DATION

. Fiel

dbus

. [IEC

61158],

. PROF

IBUS

. [IEC

61158],

. and. HART.

[HAR

T])

.tran

smitters.

.In.this.sett

ing,

.the.wire

less

.tran

smitters

.can.also.func

tion

.as.an.exte

nsion

of.a.wire

.netw

ork.

.orde

.for.WSNs.to.be.viab

.for.indu

strial

.appl

ications,

.they.have.to.ful

.a.set.of.requ

irements.

In.[PDA

08],

.the.gene

ral

.tech

nical

.requ

irements

.for.the.use.of.WSN.tech

nology

.in.both.onsh

ore

.and.o-

ore

.faci

lities

.in.the.oil.and.gas.indu

stry

.have.been.iden

tied.

. ese.requ

irements

.shou

.be.appl

icable

to.othe

.indu

stries

.as.well

.since.the.oil.and.gas.indu

stry

.can.be.consi

dered

.as.one.of.the.most.dema

nd-

ing

.indu

stries,

.repr

esenting

.the.stri

ctest

.requ

irements

.rega

rding

.tech

nology

.robu

stness

.and.reli

ability.

Note.that.some.requ

irements

.are.appl

ication

.depe

ndent

.and.will.vary.depe

nding

.on.the.indi

vidual

usag

.sce

narios.

12.4.1 Standardized Solutions

By.using.standardized,.open.communication.protocols.over.proprietary.protocols,.the.industry.is.pro-

vided

.with.the.exi

bility

.and.free

dom

.to.choo

.betw

een

.mult

iple

.suppl

iers

.and.stil

.have.guar

an-

teed

.inte

roperability.

.In.addi

tion,

.a.stan

dardized

.solu

tion

.usua

lly

.has.a.long

.life.span.with.resp

ect

.to.

comp

onent

.avai

lability

.and.suppo

.comp

ared

.to.thei

.propr

ietary

.coun

terparts

.as.well.as.the.adde

bene

t

.of.not.bein

.comm

itted

.to.a.sing

.vend

or.

.When.it.comes.to.repl

acing

.a.broken.tran

smitter

.in.a.

netw

ork,

.the.new.tran

smitter

.need

.to.be.of.the.same.stan

dard,

.but.with.guar

anteed

.inte

roperability

.it.

does.not.nece

ssarily

.have.to.come.from.the.same.provi

der.

Section

.12.

.pro

vides

.a.sur

vey

.and.eva

luation

.of.int

ernational

.WSN.sta

ndards

.whi

.are.sui

table

.for.

indu

strial

.app

lications.

12.4.2 reliable Network Performance

 e.most.basic.requirement.on.a.WSN.is.that.it.should.have.a.reliable.and.quantiable.network.perfor-

mance.

.As.the.perf

ormance

.of.a.wire

less

.netw

ork

.is.more.susc

eptible

.to.chan

ges

.in.the.loca

.envi

ron-

ment,

.such.as.ante

nna

.adju

stments,

.movi

.pers

onnel

.or.equi

pment,

.and.uct

uations

.in.temp

erature

and.humi

dity,

.comp

ared

.to.a.wire

.netw

ork,

.it.is.impo

rtant

.to.be.able.to.quan

tify

.the.expe

cted

.oper

tional

.perf

ormance

.of.the.wire

less

.netw

ork.

.For.most.appl

ications,

.it.is.desir

able

.to.have.the.netw

ork

reli

ability

.clo

.to.100

.i.e

.the

.sho

uld

.be.pra

ctically

.no.los

.of.sen

sor

.dat

A Survey of Wireless Sensor Networks for Industrial Applications 12-5

It.is. possible. to.achieve.reliable. operation. of. wireless. networks,. even. in. harsh.environments,. by.

emp

loying

.re

dundant

.pa

ths,

.se

lf-healing

.al

gorithms,

.an

.re

transmissions

.of.lo

.da

.pa

ckets.

12.4.3 Battery Lifetime

One.of.the.main.benets.of.using.WSNs.is.the.fact.that.they.do.not.require.any.cabling..However,.this.

mea

.tha

.the.pow

.nee

ded

.to.ope

rate

.the.wir

eless

.sen

sor

.mus

.com

.fro

.a.loc

.pow

.sou

rce,

.in.

mos

.cas

.a.bat

tery.

. is.mak

.it.imp

ortant

.to.kee

.the.pow

.con

sumption

.of.a.wir

eless

.sen

sor

.as.

low.as.po

ssible

.in.or

der

.to.in

crease

.th

.ba

ttery

.li

fetime.

