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Mascherpa, M., Haasler, I., Ahlgren, B. & Karlsson, J. (2023). Estimating pollution spread in water networks as a Schrödinger bridge problem with partial information. European Journal of Control, Article ID 100846.
Open this publication in new window or tab >>Estimating pollution spread in water networks as a Schrödinger bridge problem with partial information
2023 (English)In: European Journal of Control, ISSN 0947-3580, E-ISSN 1435-5671, article id 100846Article in journal (Refereed) Published
Abstract [en]

Incidents where water networks are contaminated with microorganisms or pollutants can result in a large number of infected or ill persons, and it is therefore important to quickly detect, localize and estimate the spread and source of the contamination. In many of today's water networks only limited measurements are available, but with the current internet of things trend the number of sensors is increasing and there is a need for methods that can utilize this information. Motivated by this fact, we address the problem of estimating the spread of pollution in a water network given measurements from a set of sensors. We model the water flow as a Markov chain, representing the system as a set of states where each state represents the amount of water in a specific part of the network, e.g., a pipe or a part of a pipe. Then we seek the most likely flow of the pollution given the expected water flow and the sensors observations. This is a large-scale optimization problem that can be formulated as a Schrödinger bridge problem with partial information, and we address this by exploiting the connection with the entropy regularized multimarginal optimal transport problem. The software EPANET is used to simulate the spread of pollution in the water network and will be used for testing the performance of the methodology. © 2023 The Author(s)

Place, publisher, year, edition, pages
Elsevier Ltd, 2023
Keywords
Markov processes, Optimization algorithms, Schrödinger bridge, Sensor and signal fusion, Flow of water, Hydraulics, Optimization, Software testing, Water pollution, 'current, Bridge problems, Most likely, Partial information, Schrödinge bridge, Sensor fusion, Signal fusions, Water flows, Water networks
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-65675 (URN)10.1016/j.ejcon.2023.100846 (DOI)2-s2.0-85163881960 (Scopus ID)
Note

This work was supported by KTH Digital Futures, the Knut and Alice Wallenberg foundation under grant KAW 2021.0274, and the Swedish Research Council (VR) under grant 2020-03454.

Available from: 2023-08-07 Created: 2023-08-07 Last updated: 2023-08-07Bibliographically approved
Rabitsch, A., Grinnemo, K. J., Brunstrom, A., Abrahamsson, H., Ben Abdesslem, F., Alfredsson, S. & Ahlgren, B. (2022). Utilizing Multi-Connectivity to Reduce Latency and Enhance Availability for Vehicle to Infrastructure Communication. IEEE Transactions on Mobile Computing, 21(1), 352-365
Open this publication in new window or tab >>Utilizing Multi-Connectivity to Reduce Latency and Enhance Availability for Vehicle to Infrastructure Communication
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2022 (English)In: IEEE Transactions on Mobile Computing, ISSN 1536-1233, E-ISSN 1558-0660, Vol. 21, no 1, p. 352-365Article in journal (Refereed) Published
Abstract [en]

Cooperative Intelligent Transport Systems (C-ITS) enable information to be shared wirelessly between vehicles and infrastructure in order to improve transport safety and efficiency. Delivering C-ITS services using existing cellular networks offers both financial and technological advantages, not least since these networks already offer many of the features needed by C-ITS, and since many vehicles on our roads are already connected to cellular networks. Still, C-ITS pose stringent requirements in terms of availability and latency on the underlying communication system; requirements that will be hard to meet for currently deployed 3G, LTE, and early-generation 5G systems. Through a series of experiments in the MONROE testbed (a cross-national, mobile broadband testbed), the present study demonstrates how cellular multi-access selection algorithms can provide close to 100% availability, and significantly reduce C-ITS transaction times. The study also proposes and evaluates a number of low-complexity, low-overhead single-access selection algorithms, and shows that it is possible to design such solutions so that they offer transaction times and availability levels that rival those of multi-access solutions.

