wifi wireless networking.doc

8/11/2019 WIFI WIRELESS NETWORKING.doc

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WIFI wireless fidelity

WIRELESSLESSNETWORKING

WIFI( wireless fidelity )

HARDES Frederic:[email protected] Yoann

Wireless networking 1/29 HARDES Frederic

LECURIEU!"ELF#$D %oa&&
mailto:[email protected]:[email protected]


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TABLE OF CONTENTS

! INTRODUCTION"! #$"! %&andard and HISTORY OF WIRELESS NETWORK

a! HISTORY OF WIRELESS NETWORK

'! W(a& i% WIFIc! #$"! nor)% %*eci+ica&ion%

,! NETWORK LAYOUT

a! WIFI *(%ica. arc(i&ec&/re and (o0 &o '/i.d a WIFI ne&0or1'! Tran%)i%%ion .ao/&

c! Sec/ri& con%idera&ion

2! RADIO FREE NETWORK

3! FUTURE WIFI TECHNOLOGIES and SOLUTIONS4! CONCLUSION

5! REFERENCES

#! GLOSSARY




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! INTRODUCTION

O6er &(e *a%& +e0 ear% 0ire.e%% a&&i&/de a% .ar7e. 'een de6e.o*ed o6er &(e 0or.d !A+&er0ire.e%% 6oice &ran%)i%%ion &(ro/7( ce../.ar *(one (ere i% a ne0 &endenc 0ire.e%% da&a

&ran%)i%%ion &(ro/7( WIFI 8Wire.e%% Fide.i& 9 !Indeed i& no& an 'rand ne0 a&&i&/de +or

+ir%& WLAN 8 Wire.e%% Loca. Area Ne&0or1% 9 'e7an in &(e #$% !

T(ro/7( o/r *re%en&a&ion 0e 0i.. e)*(a%i% on #$"!!' 8 %o ca.. WIFI 9 &(a& i% &(e

%&andard na)e +or WLAN ne&0or1in7 !

A& +ir%& 0e 0i.. in&rod/ce WLAN IEE (i%&or and %&andardia&ion &(en 0e 0i.. di%c/%%

&ec(nica. i%%/e a'o/& 0ire.e%% ne&0or1in7 !T(e )ain i%%/e a'o/& WIFI 0i.. 'e %ec/ri&

and &ran%)i%%ion 'eca/%e i& i% no& de*endin7 on o/r (ard0are !E6en&/a.. 0e 0i..

de6e.o* a +e0 %&/++ a'o/& WIFI +/&/re and c/rren& de6e.o*)en& !

Wireless networking '/29 HARDES Frederic



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"! #$"! %&andard and HISTORY OF

WIRELESS NETWORK

a. HISTORY OF WIRELESS NETWORK

In recen& &i)e ne0 )/.&i)edia a**.ica&ion% and co))ercia. need +or 6e.oci& (a%

i)*ro6ed (i7( %*eed ne&0or1in7 and need +or )o'i.i& !

S&ar&in7 &(e #$% +ir%& &e%& (a% 'een .ead o6er Wire.e%% Area Ne&0or1in7 ! Wire.e%%

Ne&0or1in7 a% a.read 'een de6e.o*ed on )o'i.e *(one '/& %&ar&in7 &(e ;$% i&


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b. W(a& i% WIFI

WIFI )ean% 0ire.e%% +ide.i& i& i% &(e co))on na)e +or IEE #$"! %&andard! Bein7 a'.e

&o connec& &o &(e 0e' an0(ere o/ 7o +ro) a .a*&o* or (and(e.d co)*/&er (a% a .o& o+a**ea.! In )an ca%e% a.. o/ need i% an an&enna! Ho& %*o&% are a**earin7 in co++ee %(o*%=

air*or&%= and (o&e. .o/n7e 0(ere *eo*.e can connec& and .o7 on&o /n-a)*.i+ied WIFI

ne&0or1%= /%/a.. +or +ree!

I&% a.%o a *(eno)enon &(a&% &a1in7 on a .i+e o+ i&% o0n! In addi&ion &o &(e co)*anie%%e..in7 %er6ice &o &(e '/%ine%%e% and a7encie% o++erin7 */'.ic (o& %*o&%= a 6arie& o+

en&re*rene/r% are no0 .oo1in7 +or 0a% &o *ac1a7e &(e %er6ice +or &(e 7enera. */'.ic!

T(e c/rren& 7enera&ion o+ WIFI i% ca*a'.e o+ carrin7 In&erne& &ra++ic and da&a a& %*eed%

/* &o @'*%= )/c( +a%&er &(an con%/)er DSL= and e6en +a%&er +.a6or% o+ #$!a.read ei%&!

I&% on. na&/ra. &(a& i&% 'ein7 %een a% a.&erna&i6e &o &(e 'road'and %er6ice% *ro6ided '

&e.e*(one and ca'.e co)*anie% &(a& are o+&en e*en%i6e and /na6ai.a'.e! T(ere arec/rren&. a'o/& $$ WIS>% 8Wire.e%% In&erne& %er6ice *ro6ider%9 in &(e Uni&ed S&a&e%

&(a& /%e #$"! 7ear &o *ro6ide (o)e% and o++ice% 0i&( 'road'and %er6ice! 8To +ind one

near o/= 7o &o &(e WIS>% Direc&or a& 000!''0ec(an7e!co)!9 And en&ren*rene/r% are'/i.din7 ne&0or1% o+ WIS>% &o 'e&&er %e.. o/ %er6ice= )o%& no&a'. Boin7o Wire.e%%%

S1 Da&on= &(e +o/nder o+ Ear&(.in1!

B/& i&% no& ?/%& '/%ine%%)en .oo1in7 &o )a1e a '/c1 &(a& are di%co6erin7 and %*readin7WIFI acce%%! T(ro/7(o/& A)erica and )an o&(er *ar&% o+ &(e 0or.d an e)er7in7

7ra%%roo&% a**roac( &o '/i.din7 WIFI ne&0or1% (a% &a1en on a .i+e o+ i&% o0n!Ca.. &(e) >ara%i&ic ne&0or1%= +ree ne&0or1%= 0ire.e%% co))/ni&ie%= or *er%ona. &e.eco)%&(e%e ne&0or1% are no0 0e.. e%&a'.i%(ed and 7ro0in7 in Sea&&.e= Ne0 Yor1= >or&.and=

Ber1e.e= Ho/%&on= and )an o&(er ci&ie%!

T(e 0or1 ' %(arin7 %i7na.% o6er ine*en%i6e radio recei6er%! A %in7.e DSL .ine can

*ro6ide %er6ice &o a doen or )ore *eo*.e 0(o are 0i&(in radio ran7e 8and .ine o+ %i7(&9and ' *i77'ac1in7 %i7na.% i&% *o%%i'.e &o '/i.d /* a ne&0or1 &(a& co6er% an en&ire

nei7('or(ood= ci&= or re7ion!

