@misc{PrescherRottaNolte, author = {Prescher, Thomas and Rotta, Randolf and Nolte, J{\"o}rg}, title = {Flexible Sharing and Replication Mechanisms for Hybrid Memory Architectures}, series = {Proceedings of the 4th Many-Core Applications Research Community (MARC) Symposium}, journal = {Proceedings of the 4th Many-Core Applications Research Community (MARC) Symposium}, publisher = {Univ.-Verl.}, address = {Potsdam}, isbn = {978-3-86956-169-1}, pages = {67 -- 72}, language = {en} } @misc{Rotta, author = {Rotta, Randolf}, title = {On Efficient Message Passing on the Intel SCC}, series = {Proceedings, 3rd Many-core Applications Research Community (MARC) Symposium}, journal = {Proceedings, 3rd Many-core Applications Research Community (MARC) Symposium}, publisher = {KIT Scientific Publishing}, address = {Karlsruhe}, isbn = {978-3-86644-717-2}, pages = {53 -- 58}, language = {en} } @misc{RottaNoack, author = {Rotta, Randolf and Noack, Andreas}, title = {Multilevel local search algorithms for modularity clusterin}, series = {Journal on Experimental Algorithmics}, volume = {16}, journal = {Journal on Experimental Algorithmics}, number = {2}, issn = {1084-6654}, language = {en} } @misc{RottaPrescherTraueetal., author = {Rotta, Randolf and Prescher, Thomas and Traue, Jana and Nolte, J{\"o}rg}, title = {Data Sharing Mechanisms for Parallel Graph Algorithms on the Intel SCC}, series = {MARC Symposium at ONERA'2012, July 19th-20th 2012, Toulouse, Frankreich}, journal = {MARC Symposium at ONERA'2012, July 19th-20th 2012, Toulouse, Frankreich}, isbn = {978-2-7257-0016-8}, pages = {13 -- 18}, language = {en} } @misc{RottaBuechnerNolte, author = {Rotta, Randolf and B{\"u}chner, Steffen and Nolte, J{\"o}rg}, title = {Middleware for Many-Cores - Why It Is Needed and What Functionality It Should Provide}, series = {4th USENIX Workshop on Hot Topics in Parallelism (HotPar '12), Berkeley, 2012}, journal = {4th USENIX Workshop on Hot Topics in Parallelism (HotPar '12), Berkeley, 2012}, abstract = {Today's multi-cores and future many-cores are NUMA architectures with complex cache hierarchies and multiple memory channels. Depending on the topologies of these memory networks we find everything from true data sharing with shared caches to distributed memory architectures which just pretend to be physical shared memory systems. In fact, most many-cores are hybrid systems that exhibit the characteristics of both distributed systems and SMPs. In this paper we argue in favor of middleware platforms for many-cores. We will discuss the needed functionality in contrast to common distributed system middleware and present micro benchmarks on several architectures to substantiate our claims.}, language = {en} } @misc{RottaPrescherTraueetal., author = {Rotta, Randolf and Prescher, Thomas and Traue, Jana and Nolte, J{\"o}rg}, title = {In-Memory Communication Mechanisms for Many-Cores - Experiences with the Intel SCC}, series = {TACC-Intel Highly Parallel Computing Symposium (TIHPCS), Austin/Texas, 2012}, journal = {TACC-Intel Highly Parallel Computing Symposium (TIHPCS), Austin/Texas, 2012}, abstract = {Many-core processors combine fast on-chip communication with access to large amounts of shared memory. This makes it possible to exploit the benefits of distributed as well as shared memory programming models within single parallel algorithms. While large amounts of data can be shared in the memory and caches, coordinating the activities of hundreds of cores relies on cross core communication mechanisms with ultra low latency for very small messages. In this paper we discuss two communication protocols for the Intel SCC and compare them to the MPI implementation of the SCC. Our micro-benchmark results underline that special purpose protocols for small messages make much finer levels of parallelism possible than general purpose message passing systems. Index Terms—many-core, message passing, shared memory}, language = {en} } @misc{RottaTrauePrescheretal., author = {Rotta, Randolf and Traue, Jana and Prescher, Thomas and Nolte, J{\"o}rg}, title = {Interrupt-Driven Cross-Core Invocation Mechanisms on the Intel SCC}, series = {Proceedings of the Many-core Applications Research Community (MARC) Symposium at RWTH Aachen University 2012}, journal = {Proceedings of the Many-core Applications Research Community (MARC) Symposium at RWTH Aachen University 2012}, publisher = {Technische Hochschule}, address = {Aachen}, isbn = {978-3-00-039545-1}, pages = {1 -- 6}, abstract = {On many-core processors, both operating system kernels and bare metal applications need efficient cross-core coordination and communication. Although explicit shared- memory programming and message passing might provide the best performance, they also limit the system's control over scheduling. In contrast, interrupt-driven cross-core invocations provide universal coordination mechanisms that also enable preemptive operations across cores. This paper surveys cross- core invocation mechanisms and their usability with respect to prevalent coordination scenarios. We integrated some of these mechanisms into a bare-metal environment for the Intel SCC pro- cessor and will discuss implementation aspects of the interrupt- driven invocations. In conclusion, such invocation mechanisms provide an expressive platform for future operating systems kernels and bare-metal applications.}, language = {en} } @misc{NuernbergerRottaDrescheretal., author = {N{\"u}rnberger, Stefan and Rotta, Randolf and Drescher, Gabor and Danner, Daniel and Nolte, J{\"o}rg}, title = {Diamond Rings: Acknowledged Event Propagation in Many-Core Processors}, series = {Euro-Par 2015: Parallel Processing Workshops, Vienna, 2015}, journal = {Euro-Par 2015: Parallel Processing Workshops, Vienna, 2015}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-319-27308-2}, doi = {10.1007/978-3-319-27308-2_58}, pages = {722 -- 733}, abstract = {Hardware and software consistency protocols rely on global observability of consistency events. Acknowledged broadcast is an obvious choice to propagate these events. This paper presents a generalized ring topology for parallel event propagation with acknowledged delivery. Implementations for various many-core architectures show increased performance over conventional approaches. Therefore, diamond rings are a prime candidate for implementations of distributed memory models.}, language = {en} } @misc{NuernbergerDrescherRottaetal., author = {N{\"u}rnberger, Stefan and Drescher, Gabor and Rotta, Randolf and Nolte, J{\"o}rg and Schr{\"o}der-Preikschat, Wolfgang}, title = {Shared Memory in the Many-Core Age}, series = {Euro-Par 2014: Parallel Processing Workshops, Porto, 2014}, journal = {Euro-Par 2014: Parallel Processing Workshops, Porto, 2014}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-319-14312-5}, doi = {10.1007/978-3-319-14313-2_30}, pages = {351 -- 362}, abstract = {With the evolution toward fast networks of many-core processors, the design assumptions at the basis of software-level distributed shared memory (DSM) systems change considerably. But efficient DSMs are needed because they can significantly simplify the implementation of complex distributed algorithms. This paper discusses implications of the many-core evolution and derives a set of reusable elementary operations for future software DSMs. These elementary operations will help in exploring and evaluating new memory models and consistency protocols.}, language = {en} } @misc{RottaNolteNikolovetal., author = {Rotta, Randolf and Nolte, J{\"o}rg and Nikolov, Vladimir and Schubert, Lutz and Bonfert, Stefan and Wesner, Stefan}, title = {MyThOS — Scalable OS Design for Extremely Parallel Applications}, series = {2016 Intl IEEE Conferences on Ubiquitous Intelligence Computing, Advanced and Trusted Computing, Scalable Computing and Communications, Cloud and Big Data Computing, Internet of People, and Smart World Congress, 18-21 July 2016}, journal = {2016 Intl IEEE Conferences on Ubiquitous Intelligence Computing, Advanced and Trusted Computing, Scalable Computing and Communications, Cloud and Big Data Computing, Internet of People, and Smart