Schedulability-Driven Frame Packing for Multi-Cluster Distributed Embedded Systems

We present an approach to frame packing for multi-cluster distributed embedded systems consisting of time-triggered and event-triggered clusters, interconnected via gateways. In our approach, the application messages are packed into frames such that the application is schedulable. Thus, we have also proposed a schedulability analysis for applications consisting of mixed event-triggered and time-triggered processes and messages, and a worst case queuing delay analysis for the gateways, responsible for routing inter-cluster traffic. Optimization heuristics for frame packing aiming at producing a schedulable system have been proposed. Extensive experiments and a real-life example show the efficiency of our frame-packing approach

Frame Packing under real-time constraints

Colloque avec actes et comité de lecture. internationale.International audienceThe set of frames of an in-vehicle application must meet two constraints: it has to be feasible from a schedulability point of view and it should minimize the network bandwidth consumption. The latter point is crucial for enabling the use of low cost electronic components and for facilitating an incremental design process. This study proposes two heuristics for the NP-complete problem of generating a set of schedulable frames that minimizes the bandwidth usage. The proposed strategies are complementary. The first one can be applied to large sized problems (in the context of in-vehicle applications) while the second one, slightly more efficient in our experiments, is limited to small size problems (less than 12 signals emitted by each stations). These proposals has proved to be effective in comparison with other possible strategies

Frame packing algorithms for automotive applications

International audienceThe set of frames exchanged in automotive applications must meet two constraints: it has to be feasible from a schedulability point of view and it should minimize the network bandwidth consumption. This latter point is important since it allows the use of low cost electronic components and it facilitates an incremental design process. The purpose of this study is to propose efficient algorithms for solving the NP-hard problem of generating a set of schedulable frames that minimize the bandwidth usage. This study presents novel algorithms for building bandwidth-minimizing sets of frames that meet the schedulability requirement. In our experiments, these proposals have proved to be more effective than the existing approaches

Frame Packing Algorithms for Automotive Applications

The set of frames exchanged in an in-vehicle applications must meet two constraints: it has to be feasible from a schedulability point of view and it should minimize the network bandwidth consumption. This latter point is important since it allows the use of low cost electronic components and it facilitates an incremental design process. The purpose of this study is to propose efficient algorithms for solving the NP-hard problem of generating a set of schedulable frames that minimizes the bandwidth usage. This study presents two algorithms: one for building the set of frames while the other aims at finding a feasible set of frames starting from an unfeasible one. On our experiments, these proposals have proved to be more effective than the existing approaches

Hierarchical Traffic Shaping and Frame Packing to Reduce Bandwidth Utilization in the AFDX

The increasing complexity and heterogeneity of avionic networks make resource savings a challenging task to guarantee easy incremental design during the long lifetime of an aircraft. In this paper, we focus on the optimization of interconnection devices for multi-cluster avionic networks, called Remote Data Concentrators (RDC), and especially for the CAN-AFDX network. The design of this optimized RDC device consists in implementing frame packing strategies to manage upstream (sensors) flows to improve bandwidth utilization in the AFDX; and Hierarchical Traffic Shaping (HTS) algorithm to control downstream (actuators) flows to guarantee bandwidth isolation on CAN. Schedulability analysis integrating the effects of these new mechanisms is detailed and validated. Furthermore, a heuristic approach to tune the Hierarchical Traffic Shaping parameters within the RDC device is proposed to reduce as much as possible bandwidth utilization in the AFDX, while ensuring flows schedulability. The performance analysis conducted on a realistic avionic case study proves the efficiency of the optimized RDC device to reduce bandwidth utilization in the AFDX, compared to the basic device currently implemented in avionics

Interconnection optimization for multi-cluster avionics networks

National audienceThe increasing complexity and heterogeneity of avionics networks make resource optimization a challenging task. In contrast to many previous approaches pursuing the optimization of traffic-source mapping and backbone network analysis, our work presented herein mainly focuses on the optimization of interconnection devices for multi-cluster avionics networks. In this paper, we introduce an optimized interconnection device, integrating novel frame packing strategies and schedulability analysis to enhance the communications between an AFDX-like backbone network and various peripheral sensor/actuator networks in terms of resource savings. The performance analysis conducted on a representative avionics communication architecture highlights the efficiency of our proposal to save resources particularly consumed bandwidth. These latter is considered as an important feature for avionics applications to guarantee easy incremental design during the long lifetime of an aircraft

Video summarization by group scoring

In this paper a new model for user-centered video summarization is presented. Involvement of more than one expert in generating the final video summary should be regarded as the main use case for this algorithm. This approach consists of three major steps. First, the video frames are scored by a group of operators. Next, these assigned scores are averaged to produce a singular value for each frame and lastly, the highest scored video frames alongside the corresponding audio and textual contents are extracted to be inserted into the summary. The effectiveness of this approach has been evaluated by comparing the video summaries generated by this system against the results from a number of automatic summarization tools that use different modalities for abstraction