T(e )ini)a. co)*onen&% are a 'a%e %&a&ion= a.%o 1no0n a% an acce%% *oin& or node=0(ic( i% &(e ne&0or1 (/' &(a& o/r 0ire.e%% .a*&o* &a.1% &o= and an an&enna &o recei6e a

radio %i7na.! Lar7er 'a%e %&a&ion%= an&enna%= and a)*.i+ier% are o+&en ca..ed in&o %er6ice &o

e&end &(e ran7e!A& 6ario/% *oin&% &(ere )/%& 'e 0a% &o connec& &o &(e We'= ' *./77in7 in&o a DSL or

T or a >oin& &o >oin& Broad'and Wire.e%% %%&e)= %o &(ere are co%&% a'o6e &(e 'a%ic

(ard0are e*endi&/re%! B/& &(e%e can 'e di%&ri'/&ed! W(ere *eo*.e in &(e co))/ni& are

0i..in7 &o coo*era&e in '/i.din7 and )ana7in7 i&= &(i% 1ind o+ ne&0or1 i% 6er%a&i.e=e++icien&= and ine*en%i6e &o o*era&e!

Wireless networking )/29 HARDES Frederic



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c. #$"! nor)% %*eci+ica&ion%

IEEE #$"!a 32 @'i&%= 3 GH %&andard 8"$$"9

IEEE #$"!' @'i&%= "!2 GH %&andard 8;;;9

IEEE #$"!B - S>ECIFICATION

Key Data

S&andard T*e Fied Wire.e%% 8LAN9

Loca&ion Wor.d0ide

Co)*.e&ion On7oin7

Key Players

Con&ro..in7 Bod In%&i&/&e o+ E.ec&ronic and E.ec&rica. En7ineer%

De6e.o*er% Ci%co S%&e)%Airone& Wire.e%% Co))/nica&ion%

IEEE #$"!d ne0 co/n&rie%IEEE #$"!e en(ance)en&%: oS= %ec/ri&

IEEE #$"!+ In&er-Acce%% >oin& >ro&oco. 8IA>>9

IEEE #$"!7 "$ @'i&%= "!2 GH %&andard 8+or&(co)in79IEEE #$"!( 3 GH %*ec&r/) and &ran%)i& *o0er )ana7e)en&

IEEE #$"!" './e&oo&(

BLUETOOTH - S>ECIFICATION

Key Data

S&andard &*e Fied Wire.e%% 8LAN9

Loca&ion Wor.d0ide

Co)*.e&ion ;;;

Key Players

Con&ro..in7 'od B./e&oo&( S*ecia. In&ere%& Gro/*

De6e.o*er%

Wireless networking */29 HARDES Frederic



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,! NETWORK LAYOUT

In &(i% *ar& 0e 0i.. &r &o de6e.o* 'a%ic re/ire)en& &o .in1 &o *oin& o+ a WIFI ne&0or1

%/c( a% &ran%)i%%ion and ne&0or1 .aer% con+i7/ra&ion !

Wireless networking +/29 HARDES Frederic



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a! WIFI *(%ica. arc(i&ec&/re and (o0 &o '/i.d a WIFI

ne&0or1

Wire.e%% LAN To*o.o7ie%

Wire.e%% LAN% are '/i.& /%in7 &0o 'a%ic &o*o.o7ie%! T(e%e &o*o.o7ie% are 6ario/%.

&er)ed inc./din7 )ana7ed and /n)ana7ed= (o%&ed and *eer &o *eer= and in+ra%&r/c&/re

and ad-(oc! 0e 0i.. /%e &(e &er)% in+ra%&r/c&/re and ad-(oc in &(i% doc/)en&! T(e%e

&er)% re.a&e &o e%%en&ia.. &(e %a)e 'a%ic di%&inc&ion% in &o*o.o7!An in+ra%&r/c&/re &o*o.o7 i% one &(a& e&end% an ei%&in7 0ired LAN &o 0ire.e%% de6ice%

' *ro6idin7 a 'a%e %&a&ion 8ca..ed an acce%% *oin&9! T(e acce%% *oin& 'rid7e% &(e 0ire.e%%

and 0ired LAN and ac&% a% a cen&ra. con&ro..er +or &(e 0ire.e%% LAN! T(e acce%% *oin&

coordina&e% &ran%)i%%ion and rece*&ion +ro) )/.&i*.e 0ire.e%% de6ice% 0i&(in a %*eci+icran7e &(e ran7e and n/)'er o+ de6ice% de*end on &(e 0ire.e%% %&andard 'ein7 /%ed and

6endor


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An ad-(oc &o*o.o7 i% one in 0(ic( a LAN i% crea&ed %o.e. ' &(e 0ire.e%% de6ice%

&(e)%e.6e%= 0i&( no cen&ra. con&ro..er or acce%% *oin&! Eac( de6ice co))/nica&e% direc&.0i&( o&(er de6ice% in &(e ne&0or1 ra&(er &(an &(ro/7( a cen&ra. con&ro..er! T(i% i% /%e+/. in*.ace% 0(ere %)a.. 7ro/*% o+ co)*/&er% )i7(& con7re7a&e and no& need acce%% &o ano&(er

ne&0or1! For ea)*.e= a (o)e 0i&(o/& a 0ired ne&0or1= or a con+erence roo) 0(ere

&ea)% )ee& re7/.ar. &o ec(an7e idea%= are ea)*.e% o+ 0(ere ad-(oc 0ire.e%% ne&0or1%)i7(& 'e /%e+/.!

Fi7/re ": An Ad Hoc Ne&0or1For ea)*.e= 0(en co)'ined 0i&( &odaC% or %)ar& de6ice% 0ire.e%%.!

Ho0 i& Wor1% O6er6ie0 In+ra%&r/c&/re @ode

T(e .a*&o* or %)ar& de6ice= 0(ic( i% c(arac&eried a% a %&a&ion in 0ire.e%% LAN*ar.ance= +ir%& (a% &o iden&i+ &(e a6ai.a'.e acce%% *oin&% and ne&0or1%! T(i% i% done

&(ro/7( )oni&orin7 +or J'eacon< +ra)e% +ro) acce%% *oin&% anno/ncin7 &(e)%e.6e%= or

ac&i6e. *ro'in7 +or a *ar&ic/.ar ne&0or1 ' /%in7 *ro'e +ra)e%!

T(e %&a&ion c(oo%e% a ne&0or1 +ro) &(o%e a6ai.a'.e and 7oe% &(ro/7( an a/&(en&ica&ion

*roce%% 0i&( &(e acce%% *oin&! Once &(e acce%% *oin& and %&a&ion (a6e 6eri+ied eac( o&(er=&(e a%%ocia&ion *roce%% i% %&ar&ed!

A%%ocia&ion a..o0% &(e acce%% *oin& and %&a&ion &o ec(an7e in+or)a&ion and ca*a'i.i&ie%!T(e acce%% *oin& can /%e &(i% in+or)a&ion and %(are i& 0i&( o&(er acce%% *oin&% in &(e



Desktop

Laptop

Tablet

AD HOC Network


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T(i% i% &(e e/i6a.en& &o a co))on ne&0or1 card *./% i& ena'.e WE> "# 'i& 8e*.ain.a&er9

T(en o/ 0i.. need a acce%% *oin& &o connec& o/r LAN an o&(er re)o&e node 8acce%%*oin& =A>9 ! Genera.. &(i% de6ice %/**or& .on7er di%&ance &(an &(e *c card &(a& 0( I ca..

&(e IS> re)o&e ne&0or1 !