.Wit

.th

.ex

pectation

.th

.po

ssibly

.hu

ndreds

.or.

eve

.tho

usands

.of.wir

eless

.sen

sors

.cou

.be.dep

loyed

.in.a.fac

ility,

.exc

hanging

.bat

teries

.can.be.a.tim

consuming

.and.cos

tly

.mai

ntenance

.tas

.esp

ecially

.if.the.wir

eless

.sen

sors

.are.ins

talled

.in.haz

ardous

are

as.

.Wir

eless

.se

nsors

.sh

ould

.th

erefore

.be.ab

.to.pr

ovide

.a.ba

ttery

.li

fetime

.in.ex

cess

.of.a.fe

.ye

ars.

Due

.to.the.mul

ti-hop

.mes

.net

work

.topo

logies

.and.the.sel

f-conguring

.and.sel

f-healing

.cap

abilities

oe

.pre

sent

.in.WSN

.the.pow

.con

sumption

.of.a.wir

eless

.sen

sor

.nod

.is.usu

ally

.non

determinis-

tic.

.Mea

surements

.in.[PD

A08]

.hav

.sho

.tha

.the.pow

.con

sumption

.of.a.nod

.in.a.mes

.net

work

dep

ends

.on.the.amo

unt

.of.pac

kets

.it.has.to.for

ward

.for.oth

.nod

.in.the.net

work.

.With.con

stant

cha

nges

.in.the.RF.env

ironment

.due.to.cli

matic

.cha

nges,

.RF.noi

se/interference,

.and.mov

ing

.per

sonnel

or.equ

ipment,

.the.rou

ting

.pat

.in.a.WSN.are.dyn

amic

.and.are.sub

ject

.to.cha

nge

.ove

.tim

. is.mea

tha

.th

.po

wer

.co

nsumption

.of.th

.no

des

.in.a.ne

twork

.wi

.ch

ange

.ac

cordingly.

.way.to.eli

minate

.the.nee

.for.bat

teries

.is.to.hav

.sel

f-powered

.wir

eless

.sen

sors.

. is.can.be.ach

ieved

thr

ough

.ene

rgy

.har

vesting,

.whe

.a.wir

eless

.sen

sor

.capt

ures

.and.stor

.ene

rgy

.fro

.its.env

ironment.

Ene

rgy

.har

vesting

.can.eit

her

.rep

lace

.or.aug

ment

.the.bat

tery

.usa

.of.a.wir

eless

.sen

sor,

.dep

ending

.on.the.

amo

unt

.of.har

vested

.ene

rgy.

. e.pow

.gen

eration

.cap

ability

.of.the.har

vesting

.met

hods

.are.at.the.tim

of.wri

ting

.40.μW/c

.for.thermoelectric,.116.μW/cm

.for.vibration,.and.330.μW/cm

.for.piezoelectric.

har

vesting

.[C

C08].

12.4.4 Friendly Coexistence with Wireless Local area Networks

Wireless.local.area.networks.(WLANs).based.on.the.IEEE.802.11.family.of.standards.[802.11],.[802.11n],.

whi

.pro

vide

.acc

ess

.to.int

ranet/Internet

.fro

.the.el

.are.bec

oming

.inc

reasingly

.pop

ular

.in.ind

us-

trial

.pla

nts

.and.fac

ilities.

.To.ena

ble

.the.pos

sibility

.of.dep

loying

.bot

.WSN.and.WLA

.in.the.sam

fac

ility,

.whi

.rep

resents

.a.hig

hly

.rel

evant

.sce

nario,

.it.is.imp

erative

.tha

.the.two.tec

hnologies

.are.abl

.to.

coe

xist

.in.a.fri

endly

.man

ner.

. is.mea

.no.cri

tical

.deg

radation

.of.eit

her

.WSN.or.WLA

.per

formance

whe

.th

.ar

.op

erating

.in.th

.sa

.ar

ea.

Coexistence

.be

tween

.WS

.an

.WL

.ar

.di

scussed

.in.mo

.de

tail

.in.Se

ction

.12

.5.5.

12.4.5 Security

 e.data.in.a.WSN.are.transmitted.over.the.air,.which.makes.it.more.susceptible.to.eavesdropping.and.

oth

.sec

urity

.bre

aches

.com

pared

.to.wir

.com

munication.

.Pri

vacy

.and.acc

ess

.vio

lations

.are.the.mos

com

mon

.th

reats

.to.a.wi

reless

.ne

twork.

For

.WSN

.enc

ryption

.tec

hniques

.are.emp

loyed

.to.pro

tect

.the.pri

vacy

.of.the.tra

nsmitted

.dat

.in.

the.net

work.

.Tra

nsmitter

.aut

hentication

.and.dat

.con

sistency

.tool

.are.use

.to.comb

.and.cou

nteract

acc

ess

.th

reats.

