Tag: rtas

Reflections on RTAS 2025 from the General Chair

Posted on by bennyakesson

It has been a pleasure to serve as the General Chair of the 31st IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS 2025). RTAS is a top-tier conference on real-time systems that is a part of the CPS-IoT Week. This year, CPS-IoT week was hosted at UC Irvine, USA, and it was one of the most well-attended instances so far with over 550 registrations from all over the world.

Here are some personal highlights:

  • Keynote: “Trusted AI on Mars” by Dr. Steve Chien: This keynote discussed the challenge of controlling the Perseverance rover on Mars. The original planner was time-triggered and struggled to efficiently adapt to unexpected changes, e.g. in temperature and battery state. The core of the presentation covered the design, analysis, prototyping and testing of a new AI-based Onboard Planner that was deployed in October 2023. This planner enabled the schedule to be revised on average 16 times per day to manage resources, such as energy, more efficiently and maximize the scientific operations conducted by the rover. This presentation was very interesting to the real-time systems community as it focused on planning inside a heavily resource-constrained cyber-physical system in a dynamic environment far away from earth. It was interesting to hear the challenges of getting new technology adopted in such a critical system, where the cost of verification and validation is a key driver for decision-making.
  • Inaugural CPS-IoT Debate: We have all attended bland panel discussions at conferences. This was different, as it had the format of an Oxford debate and discussed whether the inherent complexity of modern engineering challenges renders exhaustive mathematical analysis overkill, and that an iterative, adaptive design approach should be prioritized—even for life-critical systems. The format, the existential nature of this question for our community, and the excellent choice of the debate team resulted in an engaging session with high audience participation that sparked conversations throughout the day. I strongly encourage other conferences to try out this format.
  • RTAS Technical Sessions: The technical sessions of RTAS are always of high quality and interesting. I particularly enjoy the papers that help bring theory into practice. Here are a few papers that stood out to me:
    • LiME: The Linux Real-Time Task Model Extractor by Bjorn Brandenburg et al. describes a tool to extract real-time task models from real-time threads in a Linux environment.  LiME runs on unmodified Linux kernels and requires neither knowledge of real-time theory nor familiarity with Linux internals to be used effectively. Such a tool can significantly reduce the engineering, modeling, and analysis effort required to develop real-time systems whose timing behavior can be formally verified.
    • Reconciling ROS 2 with Classical Real-Time Scheduling of Periodic Tasks by Harun Teper et al. explains how minor changes to the event executor of ROS2 makes a large body of research results from classical real-time scheduling theory directly applicable to ROS 2. This enables analytical bounds on the worst-case response time and the end-to-end latency, outperforming bounds for the default ROS 2 executor in many scenarios.
    • CROS-RT: Cross-Layer Priority Scheduling for Predictable Inter-Process Communication in ROS 2 by Kim et al., which won the Best Paper Award, addresses the challenge of providing real-time guarantees in ROS2 due to unpredictable delays and priority inversions across ROS 2’s multi-layered communication architecture. They present a cross-layer scheduler explicitly designed to tackle the unpredictability in ROS 2 inter-process communication that has been implemented and evaluated on the current stable release of ROS 2.

These works all make significant strides in bringing theory to practice. Just imagine what happens if you combine them all!

All in all, it was a very successful event thanks to the excellent work done by Program Chair Tam Chantem, Program Co-chair Geoffrey Nelissen, the General Co-chairs of CPS-IoT Week Mohammad Al Faruque and Yasser Shoukry, Local Arrangement Chairs Fadi Kurdahi and Halle Gonzales, and many others involved in the organization. Of course, RTAS would not have been possible without the many authors who submitted their work and the members of the TPC who took the time to read the submissions and provide high-quality reviews.

 

Highlights from the RTAS Awards Ceremony

Posted on by bennyakesson

The Award Ceremony of the 31st IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS) has concluded, and it is our pleasure to announce the highlights of this year’s awards.

The RTAS 2025 Technical Program Committee nominated four papers for awards, evaluating them based on novelty, presentation, applicability to real-world applications/systems, and relevance and completeness of experimental evidence. The four papers were selected as Outstanding Papers and candidates for the Best (Student) Paper Award.