T(i% acce%% *oin& i% 7enera.. 'road'and %*eci+ic I )ean &(ere i% on. E&(erne& *or& ! So i+o/ need &o %(are a in&erne& connec&ion 0i&( a USB ADSL )ode) i&


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T(i% acce%% *oin& co))on. ca.. node i% &(e *oin& +or &(e ne&0or1 0i.. 'e +ree or no& !T(ere i% +ree node &(a& can 'e '/i.& ' an /%er re%*ec&in7 &(e $$)0 )a e)i%%ion

&ro/7( &(e "!2 GH 'and &(i% 0i.. 'e de6e.o*ed in &(e &ran%)i%%ion *ar& !A co))on

acce%% *oin& can ea%i. %/**or& "$ &o ,$ /%er !

No0 &(a& o/ 0i%( &o %(are o/ IS> connec&ion o/ need on o+ &(i% &0o 'road'and

*ro&oco.% >>> e& >>>oE !T(e A> a..o0in7 ne&0or1 %(arin7 a..o0% NAT 8Ne&0or1

Addre%% Tran%.a&ion9! T(i% i% nece%%ar +or o/ (a6e on. one I> addre%% on &(ein&erne& !To a..o0% o/ &o co))/nica&e 0i&( o&(er &er)ina. o/ )/%& 7a&(er o/ I>

addre%%e% 8 i)a7e i& =i& no& rea. 9 in on. on co))on */'.ic addre%% &(e addre%% +or o/

IS> .in1 !T(en 0(en &(e re%*on%e arri6e i& 0i.. 'e &(e in6er%e *roce%% &(en &ran%+errin7 i& &o &(e

7ood &er)ina. !

Wireless networking 12/2

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HARDES Frederic



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'! Tran%)i%%ion .ao/&

One o+ &(e +ac&or% &(a& a++ec&% ran7e and *er+or)ance o+ a WIFIne&0or1 i% &(e di%&ance o+&(e c.ien& de6ice% 8o/r WIFIe/i*)en&9 &o o/r 'a%e %&a&ion 8o/r acce%% *oin& or7a&e0a9! In an o*en area 0i&( no 0a..%= +/rni&/re or in&er+erin7 radio de6ice%= o/ )a

'e a'.e &o 7e& a ran7e o+ 3$$ +ee& or )ore +ro) o/r 'a%e %&a&ion &o o/r WIFIe/i**ed

co)*/&er! In +ac&= o/ co/.d 7e& a %i7na. +ro) /* &o a )i.e a0a de*endin7 on &(ean&enna% o/ /%e and en6iron)en&a. condi&ion%

@an 'a%e %&a&ion% can a.%o ac& a% re*ea&er or re.a %&a&ion% +or o/r ne&0or1! For

ea)*.e= i+ o/ .oca&e one WIFIe/i**ed co)*/&er $$ +ee& a0a +ro) o/r 'a%e %&a&ion=ano&(er WIFIco)*/&er $$ +ee& a0a in ano&(er direc&ion= and &(en *o%i&ion o/r 'a%e

%&a&ion in &(e )idd.e= o/ can crea&e a ne&0or1 0i&( a ran7e o+ "$$ +ee& +ro) one

WIFIco)*/&er &o &(e o&(er!

Wi-Fi= or IEEE #$"!'= %*eed decrea%e% &(e +ar&(er o/ )o6e +ro) &(e 'a%e %&a&ion! For

ea)*.e= 0(en o/ are c.o%e &o &(e 'a%e %&a&ion= o/r WIFIco)*/&er %(o/.d 'e a'.e &o

7e& &(e +/.. @'*% da&a ra&e! @o6e +ar&(er a0a= and de*endin7 on en6iron)en&= &(eda&a ra&e 0i.. dro* &o 3!3 @'*%! @o6e e6en +ar&(er= and &(e da&a ra&e 0i.. dro* &o " @'*%=

and +ina.. &o @'*%! B/& 7e&&in7 ?/%& @'*% &(ro/7(*/& i% %&i.. a *er+ec&. acce*&a'.e

*er+or)ance .e6e.! @'*% i% +a%&er &(an )o%& DSL and ca'.e connec&ion%= 0(ic( )ean%i&% %&i.. a %a&i%+ac&or (i7(-%*eed &ran%)i%%ion i+ o/re %endin7 and recei6in7 e-)ai.=

cr/i%in7 &(e In&erne& or ?/%& *er+or)in7 da&a en&r &a%1% +ro) a )o'i.e co)*/&er!

B/& &(e di%&ance de*end% on &(e an&enna and 8e6en&/a.. a)*.i+ier9 /%ed: "!,$$ )e&er%0i&( a o)nidirec&iona. an&enna 1) 0i&( a direc&i6e one "!, 1) 0i&( a o)nidirec&iona.

a)*.i+ied 8"$$)W9 %o)e 1) 0i&( *ara'o.ic an&enna! 3$!4$ 1) 0i&( *ara'o.ic ordirec&i6e an&enna a)*.i+ied 8%o)e Wa&&%9!

WIFIRange Estimates

Maximum Range Range At 11 Mbps

O/&door% o*en %*ace 0i&( %&andard an&enna 53$-=$$$ +& 3$-,3$ +&

O++ice .i7(& ind/%&ria. %e&&in7 "3$-,3$ +& $$-3$ +&

Re%iden&ia. %e&&in7 "3-"$$ +& 4$-#$ +&

Walls and Oter Obstru!ti"ns

Wireless networking 1'/2

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HARDES Frederic



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@e&a. and o&(er den%e )a&eria.% can a++ec& &(e &ran%)i%%ion o+ radio 0a6e%! Yo/ can

e*ec& &(a& o/r WIFI%%&e) 0i.. (a6e di++ic/.& &ran%)i&&in7 +ro) one roo) &o ano&(er i+&(e 0a..% in o/r (o)e are co)*o%ed o+= or (ea6i. rein+orced 0i&(= )e&a.! S&one= 'ric1=

(ea6 0ood% and e6en 0a&er can a.%o a++ec& ran7e!

Wat #an $"u D" t" Maximi%e te Range and Per&"rman!e "& $"ur '"me(et)"r*ing System+

To i)*ro6e o/r WIFIne&0or1% ran7e and *er+or)ance= &r e*eri)en&in7 0i&( &(e

*.ace)en& o+ o/r 'a%e %&a&ion= an&enna% and c.ien& de6ice% .i1e .a*&o* co)*/&er% and>DA%! I+ o/ can )o6e o/r 'a%e %&a&ion and i&% In&erne& connec&ion= &r di++eren&

*o%i&ion% aro/nd &(e roo)! >/& o/r 'a%e %&a&ion and i&% an&enna (i7( /*= o++ &(e +.oor and

a0a +ro) )e&a.= *o0er %/**.ie% and e.ec&rica. o/&.e&% and 0irin7! So)e&i)e% ?/%&%0i6e.in7 &(e an&enna% or an7.in7 o/r 'a%e %&a&ion can )ea%/ra'. i)*ro6e ran7e!

I& i% a.%o *o%%i'.e &o add )ore e&erna. an&enna% &o )an WIFIne&0or1in7 %%&e)%= and

&(e can 7rea&. i)*ro6e ran7e and *er+or)ance! A /nidirec&iona. an&enna can narro0 &(e

o6era.. 'ea) 0id&( o+ o/r 'a%e %&a&ion= *ro6idin7 )/c( i)*ro6ed ran7e! A narro0-'ea)an&enna can ena'.e o/ &o &ran%)i& )an &i)e% &(e di%&ance o+ o/r 'a%e %&a&ion%

o)nidirec&iona. an&enna% nor)a. ran7e= a.'ei& in ?/%& one or &0o direc&ion% in%&ead o+

&ran%)i&&in7 &(e %(or&er di%&ance in a.. direc&ion%! Yo/ 7ain 7rea&er ran7e +or o/r ne&0or1'/& o/ red/ce )o'i.i& 'eca/%e o/r &ran%)i%%ion% (a6e narro0er co6era7e!