12.4.6 Operation in Harsh and Hazardous Environments

WSNs.are.a.viable.solution.for.noncritical.monitoring.applications.for.practically.any.industrial.plant.or.

fac

ility

.wor

ldwide.

. e.env

ironment

.in.whi

.the.wir

eless

.sen

sors

.can.be.dep

loyed

.wil

.thu

.var

.gre

atly

fro

.site.to.site

.ran

ging

.fro

.col

.win

ter

.con

ditions

.wit

.sno

.and.ice.in.arc

tic

.reg

ions,

.to.hea

.and.

12-6 Industrial Communication Systems

humidity.in.equatorial.regions..In.addition,.many.plants.and.facilities.are.dened.as.hazardous.locations,.

wher

.str

ict

.req

uirements

.app

.to.any.equ

ipment

.ins

talled

.in.pot

entially

.exp

losive

.are

as.

National

.regu

lations

.for.equi

pment

.oper

ating

.in.haza

rdous

.area

.vary. from. coun

try

.to. coun

try.

In.the.Euro

pean

.Unio

.the.94/9

/EC

.ATEX.(ATmo

sphère EXplosible)

.[94/

9/EC]

.dire

ctive

.is.the.gov-

rning

.docu

ment,

.and.for.the.Unit

.State

.and.Cana

da,

.the.Nort

.Amer

ican

.Haza

rdous

.Loca

tions

Inst

allation

.Code

.(Nat

ional

.Elec

tric

.Code.for.the.Unit

.State

.and.the.Cana

dian

.Elec

trical

.Code.for.

Cana

da)

.den

.rule

.and.regu

lations

.on.equi

pment

.and.area.clas

sications’

.requ

irements

.for.haza

rdous

loca

tions.

.Most.othe

.coun

tries

.in.the.worl

.adhe

.to.the.haza

rdous

.loca

tions

.cert

ication

.docu

ments

from.the.Int

ernational

.Ele

ctrotechnical

.Com

mission

.(IE

C).

Before

.depl

oyment

.of.a.WSN.in.a.plan

.or.faci

lity,

.it.is.impe

rative

.to.veri

.that.the.equi

pment

.is.con-

tructed

.to.with

stand

.loca

.weat

her

.cond

itions,

.and.in.the.case.of.depl

oyment

.in.a.haza

rdous

.loca

tion,

that.the.equ

ipment

.has.the.req

uired

.cer

tications

.acc

ording

.to.nat

ional

.rul

.and.reg

ulations.

12.5 technology Survey and Evaluation

In.Section.12.4,.a.set.of.requirements.for.the.operation.of.wireless.instrumentation.in.industrial.appli-

cation

.was.iden

tied.

.One.of.the.requ

irements

.stat

.that.the.wire

less

.tech

nology

.shou

.be.base

.on.

inte

rnational

.stan

dards.

.A.grow

ing

.numbe

.of.stan

dards

.for.WSNs.are.emer

ging.

. is.chapt

.cont

ains

a.sur

vey

.and.eva

luation

.of.the.sta

ndards

.whi

.are.sui

table

.for.ind

ustrial

.wir

eless

.ins

trumentation.

12.5.1 IEEE Std 802.15.4

 e.IEEE.Std.802.15.4.denes.the.PHY.and.the.MAC.sublayer.for.low-rate.wireless.personal.area.net-

works

.[802

.15.4].

. e.stan

dard

.spec

ies

.four.die

rent

.PHYs

.show

.in.Tabl

.12.1

. e.two.optio

nal

high

-data-rate

.PHY

.in.the.868

/915

.MHz.ban

.wer

.int

roduced

.in.the.200

.rev

ision

.of.the.sta

ndard.

.IEEE.Std.802.

15.4

.den

.a.total.of.27.chan

nels,

.numbe

red

.0–26

.Chan

nel

.0.is.in.the.868.MHz.

band.with.a.cent

.freq

uency

.of.868.

.MHz..Chan

nels

.1–10.are.in.the.915.MHz.band

.with.a.chan

nel

spac

ing

.of.2.MHz,.and.chan

nel

.1.havi

.a.cent

.freq

uency

.of.906.MHz..Chan

nels

.11–2

.are.in.the.

2.4.GHz.ban

.the.cha

nnel

.spa

cing

.is.5.MHz;.and.the.cen

ter

.fre

quency

.of.cha

nnel

.11.is.2.4

.GHz.

12.5.2 ZigBee

 e.ZigBee.specication.[ZigBee],.initially.released.in.2004.and.updated.in.2006,.is.a.low-rate,.low-

power

.WSN.stan

dard

.deve

loped

.by.the.ZigB

.Alli

ance.

