Romain Jacob

Last Name

Jacob

First Name

Romain

ORCID

0000-0002-2218-5750

Organisational unit

09477 - Vanbever, Laurent / Vanbever, Laurent

Show all metadata

Search Results

Publications1 - 10 of 46

Enhancing Global Network Monitoring with Magnifier
Bühler, Tobias; Jacob, Romain; Poese, Ingmar; et al. (2023)
Proceedings of the 20th USENIX Symposium on Networked Systems Design and Implementation
Monitoring where traffic enters and leaves a network is a routine task for network operators. In order to scale with Tbps of traffic, large Internet Service Providers (ISPs) mainly use traffic sampling for such global monitoring. Sampling either provides a sparse view or generates unreasonable overhead. While sampling can be tailored and optimized to specific contexts, this coverage–overhead trade-off is unavoidable. Rather than optimizing sampling, we propose to “magnify” the sampling coverage by complementing it with mirroring. Magnifier enhances the global network view using a two-step approach: based on sampling data, it first infers traffic ingress and egress points using a heuristic, then it uses mirroring to validate these inferences efficiently. The key idea behind Magnifier is to use negativemirroring rules; i.e., monitor where traffic should not go. We implement Magnifier on commercial routers and demonstrate that it indeed enhances the global network view with negligible traffic overhead. Finally, we observe that monitoring based on our heuristics also allows to detect other events, such as certain failures and DDoS attacks.
The Time-Triggered Wireless Architecture
Jacob, Romain; Zhang, Licong; Zimmerling, Marco; et al. (2020)
Leibniz International Proceedings in Informatics (LIPIcs) ~ 32nd Euromicro Conference on Real-Time Systems (ECRTS 2020)
Wirelessly interconnected sensors, actuators, and controllers promise greater flexibility, lower installation and maintenance costs, and higher robustness in harsh conditions than wired solutions. However, to facilitate the adoption of wireless communication in cyber-physical systems (CPS), the functional and non-functional properties must be similar to those known from wired architectures. We thus present Time-Triggered Wireless (TTW), a wireless architecture for multi-mode CPS that offers reliable communication with guarantees on end-to-end delays among distributed applications executing on low-cost, low-power embedded devices. We achieve this by exploiting the high reliability and deterministic behavior of a synchronous transmission based communication stack we design, and by coupling the timings of distributed task executions and message exchanges across the wireless network by solving a novel co-scheduling problem. While some of the concepts in TTW have existed for some time and TTW has already been successfully applied for feedback control and coordination of multiple mechanical systems with closed-loop stability guarantees, this paper presents the key algorithmic, scheduling, and networking mechanisms behind TTW, along with their experimental evaluation, which have not been known so far. TTW is open source and ready to use: https://ttw.ethz.ch.
Synchronous Transmissions Made Easy: Design Your Network Stack with Baloo
Jacob, Romain; Bächli, Jonas; Da Forno, Reto; et al. (2019)
Proceedings of the 2019 International Conference on Embedded Wireless Systems and Networks (EWSN '19)
Synchronous Transmissions is a technology that combines energy efficiency and reliability for low-power wireless multi-hop networks. But using this technology to design network stacks is a complex task, in part due to the tight timing requirements on the execution of radio operations. To facilitate the development of protocols based on Synchronous Transmissions, we developed Baloo, a flexible network stack design framework, which we present in this paper. We show that Baloo is flexible enough to implement a wide variety of network layer protocols, while introducing only limited memory and energy overhead. Most importantly Baloo makes Synchronous Transmissions accessible: The software is open source and well documented. We believe that Baloo will be an important enabler for a whole new class of Internet of Things applications leveraging the reliability, efficiency, and flexibility of Synchronous Transmissions.
[Re] Ensuring Connectivity via Data Plane Mechanisms
Liu, Zhengqing; Jacob, Romain; Schmid, Roland; et al. (2021)
ReScience
The connectivity is of paramount importance to a network, whose basic function is to route packets between end points. Junda Liu et al. proposed Data‐Driven Connectivity (DDC) to ensure routing connectivity via data plane mechanisms, which allows networks to provide a much higher degree of availability, while still providing flexible routing control [1]. Nowadays, against the backdrop of the development of P4, Programming Protocol‐independent Packet Processors (a domain‐specific language) [2], one can enable the programmabilitiy of network devices to perform simple but extremely fast packet processing directly in the data plane. This article is a replication work of [1] within P4 ecosystem. Specifically, we implement DDC to the behavioral model version 2 (BMv2), a P4‐based and vastly used software switch. We evaluate our implementation against several benchmarks from the original paper, and we find that our results essentially align with the original work.