World Congress, 18-21 July 2016}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-5090-2771-2}, doi = {10.1109/UIC-ATC-ScalCom-CBDCom-IoP-SmartWorld.2016.0179}, pages = {1165 -- 1172}, abstract = {Many-core architectures trade single-thread performance for a larger number of cores. Scalable throughput can be attained only by a high degree of parallelism, minimized synchronization. Whilst this is achievable for many applications, the operating system still introduces bottlenecks through non-local sharing, synchronization,, message passing. A particular challenge for highly dynamic applications, for example invasive HPC applications, elastic compute clouds, is the management of short-living application threads, processes. This paper discusses OS architecture choices based on microkernel, multikernel, distributed systems designs, our development experience in the context of the MyThOS project. Initial experiments show a much faster thread creation, activation compared to monolithic systems like Linux while providing a more flexible protection, threading model that is better suited for dynamic scenarios. However, despite significant progress in the overall domain of operating systems, the design space for scalable many-core operating systems is yet to be fully explored.}, language = {en} } @misc{RottaKubanSchoepsetal., author = {Rotta, Randolf and Kuban, Robert and Sch{\"o}ps, Mark Simon and Nolte, J{\"o}rg}, title = {Dealing with Layers of Obfuscation in pseudo-Uniform Memory Architectures}, series = {Euro-Par 2016: Parallel Processing Workshops, Euro-Par 2016 International Workshops, Grenoble, France, August 24-26, 2016}, journal = {Euro-Par 2016: Parallel Processing Workshops, Euro-Par 2016 International Workshops, Grenoble, France, August 24-26, 2016}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-319-58942-8}, doi = {10.1007/978-3-319-58943-5_55}, pages = {685 -- 696}, abstract = {Pseudo-Uniform Memory Architectures hide the memory's throughput bottlenecks and the network's latency differences in order to provide near-peak average throughput for computations on large datasets. This obviates the need for application-level partitioning and load balancing between NUMA domains but the performance of cross-core communication still depends on the actual placement of the involved variables and cores, which can result in significant variation within applications and between application runs. This paper analyses the pseudo-uniform memory latency on the Intel Xeon Phi Knights Corner processor, derives strategies for the optimised placement of important variables, and discusses the role of localised coordination in pUMA systems. For example, a basic cache line ping-pong benchmark showed a 3x speedup between adjacent cores. Therefore, pUMA systems combined with support for controlled placement of small datasets are an interesting option when processor-wide load balancing is difficult while localised coordination is feasible.}, language = {en} } @misc{KubanRottaNolte, author = {Kuban, Robert and Rotta, Randolf and Nolte, J{\"o}rg}, title = {Help Your Busy Neighbors: Dynamic Multicasts over Static Topologies}, series = {Euro-Par 2017: Parallel Processing Workshops}, journal = {Euro-Par 2017: Parallel Processing Workshops}, editor = {Heras, Dora B. and Boug{\´e}, Luc}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-75177-1}, doi = {10.1007/978-3-319-75178-8_51}, pages = {636 -- 657}, language = {en} } @misc{RottaSegabinazziFerreiraNolte, author = {Rotta, Randolf and Segabinazzi Ferreira, Raphael and Nolte, J{\"o}rg}, title = {Real-time dynamic hardware reconfiguration for processors with redundant functional units}, series = {Proceedings of the 2020 IEEE 23rd International Symposium on Real-Time Distributed Computing (ISORC)}, journal = {Proceedings of the 2020 IEEE 23rd International Symposium on Real-Time Distributed Computing (ISORC)}, publisher = {Institute of Electrical and Electronics Engineers Inc. (IEEE)}, address = {Nashville, TN, USA}, isbn = {978-1-7281-6958-3}, issn = {2375-5261}, doi = {10.1109/ISORC49007.2020.00035}, pages = {2}, abstract = {The tiny logic elements in modern integrated circuits increase the rate of transient failures significantly. Therefore, redundancy on various levels is necessary to retain reliability. However, for mixed-criticality scenarios, the typical processor designs offer either too little fault-tolerance or too much redundancy for one part of the applications. Amongst others, we specifically address redundant processor internal functional units (FU) to cope with transient errors and support wear leveling. A real-time operating system (RTOS) was extended to control our prototypical hardware platform and, since it can be configured deterministically within few clock cycles, we are able to reconfigure the FUs dynamically, at process switching time, according to the specified critically of the running processes. Our mechanisms were integrated into the Plasma processor and the Plasma-RTOS. With few changes to the original software code, it was, for example, possible to quickly change from fault-detecting to fault-correcting modes of the processor on demand.}, language = {en} } @misc{RottaMykytyn, author = {Rotta, Randolf and Mykytyn, Pavlo}, title = {Secure Multi-hop Telemetry Broadcasts for UAV Swarm Communication}, series = {20. GI/ITG KuVS Fachgespr{\"a}ch Sensornetze (FGSN 2023)}, journal = {20. GI/ITG KuVS Fachgespr{\"a}ch Sensornetze (FGSN 2023)}, doi = {10.48550/arXiv.2401.11915}, pages = {13 -- 14}, abstract = {Unmanned Aerial Vehicles (UAVs) are evolving as adaptable platforms for a wide range of applications such as precise inspections, emergency response, and remote sensing. Autonomous UAV swarms require efficient and stable communication during deployment for a successful mission execution. For instance, the periodic exchange of telemetry data between all swarm members provides the foundation for formation flight and collision avoidance. However, due to the mobility of the vehicles and instability of wireless transmissions, maintaining a secure and reliable all-to-all communication remains challenging. This paper investigates encrypted and authenticated multi-hop broadcast communication based on the transmission of custom IEEE 802.11 Wi-Fi data frames.}, language = {en} } @misc{ChatharajupalliRottaKarnapkeetal., author = {Chatharajupalli, Navya Sneha and Rotta, Randolf and Karnapke, Reinhardt and Nolte, J{\"o}rg}, title = {Assessing the Feasibility of Combined BLE and Wi-Fi Communication for High Data Sensing Applications}, series = {EWSN '23: Proceedings of the 2023 International Conference on Embedded Wireless Systems and Networks}, journal = {EWSN '23: Proceedings of the 2023 International Conference on Embedded Wireless Systems and Networks}, publisher = {Association for Computing Machinery}, address = {New York}, doi = {10.5555/3639940.3639948}, pages = {56 -- 59}, abstract = {Advanced sensors generate more data than can be transmitted using classic battery-powered wireless sensor networks. While using Wi-Fi would provide plenty of throughput, the receivers are energy hungry and, thus, the radio time needs to be reduced. Previous research suggests to combine Wi-Fi with low-power technologies such as BLE for an energy efficient coordination of the Wi-Fi radios. Existing approaches focus on individual point-to-point routes whereas certain applications require concurrent transmissions. We evaluated the combination of BLE and Wi-Fi on the ESP32-S3 multi-radio microcontroller through detailed energy and throughput measurements. The results show that established BLE connections allow to activateWi-Fi quickly on-demand; the energy efficiency of the data transmission is significantly improved over previous works but the BLE connection setup is prohibitively slow. While the combination of BLE and Wi-Fi provides high throughput with good energy efficiency, careful design of the BLE-based signalling protocol is necessary to also achieve low latency.