. e.spec

ication

.den

.netw

ork

.and.appl

ica-

tion

.laye

.on.top.of.the.PHY.and.MAC.laye

.of.the.IEEE.Std.802.

15.4,

.and.it.is.prim

arily

.targ

eting

home.auto

mation

.and.cons

umer

.elec

tronics

.appl

ications.

.Sinc

.the.ZigB

.spec

ication

.uses.the.PHY.

and.MAC.laye

.of.the.IEEE.Std.802.

15.4,

.they.have.the.same.modu

lation

.tech

niques,

.band

width,

.and.

chan

nel

.con

gurations.

.A.ZigB

.netw

ork

.oper

ates

.on.the.same

.user

-dened

.chan

nel

.thro

ughout

.its.

TABLE 12.1 IEEE.Std.802.15.4.Frequency.

Bands.and.Data.Rate

PHY.(MHz)

Frequency.

Band.(MHz)

Bit.Rate.

(kb/s)

868/915 868–868.6

902–928

868/915

.(opt

ional) 868–868.6

902–928

250

868/915

.(opt

ional) 868–868.6

902–928

100

250

2450 2400–2483.5 250

A Survey of Wireless Sensor Networks for Industrial Applications 12-7

entire.lifetime.. is.makes.it.susceptible.both.to.interference.from.other.networks.operating.on.the.

sam

.fre

quency

.and.to.noi

.fro

.othe

.sou

rces

.in.the.env

ironment.

.As.a.res

ult,

.Zig

Bee

.has.thu

.not.

bee

.reg

arded

.as.rob

ust

.eno

ugh

.for.har

.ind

ustrial

.env

ironments

.[PD

A08].

.To.com

bat

.thi

.cha

llenge,

the.Zig

Bee

.All

iance

.rel

eased

.the.Zig

Bee

.PRO.spe

cication

.[Zi

gBeeP]

.in.200

.Zig

Bee

.PRO.is.spe

ci-

cally

.aim

.at.the.ind

ustrial

.mar

ket,

.hav

ing

.enh

anced

.sec

urity

.fea

tures

.and.a.fre

quency agility

.con

cept

wher

.the.ent

ire

.net

work

.may.cha

nge

.its.ope

rating

.cha

nnel

.when.fac

.wit

.lar

.amo

unts

.of.noi

and

/or

.int

erference.

.Zig

Bee

.All

iance

.ann

ounced

.in.Apr

.200

.tha

.it.wil

.inc

orporate

.sta

ndards

.fro

.the.Int

ernet

Eng

ineering

.Tas

.For

.(IE

TF)

.into.fut

ure

.Zig

Bee

.rel

eases,

.the

reby

.ope

ning

.up.for.IP-b

ased

.com

mu-

nication

.in.Zig

Bee

.net

works.

.Of.spe

cial

.int

erest

.for.the.Zig

Bee

.All

iance

.in.the.IET

.sta

ndard

.por

tfolio

is.the.6lo

WPAN

.wor

king

.gro

.tha

.has.cre

ated

.a.Req

uest

.for.Com

ments

.(RF

C4944)

.inv

estigating

.the.

tra

nsmission

.of.IP

.pa

ckets

.ov

.IE

.80

2.15.4

.ne

tworks

.[6

loWPAN].

12.5.3 WirelessHart

WirelessHART. is. a. part. of. the. HART. Field. Communication. Specication,. Revision. 7.0. [HART],.

whi

.was.rat

ied

.in.Sep

tember

.200

.as.the.rs

.sta

ndard

.spe

cically

.tar

geting

.ind

ustrial

.app

lica-

tions.

.Wir

elessHART

.is.bas

.on.the.PHY.and.MAC.lay

ers

.of.the.IEE

.Std.802

.15.4,

.alt

hough

.the.MAC.

lay

.has.bee

.mod

ied

.to.all

.for.fre

quency

.hop

ping.

.Ano

ther

.mod

ication

.is.tha

.Wir

elessHART

ope

rates

.exc

lusively

.in.the.2.4.GHz.ban

.and.to.all

.for.ful

.glo

bal

.ava

ilability,

.cha

nnel

.26.as.de

ned

by.the.IEE

.802

.15.4

.is.not.util

ized,

.sin

.it.is,.due.to.nat

ional

.reg

ulations,

.not.leg

.to.use.in.som

cou

ntries.

WirelessHART

.emp

loys

.a.mul

ti-hop

.ful

.mes

.net

work

.topo

logy,

.usin

.tim

e-division

.mul

tiple

.acc

ess

(TD

MA)

.as.the.cha

nnel

.acc

ess

.met

hod

.[KH

P08].