Keywords
Cooperative intelligent transport systems (C-ITS), multi-connectivity, multi-access, cellular networks, interface selection
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-49084 (URN)10.1109/TMC.2020.3028306 (DOI)85099742008 (Scopus ID)
Available from: 2020-10-13 Created: 2020-10-13 Last updated: 2023-05-19Bibliographically approved
Ahlgren, B. & Grinnemo, K.-J. (2022). ZQTRTT: A Multipath Scheduler for Heterogeneous Traffic in ICNs Based on Zero Queueing Time Ratio. In: ICN 2022 - Proceedings of the 2022 9th ACM Conference on Information-Centric Networking: . Paper presented at 9th ACM Conference on Information-Centric Networking, ICN 2022, 19 September 2022 through 21 September 2022. Association for Computing Machinery, Inc
Open this publication in new window or tab >>ZQTRTT: A Multipath Scheduler for Heterogeneous Traffic in ICNs Based on Zero Queueing Time Ratio
2022 (English)In: ICN 2022 - Proceedings of the 2022 9th ACM Conference on Information-Centric Networking, Association for Computing Machinery, Inc , 2022Conference paper, Published paper (Refereed)
Abstract [en]

Information-centric networks (ICNs) intrinsically support multipath transfer and thus have been seen as an exciting paradigm for IoT and edge computing, not least in the context of 5G mobile networks. One key to ICN's success in these and other networks that have to support a diverse set of services over a heterogeneous network infrastructure is to schedule traffic over the available network paths efficiently. This paper presents and evaluates ZQTRTT, a multipath scheduling scheme for ICN that load balances bulk traffic over available network paths and schedules latency-sensitive, non-bulk traffic to reduce its transfer delay. A new metric called zero queueing time (ZQT) ratio estimates path load and is used to compute forwarding fractions for load balancing. In particular, the paper shows through a simulation campaign that ZQTRTT can accommodate the demands of both latency-sensitive and-insensitive traffic as well as evenly distribute traffic over available network paths. 

Place, publisher, year, edition, pages
Association for Computing Machinery, Inc, 2022
Keywords
ICN, low latency, multipath scheduling, zero queue time, 5G mobile communication systems, Queueing networks, Queueing theory, Scheduling, Heterogeneous traffic, Information Centric Networks, Multipath, Network paths, Network-based, Queue time, Time ratio, Heterogeneous networks
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:ri:diva-60260 (URN)10.1145/3517212.3558080 (DOI)2-s2.0-85138683785 (Scopus ID)9781450392570 (ISBN)
Conference
9th ACM Conference on Information-Centric Networking, ICN 2022, 19 September 2022 through 21 September 2022
Note

Funding details: 101015922; Funding details: Stiftelsen för Kunskaps- och Kompetensutveckling, KKS; Funding text 1: This work was partly funded by The Knowledge Foundation (KKS) through the SIDUS READY project. B. Ahlgren was additionally supported by the Democritus project within the Digital Futures centre, and the AI@EDGE EU Horizon 2020 project under grant agreement No 101015922.

Available from: 2022-10-10 Created: 2022-10-10 Last updated: 2023-05-10Bibliographically approved
Hazra, S., Voigt, T., Ahlgren, B., Lu, C., Cederholm, D. & Patra, G. (2020). Demo: Multi-Radio Access Technology IoT Gateway. In: Proceedings of the 2020 International Conference on Embedded Wireless Systems and Networks: . Paper presented at 2020 International Conference on Embedded Wireless Systems and Networks. Lyon, France. 17-19 Feb, 2020. (pp. 189-191). Junction Publishing
Open this publication in new window or tab >>Demo: Multi-Radio Access Technology IoT Gateway
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2020 (English)In: Proceedings of the 2020 International Conference on Embedded Wireless Systems and Networks, Junction Publishing , 2020, p. 189-191Conference paper, Published paper (Other academic)
Abstract [en]

We present VGATE, a softwarised, multiple-RAT IoT gateway. The baseband of IEEE 802.15.4, LoRa and NB-IoT are implemented with software-defined radio in containers that can execute in an edge computing platform. The demo shows simultaneous multi-channel access and simultaneous execution of multiple RATs in a shared infrastructure.