Yo/ can a.%o i)*ro6e ran7e ' &/rnin7 o++ or re)o6in7 e.ec&rica. a**.iance% &(a& e)i&

in&er+erin7 radio 0a6e%! So)e cord.e%% *(one% = )icro0a6e o6en%= and radio-o*era&ed &ocon&ro.% o*era&e in &(e %a)e */'.ic "!2 GH 0ire.e%% +re/enc 'and a% WIFI ! Yo/ can

)o6e &(e %%&e)% +ar&(er a*ar& or &r &o re%&ric& /%e o+ in&er+erin7 de6ice% &o &i)e% 0(en

o/re no& /%in7 o/r WIFI%%&e)! I& i% a.%o *o%%i'.e &o c(an7e o/r WIFIne&0or1c(anne. &o a6oid &(e c(anne.% /%ed ' &(e co)*e&in7 de6ice%! @o%& WIFI%%&e)% /%e

c(anne. = 4 or a% &(e de+a/.& &r %0i&c(in7 &(e c(anne. &o 5 or $!In addi&ion= %o)e 'rand% o+ WIFI7ear (a6e 6ario/% *ro*rie&ar %o./&ion% &o (e.* red/ce

in&er+erence! Read &(e in%&r/c&ion% +or o/r )a1e and )ode.!

M"dulati"n

#$"!' e)*.o% DSSS )od/.a&ion /%in7 &(e Bar1er code c(i**in7 %e/ence! Eac( 'i& i%

encoded in&o an -'i& Bar1er code 8e!7!= $$$$$9= 0i&( eac( re%/.&in7 da&a o'?ec&

+or)in7 a c(i*! T(e c(i* i% */& on a carrier +re/enc 8i!e!= a %)a.. +re/enc ran7e &(a&

carrie% &(e %i7na.9 in &(e "!2 GH ran7e= and &(e 0a6e+or) i% )od/.a&ed /%in7 one o+%e6era. &ec(ni/e%!

Wireless networking 1(/2

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HARDES Frederic



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#$"!' %%&e)% r/nnin7 a& @'*% /%e Bar1er code and B>SK 8Binar >(a%e S(i+&

Kein79 )od/.a&ion= and &(o%e r/nnin7 a& " @'*% /%e Bar1er code and >SK8/a&ernar >(a%e S(i+& Kein79 )od/.a&ion!

S%&e)% r/nnin7 a& 3!3 @'*% and @'*% /%e CCK 8Co)*.e)en&ar Code Kein79 and>SK )od/.a&ion! CCK in6o.6e% 42 /ni/e code %e/ence%= eac( o+ 0(ic( %/**or&% 4

'i&% *er code 0ord! T(e CCK code 0ord i% &(en )od/.a&ed on&o &(e RF carrier /%in7>SK= 0(ic( a..o0% ano&(er &0o 'i&% &o 'e encoded +or eac( 4-'i& %)'o.! T(ere+ore=

eac( 4-'i& %)'o. con&ain% # 'i&% 8i!e!= '&e9!

T(e FCC .i)i&% &(e *o0er o/&*/& o+ &(e #$"!' %%&e) &o 0a&& EIR> 8E/i6a.en&

I%o&ro*ica.. Radia&ed >o0er9! A& &(i% .o0 *o0er .e6e. &(e *(%ica. di%&ance 'e&0een &(e&ran%)i&&in7 de6ice% 'eco)e% an i%%/e d/e &o %i7na. a&&en/a&ion= 0i&( error *er+or)ance

%/++erin7 a% &(e di%&ance increa%e%! 8No&e: $$ )e&er% i% a *re&& 7ood r/.e o+ &(/)' +or

an #$"!' WLAN 0i&( c.ear .ine-o+-%i7(&!9

An den%e *(%ica. o'%&r/c&ion% 'e&0een &ran%)i&&er and recei6er add con%idera'. &o &(e*ro'.e)! T(ere+ore= &(e de6ice% ada*& &o .on7er di%&ance%= *(%ica. o'%&r/c&ion% and o&(er

+ac&or% &(a& i)*ac& %i7na. %&ren7&( ' /%in7 a .e%% co)*.e encodin7 &ec(ni/e= and a

re%/.&in7 .o0er %i7na..in7 %*eed= 0(ic( &ran%.a&e% in&o a .o0er da&a ra&e!

For ea)*.e= a %%&e) r/nnin7 a& @'*% /%in7 CCK and >SK= )i7(& &(ro&&.e 'ac1 &o3!3 @'*% ' (a.6in7 &(e %i7na..in7 ra&e a% &(e di%&ance% increa%e= door% and 0a..% 7e& in

&(e 0a= and error *er+or)ance dro*%!

T(e %i&/a&ion 7e&% 0or%e 0(en o/ )o6e o/r .a*&o* o/& &o &(e dec1 &o 0or1 on a %/nn

%/))er a+&ernoon= %o &(e %%&e) )i7(& &(ro&&.e 'ac1 &o " @'*% /%in7 on. >SK= and @'*% /%in7 B>SK! T(i% *roce%% i% )/c( &(e %a)e a% &(a& /%ed ' con6en&iona. +a..'ac1

)ode)% &(a& )i7(& ini&ia&e a ca.. a& 34 K'*% 8ac&/a.. 3,!, K'*%9= and +a.. 'ac1 &o ra&e%

o+ *er(a*% "#!# K'*% or 2!2 K'*% a% &(e /a.i& o+ &(e dia.-/* >STN connec&ionde7rade%!

No&e: A% I )en&ioned ear.ier= &(e ac&/a. &(ro/7(*/& o+ an #$"!' %%&e) i% )/c( .e%%

&(an &(e ra0 'and0id&(! >(%ica. .aer o6er(ead con%/)e% ,$-3$ o+ &(e 'and0id&(!

An #$"!' %%&e) r/nnin7 a& &(e +/.. ra&e o+ @'*%= &(ere+ore *ro6ide% &(ro/7(*/& o+on. 4 @'*% or %o= a%%/)in7 o6er(ead in &(e ran7e o+ 2$!

I+ &(ere are a .o& o+ error% in &ran%)i%%ion= &(ro/7(*/& dro*% *reci*i&o/%.= a% &(e recei6in7%&a&ion )/%& ad6i%e &(e &ran%)i&&in7 %&a&ion o+ &(e errored +ra)e% and &(en 0ai& +or

re&ran%)i%%ion%! I+= +or ea)*.e= &(e error ra&e i% 3$= &(e ac&/a. &(ro/7(*/& dro*% &oa'o/& " @'*%!

Wireless networking 1)/2

9

HARDES Frederic



16/29


T(i% %cenario i% a '.end o+ a 'e%& ca%e @'*% and a 0or%& ca%e error ra&e! In ac&/a.i&=

%/c( an error ra&e 0o/.d ca/%e &(e %%&e) &o +a.. 'ac1 &o a .o0er &ran%)i%%ion ra&e o+*er(a*% " @'*%= a& 0(ic( ra&e Bar1er code and >SK 0o/.d 'e /%ed and &(e error ra&e

0o/.d dro*!