.With.TDM

.the.net

work

.com

munication

.is.div

ided

into.gua

ranteed

.tim

.slo

.(GTS

.whe

.eac

.GTS.is.res

erved

.for.a.spe

cic

.com

munication

.lin

. is.

ens

ures

.con

tention-free

.uti

lization

.of.the.rad

.cha

nnel.

.Eac

.tim

.slo

.is.10.ms.lon

.pro

viding

.eno

ugh

tim

.for.the.tra

nsmission

.of.one.dat

.pac

ket

.fro

.the.sou

rce

.dev

ice

.and.the.ack

nowledgment

.fro

the.rec

ipient

.of.the.dat

.pac

ket.

.A.col

lection

.of.tim

.slo

.is.cal

led

.a.sup

erframe,

.and.the.sup

erframe

is.rep

eated

.per

iodically

.thr

oughout

.the.net

work

.lif

etime.

.At.the.beg

inning

.of.a.new.sup

erframe,

.the.

gat

eway

.tr

ansmits

.a.be

acon

.wh

ich

.is.us

.fo

.ti

.sy

nchronization

.of.th

.ne

twork.

With

.cap

abilities

.suc

.as.sel

f-conguration

.and.sel

f-healing,

.dep

loying

.a.Wir

elessHART

.net

work

.sho

uld

req

uire

.mini

mal

.det

ailed

.und

erstanding

.of.low

-level

.com

munication

.and.rad

.pro

pagation

.asp

ects.

12.5.4 ISa-100

 e.goal.of.the.ISA-100.standards.committee.of.the.International.Society.of.Automation.(ISA).is.to.

del

iver

.a.fam

ily

.of.sta

ndards

.de

ning

.wir

eless

.sys

tems

.for.ind

ustrial

.aut

omation

.and.con

trol

.app

lications

[IS

A-100].

. e.ISA

-100.11a,

.rat

ied

.in.Sep

tember

.200

.was.the.rs

.sta

ndard

.to.eme

rge.

.ISA

-100.11a

aim

.to.pro

vide

.sec

ure

.and.rel

iable

.wir

eless

.com

munication

.for.non

critical

.mon

itoring

.and.con

trol

app

lications,

.whi

.cri

tical

.app

lications

.are.pla

nned

.to.be.add

ressed

.in.lat

.rel

eases

.of.the.sta

ndard.

.ISA

-100.11a

.is.based.on.the.IEE

.Std.802

.15.4

.PHY.and.MAC

.ope

rating

.in.the.2.4.GHz.ban

de

ning

.a.fre

quency

.hop

ping,

.mul

ti-hop

.mes

.net

work.

.Lik

.Wir

elessHART,

.TDM

.is.used.as.the.cha

nel

.acce

.met

hod,

.alo

.wit

.net

work

.self

-conguring

.and.self

-healing

.alg

orithms.

. e.ISA

-100.11a

.also.

ena

bles

.a.net

work

.to.car

.exi

sting

.wir

.el

dbus

.pro

tocols

.suc

.as.FOU

NDATION

.Fie

ldbus

.[IE

C61158],

PRO

FIBUS

.[IE

C61158],

.and.HAR

.[HA

RT].

.Exi

sting

.wir

.ins

tallations

.can.thu

.be.con

veniently

con

verted

.to.a.wir

eless

.inf

rastructure,

.wit

.a.tra

nsparent

.dat

.tra

nsfer

.bet

ween

.sys

tems.

.ISA

-100.11a

.also.

sup

ports

.the.IPv

.pro

tocol,

.hav

ing

.ado

pted

.6lo

WPAN

.[60

loWPAN]

.as.the

.net

work

.lay

er.

.ISA

-100

.has.est

ablished

.the.ISA

-100.12

.sub

committee

.to.inv

estigate

.opti

ons

.for.the.con

vergence

of.WirelessHART.and.ISA-100.11a.. e.goal.of.the.committee.is.to.merge.the.two.standards.into.a.single.

sta

ndard,

.wh

ich

.wi

.th

.be.pu

blished

.as.a.fu

ture

.re

lease

.of.th

.IS

A-100.11a.

12-8 Industrial Communication Systems

12.5.5 Coexistence in the 2.4 GHz Band

Friendly.coexistence.between.WLANs.and.WSNs.is.an.absolute.requirement.for.the.successful.deploy-

ment

.of.both.solutions.in.the.same.area.of.a.plant.or.facility,.as.both.the.IEEE.Std.802.11b/g/n.and.the.

IEEE.Std.802.15.4.dene.operation.in.the.2.4.GHz.ISM-band.

.IEEE.Std.802.11b/g/n.divides.the.2.4.GHz.band.into.14.overlapping.channels.with.a.bandwidth.of.