Place, publisher, year, edition, pages
Junction Publishing, 2020
Series
EWSN ’20
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-49109 (URN)
Conference
2020 International Conference on Embedded Wireless Systems and Networks. Lyon, France. 17-19 Feb, 2020.
Available from: 2020-10-15 Created: 2020-10-15 Last updated: 2023-06-08Bibliographically approved
Ahlgren, B., Claesson, Å., Honfi, D., Kardeby, V., Karoumi, R. & Leander, J. (2020). Digitaliseringens möjligheter och utmaningar inom förvaltning och underhållsplanering av broar: Förstudie.
Open this publication in new window or tab >>Digitaliseringens möjligheter och utmaningar inom förvaltning och underhållsplanering av broar: Förstudie
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2020 (Swedish)Report (Other academic)
Abstract [en]

Rapporten behandlar digitalisering – att införa ny digital teknik – i förvaltningsverksamheten av broar. Omfattningen är en förstudie med syftet att identifiera behovet av framtida forskning för en långsiktig utveckling av broförvaltningen. En grundläggande ansats var att en digitalisering ska minska behovet av kostsamma underhållsåtgärder men bibehålla en hög säkerhet för våra broar. Projektets mål var att samla information om digitala informationsmodeller som skapas under investeringsskedet, utvärdera överlämningen av digitala modeller till förvaltningsskedet, och värdera den eventuella nyttan med digital informationsinsamling för tillståndsbedömning och underhållsplanering. En viktig del av detta var beskrivningen av dagens förvaltningssystem och hur det skulle kunna utvecklas. Studierna har bedrivits genom en enkätundersökning med respondenter från konsultfirmor aktiva inom broprojektering, intervjuer med tekniska experter och litteratursökningar. Resultatet visar att projekteringen av broar idag huvudsakligen görs genom byggnads-informationsmodellering (BIM). Inriktningen är mot byggskedet där samordning och kommunikation bedöms vara de största nyttorna. Överlämningen till förvaltningen består dock av relationsritningar i formen av enkla ritningsfiler. Trots att Trafikverkets strategi för BIM beskriver att en informationsmodell bör leva kvar under hela brons livslängd, finns det tveksamheter huruvida en modell från projekteringen är lämplig som förvaltningsmodell. Istället lyfts andra metoder fram för att skapa en modell av det byggda utförandet. Till exempel optiska metoder för skanning och fotogrammetri. Förvaltningssystemen bör utvecklas med funktioner för att lagra och tillgängliggöra stora mängder digital information från sensorer maskinella inspektioner. Syftet är att minska osäkerheterna i det byggda utförandet och graden av nedbrytning, för att slutligen skapa ett bättre underlag för beslut om åtgärder. Ett framtida scenario är en digital tvilling som speglar den verkliga konstruktionen och uppdateras kontinuerligt genom sensordata. Gällande hårdvara för mätningar behöver sensorer och system utvecklas med avseende på energiförbrukning, energiskördning och underhållsåtgärder, t.ex. genom kombinationer av utbytbara komponenter med kort livslängd och andra delar med lång livslängd. Fiberoptiska sensorer visar på lovande egenskaper men utveckling behövs för att göra dem mer kostnadseffektiva i relation till konventionella sensorer.