T(e #$"!' %*eci+ica&ion di6ide% &(e a%%i7ned RF %*ec&r/) in&o 2 c(anne.%! T(e FCC

a..o0% &(e /%e o+ c(anne.%! Since &(e U!S! "!2 GH 'and i% on. #, @H 0ide and &(e#$"!' c(anne.% are "3 @H 0ide= (o0e6er= on. &(ree 8,9 c(anne.% can 'e /%ed

%i)/.&aneo/%.!

W(i.e o&(er re7/.a&or% in o&(er ?/ri%dic&ion% a..o0 &(e /%e o+ )ore or +e0er c(anne.%

8e!7!= Ma*an a..o0% &(e /%e o+ on. one9= none a..o0% &(e /%e o+ a.. 2= a& .ea%& no& a% +ar a%I 1no0! So= no& on. i% &(e a)o/n& o+ %*ec&r/) (i7(. .i)i&ed &o 'e7in 0i&(= '/& no& e6en

a.. o+ &(a& i% /%ed!

T(ere a.%o i% o6er.a* 'e&0een ad?acen& c(anne.% 8e!7!= c(anne.% &0o and &(ree9= 0(ic(a++ec&% *er+or)ance and 0(ic(= &(ere+ore= re/ire% &(a& an 7i6en %%&e) )ain&ain)ai)/) c(anne. %e*ara&ion +ro) o&(er %%&e)% in *roi)i&!

#$"!' %*eci+ie% &0o %ec/ri& )ec(ani%)%! T(e )o%& 'a%ic i% &(e E.ec&ronic S%&e) ID

8ESSID= or SSID9= 0(ic( i% in &(e +or) o+ a iden&i+ier code /%ed +or a/&(en&ica&ion! T(e

SSID i% e%&a'.i%(ed ' &(e %%&e) ad)ini%&ra&or +or eac( de6ice %e& /* &o 7ain acce%%&(ro/7( eac( acce%% *oin&! SSID doe%n& *ro6ide )/c( %ec/ri& a& a..!

T(e ne& .e6e. i% WE> 8Wired E/i6a.en& >ri6ac9= 0(ic( /%e% a 2$- or "#-'i&

encr*&ion 1e &o *ro&ec& da&a in &ran%i&! WE> doe%n& *ro6ide 7rea& *ro&ec&ion= ei&(er= a%

i& (a% 'een %(o0n &o 'e ea%i. co)*ro)i%ed!

An rea. in(eren& %ec/ri& 0i.. (a6e &o 0ai& +or ano&(er %&andard%-'a%ed %o./&ion! In &(e

)ean&i)e= /%er or7ania&ion% (a6e &o o6er.a &(eir o0n (i7(er-%&ren7&( %ec/ri&

)ec(ani%)%= 7enera.. in &(e +or) o+ a >N 8ir&/a. >ri6a&e Ne&0or19!

Wireless networking 1*/2

9

HARDES Frederic



17/29


c! Sec/ri& con%idera&ion%

T(e #$"! %&andard *ro6ide% +or &0o *ri)ar %ec/ri& +ea&/re% &(a&= /n+or&/na&e.=+a.. %(or& o+ a &r/. %ec/re %o./&ion! Bo&( o+ &(e %o./&ion% o*era&e on &(e da&a .in1.aer o+ &(e ne&0or1!

SSID , Ser-i!e Set Identi&ier

T(e SSID i% a *iece o+ in+or)a&ion /%ed &o iden&i+ a *ar&ic/.ar acce%% *oin& &o

%&a&ion% 0i%(in7 &o /%e a 0ire.e%% ne&0or1! T(/%= &(e SSID i% ana.o7o/% &o aco))on ne&0or1 na)e %(ared ' &(e 0ire.e%% %&a&ion and acce%% *oin&%! T(e SSID

)/%& ei&(er 'e *re-con+i7/red or ad6er&i%ed in 'eacon 'roadca%&%!

Beca/%e &(e SSID i% &ran%)i&&ed in &(e c.ear in 'eacon +ra)e% ' de+a/.&= i& *ro6ide%

6er .i&&.e %ec/ri&! A ro7/e acce%% *oin& co/.d read &(e SSID +ro) 'eacon +ra)e%and a%%/)e &(e iden&i& o+ &(e .e7i&i)a&e acce%% *oin&! T(i% co/.d *o&en&ia.. a..o0

&(e (i?ac1in7 o+ &(e %&a&ion%< &ra++ic!

WEP . Wired E/ui-alent Pri-a!y

Accordin7 &o &(e #$"! %&andard= Wired E/i6a.en& >ri6ac 8WE>9 0a% in&ended &o

*ro6ide con+iden&ia.i& &(a& i% %/'?ec&i6e. e/i6a.en& &o &(e con+iden&ia.i& o+ a0ired .oca. area ne&0or1 8LAN9 )edi/) &(a& doe% no& e)*.o cr*&o7ra*(ic

&ec(ni/e% &o en(ance *ri6ac!

WE> re.ie% on a %ecre& 1e &(a& i% %(ared 'e&0een a )o'i.e %&a&ion and an acce%%*oin&! WE> /%e% &(e RC2 %&rea) ci*(er in6en&ed ' RSA Da&a Sec/ri&! RC2 i% a

%))e&ric %&rea) ci*(er &(a& /%e% &(e %a)e 6aria'.e .en7&( 1e +or encr*&ion anddecr*&ion! Wi&( WE> ena'.ed= &(e %ender encr*&% &(e da&a +ra)e *a.oad andre*.ace% &(e ori7ina. *a.oad 0i&( &(e encr*&ed *a.oad! T(e %ender &(en +or0ard%

&(e encr*&ed +ra)e &o i&% de%&ina&ion! T(e encr*&ed da&a +ra)e% are %en& 0i&( &(e

@AC (eader WE> 'i& %e&! T(/%= &(e recei6er 1no0% &o /%e &(e %(ared WE> 1e &o

decr*& &(e *a.oad and reco6er &(e ori7ina. +ra)e! T(e ne0 +ra)e= 0i&( an/nencr*&ed *a.oad can &(en 'e *a%%ed &o an /**er .aer *ro&oco.!

WE> *ro6ide% &0o )ain +ea&/re%! I& denie% acce%% &o &(e ne&0or1 ' /na/&(oried/%er% &(a& do no& (a6e &(e a**ro*ria&e WE> 1e! I& a.%o *re6en&% &(e decodin7 o+

ca*&/red &(e encr*&ed WLAN &ra++ic 0i&(o/& &(e *o%%e%%ion o+ &(e WE> 1e!

U%in7 &(e #$"! %ec/ri& +ea&/re% cer&ain. increa%e% &(e %ec/ri& o+ &(e WLAN!

Ho0e6er= &(e%e +ea&/re% a.one do no& *ro6ide a co)*.e&e 0ire.e%% %ec/ri& %o./&ion!

A n/)'er o+ %ec/ri& concern% (a6e 'een rai%ed! T(e%e concern% 0ere )o&i6a&in7

+ac&or% in &(e de6e.o*)en& o+ Ci%co-LEA> and In&er.in1 Ne&0or1%< RAD-Serie%

Wireless networking 1+/2

9

HARDES Frederic



18/29


EA>-LEA> %/**or&!MA# Address Autenti!ati"n

O*en and S(ared Ke A/&(en&ica&ion in6o.6e% &(e %&a&ion a/&(en&ica&in7 &o an

acce%% *oin& /%in7 &(e %&a&ion 1e% can o'&ain ne&0or1 acce%%!