20.MHz.[802.11],.although.to.follow.national.regulations,.only.channels.1–11.are.available.in.the.United.

States.and.Canada,.and.channels.1.through.13.in.the.rest.of.the.world.except.Japan.

.avoid.interference.between.neighboring.channels.in.an.IEEE.Std.802.11b/g/n.network.and.at.the.

same. time. enable.friendly.coexistence.with. IEEE. Std.802.15.4.based. networks,. the.nonoverlapping.

channels.1,.6,.and.11.should.be.used.for.WLAN.installations..As.illustrated.in.Figure.12.3,.this.allows.

the.IEEE.Std.802.15.4.channels.15,.20,.25,.and.26.(only.channel.15,.20,.and.25.in.the.United.States.and.

Canada).to.operate.in-between.the.IEEE.Std.802.11b/g/n.channels.without.suering.major.interference,.

and.vice.versa..As.the.IEEE.Std.802.11b/g/n.has.both.higher.maximum-allowed.transmit.power.and.a.

wider.channel.bandwidth.compared.to.the.IEEE.Std.802.15.4,.the.risk,.and.the.consequences,.of.inter-

ference

.between.coexisting.WLAN.and.WSN.are.higher.for.the.WSN.than.for.the.WLAN..Experiments.

performed.in.[ABFS08].and.[PDA08].show.that.the.packet.loss.for.the.IEEE.802.15.4.networks.increase.

signicantly.when.coexisting.with.active.IEEE.802.11b/g/n.networks.

When

.it.comes.to.the.three.international.standards.described.in.the.previous.section,.they.each.

employ.dierent.mechanisms.for.coexistence.with.IEEE.802.11.networks..ISA-100.11a.utilizes.adaptive.

frequency.hopping.and.will.blacklist.channels.which.suer.from.high.packet.loss.due.to.noise/interfer-

ence.

.An.ISA-100.11a.network.will.therefore.aer.a.period.of.time.stop.using.the.channels.which.are.

subject.to.interference.from.the.WLAN.networks,.and.might,.in.a.worst-case.scenario,.end.up.using.the.

interference-free.channels.15,.20,.25,.and.26.(as.illustrated.in.Figure.12.3).

2.412 GHz 2.437 GHz 2.462 GHz

Channel 1 Channel 6 Channel 11

IEEE Std 802.11b/g

2.425 GHz 2.475 GHz2.450 GHz

IEEE 802.15.4

252015 2611 12 13 14 16 17 18 19 21 22 23 24

FIGURE 12.3 IEEE.Std.802.11b/g.and.IEEE.Std.802.15.4.coexistence.

A Survey of Wireless Sensor Networks for Industrial Applications 12-9

WirelessHART,.on.the.other.hand,.employs.frequency.hopping.with.no.blacklisting,.meaning.that.

the.netw

ork

.comm

unication

.is.cons

tantly

.chan

ging

.betw

een

.the.15.avai

lable

.chan

nels.

. e.netw

ork

.will.

in.othe

.word

.take.no.prev

entive

.meas

ures

.to.cope.with.the.inte

rference

.from.IEEE.802.

.netw

orks

.in.

the.area

.As.a.resu

lt,

.the.aver

age

.pack

.loss.for.a.Wirel

essHART

.netw

ork

.will.incr

ease

.when.coex

isting

with.IEE

.802

.11

.net

works

.[PC

09].

For

.ZigB

ee,

.one.of.the.inte

rference-free

.chan

nels

.woul

.have.to.be.select

.manu

ally

.by.an.oper

ator

when.init

ializing

.the.netw

ork,

.as.a.ZigB

.netw

ork

.is.unab

.to.dyna

mically

.swit

.chan

nels

.whil

.oper

tional.

.ZigB

.PRO,.on.the.othe

.hand

.is.capa

ble

.of.chan

ging

.the.acti

.netw

ork

.chan

nel

.when.faced.with.

noise

/interference,

.and.thus.a.ZigB

.PRO.netw

ork

.migh

.over.time

.end.up.usin

.one.of.the.inte

rference-

free

.chan

nels

.(15,.20,.25,.or.26).rega

rdless

.of.the.init

ial

.chan

nel

.con

guration.

12.6 Conclusion

Using.WSNs.as.a.replacement.or.addition.to.the.traditional.wired.industrial.networks.currently.used.

for.facto

.autom

ation

.and.comm

unication

.has.a.numbe

.of.bene

ts,

.both.expe

cted

.and.prov

en.

. ese.

incl

ude

.redu

ced

.cost

.incr

eased

.prod

uction,

.impr

oved

.exi

bility

.and.scal

ability,

.and.impr

oved

.HSE..