Best Paper Award
CROS-RT: Cross-Layer Priority Scheduling for Predictable Inter-Process Communication in ROS 2
Authors: Sohyun Kim, Juho Song, Kilho Lee, Sangeun Oh, and Hoon Sung Chwa

This paper tackles the challenges of achieving real-time guarantees in ROS2 due to unpredictable delays and priority inversions. CROS-RT, a cross-layer scheduler, ensures consistent priority-based scheduling across application, middleware, and kernel layers. Experiments show that CROS-RT significantly improves communication predictability, reducing the worst-case response time compared to baseline ROS2. The Best Paper Award committee was impressed by this paper’s practical significance and immediate, as well as long-term, impact on the field.

Best Student Paper Award
A Unified Framework for Quantitative Cache Analysis
Authors: Sophie Kahlen and Jan Reineke

This work unifies two approaches to cache analysis for non-LRU policies. It is applicable to microarchitectures with timing anomalies and enhances WCET analysis using existing persistence analyses for LRU. Experiments demonstrate that the precision of cache analysis for FIFO and MRU is comparable to that of LRU. The Best Paper Award committee viewed this paper as an excellent example of a well-integrated blend of theoretical results and implementation efforts, which embody the spirit of RTAS.

The Best Reviewer Committee evaluated six nominated reviews/reviewers based on criteria like review quality, completeness, and helpfulness to the authors. Four reviewers were recognized as Outstanding Reviewers and candidates for the Best Reviewer Award.

Best Reviewer Award
Zoe Stephenson, Rapita Systems, UK

RTAS is grateful to all members of the Technical Program Committee who volunteer their time to review submitted papers. It is particularly rewarding when industry members contribute to the conference and stand out in terms of reviewing excellence, both in thorough reviews and active participation in discussions. Thank you, Zoë!

We want to thank the members of the Award Committees and congratulate all award recipients on their achievements and thank you for your contributions to another successful RTAS!

Benny Akesson, General Chair
Tam Chantem, Program Chair
Geoffrey Nelissen, Vice Program Chair

 

 

Reflections on RTAS 2024: A Successful Symposium in Hong Kong

Posted on by bennyakesson

The 30th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS 2024) is over. As I am enjoying a last local beer at Hong Kong airport before getting on my flight home, it feels like a good opportunity to reflect on this years successful edition of the conference.

The preparation of this conference has taken me, as the Program Chair, about one year. While it was a lot of work, I enjoyed it a lot because I got to work with dedicated, clever, and proactive people from the real-time systems community to make it happen. This year, we received 124 paper submissions from around the world, marking a 40% increase from last year. This suggests that the community is recovering well post-pandemic and there is a clear interest in the topics covered by the conference.

The Program Committee comprised 61 reviewers, supported by 87 sub-reviewers, blending expertise from a diverse group of experts in both academia and industry. Each submission was evaluated through at least four reviews, resulting in a total of nearly 500 double-anonymous expert reviews. Based on these reviews, a brief author response to the reviews to clarify misunderstandings, and online discussions, 29 papers This resulted in an acceptance rate of 23.3%, which means it was very competitive! The accepted papers formed the basis for the outstanding technical program.

Having spent so much time preparing the conference, I really wanted the execution to go smoothly, giving all 100 registered participants a good experience of the technical program. I was happy to see that the preparation had paid off and that there was very little work for me during the conference itself. The session chairs did an excellent job introducing the speakers and managing the sessions. The only curve ball was that one author did not get their visa on time, so we had to quickly improvise a setup for giving remote presentations. This was handled beautifully by the local organizers and I would like to thank Nan Guan and his colleagues for their hard work and attentiveness. From my perspective, the local arrangements worked perfectly!

I was impressed with the quality of the presentations of this edition. Despite the theoretical nature of much of the research, I was pleased to see that presenters managed to focus on their main messages and used lots of figures and animations to get high-level concepts across and referring to the papers for the details. I am asking myself if we, as a community, are getting better at presenting or if this is a side-effect of that we had to reduce the presentation time of the papers from 25 minutes to 18 minutes to fit the increased number of papers in the sessions. Whatever it was, I liked it and hope that this sets the bar for next time!