One Way Autenti!ati"n

WE> a/&(en&ica&ion i% one-0a on.! T(e acce%% *oin& doe% no& need &o a/&(en&ica&e

&o &(e )o'i.e %&a&ion! T(i% )a a..o0 a ro7/e acce%% *oin& &o +a.%e. indica&e a

%/cce%%+/. a/&(en&ica&ion &o a %&a&ion and (i?ac1 &(a& %&a&ion 1e%! T(e ad)ini%&ra&i6e co%&%

o+ &(i% (and con+i7/ra&ion 6ir&/a.. 7/aran&ee &(a& &(e%e 1e% 0i.. %e.do) 'ec(an7ed!

WEP Key 0ulnerability

Recen& *a*er% (a6e de%cri'ed %/cce%%+/. a&&ac1% on &(e WE> a.7ori&()! One o+

&(e%e= 0(o%e %o/rce code i% readi. a6ai.a'.e on &(e In&erne&= i% a *a%%i6e a&&ac1 &(a&

c.ai)% &o 'e a'.e &o re&rie6e a 2$-'i& WE> 1e in 3 )in/&e% 0i&( an ordinar

.a*&o*! Beca/%e &(i% a&&ac1 %ca.e% .inear. 'a%ed on 1e %ie= a "#-'i& 1e %(o/.d 'e

a'.e &o 'e crac1ed in a'o/& 23 )in/&e%!

Wireless networking 1,/2

9

HARDES Frederic



19/29


2! RADIO FREE NETWORK

Gro/*% -- +ro) one +a)i. &o %e6era. (/ndred *eo*.e -- %(are a 0ire.e%% ne&0or1

connec&ion 0(ic( &(e %a i% a% +ree a% air!

T(e ideo.o7 'e(ind &(e )o6e)en& i% &o +ree *eo*.e +ro) &(eir )on&(. In&erne& acce%%c(ar7e%!

One +ree In&erne& )o6e)en& i% a UK-'a%ed co..ec&i6e ca..ed Con%/)e= .ed ' Ma)e%

S&e6en%= 0(o %a% anone can %e& /* &(eir o0n o*en acce%% *oin& and (e.* '/i.d 0ire.e%%

co))/ni&ie%!Anone 0i&( a .i&&.e &ec(ie 1no0.ed7e can '/ a %i)*.e 'a%e %&a&ion +or ?/%& +e0 (/ndred

E/ro% 0(ic( ac&% a% &(e co-coordina&or +or a 0ire.e%% ne&0or1!

T(en an /%er 0an&in7 &o acce%% &(i% need% a card &(a& .in1% o/r .a*&o* &o &(e ne&0or1

0(ic( can 'e 'o/7(& +or a% .i&&.e a% $$ e/ro%!Wire.e%% ne&0or1% /%e )icro0a6e radio ada*&er%= 1no0n a% WiFi%= 0(ic( can 'e arran7ed

&o +or) a con&in/o/% c.o/d o+ connec&i6i&! T(i% .oo* 7oe% ' &(e *an-E/ro*ean na)ee.e1&ro%)o7!

An .a*&o* +i&&ed 0i&( a %*ecia. 0ire.e%% ne&0or1 card 0i.. a/&o)a&ica.. %earc( and

connec& &o &(i% c.o/d 0i&(in (/ndred% o+ )e&er%!

En&(/%ia%&% 0(o r/n &(e co))/ni&ie% o+&en /%e c(a.1 %)'o.% on &(e %&ree&% &o )ar1 &(e.oca&ion o+ &(e neare%& acce%% *oin& %o anone can ?oin in! T(i% i% o+&en ca..ed 0ar

c(a.1in7!

Gro/*% are a.%o 1een &o %(o0 o&(er% (o0 &o %(are Ne& connec&ion%= %o+&0are ande*erience% o+ 0ire.e%% ne&0or1%!

S&e6en% add%: Free ne&0or1% are o0ned and con%&r/c&ed ' &(eir /%er% 0(ere no 6e%&edin&ere%&% o+ co))ercia. )ode.% can %/r6i6e! T(i% i% no& &o %a &(e 0i.. 'e +ree o+ co%&%'/& &(e *ro+i&eerin7 )o&i6e 0i.. no& 'e *re%en&!

T(e WiFi co))/ni& %a% &(e *rac&ice i% .e7a. 'eca/%e i& /%e% +ree air0a6e%!

In San Franci%co= WiFi 7ro/*% are /%in7 co++ee %(o*% &o o++er 0ire.e%% acce%% a.on7%ide&(e &a.. %1inn .a&&e%! Yo/ can %/r+ &(e Ne& 0i&(o/& (a6in7 &o *./7 in&o a *(one *oin& or

ne7o&ia&in7 a )ae o+ ca'.e% connec&ed &o a >C!

S&e6en% %a% WiFi in E/ro*e (a% )ore .oca. +.a6or! T(e U!S! )ode.% are +oc/%ed on &(e

redi%&ri'/&ion o+ co))ercia. In&erne& %er6ice% 0i&( acce%% *oin&% a&&ac(ed &o 'road'and*ro6i%ion% in&o */'.ic *ar1%= %/are% and ca)*/%e%!

In E/ro*e &(e )ode. o+ ne&0or1 acce%% (a% 'een /%ed 'e&0een .oca. *eo*.e=

or7ania&ion% and in%&i&/&ion% 0(ere In&erne& acce%% i% ?/%& one o+ &(e %er6ice% on o++er!@an E/ro*ean co))/ni&ie% o++er .oca. +i.e %(arin7= %&rea)in7 )edia= )ai. and We'

%i&e% &o &(eir 0ire.e%% /%er%!


9

HARDES Frederic



20/29


In >ari% &(e co))/ni& i% >ari%San%Fi.% 0(i.e in Ro/en i&


21/29


3! FUTURE WIFI TECHNOLOGIES

and SOLUTIONST(e +o..o0in7 %&andard% are in dra+& or condi&iona. a**ro6a. %&a7e!

Standard Des!ripti"n #urrent Status

IEEE #$"!7 Hi7(-ra&e e&en%ion &o #$"!' a..o0in7 +or

da&a ra&e% /* &o 32 @'*% in &(e "!2-GH

IS@ 'and!

Dra+& %&andard ado*&ed No6 "$$!F/.. ra&i+ica&ion e*ec&ed .a&e "$$"

or ear. "$$,!

IEEE #$"!3! Wire.e%% >er%ona. Area Ne&0or1 %&andard

'a%ed on &(e B./e&oo&(P %*eci+ica&ion=o*era&in7 in &(e "!2-GH IS@ 'and!

#$"!3!-"$$" condi&iona..a**ro6ed on @arc( "= "$$"!