Both. labo

ratory

. expe

riments

. [PDA

08,PC09]

. and. inst

allation

. on. an. oper

ational

. osh

ore

. plat

form

[CSP

08]

.show.that.WSN.tech

nology

.is.capa

ble

.of.deli

vering

.robu

.and.reli

able

.comm

unication

.in.hars

envi

ronments.

.a.cons

equence

.of.the.indu

stry’s

.dema

.for.open

.stan

dardized

.solu

tions

.on.thes

.tech

nologies,

seve

ral

.inte

rnational

.stan

dards

.for.indu

strial

.WSNs.are.emer

ging.

.Also

.with.the.indu

stry

.movi

.from.

the.wire

.worl

.into.the.wire

less

.doma

in,

.comi

.inte

rnational

.stan

dards

.are.expe

cted

.to.inte

grate

die

rent

.wire

less

.tech

nologies,

.allo

wing

.ente

rprises

.to.take.the.step.into.a.futu

.with.plan

t-wide

.wire

less

.infr

astructure

.enab

ling

.appl

ications

.like.wire

less

.netw

orking,

.wire

less

.moni

toring

.and.cont

rol,

.and.

asse

.and.per

sonnel

.tra

cking.

abbreviations

API. Application.programmers.interface

ATEX

. Atmo

sphère

.exp

losible

GTS

. Guar

anteed

.tim

.slo

HSE

. Heal

th,

.saf

ety,

.and.the.env

ironment

IEC

. Inte

rnational

.Ele

ctrotechnical

.Com

mission

IETF

. Inte

rnet

.Eng

ineering

.Tas

.For

ISA

. Inte

rnational

.Soc

iety

.of.Auto

mation

MAC

. Medi

.acc

ess

.con

trol

.sub

layer

OSI

. Open.Sys

tems

.Int

erconnection

PHY

. Physi

cal

.lay

. Radi

.fre

quency

TDMA

. Time

-division

.mul

tiple

.acc

ess

WLAN

. Wirel

ess

.loc

.are

.net

work

WSN

. Wirel

ess

.sen

sor

.net

work

references

[ABFS08].L..Angrisani,.M..Bertocco,.D..Fortin,.and.A..Sona,.Experimental.study.of.coexistence.issues.

betwe

.IEEE.802.11b.and.IEEE.802.15.4.wireles

.netwo

rks,

.IEEE Tra

nsactions on Instrumentation

and Measurement,

.57(8),.1514–1523,.2008.

[ASS02]

.I..F..Akyi

ldiz,

.W..Su,.Y..Sankara

subramaniam,

.and.E..Cayir

ci,

.A.surve

.on.senso

.netwo

rks,

.IEEE

Comm

unications Magazine,

.40(8),.102–114,.2002.

12-10 Industrial Communication Systems

[CC08].S..Chalasani.and.J..M..Conrad,.A.survey.of.energy.harvesting.sources.for.embedded.systems,.

Pro

ceedings of the IEEE Southeastcon,

.Hun

tsville,

.AL,.pp

.442–447,.Ap

ril

.3–6,.2008.

[CSP08]

.S..Car

lsen,

.A..Skav

haug,

.S..Peter

sen,

.and.P..Doy

le,

.Using.wire

less

.sens

.netw

orks

.to.enab

incre

ased

.oil.reco

very,

.Pro

ceedings of the IEEE Conference on Emerging Technologies and Factory

Automation,

.Ha

mburg,

.Ger

many,

.pp

.1039–1048,.Sep

tember

.15–18,.2008.

[HAR

.HART.Comm

unication

.Foun

dation

.(HCF),.HART.Field.Comm

unication

.Pro

tocol

.Spe

cication,

Rev

ision

.7.0.(HCF_S

PEC-13),

.Au

stin,

.TX,.2007.

[IEC61158]

.Int

ernational

.Elec

trotechnical

.Commi

ssion

.(IEC),.IEC.61158—Ind

ustrial

.communic

ation

netw

orks—Fieldbus

.sp

ecications,

.Gen

eva,

.Sw

itzerland,

.2007.

[ISA-100]

.Int

ernational

.Societ

.of.Aut

omation

.(ISA),.ISA-100.11a-2009.Sta

ndard,

.Wire

less

.system

.for.

indu

strial

.au

tomation:

.Pr

ocess

.con

trol

.an

.re

lated

.ap

plications,

.2009.

[KHP08]

.A..N..Kim,.F..Hek

land,

.S..Peter

sen,

.and.P..Doy

le,

.When.HART.goes.wire

less:

.Under

standing

.and.

implem

enting

.the.Wire

lessHART

.sta

ndard,

.Pro

ceedings of the 13th IEEE Conference on Emerging

Technologies and Factory Automation ETFA 2008,

.Ham

burg,

.Germ

any,

.pp..899–907,.Sept

ember

15–18,.2008.