On platforms for CPS - Adaptive, predictable and efficient
Thiele, Lothar; Sutton, Felix; Jacob, Romain; et al. (2016)
RSP '16 Proceedings of the 27th International Symposium on Rapid System Prototyping: Shortening the Path from Specification to Prototype
The Time-Triggered Wireless Architecture
Jacob, Romain; Zhang, Licong; Zimmerling, Marco; et al. (2020)
arXiv
Wirelessly interconnected sensors, actuators, and controllers promise greater flexibility, lower installation and maintenance costs, and higher robustness in harsh conditions than wired solutions. However, to facilitate the adoption of wireless communication in cyber-physical systems (CPS), the functional and non-functional properties must be similar to those known from wired architectures. We thus present Time-Triggered Wireless (TTW), a wireless architecture for multi-mode CPS that offers reliable communication with guarantees on end-to-end delays and jitter among distributed applications executing on low-cost, low-power embedded devices. We achieve this by exploiting the high reliability and deterministic behavior of a synchronous-transmission-based communication stack we design, and by coupling the timings of distributed task executions and message exchanges across the wireless network by solving a novel co-scheduling problem. While some of the concepts in TTW have existed for some time and TTW has already been successfully applied for feedback control and coordination of multiple mechanical systems with closed-loop stability guarantees, this paper presents the key algorithmic, scheduling, and networking mechanisms behind TTW, along with their experimental evaluation, which have not been known so far. TTW is open source and ready to use.
Leveraging Synchronous Transmissions for the Design of Real-time Wireless Cyber-Physical Systems
Jacob, Romain (2020)
TIK-Schriftenreihe
Cyber-Physical Systems (CPS) refer to systems where some intelligence is embedded into devices that interact with their environment; that is, collecting information from the physical space, processing that information, and taking actions that affect the environment. Automatically turning the heating on when room temperature gets cold is one of the simplest example of CPS. Things get more complex when applications are distributed between low-power devices that should operate autonomously for multiple years. Then, performing reliable and energy efficient wireless communication becomes paramount. Moreover, applications often specify deadlines; that is, maximal tolerable delays between the execution of distributed tasks. Systems that guarantee to meet such deadlines are called real-time systems. Wireless CPS capable of providing real-time guarantees while using low-power communication technology are desirable but they are particularly challenging to design. In the past few years, a technique known as synchronous transmissions (ST) has been shown to enable reliable and energy efficient communication in low-power multi-hop networks. In a nutshell, ST consists in letting multiple devices transmit a packet during the same time interval; communication is likely to be successful if the transmissions are well synchronized, hence the name of synchronous transmissions. ST can be leveraged to realize any multi-hop broadcast – a one-to-all communication – in a given time; a very interesting property for designing real-time systems. While the potential of ST is recognized by the low-power wireless academic community, this technique has not yet been leveraged for the design of CPS. We identify at least three issues that limit the adoption of ST in this domain: (i) ST is difficult to use due to stringent time synchronization requirements: in the order of μs. There is a lack of tools to facilitate the implementation of ST by CPS engineers, which are often not wireless communication experts. (ii) There are only few examples showcasing the use of ST for CPS applications and academic works based on ST tend to focus on communication rather than applications. Convincing proof-of-concept CPS applications are missing. (iii) The inherent variability of the wireless environment makes performance evaluation challenging. The lack of an agreed-upon methodology hinders experiment reproduciblility and limits the confidence in the performance claims. Consequently, we developed support tools and methods to facilitate the evaluation of wireless protocols and the implementation of CPS based on ST. Furthermore, we leveraged ST to design two CPS solutions targeting different classes of real-time applications. This dissertation presents these contributions. In Chapter 2, we propose to design and analyze