T(e +o..o0in7 %&andard% are %&i.. in de6e.o*)en&= i!e!= in &(e &a%1 7ro/* 8TG9 %&a7e!3as* 4r"up Pr"5e!t S!"pe

IEEE #$"!e En(ance &(e #$"! @edi/) Acce%% Con&ro. 8@AC9 &o i)*ro6e and

)ana7e

/a.i& o+ Ser6ice= *ro6ide c.a%%e% o+ %er6ice= and en(anced %ec/ri& anda/&(en&ica&ion )ec(ani%)%! T(e%e en(ance)en&% %(o/.d *ro6ide &(e /a.i&

re/ired +or %er6ice% %/c( a% I> &e.e*(on and 6ideo %&rea)in7!IEEE #$"!+ De6e.o* reco))ended *rac&ice% +or an In&er-Acce%% >oin& >ro&oco. 8IA>>90(ic(

*ro6ide% &(e nece%%ar ca*a'i.i&ie% &o ac(ie6e )/.&i-6endor Acce%% >oin&

in&ero*era'i.i& acro%% a Di%&ri'/&ion S%&e) %/**or&in7 IEEE >#$"! Wire.e%%

LAN Lin1%!IEEE #$"!( En(ance &(e #$"! @edi/) Acce%% Con&ro. 8@AC9 %&andard and #$"!a

Hi7(

S*eed >(%ica. Laer 8>HY9 in &(e 3GH 'and! O'?ec&i6e i% &o )a1e IEEE#$"!a( *rod/c&% co)*.ian& 0i&( E/ro*ean re7/.a&or re/ire)en&%!

IEEE #$"!i En(ance &(e #$"! @edi/) Acce%% Con&ro. 8@AC9 &o en(ance %ec/ri&

anda/&(en&ica&ion )ec(ani%)%

IEEE #$"!3 TG" De6e.o*in7 Reco))ended >rac&ice% &o +aci.i&a&e coei%&ence o+

Wire.e%%

>er%ona. Area Ne&0or1%P 8#$"!39 and Wire.e%% Loca. Area Ne&0or1% 8#$"!9!


9

HARDES Frederic



22/29


IEEE #$"!3 TG, Dra+& and */'.i%( a ne0 %&andard +or (i7(-ra&e 8"$@'i&% or 7rea&er9

W>AN%P!IEEE #$"!3 TG2 In6e%&i7a&e a .o0 da&a ra&e W>AN %o./&ion 0i&( )/.&i-)on&( &o )/.&i-

ear 'a&&er

.i+e and 6er .o0 co)*.ei& !

T(ere are %e6era. ini&ia&i6e% in *ro7re%% &o increa%e &(e da&a ra&e% 'eond #$"!':

Q In &(e "!2-GH +re/enc 'and= &(e IEEE i% 0or1in7 on a (i7(er da&a ra&e %&andard

ca..ed #$"!7! T(e 7oa. i% &o increa%e &(e da&a ra&e 'eond @'*% =and &o )ain&ain

'ac10ard co)*a&i'i.i& and in&ero*era'i.i& 0i&( ei%&in7 IEEE #$"!' *rod/c&%!

Q In &(e 3-GH +re/enc 'and= &(e IEEE i% 0or1in7 on #$"!a! T(e 7oa. i% &o ac(ie6e

%*eed% o+ /* &o 32 @'*%!

Le&% (a6e a co)*ari%on 0i&( &(e 3GH 'and )od/.a&ion &oo /nder%&and i)*ro6e)en&

8and &oo ?/%&i+ &(e ETH en7ineer ro.e 9 !

T(e %/cce%% o+ WLAN &ec(no.o7 0a% +ir). e%&a'.i%(ed ' Wi-Fi 8IEEE #$"!'9

*rod/c&% o*era&in7 in&(e "!2 GH 'and! Wi-Fi de.i6er% re.ia'.e %er6ice a& da&a ra&e% /* &o @'*%! O6er &(e

ne& &0e.6e )on&(%= 3 GH

%%&e)% 0i.. 'e7in en&erin7 &(e )ar1e&! Grea&er &o&a. 'and0id&( and (i7(er da&a ra&e%)a1e &(e 3 GH 'and% 6er

a&&rac&i6e +or (i7( %*eed 0ire.e%% LAN a**.ica&ion%! T(i% ar&ic.e &a1e% a .oo1 a& &(ere.a&i6e %&ren7&(% o+ "!2 GH

and 3 GH WLAN &ec(no.o7ie%!An e*.ana&ion o+ &er)ino.o7 i% re/ired! Wi-Fi i% &(e &rade na)e de6e.o*ed ' &(e

Wire.e%% E&(erne&

Co)*a&i'i.i& A..iance 8WECA9 &o deno&e IEEE #$"!' %%&e)% &(a& (a6e *a%%edri7oro/% in&ero*era'i.i& &e%&in7!

WECA 0i.. a.%o 'e *ro6idin7 in&ero*era'i.i& &e%&in7 +or IEEE #$"!a %%&e)% in &(e

6er near +/&/re= &(o/7( &(ene0 .o7o (a% e& &o 'e de+ined!

T(e IEEE #$"!a %&andard *ro6ide% da&a ra&e% /* &o 32 @'*% in &(e 3 GH 'and! In

order &o +/..a**recia&e &(e 'ene+i&% o+ &(i% e)er7in7 &ec(no.o7= i&


23/29


c(anne.%= and )od/.a&ion %c(e)e a++ec& o*era&ion! Once &(e%e +ac&or% are /nder%&ood=

)ar1e& ado*&ion +or )a?or%e7)en&% can 'e )ore readi. di%c/%%ed!

Radio Propagation

>ro*a7a&ion .o%% a& "!2 6%! 3 GH= a% 0e.. a% &(e )ean% ' 0(ic( #$"!a and Wi-Fi%%&e)% dea. 0i&()/.&i-*a&( are e%%en&ia. &o /nder%&andin7 &(e re%*ec&i6e %&ren7&(% o+ &(e &0o &ec(no.o7ie%!

Wi-Fi %%&e)% o*era&e in

&(e "!2 GH Ind/%&r Science and @edicine 8IS@9 'and= 0(i.e IEEE #$"!a %%&e)%o*era&e in &(e 3 GH 'and%!

In &(e U!S!= &(e 3 GH 'and% are co..ec&i6e. 1no0n a% &(e Un.icen%ed Na&iona.

In+or)a&ion In+ra%&r/c&/re 8UNII9'and%!

T(ere i% a .o& )ore 'and0id&( a6ai.a'.e a& 3 GH= '/& &(ere i% a .ar7e 7a* +ro) 3!,3 GH

&o 3!5"3 GH! A%

a re%/.&= )o%& radio% 0i.. on. co6er &(e .o0e%& "$$ @H o+ %*ec&r/) 83!3 GH &o 3!,3GH9! E6en %o= IEEE

#$"!a de6ice% 0i.. (a6e a& .ea%& # c(anne.%= a% co)*ared &o on. , +or Wi-Fi %%&e)%!Propagation Loss

For an 7i6en ran7e= &(e %i7na. %&ren7&( a& &(e recei6er i% red/ced a% &(e carrier +re/enc

8f 9 increa%e% d/e

&o an e++ec& ca..edpropagation loss 8L*9=! T(i% can 'e ca.c/.a&ed a%:L* X .o7$f D 2c 89

W(ere:

X .o%% coe++icien&D di%&ance 8)e&er%9

f +re/enc 8H9c %*eed o+ .i7(& 8)e&er% %ec9

Fro) E/a&ion 89= .o%%e% are 7rea&er a& (i7(er +re/encie%! Indoor%= %i7na.% )a 'e

+/r&(er a&&en/a&ed '

0a..% and +/rni&/re! T(e .o%% coe++icien& (X9 i% "$ in +ree %*ace! Indoor% i& can 6ar7rea&.= and &*ica.. 6arie%

+ro) ,$ &o 2$! "!2 GH %%&e)% 0i.. o++er 7rea&er ran7e= '/& ?/%& (o0 )/c( )ore

de*end% .ar7e. on a%%/)*&ion%re7ardin7 *ro*a7a&in7 condi&ion%! @ore a'o/& &(i% .a&er!