}, language = {en} } @misc{NattkeRottaNatarovetal., author = {Nattke, Matthias and Rotta, Randolf and Natarov, Roman and Archila, Oscar and Mykytyn, Pavlo}, title = {Precise sensors for localization in the drone swarm}, series = {Proceedings iCCC2024 - iCampµs Cottbus Conference, 2024-05-14 - 2024-05-16, Cottbus}, volume = {2024}, journal = {Proceedings iCCC2024 - iCampµs Cottbus Conference, 2024-05-14 - 2024-05-16, Cottbus}, publisher = {AMA}, isbn = {978-3-910600-00-3}, doi = {10.5162/iCCC2024/P16}, pages = {166 -- 169}, abstract = {Drones can be connected as a swarm to precisely monitor large agricultural areas and manage them more sustainable. They test sensor technology in real environments and solve complex tasks faster. Key aspects include accurate localization, reliable communication, and dynamic flight control. The localization accuracy of RTK-GNSS-enabled system, which includes GPS, GLONASS, GALILEO positioning systems is compared with Ultra-Wideband (UWB) one. The UPWARDS communication hub is presented as a processing and connection point across swarm agents. This controller also incorporates collision avoidance features and testing of evasion strategies.}, language = {en} } @inproceedings{ChatharajupalliRottaNolte, author = {Chatharajupalli, Navya Sneha and Rotta, Randolf and Nolte, J{\"o}rg}, title = {P2 - VibroMote: Energy efficient Vibration Monitoring for Railway tracks and Bridges}, series = {iCCC2024 - iCampµs Cottbus Conference 2024-05-14 - 2024-05-16}, booktitle = {iCCC2024 - iCampµs Cottbus Conference 2024-05-14 - 2024-05-16}, publisher = {AMA Service GmbH, Von-M{\"u}nchhausen-Str. 49, 31515 Wunstorf, Germany}, isbn = {978-3-910600-00-3}, doi = {10.5162/iCCC2024/P2}, pages = {123 -- 126}, abstract = {Filtering, storing, and transmitting measurements of high-resolution sensors within a limited energy budget is challenging. For instance, a 3-axis MEMS acceleration sensor for structural condition monitoring and predictive maintenance generates up to 160 kB/s at a sampling rate of 26.6 kHz. This paper discusses the design space with focus on solar harvesting solutions. VibroMote is an energy efficient sensor node that combines a multi-radio micro-controller, an ultra-low power co-processor with persistent memory, a solar harvester, and multiple energy storage options. This enables prototyping of solar-powered long-term data acquisition, in-node processing, and wireless networking for high-resolution sensors.}, language = {en} } @misc{RottaChatharajupalliNaumannetal., author = {Rotta, Randolf and Chatharajupalli, Navya Sneha and Naumann, Billy and Schulz, Julius and Karnapke, Reinhardt and Werner, Matthias and Nolte, J{\"o}rg}, title = {Demo: B.A.T.M.A.N. mesh routing on ultra low-power IEEE 802.11 modules}, series = {2024 IEEE 49th Conference on Local Computer Networks (LCN)}, journal = {2024 IEEE 49th Conference on Local Computer Networks (LCN)}, publisher = {IEEE}, isbn = {979-8-3503-8800-8}, issn = {2832-1421}, doi = {10.1109/LCN60385.2024.10639789}, pages = {4}, abstract = {When implementing multi-hop mesh network protocols, efficient direct communication, route discovery, and route repair are crucial to achieve high network throughput. To our knowledge, there is no open mesh routing protocol available for ultra low power IEEE 802.11 modules. Previous work relied on single board computers like Raspberry Pi. We implemented the B.A.T.M.A.N. mesh protocol on the popular Espressif ESP32 along with a novel hybrid rate adaptation for the selection of efficient routes. In this demo we showcase challenges and solutions related to the implementation on ESP32 and how the hybrid rate adaptation improves end-to-end throughput.