Publisher
p. 50
Series
KTH Royal Institute of Technology ; TRITA-ABE-RPT-217
Keywords
Digitalisation, Bridge management, Digital Twin, Information modelling, BIM, Condition assessment, Digitalisering, broförvaltning, digital tvilling, informationsmodeller, tillståndsbedömning, Civil Engineering, Samhällsbyggnadsteknik
National Category
Infrastructure Engineering
Identifiers
urn:nbn:se:ri:diva-58960 (URN)
Available from: 2022-03-29 Created: 2022-03-29 Last updated: 2023-06-08Bibliographically approved
Ahlgren, B. & Grinnemo, K.-J. (2020). Evaluation of the ZQTRTT latency-aware multipath scheduler. In: : . Paper presented at 16th Swedish National Computer Networking Workshop (SNCNW), Online (Kristianstad), Sweden, May 26-27, 2020.
Open this publication in new window or tab >>Evaluation of the ZQTRTT latency-aware multipath scheduler
2020 (English)Conference paper, Published paper (Refereed)
National Category
Engineering and Technology
Identifiers
urn:nbn:se:ri:diva-48790 (URN)
Conference
16th Swedish National Computer Networking Workshop (SNCNW), Online (Kristianstad), Sweden, May 26-27, 2020
Available from: 2020-09-15 Created: 2020-09-15 Last updated: 2023-05-10Bibliographically approved
Ahlgren, B., Grinnemo, K.-J., Abrahamsson, H., Brunstrom, A. & Hurtig, P. (2019). Latency-aware Multipath Scheduling in Information-centric Networks. In: Proceedings of the 15th Swedish National Computer Networking Workshop (SNCNW): . Paper presented at 15th Swedish National Computer Networking Workshop (SNCNW).
Open this publication in new window or tab >>Latency-aware Multipath Scheduling in Information-centric Networks
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2019 (English)In: Proceedings of the 15th Swedish National Computer Networking Workshop (SNCNW), 2019Conference paper, Published paper (Other academic)
Abstract [en]

We present the latency-aware multipath scheduler ZQTRTT that takes advantage of the multipath opportunities in information-centric networking. The goal of the scheduler is to use the (single) lowest latency path for transaction-oriented flows, and use multiple paths for bulk data flows. A new estimator called zero queue time ratio is used for scheduling over multiple paths. The objective is to distribute the flow over the paths so that the zero queue time ratio is equal on the paths, that is, so that each path is ‘pushed’ equally hard by the flow without creating unwanted queueing. We make an initial evaluation using simulation that shows that the scheduler meets our objectives.

National Category
Communication Systems
Identifiers
urn:nbn:se:ri:diva-39240 (URN)
Conference
15th Swedish National Computer Networking Workshop (SNCNW)
Projects
READY
Funder
Knowledge Foundation, 20130086ICT - The Next Generation
Available from: 2019-06-28 Created: 2019-06-28 Last updated: 2023-05-19Bibliographically approved
Abrahamsson, H., Ben Abdesslem, F., Ahlgren, B., Brunstrom, A., Marsh, I. & Björkman, M. (2018). Connected Vehicles in Cellular Networks: Multi-access versus Single-access Performance. In: : . Paper presented at 2nd Workshop on Mobile Network Measurement (MNM’18). , Article ID 8506559.
Open this publication in new window or tab >>Connected Vehicles in Cellular Networks: Multi-access versus Single-access Performance
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2018 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Connected vehicles can make roads traffic safer andmore efficient, but require the mobile networks to handle timecriticalapplications. Using the MONROE mobile broadbandmeasurement testbed we conduct a multi-access measurementstudy on buses. The objective is to understand what networkperformance connected vehicles can expect in today’s mobilenetworks, in terms of transaction times and availability. The goalis also to understand to what extent access to several operatorsin parallel can improve communication performance.In our measurement experiments we repeatedly transfer warningmessages from moving buses to a stationary server. Wetriplicate the messages and always perform three transactionsin parallel over three different cellular operators. This creates adataset with which we can compare the operators in an objectiveway and with which we can study the potential for multi-access.In this paper we use the triple-access dataset to evaluate singleaccessselection strategies, where one operator is chosen for eachtransaction. We show that if we have access to three operatorsand for each transaction choose the operator with best accesstechnology and best signal quality then we can significantlyimprove availability and transaction times compared to theindividual operators. The median transaction time improves with6% compared to the best single operator and with 61% comparedto the worst single operator. The 90-percentile transaction timeimproves with 23% compared to the best single operator andwith 65% compared to the worst single operator.