OFD@ %%&e)% can o+&en correc& di%&or&ed %/'-carrier%! In addi&ion= &(e da&a i% di%&ri'/&edo6er %e6era. %/'-carrier%!

Co)*.e&e .o%% o+ one or e6en %e6era. %/'-carrier% 0i.. no& di%r/*& o*era&ion!

An&enna di6er%i& i% ano&(er i)*or&an& +ea&/re &(a& can (e.* co)'a& )/.&i*a&(! A.&(o/7(

'o&( Wi-Fi and

Wireless networking 2'/2

9

HARDES Frederic



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IEEE#$"!a recei6er% can )a1e /%e o+ di6er%i&= &(e Wi-Fi *ro&oco. 0a% de%i7ned

%*eci+ica.. &o *er)i& di6er%i&rece*&ion on apacket-by-packet basi%! D/rin7 rece*&ion o+ &(e Wi-Fi *ac1e& *rea)'.e &(e

recei6er c(ec1% &(e %i7na.

/a.i& on &0o an&enna%!

Appli!ati"ns &"r Wireless LA(s

Wire.e%% LAN% +re/en&. a/7)en& ra&(er &(an re*.ace 0ired LAN ne&0or1%-o+&en

*ro6idin7 &(e +ina. +e0 )e&er% o+ connec&i6i& 'e&0een a 'ac1'one ne&0or1 and &(e)o'i.e /%er! T(e +o..o0in7 .i%& de%cri'e% %o)e o+ &(e )an a**.ica&ion% )ade *o%%i'.e

&(ro/7( &(e *o0er and +.ei'i.i& o+ 0ire.e%% LAN%:

Doctors and nurses in hospitalsare )ore *rod/c&i6e 'eca/%e (and-(e.d orno&e'oo1 co)*/&er% 0i&( 0ire.e%% LAN ca*a'i.i& de.i6er *a&ien& in+or)a&ionin%&an&.!

Consulting or accounting audit engageent teasor %)a.. 0or17ro/*% increa%e

*rod/c&i6i& 0i&( /ic1 ne&0or1 %e&/*!

!etwork anagers in dynaic en"ironents)ini)ie &(e o6er(ead o+ )o6e%=

add%= and c(an7e% 0i&( 0ire.e%% LAN%= &(ere' red/cin7 &(e co%& o+ LAN o0ner%(i*!

#raining sites at corporations and students at uni"ersities/%e 0ire.e%%

connec&i6i& &o +aci.i&a&e acce%% &o in+or)a&ion= in+or)a&ion ec(an7e%= and .earnin7!

!etwork anagers installing networked coputers in older buildings+ind &(a&

0ire.e%% LAN% are a co%&-e++ec&i6e ne&0or1 in+ra%&r/c&/re %o./&ion!

$etail store owners/%e 0ire.e%% ne&0or1% &o %i)*. +re/en& ne&0or1recon+i7/ra&ion!

#rade show and branch office workers)ini)ie %e&/* re/ire)en&% ' in%&a..in7

*recon+i7/red 0ire.e%% LAN% needin7 no .oca. @IS %/**or&!

Warehouse workers/%e 0ire.e%% LAN% &o ec(an7e in+or)a&ion 0i&( cen&ra.da&a'a%e% and increa%e &(eir *rod/c&i6i&!

Ne&0or1 )ana7er% i)*.e)en& 0ire.e%% LAN% &o *ro6ide backup for ission-

critical applicationsr/nnin7 on 0ired ne&0or1%!

Wireless networking 2(/2

9

HARDES Frederic



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%enior e&ecuti"es in conference roos)a1e /ic1er deci%ion% 'eca/%e &(e (a6e rea.-

&i)e in+or)a&ion a& &(eir +in7er&i*%!

Wireless networking 2)/2

9

HARDES Frederic



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4! CONCLUSION

Wire.e%% LAN i% an eci&in7 &ec(no.o7 &(a& i% ?/%& 'ein7 rea.ied a% a %o./&ion +oren&er*ri%e= */'.ic and re%iden&ia. de*.o)en&%! To %/**or& &(e%e de*.o)en&%= %e6era. 1e

c(a..en7e% )/%& 'e )e&! @/%& #$"! i% )ean& &o 'e &(e +/&/re o+ da&a in&ero*era'i.i&

!Fro) &(e +ir%& &e.e7ra*(ic &ran%)i%%ion /n&i. no0 &(ere a% 'een a (/7e e6o./&ion and 0e(o*e a% ETH ESIGELEC %&/den& &o 'e *ar& o+ &(i% +/&/re ! T(e 7rea& +/&/re c(an.en7e are

in radio &ran%)i%%ion )ore &(an in (ard0are !

So .e&% 0ire 'ac1 &(e ear&( &o &(an1% a.. o/r &eac(er a& ESIGELEC +or &(eir 'a%i% inWIRELESS TELECO@S =H*er +re/encie% and n/)eric &ran%)i%%ion !

@a 'e ESIGELEC 0i.. &r %oon WIFI 0e (o*e

Wireless networking 2*/2

9

HARDES Frederic



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5! REFERENCES

En7.i%( dic&ionnar:(&&*:%/n-reco)7en!/ni6-renne%!+rc7i-'indico

Wi+i re%%o/rce% :

WLANA!or7

@icro%o+&

O


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#! GLOSSARY

AP! Access oi&t

BER! "it Error Rate

BSS! "asic Serice Set

CCK! Com5leme&tar6 Code 7e6i&8

CF! Com5act Flash

DSSS! Direct Se:e&ce S5read S5ectr:m

ESS! E;te&ded Serice Set

FCC! Federal Comm:&icatio&s Commissio&

FHSS! Fre:e&c6 Ho55i&8 S5read S5ectr:m

IBSS! I&de5e&de&t "asic Serice SetIEEE! I&stit:te of Electrical < Electro&ic E&8i&eers

ISM! I&d:strial= Scie&tific= >edical

IT! I&formatio& ?ech&olo86

MAC! >edia Access Co&trol

MAN! >etro5olita& Area $et3or

Mbps! >e8aits 5er seco&d

MBps! >e8a6tes 5er seco&d

OFDM! #rtho8o&al Fre:e&c6 Diisio& >:lti5le;i&8

OSI! #5e& S6stem I&terco&&ectio&

PAN! erso&al Area $et3or

PBCC! acet "i&ar6 Co&ol:tio& Codi&8PCMCIA! erso&al Com5:ter >emor6 Card I&ter&atio&alAssociatio&

PH! h6sical La6er

PN! se:do!ra&dom $oise

!oS! :alit6 of Serice

RF! Radio Fre:e&c6

S"N r#tio! Si8&al!to!$oise Ratio

SNR! Si8&al!to!$oise Ratio

STA! Statio&

T$! ?as Bro:5%&NII! U&lice&sed $atio&al I&formatio& I&frastr:ct:re

%SB! U&iersal Serial ":s

WECA! 0ireless Ether&et Com5atiilit6 Allia&ce

WEP! 0ired E:iale&t riac6

Wireless networking 2,/2

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HARDES Frederic



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0B ! 0ori&8 Bro:5

W'AN! 0ireless LA$

(OR! e;cl:sie #R a mathematical lo8ic o5eratio&4


wifi wireless networking.doc

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