Analyse et dimensionnement de r¥seaux h¥t¥rogenes embarqu¥s

avec apparition nouvelles technologies communication nombre systemes embarqu s avionique automobile est constante augmentation gestion communications entre ces systemes devient alors plus plus complexe mettre oeuvre dans contexte ou contraintes temporelles environnementales sont tres fortes ou taux changes messages augmentation continuelle utilisation optimale r seaux pour acheminer donn es tout respectant contraintes temporelles impos es est essentielle point vue soret fonctionnement historiquement pour r pondre probl matiques efficacit soret industriels ont velopp palette r seaux embarqu s di s leurs applications cibles can lin ces r seaux pr sentaient bits relativement faibles moment ou besoin croissant bande passante se faisait ressentir choix utiliser concept composants dit sur tageres off the shelf cots permettait alors pallier ce nouveau besoin dans souci conservation capacit s r seaux garantir contraintes temporelles impos es par systemes embarqu s temps r el industriels ont do adapter ce concept composants sur tageres systemes embarqu s int rat utilisation ces composants est gain non n gligeable bande passante poids pour coots veloppements relativement faibles introduction ces composants nouveaux s est faite telle sorte que leur impact sur standards pr existants systemes connect s soit minimal c est ainsi que r seaux dit h rogenes ont vu leur apparition ces r seaux constituent hybridation entre technologies embarqu es historiques composants sur tagere ils consistent r seaux extr mit utilisant technologies prouv es telles que can interconnect s via passerelles r seau f rateur backbone utilisant composants sur tageres lors fi majeur relever lors utilisation r seau f rateur est respecter contraintes temporelles applications sollicitant diff rents r seaux objectif est mis mal sur points interconnexion r seaux h rogenes passerelles ainsi approche principale utilis e pour passage r seau autre est encapsulation trames pour atteindre optimalit performance cette technique plusieurs parametres sont prendre compte tels que nombre trames encapsuler ordonnancements utilis s coot bande passante ainsi que impact sur distributions lais gigue dans optique pr servation performances r seaux objet nos travaux porte sur tude comparaison proposition techniques permettant interconnexion r seaux h rogenes temps r els fois pour applications faibles fortes contraintes temporelles apres tat art sur r seaux temps r el nous sp cifions diff rentes techniques interconnexion r seaux h rogenes puis nous pr sentons tude cas bas e sur architecture r seau interconnectant diff rents bus can via r seau f rateur sans fil wi fi tude que nous avons men e montre par biais diff rentes simulations que cette architecture r seau est bonne candidate pour transmission flux contraintes temporelles faibles architecture r seau interconnectant diff rents bus can via r seau f rateur ethernet commut est ensuite consid r e dans seconde tude cas ciblant applications fortes contraintes temporelles dans premier temps nous prenons compte cas r seau f rateur ethernet pqse dans second temps cas ethernet avb cette tude nous permet montrer impact diff rentes techniques interconnexion sur lais flux r seau with the emergence of new communication technologies the number of avionics and automotive embedded systems is constantly increasing the management of communications between these systems becomes increasingly complex to implement in context where temporal and environmental constraints are very strong and where messages exchange rate is continuously increasing the optimal use of networks to transmit data while fulfilling the imposed temporal constraints is essential from safety point of view historically in order to address safety and efficiency issues manufacturers have developed range of embedded networks dedicated to their target applications can lin these networks have relatively low bit rates at point of time where growing need for bandwidth was felt to overcome this new need the choice of using the concept of so called off theshelf components cots has been made in order to preserve the networks abilities to guarantee the temporal constraints imposed by the real time embedded systems manufacturers had to adapt the concept of off the shelf components to embedded systems the benefits of using these components is non negligible gain in bandwidth and weight for relatively low development costs the introduction of these new components has been made in such way that their impact on pre existing standards and connected systems is minimal thereby so called heterogeneous networks have emerged these networks are hybridization of historical embedded technologies and off the shelf components they consist of stub networks using proven technologies such as can interconnected via gateways to backbone network using off the shelf components thus the major challenge while using heterogeneous network is to respect the temporal constraints of the applications requesting the different parts of the networks this objective can be damaged at the interconnection points of the heterogeneous networks gateways the main used approach to pass frames from one network to another is the encapsulation to achieve the optimum performances of this technique several parameters have to be considered such as the number of frames encapsulated the used scheduling policy the bandwidth cost as well as the impact on delay distributions jitter in order to preserve networks performances the aim of our work is to study compare and propose techniques ennabling the interconnection of real time heterogeneous networks for application with both soft and hard temporal constraints after state of the art on real time networks we have specified different techniques for the interconnection of heterogeneous networks then we have presented case study based on network architecture interconnecting different can buses via wireless backbone network wi fi the study we conducted shows through various simulations that this network architecture is good contender for the transmission of flows with soft temporal constraints network architecture interconnecting different can busses via switched ethernet backbone is considered in second case study targeting applications with hard temporal constraints two different ethernet backbone networks are taken into account we studied first the case of switched ethernet pqse backbone network then the case of switched ethernet avb backbone is considered this study enabled us to highlight the impact of the different used interconnection techniques on network flows delays