Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://lvk.cs.msu.su/~dimawolf/RTES/Lection03.pdf Äàòà èçìåíåíèÿ: Mon Apr 6 16:36:33 2015 Äàòà èíäåêñèðîâàíèÿ: Sat Apr 9 22:45:43 2016 Êîäèðîâêà:

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AFDX ( 100 Ethernet) FC-AE-ASM-RT ( Fibre Channel)




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Avionics Full-Duplex Ethernet (AFDX) ­ Ethernet


Ethernet




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BAG ­ Bandwidth Allocation Gap ­ (1-128 , ) Lmax ­ (<=1518) Jmax ­ BAG


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Bandwidth = Lmax / BAG




BAG = 32 Lmax = 200 Bandwidth = 200 / ( 32 / 1000 ) = 6250 /



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max

/ BAGVL 100 /




· ·



· BAG Jmax: · · , · ­ , ACmax · AC , ­



· , · BAG Lmax · ACmax ­ , 2 (BAG ­ Jmax) · :



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1. Aircraft Data Network. Part 7. Avionics Full Duplex Switched Ethernet (AFDX) Network. // Aeronautical Radio, Inc. ­ 2012. 2. AFDX® / ARINC 664 Tutorial. TechSAT GmbH, Poing, 2008.


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Response-time analysis




Network Calculus
Trajectory Approach Model checking



Simulation approach






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40s

iVLs

Li

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VLs ­ , - R ­ (100 /) 40 ­ ( )







R ­ (100 /) n ­ :



Lma x tlin ks n R




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Response Time Analysis


( ­ ) Busy period ­ ,







BP(0) = BAG ­ busy period BP(1) = BP(0) * BP(2) = ... BP(1) ... BP(n) = BP(n-1)




Network Calculus


( ­ ) :


R(t) ­ , [0,t]




R(t) ­ , [0,t]


R(t) ­ R*(t) - R(t) R*(t)





x(t) ­ backlog, t



· arrival curve ­
­ R(t) ­ ­ ,



· a(t) = r*t + l
­ r ­ ­ l ­ backlog · AFDX ( ):
a(t ) ( Lma x / B A G) t Lma x



· Service curve ­ ( ­ FIFO
­ R*(t) ­ FIFO: (t ) R[t T ] ­ R ­ ­ T ­



· arrival curve service curve :



·
­ arrival curve ­ ()
a(t )

( Lvl
vl

,ma x

/ B A Gvl ) t

Lvl
vl

,ma x

­ ­



· arrival curve
­ n * BAG ­ Jmax n t J ma x ­ t BAG + 1 (.. t=0 ) ­arrival curve: a(t ) ( t J max 1) Lmax
BAG

­ :

a( t )

J t Lma x Lma x (1 ma x ) BAG BAG



·2 :
­ , = 0 ­ : max_delay ( Network Calculus)

· ­ · ! ·, arrival curve


FC-RT
· (1 /) · · BAG ­ ( ) · « »



1. 2. Scharbarg, Jean-Luc, and Christian Fraboul. Methods and Tools for the Temporal Analysis of Avionic Networks. 2010. Le Boudec, J.-Y. & Thiran, P. Network Calculus: A Theory of Deterministic Queuing. Systems for the Internet, Vol. 2050 of Lecture Notes in Computer Science, Springer-Verlag. 2001. GutiÈrrez, J. Javier, J. Carlos Palencia, and Michael GonzÀlez Harbour. Response time analysis in AFDX networks with subvirtual links and prioritized switches. XV Jornadas de Tiempo Real, Santander. ­ 2012. FIXED PRIORITY SCHEDULING OF HARD REAL-TIME SYSTEMS. K.W. Tindell. Ph.D. Thesis, University of York, 1995

3.

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