}, language = {en} } @misc{RottaSchulzNaumannetal., author = {Rotta, Randolf and Schulz, Julius and Naumann, Billy and Chatharajupalli, Navya Sneha and Nolte, J{\"o}rg and Werner, Matthias}, title = {B.A.T.M.A.N. Mesh Networking on ESP32's 802.11}, series = {2024 IEEE 49th Conference on Local Computer Networks (LCN)}, journal = {2024 IEEE 49th Conference on Local Computer Networks (LCN)}, publisher = {IEEE}, isbn = {979-8-3503-8800-8}, issn = {2832-1421}, doi = {10.1109/LCN60385.2024.10639698}, pages = {1 -- 7}, abstract = {Mesh routing protocols are widely used in IoT and sensor networks. In recent years, the ESP32 Wi-Fi/BLE SoC became popular for prototyping IoT applications. However, the existing mesh networks for this platform lack efficient node to node communication, fast route discovery and repair, and energy efficiency. This paper addresses the formation of IEEE 802.11 based ad-hoc mesh networks without the delays inflicted by the Station to Access Point association protocol. We implemented the B.A.T.M.A.N. protocol on top of the ESP32 Wi-Fi MAC interface and integrated it into the LwIP network stack. The performance evaluation with respect to UDP/IP and TCP/IP end-to-end throughput shows the general usefulness but also identifies bottlenecks caused by limitations of the existing MAC interface. Overall, this opens an interesting opportunity for research on mesh protocols by providing a simpler platform than full featured Wi-Fi routers; and for wireless IoT applications by providing higher throughput than subGHz and BLE technologies.}, language = {en} } @misc{ShahinRottaArchilaetal., author = {Shahin, Keyvan and Rotta, Randolf and Archila, Oscar and Mykytyn, Pavlo and Nattke, Matthias and Reichenbach, Marc and Nolte, J{\"o}rg and Natarov, Roman}, title = {A Modular Communication Architecture for Adaptive UAV Swarms}, series = {2023 IEEE International Conference on Omni-layer Intelligent Systems (COINS)}, journal = {2023 IEEE International Conference on Omni-layer Intelligent Systems (COINS)}, publisher = {IEEE}, address = {Berlin}, isbn = {979-8-3503-4647-3}, doi = {10.1109/COINS57856.2023.10189245}, pages = {6}, abstract = {Small Unmanned Aerial Vehicles (UAVs) have vast application potential from industrial logistics and disaster monitoring to smart farming, for example, to create maps with Normalized Difference Vegetation Index (NDVI) cameras and AI-based image classification or the precision spot application of fertilizers. Operating multiple UAVs in parallel, including those with different specializations, enables efficient coverage of large areas. While existing research focused mainly on predefined flight formations for swarms or autonomous missions for single UAVs, the focus of this work is on multiple UAVs with individually adaptable missions. We derive communication system requirements from swarm coordination algorithms and present a respective design. The resulting modular architecture enables future research on autonomous adaptive UAV swarms and their use as flying sensor platforms.}, language = {en} } @misc{ChatharajupalliRottaKarnapkeetal., author = {Chatharajupalli, Navya Sneha and Rotta, Randolf and Karnapke, Reinhardt and Nolte, J{\"o}rg}, title = {Probing considered harmful : leveraging RSSI for link quality prediction}, series = {Proceedings of the IEEE 50th Conference on Local Computer Networks : LCN 2025 : October 14-16, 2025, Sydney, Australia}, journal = {Proceedings of the IEEE 50th Conference on Local Computer Networks : LCN 2025 : October 14-16, 2025, Sydney, Australia}, publisher = {IEEE}, address = {New York, NY}, isbn = {979-8-3315-3704-3}, issn = {2831-7742}, doi = {10.1109/LCN65610.2025.11146347}, pages = {1 -- 9}, abstract = {Wireless mesh protocols that use a routing metric based on throughput or airtime require predictions about future throughput for all mesh neighbors. Typically, the Wi-Fi rate controller provides this information, and state-of-the-art rate control algorithms estimate it based on statistics from past unicast transmissions. This introduces an adverse cross-layer dependency because meaningful statistics are only available for the links that were used by the routing layer. Existing implementations either ignore this, or use other routing metrics, such as distance, or generate artificial periodic probe traffic to all neighbors. Unfortunately, probing reacts slowly to changing conditions, increases the medium contention, and can lead to overly optimistic predictions. To overcome this, we introduce an RSSI-based link quality prediction for the routing layer. Benchmarks in a B.A.T.M.A.N. version V mesh show a decrease of round-trip time by three orders of magnitude and an increase of the end-to-end packet delivery ratio. TCP connections became possible over long routes that were previously unusable. Although highly imprecise, the easy to acquire RSSI provided sufficiently good predictions for our mesh network.