There were many excellent contributions in the technical program. From Marco Caccamo’s Outstanding Technical Achievement and Leadership Award lecture, we learned that there are many software-based memory management techniques and execution models that can improve the predictability of commercial-of-the-shelf (COTS) multi-processor systems-on-chip and make them suitable for hard real-time or mixed-criticality applications. This is an area where I feel we are making good progress. COTS systems are getting increasingly configurable and observable, allowing our community to propose solutions for real-time systems that do not require custom hardware. This lowers the threshold for transferring our research results to industry significantly.

Looking at the topics addressed at the conference, I was surprised by the large number of papers looking at the intersection of real-time systems and security, so many we needed two sessions to fit all of them! I particularly remember work considering how to ensure control-flow integrity when faced with malicious actors. Two papers looked into how this could be addressed leveraging features recently introduced in COTS platforms. There were also works looking at the effects of performance interference, such as random delays, on cyber-physical systems and how they could be mitigated using robust control strategies in stochastic control systems.

Considering the technical solutions that were presented, I really enjoyed the work by Soni et al. that addressed the scalability of timing analysis of AFDX networks in the avionics domain. The paper proposed a hybrid approach that combined an exact analysis using model checking with a faster and more pessimistic analysis using network calculus. The key idea was to use the bounds provided by network calculus to prune the state space for the model checker to reduce analysis time. I really liked that this hybrid approach worked both ways and allowed the exact analysis done so far by the model checker, to be leveraged by the network calculus to reduce its pessimism. This allowed the proposed analysis to scale to large industrial use cases with more than 1000 network flows.

There is of course a lot more to say about the conference and the papers featured in it, but it is time to fly home.
I want to conclude by thanking all the people that contributed to the organization of the conference. I also want to thank all authors who submitted their work to RTAS 2024. Lastly, I want to thank all conference participants for coming to Hong Kong to listen, learn, discuss, and network. That is what the community is all about!

For more information about RTAS 2024 and the papers featured in its program, please refer to the RTAS 2024 website.

Paper Accepted at RTAS

Posted on by bennyakesson

A paper entitled “Partitioning and Analysis of the Network-on-Chip on a COTS Many-Core Platform” was recently accepted for publication at RTAS. This paper was a collaboration with former colleagues at the CISTER Research Unit, as well as friends from MDH in Sweden. The paper addresses the issue of interference between applications in many-core platforms interconnected using rate-regulated Networks-on-Chip (NoC), such as the Kalray MPPA. The main contributions of the paper are 1) a partitioning strategy for reducing contention on the NoC, 2) an analysis technique to determine the Worst-Case Traversal Time of packages under the proposed strategy, and 3) a method to determine parameters for the NoCs rate regulators to get minimal WCTT and ensure that buffers never overflow. The benefits of the proposed approach is evaluated both using simulation and by experiments on a Kalray MPPA. Furthermore, an industrial case study from the automotive domain shows the tightness of the proposed analysis.

Paper Accepted at RTAS 2016

Posted on by bennyakesson

Yonghui Li is on a roll! Two months ago he received the best paper award at ESTIMEDIA for his work on modelling and analysis of a dynamically scheduled DRAM controller using mode-controlled data-flow graphs. Now, he just had a paper entitled “Modeling and Verification of Dynamic Command Scheduling for Real-Time Memory Controllers” that models and analyses the same memory controller using timed atomata. A key highlight of this work is that it quantitatively compares data-flow analysis, timed automata, and two other approaches from Yonghui’s 2015 article in Real-Time Systems in terms of guaranteed bandwidth and worst-case execution time. This gives interesting insights into what these different approaches can and cannot model and what the impact of those limitations are on the performance guarantees. This work was the result of a fruitful collaboration with Kai Lampka from Uppsala University in Sweden.

Paper Accepted at RTAS 2015

Posted on by bennyakesson

We just had a paper accepted at the Real-Time and Embedded Technology and Applications Symposium (RTAS) in Seattle. The paper is entitled “An Efficient Configuration Methodology for Time-Division Multiplexed Single Resources” and presents an ILP-based methodology to allocate TDM slots to resource clients, such that bandwidth and latency constraints are satisfied while resource utilization is minimized. A heuristic algorithm is furthermore proposed to determine the number of TDM slots in the schedule. This paper is a collaboration both with colleagues here at CTU Prague and with Andrew Nelson from Eindhoven University of Technology.

For the camera-ready version of the paper, please click here.