National Category
Communication Systems
Identifiers
urn:nbn:se:ri:diva-34311 (URN)10.23919/TMA.2018.8506559 (DOI)2-s2.0-85057241219 (Scopus ID)
Conference
2nd Workshop on Mobile Network Measurement (MNM’18)
Available from: 2018-07-30 Created: 2018-07-30 Last updated: 2023-05-19Bibliographically approved
Ahlgren, B., Hurtig, P., Abrahamsson, H., Grinnemo, K.-J. & Brunstrom, A. (2018). ICN congestion control for wireless links. In: : . Paper presented at 2018 IEEE Wireless Communications and Networking Conference (WCNC) (pp. 1-6).
Open this publication in new window or tab >>ICN congestion control for wireless links
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2018 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Information-centric networking (ICN) with its design around named-based forwarding and in-network caching holds great promises to become a key architecture for the future Internet. Many proposed ICN hop-by-hop congestion control schemes assume a fixed and known link capacity, which rarely - if ever - holds true for wireless links. Firstly, we demonstrate that although these congestion control schemes are able to fairly well utilise the available wireless link capacity, they greatly fail to keep the delay low. In fact, they essentially offer the same delay as in the case with no hop-by-hop, only end-to-end, congestion control. Secondly, we show that by complementing these schemes with an easy-to-implement, packet-train capacity estimator, we reduce the delay to a level significantly lower than what is obtained with only end-to-end congestion control, while still being able to keep the link utilisation at a high level.

Keywords
Internet, radio links, telecommunication congestion control, ICN congestion control, wireless links, information-centric networking, in-network caching, packet-train capacity estimator, end-to-end congestion control, named based forwarding, hop-by-hop congestion control, Wireless communication, Delays, Throughput, Bandwidth, Protocols, Estimation
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-34334 (URN)10.1109/WCNC.2018.8377396 (DOI)2-s2.0-85049217847 (Scopus ID)
Conference
2018 IEEE Wireless Communications and Networking Conference (WCNC)
Available from: 2018-08-07 Created: 2018-08-07 Last updated: 2023-05-19Bibliographically approved
Tanyingyong, V., Olsson, R., Hidell, M., Sjödin, P. & Ahlgren, B. (2018). Implementation and Deployment of an Outdoor IoT-Based Air Quality Monitoring Testbed. In: 2018 IEEE Global Communications Conference, GLOBECOM 2018 - Proceedings: . Paper presented at 2018 IEEE Global Communications Conference, GLOBECOM 2018, 9 December 2018 through 13 December 2018. Institute of Electrical and Electronics Engineers Inc.
Open this publication in new window or tab >>Implementation and Deployment of an Outdoor IoT-Based Air Quality Monitoring Testbed
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2018 (English)In: 2018 IEEE Global Communications Conference, GLOBECOM 2018 - Proceedings, Institute of Electrical and Electronics Engineers Inc. , 2018Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents an outdoor IoT-based air quality monitoring testbed deployed in the city of Uppsala, Sweden. Our IoT sensing unit is designed and developed using low-cost hardware components and open source software, which makes it easy to replicate. We demonstrate that it can serve as an affordable solution for real-time measurements and has potential to complement traditional monitoring to cover larger areas. We use low-power communication based on IEEE 802.15.4, RPL, and MQTT, and achieve high end-to-end delivery ratio (>98%) in an outdoor setting. Moreover, we carry out network analysis of our testbed and provide detailed insights into its characteristics.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2018
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-38422 (URN)10.1109/GLOCOM.2018.8647287 (DOI)2-s2.0-85063521242 (Scopus ID)9781538647271 (ISBN)
Conference
2018 IEEE Global Communications Conference, GLOBECOM 2018, 9 December 2018 through 13 December 2018
Available from: 2019-05-10 Created: 2019-05-10 Last updated: 2023-05-10Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-1445-2169

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