}, language = {en} } @misc{ChatharajupalliRottaKarnapkeetal., author = {Chatharajupalli, Navya Sneha and Rotta, Randolf and Karnapke, Reinhardt and Nolte, J{\"o}rg}, title = {Animal health monitoring and tracking through solar-powered mesh network}, series = {22. GI/ITG KuVS Fachgespr{\"a}ch Sensornetze : 11. und 12. September 2025, Clausthal-Zellerfeld}, journal = {22. GI/ITG KuVS Fachgespr{\"a}ch Sensornetze : 11. und 12. September 2025, Clausthal-Zellerfeld}, publisher = {TU Clausthal-Zellerfeld}, address = {Clausthal-Zellerfeld}, doi = {10.21268/20250805-0}, pages = {1 -- 3}, abstract = {Various health and movement sensors, especially bolus sensors inside a cow's stomach, are crucial for timely medical interventions. Commonly, wall-powered gateways are used to retrieve sensor updates and forward them quickly to an analysis service. In large outdoor farmlands, however, localisation of individual cows becomes important while the long-term operation of wall-powered gateways is costly. Previous solutions that use a LoRaWAN gateway with bigger antennas are still limited to 500m and provide only poor localization information. Existing solutions based on a mesh network of repeaters provide good localization but still depend on external wall power. Solar-powered mesh nodes would simplify the long-term operation. In order to achieve this, a significant improvement of the energy efficiency of the mesh nodes is necessary. This paper explores protocol design choices for the energy-efficient communication between mesh nodes and the bolus sensors. By introducing synchronised sleep and communication intervals, the size of the solar panels and energy storage can be reduced.}, language = {en} } @misc{ChatharajupalliRottaKarnapkeetal., author = {Chatharajupalli, Navya Sneha and Rotta, Randolf and Karnapke, Reinhardt and Nolte, J{\"o}rg}, title = {VibroMote : Wi-Fi-based mesh communication for railway bridge inspection and monitoring}, series = {2025 International Symposium on Networks, Computers and Communications (ISNCC)}, journal = {2025 International Symposium on Networks, Computers and Communications (ISNCC)}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-6654-5769-9}, issn = {2768-0940}, doi = {10.1109/ISNCC66965.2025.11250402}, pages = {1 -- 6}, abstract = {Vibration sensing provides insights into the dynamic behaviour of engineering constructions such as railway bridges. Cable-based sensors are viable only for long-term condition monitoring and rare special inspections because of the labor-intensive deployment. Although wireless sensors significantly reduce this overhead, their energy constraints limited the network throughput and, hence, their resolution in space and time. Batteryor solar-powered sensor nodes with high network throughput would enable in-depth measurements during regular inspections and improve the access to high-quality monitoring data. We present "VibroMote", which combines energy harvesting, a high-bandwidth 3-axis MEMS accelerometer, and high-throughput, self-organizing mesh communication via IEEE 802.11 Wi-Fi. The evaluation on a real bridge with 18 VibroMotes shows that the deployment time can be reduced from hours to minutes; the multi-hop mesh provides sufficient throughput reserves for the application whereas direct one-hop communication failed; the battery runtime is sufficient for temporary measurements during inspections; and the energy consumption during sleep modes would be low enough for solar-powered long-term monitoring. Hence, the combination of high-throughput Wi-Fi with mesh networking is a strong alternative to the commonly used low-power radio technologies when long range between the sensors is not needed.}, language = {en} }