[PC09]

.S..Peter

sen

.and.S..Car

lsen,

.Perf

ormance

.eval

uation

.of.Wire

lessHART

.for.facto

.aut

omation,

Pro

ceedings of the IEEE Conference on Emerging Technologies and Factory Automation,

.Palm

.Spa

in,

Sept

ember

.22–25,.2009.

[PD

A08]

. S.. Peter

sen,

. P..Doy

le,

. S.. Vat

land

. et. al.,. Req

uirements,

. driv

ers

. and. ana

lysis

. of. wire

less

. sen-

r.network.solutions.for.the.oil.&.gas.industry,.Proceedings of the IEEE Conference on Emerging

Technologies and Factory Automation,

.Pa

tras,

.Gr

eece,

.pp

.219–226,.Sep

tember

.25–28,.2007.

[SM

CN06]

.J..Son

.A..Mok,.D..Chen,.and.M..Nixo

.Cha

llenge

.of.wire

less

.cont

rol

.in.pro

cess

.indu

stry,

Wor

kshop on Research Directions for Security and Networking in Critical Real-Time and Embedded

Systems in conjunction with the IEEE Real-Time and Embedded Technology and Applications

Symposium,

.San.Jos

.CA,.Ap

ril,

.7,.2006.

[X.200]

.ITU-T.X.200.(07/94),.Info

rmation

.Tec

hnology—Open

.Syst

ems

.Int

erconnection—Basic

.Refer

ence

Mode

. e.Ba

sic

.Mo

del,

.1994.

[YXZ06]

.Q..Yu,.J..Xing

.and.Y..Zhou

.Perf

ormance

.rese

arch

.of.the.IEEE.802.15.4.pro

tocol

.in.wire

less

sens

.netw

orks,

.Pro

ceedings of the 2nd IEEE/ASME International Conference on Mechatronic and

Embedded Systems and Applications,

.Bei

jing,

.Chin

.pp

.1–4,.Augu

.13–16,.2006.

[ZigB

ee]

.ZigB

.Al

liance,

.ZigB

ee-2006

.Sp

ecication,

.2006.

[ZigB

eeP]

.ZigB

.Al

liance,

.ZigB

.PR

.Sp

ecication,

.2007.

[6loWPAN]

. e. Int

ernet

. Engin

eering

. Tas

. For

. (IETF),. Req

uest

. for. Comm

ents

. (RFC). 4944:.

Tran

smission

.of.IPv6.Pac

kets

.ov

.IEEE.802.15.4.Net

works,

.2007.

[802.11]

.IEEE.Sta

ndards

.Ass

ociation,

.IEEE.Std.802.11-2007,.IEEE.Sta

ndard

.for.Info

rmation

.Tec

hnology—

Telecommunications

.and.Info

rmation

.Exc

hange

.betw

een

.Syst

ems—Local

.and.Metr

opolitan

.Are

Netw

orks—Specic

.Req

uirements—Part

.11:.Wire

less

.LAN.Medi

.Access.Con

trol

.(MAC).and.

Physic

.La

yer

.(PHY

)

.Sp

ecications,

.2007.

[802.11n]

.IEEE.Sta

ndards

.Ass

ociation,

.IEEE.Std.802.11n,.IEEE.Sta

ndard

.for.Info

rmation

.Tec

hnology—

Telecommunications

.and.Info

rmation

.Exc

hange

.betw

een

.Syst

ems—Local

.and.Metr

opolitan

.Are

Netw

orks—Specic

.Req

uirements—Part

.11:.Wire

less

.LAN.Medi

.Access.Con

trol

.(MAC).and.

Physic

.La

yer

.(PHY

)

.Sp

ecications

.Am

endment

.5:.Enh

ancements

.fo

.Hig

her

. ro

ughput,

.2009.

[802.15.4]

. IEEE. Sta

ndards

. Ass

ociation,

. IEEE. Std. 802.15.4-2006,. IEEE. Sta

ndard

. for. Info

rmation

Tec

hnology—Telecommunications

. and. Info

rmation

. Exc

hange

. betw

een

. Syst

ems—Local

. and.

Metr

opolitan

.are

.Netw

orks—Specic

.Req

uirements—Part

.15.4:.Wire

less

.Medi

.Access.Con

trol

(MAC).and.Physic

.Lay

.(PHY).Spe

cications

.for.Low-R

ate

.Wire

less

.Pers

onal

.Are

.Netw

orks

(WPANs),.2006.

[94/9/EC]

.Eur

opean

.Pa

rliament

.an

.th

.Co

uncil,

.Dire

ctive

.94/9/EC,.1994.