performance evaluation experiments for networking protocols using a concrete, rational, and statistically sound methodology. We implement this methodology in a framework called TriScale which allows to make performance claims with quantifiable levels of confidence. Furthermore, we leverage the TriScale framework to propose the first formalized definition of reproducibility for networking experiments. Chapter 3 presents Baloo, a flexible design framework for network stacks based on ST. Users implement their protocol through the programming interface offered by Baloo while the framework handles the complex low- level operations; e.g., meeting the time synchronization requirements of ST. We show that Baloo is flexible enough to implement a wide variety of commu- nication protocols while introducing only limited memory and energy overhead. Finally, we design and implement two wireless CPS based on ST: – the Distributed Real-time Protocol (DRP) uses contracts to maximize the flexibility of execution between distributed tasks (Chapter 4); – Time-Triggered Wireless (TTW ) statically co-schedules all task executions and packet transfers to minimize end-to-end latency (Chapter 5). We demonstrate that real-time guarantees can be provided in a reliable and energy efficient manner. Furthermore, TTW supports update rates of tens of ms, which is sufficient to perform distributed closed-loop control of inverted pendulums – a fundamental benchmark for control and robotic applications. With this dissertation, we showcase that ST is suitable to meet the requirements of real-time wireless CPS. Furthermore, we facilitate the implementation of such systems with Baloo, a design framework that makes ST accessible to the non-expert. Finally, TriScale provides an important building block to confidently evaluate the performance of networking protocols – an essential building block of wireless CPS. Building on TriScale, it would be useful to define benchmark problems representative of different classes of applications to serve as baseline for the evaluation of future wireless CPS solutions. Ultimately, we must transition from proof-of-concepts to real-world wireless CPS applications; this would be further facilitated by porting Baloo to newer and more powerful platforms, thereby pushing the limits of achievable performance levels.
Towards real-time wireless cyber-physical systems
Jacob, Romain; Zimmerling, Marco; Huang, Pengcheng; et al. (2016)
ECRTS 2016 Work-in-Progress Proceedings
The Internet of tomorrow must sleep more and grow old
Jacob, Romain; Vanbever, Laurent (2022)
Today, the ICT industry has a massive carbon footprint (a few percent of the worldwide emissions) and one of the fastest growth rates. The Internet accounts for a large part of that footprint while being also energy inefficient; i.e., the total energy cost per byte transmitted is very high. Thankfully, there are many ways to improve on the current status; we discuss two relatively unexplored directions in this paper. Putting network devices to “sleep,” i.e., turning them off, is known to be an efficient vector to save energy; we argue that harvesting this potential requires new routing protocols, better suited to devices switching on/off often, and revising the cor- responding hardware/software co-design. Moreover, we can reduce the embodied carbon footprint by using networking hardware longer, and we argue that this could even be benefi- cial for reliability! We sketch our first ideas in these directions and outline practical challenges that we (as a community) need to address to make the Internet more sustainable.
Synchronous transmissions on Bluetooth 5 and IEEE 802.15.4 – A replication study
Jacob, Romain; Schaper, Anna-Brit; Biri, Andreas; et al. (2020)
Synchronous transmissions (ST) is a wireless communication technique that has been shown to be particularly efficient in low-power multi-hop networks. Since 2011, research on ST mainly focused on the physical layer defined by the IEEE 802.15.4 standard. Nowadays, Bluetooth is another pervasive technology embedded by default in almost all connected objects; researchers recently started to investigate whether the benefits of ST also apply to Bluetooth. This paper presents the results of a replication study of ST using the popular and low-cost nRF52840 Dongle, which supports all modes of the Bluetooth 5 standard as well as IEEE 802.15.4. We measure the packet reception rate for different parameters known to affect ST for all physical layers supported by the platform. We use a data exploration application that allows to extract useful information from the measurements and uncover new insights. We confirm that ST is viable on Bluetooth, as previously shown. Moreover, our data show that successful ST on Bluetooth cannot be explained by “constructive interference” or capture effect alone: multiple effects interplay in a way that is not yet fully understood.

Publications1 - 10 of 46

Romain Jacob

Last Name

First Name

ORCID

Organisational unit

Filters

Search Results